/*
 * pgbench.c
 *
 * A simple benchmark program for PostgreSQL
 * Originally written by Tatsuo Ishii and enhanced by many contributors.
 *
 * src/bin/pgbench/pgbench.c
 * Copyright (c) 2000-2015, PostgreSQL Global Development Group
 * ALL RIGHTS RESERVED;
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without a written agreement
 * is hereby granted, provided that the above copyright notice and this
 * paragraph and the following two paragraphs appear in all copies.
 *
 * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
 * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
 * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 */

#ifdef WIN32
#define FD_SETSIZE 1024			/* set before winsock2.h is included */
#endif   /* ! WIN32 */

#include "postgres_fe.h"

#include "getopt_long.h"
#include "libpq-fe.h"
#include "portability/instr_time.h"

#include <ctype.h>
#include <math.h>
#include <signal.h>
#include <sys/time.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>		/* for getrlimit */
#endif

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#include "pgbench.h"

/*
 * Multi-platform pthread implementations
 */

#ifdef WIN32
/* Use native win32 threads on Windows */
typedef struct win32_pthread *pthread_t;
typedef int pthread_attr_t;

static int	pthread_create(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
static int	pthread_join(pthread_t th, void **thread_return);
#elif defined(ENABLE_THREAD_SAFETY)
/* Use platform-dependent pthread capability */
#include <pthread.h>
#else
/* No threads implementation, use none (-j 1) */
#define pthread_t void *
#endif


/********************************************************************
 * some configurable parameters */

/* max number of clients allowed */
#ifdef FD_SETSIZE
#define MAXCLIENTS	(FD_SETSIZE - 10)
#else
#define MAXCLIENTS	1024
#endif

#define LOG_STEP_SECONDS	5	/* seconds between log messages */
#define DEFAULT_NXACTS	10		/* default nxacts */

#define MIN_GAUSSIAN_THRESHOLD		2.0 /* minimum threshold for gauss */

int			nxacts = 0;			/* number of transactions per client */
int			duration = 0;		/* duration in seconds */

/*
 * scaling factor. for example, scale = 10 will make 1000000 tuples in
 * pgbench_accounts table.
 */
int			scale = 1;

/*
 * fillfactor. for example, fillfactor = 90 will use only 90 percent
 * space during inserts and leave 10 percent free.
 */
int			fillfactor = 100;

/*
 * create foreign key constraints on the tables?
 */
int			foreign_keys = 0;

/*
 * use unlogged tables?
 */
int			unlogged_tables = 0;

/*
 * log sampling rate (1.0 = log everything, 0.0 = option not given)
 */
double		sample_rate = 0.0;

/*
 * When threads are throttled to a given rate limit, this is the target delay
 * to reach that rate in usec.  0 is the default and means no throttling.
 */
int64		throttle_delay = 0;

/*
 * Transactions which take longer than this limit (in usec) are counted as
 * late, and reported as such, although they are completed anyway. When
 * throttling is enabled, execution time slots that are more than this late
 * are skipped altogether, and counted separately.
 */
int64		latency_limit = 0;

/*
 * tablespace selection
 */
char	   *tablespace = NULL;
char	   *index_tablespace = NULL;

/*
 * end of configurable parameters
 *********************************************************************/

#define nbranches	1			/* Makes little sense to change this.  Change
								 * -s instead */
#define ntellers	10
#define naccounts	100000

/*
 * The scale factor at/beyond which 32bit integers are incapable of storing
 * 64bit values.
 *
 * Although the actual threshold is 21474, we use 20000 because it is easier to
 * document and remember, and isn't that far away from the real threshold.
 */
#define SCALE_32BIT_THRESHOLD 20000

bool		use_log;			/* log transaction latencies to a file */
bool		use_quiet;			/* quiet logging onto stderr */
int			agg_interval;		/* log aggregates instead of individual
								 * transactions */
int			progress = 0;		/* thread progress report every this seconds */
int			progress_nclients = 0;		/* number of clients for progress
										 * report */
int			progress_nthreads = 0;		/* number of threads for progress
										 * report */
bool		is_connect;			/* establish connection for each transaction */
bool		is_latencies;		/* report per-command latencies */
int			main_pid;			/* main process id used in log filename */

char	   *pghost = "";
char	   *pgport = "";
char	   *login = NULL;
char	   *dbName;
const char *progname;

volatile bool timer_exceeded = false;	/* flag from signal handler */

/* variable definitions */
typedef struct
{
	char	   *name;			/* variable name */
	char	   *value;			/* its value */
} Variable;

#define MAX_FILES		128		/* max number of SQL script files allowed */
#define SHELL_COMMAND_SIZE	256 /* maximum size allowed for shell command */

/*
 * structures used in custom query mode
 */

typedef struct
{
	PGconn	   *con;			/* connection handle to DB */
	int			id;				/* client No. */
	int			state;			/* state No. */
	int			listen;			/* 0 indicates that an async query has been
								 * sent */
	int			sleeping;		/* 1 indicates that the client is napping */
	bool		throttling;		/* whether nap is for throttling */
	Variable   *variables;		/* array of variable definitions */
	int			nvariables;
	int64		txn_scheduled;	/* scheduled start time of transaction (usec) */
	instr_time	txn_begin;		/* used for measuring schedule lag times */
	instr_time	stmt_begin;		/* used for measuring statement latencies */
	bool		is_throttled;	/* whether transaction throttling is done */
	int			use_file;		/* index in sql_files for this client */
	bool		prepared[MAX_FILES];

	/* per client collected stats */
	int			cnt;			/* xacts count */
	int			ecnt;			/* error count */
	int64		txn_latencies;	/* cumulated latencies */
	int64		txn_sqlats;		/* cumulated square latencies */
} CState;

/*
 * Thread state
 */
typedef struct
{
	int			tid;			/* thread id */
	pthread_t	thread;			/* thread handle */
	CState	   *state;			/* array of CState */
	int			nstate;			/* length of state[] */
	instr_time	start_time;		/* thread start time */
	instr_time *exec_elapsed;	/* time spent executing cmds (per Command) */
	int		   *exec_count;		/* number of cmd executions (per Command) */
	unsigned short random_state[3];		/* separate randomness for each thread */
	int64		throttle_trigger;		/* previous/next throttling (us) */

	/* per thread collected stats */
	instr_time	conn_time;
	int64		throttle_lag;	/* total transaction lag behind throttling */
	int64		throttle_lag_max;		/* max transaction lag */
	int64		throttle_latency_skipped;		/* lagging transactions
												 * skipped */
	int64		latency_late;	/* late transactions */
} TState;

#define INVALID_THREAD		((pthread_t) 0)

/*
 * queries read from files
 */
#define SQL_COMMAND		1
#define META_COMMAND	2
#define MAX_ARGS		10

typedef enum QueryMode
{
	QUERY_SIMPLE,				/* simple query */
	QUERY_EXTENDED,				/* extended query */
	QUERY_PREPARED,				/* extended query with prepared statements */
	NUM_QUERYMODE
} QueryMode;

static QueryMode querymode = QUERY_SIMPLE;
static const char *QUERYMODE[] = {"simple", "extended", "prepared"};

typedef struct
{
	char	   *line;			/* full text of command line */
	int			command_num;	/* unique index of this Command struct */
	int			type;			/* command type (SQL_COMMAND or META_COMMAND) */
	int			argc;			/* number of command words */
	char	   *argv[MAX_ARGS]; /* command word list */
	int			cols[MAX_ARGS]; /* corresponding column starting from 1 */
	PgBenchExpr *expr;			/* parsed expression */
} Command;

typedef struct
{

	long		start_time;		/* when does the interval start */
	int			cnt;			/* number of transactions */
	int			skipped;		/* number of transactions skipped under --rate
								 * and --latency-limit */

	double		min_latency;	/* min/max latencies */
	double		max_latency;
	double		sum_latency;	/* sum(latency), sum(latency^2) - for
								 * estimates */
	double		sum2_latency;

	double		min_lag;
	double		max_lag;
	double		sum_lag;		/* sum(lag) */
	double		sum2_lag;		/* sum(lag*lag) */
} AggVals;

static Command **sql_files[MAX_FILES];	/* SQL script files */
static int	num_files;			/* number of script files */
static int	num_commands = 0;	/* total number of Command structs */
static int	debug = 0;			/* debug flag */

/* default scenario */
static char *tpc_b = {
	"\\set nbranches " CppAsString2(nbranches) " * :scale\n"
	"\\set ntellers " CppAsString2(ntellers) " * :scale\n"
	"\\set naccounts " CppAsString2(naccounts) " * :scale\n"
	"\\setrandom aid 1 :naccounts\n"
	"\\setrandom bid 1 :nbranches\n"
	"\\setrandom tid 1 :ntellers\n"
	"\\setrandom delta -5000 5000\n"
	"BEGIN;\n"
	"UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
	"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
	"UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;\n"
	"UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;\n"
	"INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
	"END;\n"
};

/* -N case */
static char *simple_update = {
	"\\set nbranches " CppAsString2(nbranches) " * :scale\n"
	"\\set ntellers " CppAsString2(ntellers) " * :scale\n"
	"\\set naccounts " CppAsString2(naccounts) " * :scale\n"
	"\\setrandom aid 1 :naccounts\n"
	"\\setrandom bid 1 :nbranches\n"
	"\\setrandom tid 1 :ntellers\n"
	"\\setrandom delta -5000 5000\n"
	"BEGIN;\n"
	"UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
	"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
	"INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
	"END;\n"
};

/* -S case */
static char *select_only = {
	"\\set naccounts " CppAsString2(naccounts) " * :scale\n"
	"\\setrandom aid 1 :naccounts\n"
	"SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
};

/* Function prototypes */
static void setalarm(int seconds);
static void *threadRun(void *arg);

static void doLog(TState *thread, CState *st, FILE *logfile, instr_time *now,
	  AggVals *agg, bool skipped);

static void
usage(void)
{
	printf("%s is a benchmarking tool for PostgreSQL.\n\n"
		   "Usage:\n"
		   "  %s [OPTION]... [DBNAME]\n"
		   "\nInitialization options:\n"
		   "  -i, --initialize         invokes initialization mode\n"
		   "  -F, --fillfactor=NUM     set fill factor\n"
		"  -n, --no-vacuum          do not run VACUUM after initialization\n"
	"  -q, --quiet              quiet logging (one message each 5 seconds)\n"
		   "  -s, --scale=NUM          scaling factor\n"
		   "  --foreign-keys           create foreign key constraints between tables\n"
		   "  --index-tablespace=TABLESPACE\n"
	"                           create indexes in the specified tablespace\n"
	 "  --tablespace=TABLESPACE  create tables in the specified tablespace\n"
		   "  --unlogged-tables        create tables as unlogged tables\n"
		   "\nBenchmarking options:\n"
		   "  -c, --client=NUM         number of concurrent database clients (default: 1)\n"
		   "  -C, --connect            establish new connection for each transaction\n"
		   "  -D, --define=VARNAME=VALUE\n"
	  "                           define variable for use by custom script\n"
		 "  -f, --file=FILENAME      read transaction script from FILENAME\n"
		   "  -j, --jobs=NUM           number of threads (default: 1)\n"
		   "  -l, --log                write transaction times to log file\n"
	"  -L, --latency-limit=NUM  count transactions lasting more than NUM ms\n"
		   "                           as late.\n"
		   "  -M, --protocol=simple|extended|prepared\n"
		   "                           protocol for submitting queries (default: simple)\n"
		   "  -n, --no-vacuum          do not run VACUUM before tests\n"
		   "  -N, --skip-some-updates  skip updates of pgbench_tellers and pgbench_branches\n"
		   "  -P, --progress=NUM       show thread progress report every NUM seconds\n"
		   "  -r, --report-latencies   report average latency per command\n"
		"  -R, --rate=NUM           target rate in transactions per second\n"
		   "  -s, --scale=NUM          report this scale factor in output\n"
		   "  -S, --select-only        perform SELECT-only transactions\n"
		   "  -t, --transactions=NUM   number of transactions each client runs (default: 10)\n"
		 "  -T, --time=NUM           duration of benchmark test in seconds\n"
		   "  -v, --vacuum-all         vacuum all four standard tables before tests\n"
		   "  --aggregate-interval=NUM aggregate data over NUM seconds\n"
		   "  --sampling-rate=NUM      fraction of transactions to log (e.g. 0.01 for 1%%)\n"
		   "\nCommon options:\n"
		   "  -d, --debug              print debugging output\n"
	  "  -h, --host=HOSTNAME      database server host or socket directory\n"
		   "  -p, --port=PORT          database server port number\n"
		   "  -U, --username=USERNAME  connect as specified database user\n"
		 "  -V, --version            output version information, then exit\n"
		   "  -?, --help               show this help, then exit\n"
		   "\n"
		   "Report bugs to <pgsql-bugs@postgresql.org>.\n",
		   progname, progname);
}

/*
 * strtoint64 -- convert a string to 64-bit integer
 *
 * This function is a modified version of scanint8() from
 * src/backend/utils/adt/int8.c.
 */
int64
strtoint64(const char *str)
{
	const char *ptr = str;
	int64		result = 0;
	int			sign = 1;

	/*
	 * Do our own scan, rather than relying on sscanf which might be broken
	 * for long long.
	 */

	/* skip leading spaces */
	while (*ptr && isspace((unsigned char) *ptr))
		ptr++;

	/* handle sign */
	if (*ptr == '-')
	{
		ptr++;

		/*
		 * Do an explicit check for INT64_MIN.  Ugly though this is, it's
		 * cleaner than trying to get the loop below to handle it portably.
		 */
		if (strncmp(ptr, "9223372036854775808", 19) == 0)
		{
			result = PG_INT64_MIN;
			ptr += 19;
			goto gotdigits;
		}
		sign = -1;
	}
	else if (*ptr == '+')
		ptr++;

	/* require at least one digit */
	if (!isdigit((unsigned char) *ptr))
		fprintf(stderr, "invalid input syntax for integer: \"%s\"\n", str);

	/* process digits */
	while (*ptr && isdigit((unsigned char) *ptr))
	{
		int64		tmp = result * 10 + (*ptr++ - '0');

		if ((tmp / 10) != result)		/* overflow? */
			fprintf(stderr, "value \"%s\" is out of range for type bigint\n", str);
		result = tmp;
	}

gotdigits:

	/* allow trailing whitespace, but not other trailing chars */
	while (*ptr != '\0' && isspace((unsigned char) *ptr))
		ptr++;

	if (*ptr != '\0')
		fprintf(stderr, "invalid input syntax for integer: \"%s\"\n", str);

	return ((sign < 0) ? -result : result);
}

/* random number generator: uniform distribution from min to max inclusive */
static int64
getrand(TState *thread, int64 min, int64 max)
{
	/*
	 * Odd coding is so that min and max have approximately the same chance of
	 * being selected as do numbers between them.
	 *
	 * pg_erand48() is thread-safe and concurrent, which is why we use it
	 * rather than random(), which in glibc is non-reentrant, and therefore
	 * protected by a mutex, and therefore a bottleneck on machines with many
	 * CPUs.
	 */
	return min + (int64) ((max - min + 1) * pg_erand48(thread->random_state));
}

/*
 * random number generator: exponential distribution from min to max inclusive.
 * the threshold is so that the density of probability for the last cut-off max
 * value is exp(-threshold).
 */
static int64
getExponentialRand(TState *thread, int64 min, int64 max, double threshold)
{
	double		cut,
				uniform,
				rand;

	Assert(threshold > 0.0);
	cut = exp(-threshold);
	/* erand in [0, 1), uniform in (0, 1] */
	uniform = 1.0 - pg_erand48(thread->random_state);

	/*
	 * inner expresion in (cut, 1] (if threshold > 0), rand in [0, 1)
	 */
	Assert((1.0 - cut) != 0.0);
	rand = -log(cut + (1.0 - cut) * uniform) / threshold;
	/* return int64 random number within between min and max */
	return min + (int64) ((max - min + 1) * rand);
}

/* random number generator: gaussian distribution from min to max inclusive */
static int64
getGaussianRand(TState *thread, int64 min, int64 max, double threshold)
{
	double		stdev;
	double		rand;

	/*
	 * Get user specified random number from this loop, with -threshold <
	 * stdev <= threshold
	 *
	 * This loop is executed until the number is in the expected range.
	 *
	 * As the minimum threshold is 2.0, the probability of looping is low:
	 * sqrt(-2 ln(r)) <= 2 => r >= e^{-2} ~ 0.135, then when taking the
	 * average sinus multiplier as 2/pi, we have a 8.6% looping probability in
	 * the worst case. For a 5.0 threshold value, the looping probability is
	 * about e^{-5} * 2 / pi ~ 0.43%.
	 */
	do
	{
		/*
		 * pg_erand48 generates [0,1), but for the basic version of the
		 * Box-Muller transform the two uniformly distributed random numbers
		 * are expected in (0, 1] (see
		 * http://en.wikipedia.org/wiki/Box_muller)
		 */
		double		rand1 = 1.0 - pg_erand48(thread->random_state);
		double		rand2 = 1.0 - pg_erand48(thread->random_state);

		/* Box-Muller basic form transform */
		double		var_sqrt = sqrt(-2.0 * log(rand1));

		stdev = var_sqrt * sin(2.0 * M_PI * rand2);

		/*
		 * we may try with cos, but there may be a bias induced if the
		 * previous value fails the test. To be on the safe side, let us try
		 * over.
		 */
	}
	while (stdev < -threshold || stdev >= threshold);

	/* stdev is in [-threshold, threshold), normalization to [0,1) */
	rand = (stdev + threshold) / (threshold * 2.0);

	/* return int64 random number within between min and max */
	return min + (int64) ((max - min + 1) * rand);
}

/*
 * random number generator: generate a value, such that the series of values
 * will approximate a Poisson distribution centered on the given value.
 */
static int64
getPoissonRand(TState *thread, int64 center)
{
	/*
	 * Use inverse transform sampling to generate a value > 0, such that the
	 * expected (i.e. average) value is the given argument.
	 */
	double		uniform;

	/* erand in [0, 1), uniform in (0, 1] */
	uniform = 1.0 - pg_erand48(thread->random_state);

	return (int64) (-log(uniform) * ((double) center) + 0.5);
}

/* call PQexec() and exit() on failure */
static void
executeStatement(PGconn *con, const char *sql)
{
	PGresult   *res;

	res = PQexec(con, sql);
	if (PQresultStatus(res) != PGRES_COMMAND_OK)
	{
		fprintf(stderr, "%s", PQerrorMessage(con));
		exit(1);
	}
	PQclear(res);
}

/* call PQexec() and complain, but without exiting, on failure */
static void
tryExecuteStatement(PGconn *con, const char *sql)
{
	PGresult   *res;

	res = PQexec(con, sql);
	if (PQresultStatus(res) != PGRES_COMMAND_OK)
	{
		fprintf(stderr, "%s", PQerrorMessage(con));
		fprintf(stderr, "(ignoring this error and continuing anyway)\n");
	}
	PQclear(res);
}

/* set up a connection to the backend */
static PGconn *
doConnect(void)
{
	PGconn	   *conn;
	static char *password = NULL;
	bool		new_pass;

	/*
	 * Start the connection.  Loop until we have a password if requested by
	 * backend.
	 */
	do
	{
#define PARAMS_ARRAY_SIZE	7

		const char *keywords[PARAMS_ARRAY_SIZE];
		const char *values[PARAMS_ARRAY_SIZE];

		keywords[0] = "host";
		values[0] = pghost;
		keywords[1] = "port";
		values[1] = pgport;
		keywords[2] = "user";
		values[2] = login;
		keywords[3] = "password";
		values[3] = password;
		keywords[4] = "dbname";
		values[4] = dbName;
		keywords[5] = "fallback_application_name";
		values[5] = progname;
		keywords[6] = NULL;
		values[6] = NULL;

		new_pass = false;

		conn = PQconnectdbParams(keywords, values, true);

		if (!conn)
		{
			fprintf(stderr, "connection to database \"%s\" failed\n",
					dbName);
			return NULL;
		}

		if (PQstatus(conn) == CONNECTION_BAD &&
			PQconnectionNeedsPassword(conn) &&
			password == NULL)
		{
			PQfinish(conn);
			password = simple_prompt("Password: ", 100, false);
			new_pass = true;
		}
	} while (new_pass);

	/* check to see that the backend connection was successfully made */
	if (PQstatus(conn) == CONNECTION_BAD)
	{
		fprintf(stderr, "connection to database \"%s\" failed:\n%s",
				dbName, PQerrorMessage(conn));
		PQfinish(conn);
		return NULL;
	}

	return conn;
}

/* throw away response from backend */
static void
discard_response(CState *state)
{
	PGresult   *res;

	do
	{
		res = PQgetResult(state->con);
		if (res)
			PQclear(res);
	} while (res);
}

static int
compareVariables(const void *v1, const void *v2)
{
	return strcmp(((const Variable *) v1)->name,
				  ((const Variable *) v2)->name);
}

static char *
getVariable(CState *st, char *name)
{
	Variable	key,
			   *var;

	/* On some versions of Solaris, bsearch of zero items dumps core */
	if (st->nvariables <= 0)
		return NULL;

	key.name = name;
	var = (Variable *) bsearch((void *) &key,
							   (void *) st->variables,
							   st->nvariables,
							   sizeof(Variable),
							   compareVariables);
	if (var != NULL)
		return var->value;
	else
		return NULL;
}

/* check whether the name consists of alphabets, numerals and underscores. */
static bool
isLegalVariableName(const char *name)
{
	int			i;

	for (i = 0; name[i] != '\0'; i++)
	{
		if (!isalnum((unsigned char) name[i]) && name[i] != '_')
			return false;
	}

	return true;
}

static int
putVariable(CState *st, const char *context, char *name, char *value)
{
	Variable	key,
			   *var;

	key.name = name;
	/* On some versions of Solaris, bsearch of zero items dumps core */
	if (st->nvariables > 0)
		var = (Variable *) bsearch((void *) &key,
								   (void *) st->variables,
								   st->nvariables,
								   sizeof(Variable),
								   compareVariables);
	else
		var = NULL;

	if (var == NULL)
	{
		Variable   *newvars;

		/*
		 * Check for the name only when declaring a new variable to avoid
		 * overhead.
		 */
		if (!isLegalVariableName(name))
		{
			fprintf(stderr, "%s: invalid variable name: \"%s\"\n",
					context, name);
			return false;
		}

		if (st->variables)
			newvars = (Variable *) pg_realloc(st->variables,
									(st->nvariables + 1) * sizeof(Variable));
		else
			newvars = (Variable *) pg_malloc(sizeof(Variable));

		st->variables = newvars;

		var = &newvars[st->nvariables];

		var->name = pg_strdup(name);
		var->value = pg_strdup(value);

		st->nvariables++;

		qsort((void *) st->variables, st->nvariables, sizeof(Variable),
			  compareVariables);
	}
	else
	{
		char	   *val;

		/* dup then free, in case value is pointing at this variable */
		val = pg_strdup(value);

		free(var->value);
		var->value = val;
	}

	return true;
}

static char *
parseVariable(const char *sql, int *eaten)
{
	int			i = 0;
	char	   *name;

	do
	{
		i++;
	} while (isalnum((unsigned char) sql[i]) || sql[i] == '_');
	if (i == 1)
		return NULL;

	name = pg_malloc(i);
	memcpy(name, &sql[1], i - 1);
	name[i - 1] = '\0';

	*eaten = i;
	return name;
}

static char *
replaceVariable(char **sql, char *param, int len, char *value)
{
	int			valueln = strlen(value);

	if (valueln > len)
	{
		size_t		offset = param - *sql;

		*sql = pg_realloc(*sql, strlen(*sql) - len + valueln + 1);
		param = *sql + offset;
	}

	if (valueln != len)
		memmove(param + valueln, param + len, strlen(param + len) + 1);
	memcpy(param, value, valueln);

	return param + valueln;
}

static char *
assignVariables(CState *st, char *sql)
{
	char	   *p,
			   *name,
			   *val;

	p = sql;
	while ((p = strchr(p, ':')) != NULL)
	{
		int			eaten;

		name = parseVariable(p, &eaten);
		if (name == NULL)
		{
			while (*p == ':')
			{
				p++;
			}
			continue;
		}

		val = getVariable(st, name);
		free(name);
		if (val == NULL)
		{
			p++;
			continue;
		}

		p = replaceVariable(&sql, p, eaten, val);
	}

	return sql;
}

static void
getQueryParams(CState *st, const Command *command, const char **params)
{
	int			i;

	for (i = 0; i < command->argc - 1; i++)
		params[i] = getVariable(st, command->argv[i + 1]);
}

/*
 * Recursive evaluation of an expression in a pgbench script
 * using the current state of variables.
 * Returns whether the evaluation was ok,
 * the value itself is returned through the retval pointer.
 */
static bool
evaluateExpr(CState *st, PgBenchExpr *expr, int64 *retval)
{
	switch (expr->etype)
	{
		case ENODE_INTEGER_CONSTANT:
			{
				*retval = expr->u.integer_constant.ival;
				return true;
			}

		case ENODE_VARIABLE:
			{
				char	   *var;

				if ((var = getVariable(st, expr->u.variable.varname)) == NULL)
				{
					fprintf(stderr, "undefined variable \"%s\"\n",
							expr->u.variable.varname);
					return false;
				}
				*retval = strtoint64(var);
				return true;
			}

		case ENODE_OPERATOR:
			{
				int64		lval;
				int64		rval;

				if (!evaluateExpr(st, expr->u.operator.lexpr, &lval))
					return false;
				if (!evaluateExpr(st, expr->u.operator.rexpr, &rval))
					return false;
				switch (expr->u.operator.operator)
				{
					case '+':
						*retval = lval + rval;
						return true;

					case '-':
						*retval = lval - rval;
						return true;

					case '*':
						*retval = lval * rval;
						return true;

					case '/':
						if (rval == 0)
						{
							fprintf(stderr, "division by zero\n");
							return false;
						}
						*retval = lval / rval;
						return true;

					case '%':
						if (rval == 0)
						{
							fprintf(stderr, "division by zero\n");
							return false;
						}
						*retval = lval % rval;
						return true;
				}

				fprintf(stderr, "bad operator\n");
				return false;
			}

		default:
			break;
	}

	fprintf(stderr, "bad expression\n");
	return false;
}

/*
 * Run a shell command. The result is assigned to the variable if not NULL.
 * Return true if succeeded, or false on error.
 */
static bool
runShellCommand(CState *st, char *variable, char **argv, int argc)
{
	char		command[SHELL_COMMAND_SIZE];
	int			i,
				len = 0;
	FILE	   *fp;
	char		res[64];
	char	   *endptr;
	int			retval;

	/*----------
	 * Join arguments with whitespace separators. Arguments starting with
	 * exactly one colon are treated as variables:
	 *	name - append a string "name"
	 *	:var - append a variable named 'var'
	 *	::name - append a string ":name"
	 *----------
	 */
	for (i = 0; i < argc; i++)
	{
		char	   *arg;
		int			arglen;

		if (argv[i][0] != ':')
		{
			arg = argv[i];		/* a string literal */
		}
		else if (argv[i][1] == ':')
		{
			arg = argv[i] + 1;	/* a string literal starting with colons */
		}
		else if ((arg = getVariable(st, argv[i] + 1)) == NULL)
		{
			fprintf(stderr, "%s: undefined variable \"%s\"\n",
					argv[0], argv[i]);
			return false;
		}

		arglen = strlen(arg);
		if (len + arglen + (i > 0 ? 1 : 0) >= SHELL_COMMAND_SIZE - 1)
		{
			fprintf(stderr, "%s: shell command is too long\n", argv[0]);
			return false;
		}

		if (i > 0)
			command[len++] = ' ';
		memcpy(command + len, arg, arglen);
		len += arglen;
	}

	command[len] = '\0';

	/* Fast path for non-assignment case */
	if (variable == NULL)
	{
		if (system(command))
		{
			if (!timer_exceeded)
				fprintf(stderr, "%s: could not launch shell command\n", argv[0]);
			return false;
		}
		return true;
	}

	/* Execute the command with pipe and read the standard output. */
	if ((fp = popen(command, "r")) == NULL)
	{
		fprintf(stderr, "%s: could not launch shell command\n", argv[0]);
		return false;
	}
	if (fgets(res, sizeof(res), fp) == NULL)
	{
		if (!timer_exceeded)
			fprintf(stderr, "%s: could not read result of shell command\n", argv[0]);
		(void) pclose(fp);
		return false;
	}
	if (pclose(fp) < 0)
	{
		fprintf(stderr, "%s: could not close shell command\n", argv[0]);
		return false;
	}

	/* Check whether the result is an integer and assign it to the variable */
	retval = (int) strtol(res, &endptr, 10);
	while (*endptr != '\0' && isspace((unsigned char) *endptr))
		endptr++;
	if (*res == '\0' || *endptr != '\0')
	{
		fprintf(stderr, "%s: shell command must return an integer (not \"%s\")\n",
				argv[0], res);
		return false;
	}
	snprintf(res, sizeof(res), "%d", retval);
	if (!putVariable(st, "setshell", variable, res))
		return false;

#ifdef DEBUG
	printf("shell parameter name: \"%s\", value: \"%s\"\n", argv[1], res);
#endif
	return true;
}

#define MAX_PREPARE_NAME		32
static void
preparedStatementName(char *buffer, int file, int state)
{
	sprintf(buffer, "P%d_%d", file, state);
}

static bool
clientDone(CState *st, bool ok)
{
	(void) ok;					/* unused */

	if (st->con != NULL)
	{
		PQfinish(st->con);
		st->con = NULL;
	}
	return false;				/* always false */
}

static void
agg_vals_init(AggVals *aggs, instr_time start)
{
	/* basic counters */
	aggs->cnt = 0;				/* number of transactions (includes skipped) */
	aggs->skipped = 0;			/* xacts skipped under --rate --latency-limit */

	aggs->sum_latency = 0;		/* SUM(latency) */
	aggs->sum2_latency = 0;		/* SUM(latency*latency) */

	/* min and max transaction duration */
	aggs->min_latency = 0;
	aggs->max_latency = 0;

	/* schedule lag counters */
	aggs->sum_lag = 0;
	aggs->sum2_lag = 0;
	aggs->min_lag = 0;
	aggs->max_lag = 0;

	/* start of the current interval */
	aggs->start_time = INSTR_TIME_GET_DOUBLE(start);
}

/* return false iff client should be disconnected */
static bool
doCustom(TState *thread, CState *st, instr_time *conn_time, FILE *logfile, AggVals *agg)
{
	PGresult   *res;
	Command   **commands;
	bool		trans_needs_throttle = false;
	instr_time	now;

	/*
	 * gettimeofday() isn't free, so we get the current timestamp lazily the
	 * first time it's needed, and reuse the same value throughout this
	 * function after that. This also ensures that e.g. the calculated latency
	 * reported in the log file and in the totals are the same. Zero means
	 * "not set yet". Reset "now" when we step to the next command with "goto
	 * top", though.
	 */
top:
	INSTR_TIME_SET_ZERO(now);

	commands = sql_files[st->use_file];

	/*
	 * Handle throttling once per transaction by sleeping.  It is simpler to
	 * do this here rather than at the end, because so much complicated logic
	 * happens below when statements finish.
	 */
	if (throttle_delay && !st->is_throttled)
	{
		/*
		 * Generate a delay such that the series of delays will approximate a
		 * Poisson distribution centered on the throttle_delay time.
		 *
		 * If transactions are too slow or a given wait is shorter than a
		 * transaction, the next transaction will start right away.
		 */
		int64		wait = getPoissonRand(thread, throttle_delay);

		thread->throttle_trigger += wait;
		st->txn_scheduled = thread->throttle_trigger;

		/*
		 * If this --latency-limit is used, and this slot is already late so
		 * that the transaction will miss the latency limit even if it
		 * completed immediately, we skip this time slot and iterate till the
		 * next slot that isn't late yet.
		 */
		if (latency_limit)
		{
			int64		now_us;

			if (INSTR_TIME_IS_ZERO(now))
				INSTR_TIME_SET_CURRENT(now);
			now_us = INSTR_TIME_GET_MICROSEC(now);
			while (thread->throttle_trigger < now_us - latency_limit)
			{
				thread->throttle_latency_skipped++;

				if (logfile)
					doLog(thread, st, logfile, &now, agg, true);

				wait = getPoissonRand(thread, throttle_delay);
				thread->throttle_trigger += wait;
				st->txn_scheduled = thread->throttle_trigger;
			}
		}

		st->sleeping = 1;
		st->throttling = true;
		st->is_throttled = true;
		if (debug)
			fprintf(stderr, "client %d throttling " INT64_FORMAT " us\n",
					st->id, wait);
	}

	if (st->sleeping)
	{							/* are we sleeping? */
		int64		now_us;

		if (INSTR_TIME_IS_ZERO(now))
			INSTR_TIME_SET_CURRENT(now);
		now_us = INSTR_TIME_GET_MICROSEC(now);
		if (st->txn_scheduled <= now_us)
		{
			st->sleeping = 0;	/* Done sleeping, go ahead with next command */
			if (st->throttling)
			{
				/* Measure lag of throttled transaction relative to target */
				int64		lag = now_us - st->txn_scheduled;

				thread->throttle_lag += lag;
				if (lag > thread->throttle_lag_max)
					thread->throttle_lag_max = lag;
				st->throttling = false;
			}
		}
		else
			return true;		/* Still sleeping, nothing to do here */
	}

	if (st->listen)
	{							/* are we receiver? */
		if (commands[st->state]->type == SQL_COMMAND)
		{
			if (debug)
				fprintf(stderr, "client %d receiving\n", st->id);
			if (!PQconsumeInput(st->con))
			{					/* there's something wrong */
				fprintf(stderr, "client %d aborted in state %d; perhaps the backend died while processing\n", st->id, st->state);
				return clientDone(st, false);
			}
			if (PQisBusy(st->con))
				return true;	/* don't have the whole result yet */
		}

		/*
		 * command finished: accumulate per-command execution times in
		 * thread-local data structure, if per-command latencies are requested
		 */
		if (is_latencies)
		{
			int			cnum = commands[st->state]->command_num;

			if (INSTR_TIME_IS_ZERO(now))
				INSTR_TIME_SET_CURRENT(now);
			INSTR_TIME_ACCUM_DIFF(thread->exec_elapsed[cnum],
								  now, st->stmt_begin);
			thread->exec_count[cnum]++;
		}

		/* transaction finished: calculate latency and log the transaction */
		if (commands[st->state + 1] == NULL)
		{
			/* only calculate latency if an option is used that needs it */
			if (progress || throttle_delay || latency_limit)
			{
				int64		latency;

				if (INSTR_TIME_IS_ZERO(now))
					INSTR_TIME_SET_CURRENT(now);

				latency = INSTR_TIME_GET_MICROSEC(now) - st->txn_scheduled;

				st->txn_latencies += latency;

				/*
				 * XXX In a long benchmark run of high-latency transactions,
				 * this int64 addition eventually overflows.  For example, 100
				 * threads running 10s transactions will overflow it in 2.56
				 * hours.  With a more-typical OLTP workload of .1s
				 * transactions, overflow would take 256 hours.
				 */
				st->txn_sqlats += latency * latency;

				/* record over the limit transactions if needed. */
				if (latency_limit && latency > latency_limit)
					thread->latency_late++;
			}

			/* record the time it took in the log */
			if (logfile)
				doLog(thread, st, logfile, &now, agg, false);
		}

		if (commands[st->state]->type == SQL_COMMAND)
		{
			/*
			 * Read and discard the query result; note this is not included in
			 * the statement latency numbers.
			 */
			res = PQgetResult(st->con);
			switch (PQresultStatus(res))
			{
				case PGRES_COMMAND_OK:
				case PGRES_TUPLES_OK:
					break;		/* OK */
				default:
					fprintf(stderr, "client %d aborted in state %d: %s",
							st->id, st->state, PQerrorMessage(st->con));
					PQclear(res);
					return clientDone(st, false);
			}
			PQclear(res);
			discard_response(st);
		}

		if (commands[st->state + 1] == NULL)
		{
			if (is_connect)
			{
				PQfinish(st->con);
				st->con = NULL;
			}

			++st->cnt;
			if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
				return clientDone(st, true);	/* exit success */
		}

		/* increment state counter */
		st->state++;
		if (commands[st->state] == NULL)
		{
			st->state = 0;
			st->use_file = (int) getrand(thread, 0, num_files - 1);
			commands = sql_files[st->use_file];
			st->is_throttled = false;

			/*
			 * No transaction is underway anymore, which means there is
			 * nothing to listen to right now.  When throttling rate limits
			 * are active, a sleep will happen next, as the next transaction
			 * starts.  And then in any case the next SQL command will set
			 * listen back to 1.
			 */
			st->listen = 0;
			trans_needs_throttle = (throttle_delay > 0);
		}
	}

	if (st->con == NULL)
	{
		instr_time	start,
					end;

		INSTR_TIME_SET_CURRENT(start);
		if ((st->con = doConnect()) == NULL)
		{
			fprintf(stderr, "client %d aborted while establishing connection\n",
					st->id);
			return clientDone(st, false);
		}
		INSTR_TIME_SET_CURRENT(end);
		INSTR_TIME_ACCUM_DIFF(*conn_time, end, start);
	}

	/*
	 * This ensures that a throttling delay is inserted before proceeding with
	 * sql commands, after the first transaction. The first transaction
	 * throttling is performed when first entering doCustom.
	 */
	if (trans_needs_throttle)
	{
		trans_needs_throttle = false;
		goto top;
	}

	/* Record transaction start time under logging, progress or throttling */
	if ((logfile || progress || throttle_delay || latency_limit) && st->state == 0)
	{
		INSTR_TIME_SET_CURRENT(st->txn_begin);

		/*
		 * When not throttling, this is also the transaction's scheduled start
		 * time.
		 */
		if (!throttle_delay)
			st->txn_scheduled = INSTR_TIME_GET_MICROSEC(st->txn_begin);
	}

	/* Record statement start time if per-command latencies are requested */
	if (is_latencies)
		INSTR_TIME_SET_CURRENT(st->stmt_begin);

	if (commands[st->state]->type == SQL_COMMAND)
	{
		const Command *command = commands[st->state];
		int			r;

		if (querymode == QUERY_SIMPLE)
		{
			char	   *sql;

			sql = pg_strdup(command->argv[0]);
			sql = assignVariables(st, sql);

			if (debug)
				fprintf(stderr, "client %d sending %s\n", st->id, sql);
			r = PQsendQuery(st->con, sql);
			free(sql);
		}
		else if (querymode == QUERY_EXTENDED)
		{
			const char *sql = command->argv[0];
			const char *params[MAX_ARGS];

			getQueryParams(st, command, params);

			if (debug)
				fprintf(stderr, "client %d sending %s\n", st->id, sql);
			r = PQsendQueryParams(st->con, sql, command->argc - 1,
								  NULL, params, NULL, NULL, 0);
		}
		else if (querymode == QUERY_PREPARED)
		{
			char		name[MAX_PREPARE_NAME];
			const char *params[MAX_ARGS];

			if (!st->prepared[st->use_file])
			{
				int			j;

				for (j = 0; commands[j] != NULL; j++)
				{
					PGresult   *res;
					char		name[MAX_PREPARE_NAME];

					if (commands[j]->type != SQL_COMMAND)
						continue;
					preparedStatementName(name, st->use_file, j);
					res = PQprepare(st->con, name,
						  commands[j]->argv[0], commands[j]->argc - 1, NULL);
					if (PQresultStatus(res) != PGRES_COMMAND_OK)
						fprintf(stderr, "%s", PQerrorMessage(st->con));
					PQclear(res);
				}
				st->prepared[st->use_file] = true;
			}

			getQueryParams(st, command, params);
			preparedStatementName(name, st->use_file, st->state);

			if (debug)
				fprintf(stderr, "client %d sending %s\n", st->id, name);
			r = PQsendQueryPrepared(st->con, name, command->argc - 1,
									params, NULL, NULL, 0);
		}
		else	/* unknown sql mode */
			r = 0;

		if (r == 0)
		{
			if (debug)
				fprintf(stderr, "client %d could not send %s\n",
						st->id, command->argv[0]);
			st->ecnt++;
		}
		else
			st->listen = 1;		/* flags that should be listened */
	}
	else if (commands[st->state]->type == META_COMMAND)
	{
		int			argc = commands[st->state]->argc,
					i;
		char	  **argv = commands[st->state]->argv;

		if (debug)
		{
			fprintf(stderr, "client %d executing \\%s", st->id, argv[0]);
			for (i = 1; i < argc; i++)
				fprintf(stderr, " %s", argv[i]);
			fprintf(stderr, "\n");
		}

		if (pg_strcasecmp(argv[0], "setrandom") == 0)
		{
			char	   *var;
			int64		min,
						max;
			double		threshold = 0;
			char		res[64];

			if (*argv[2] == ':')
			{
				if ((var = getVariable(st, argv[2] + 1)) == NULL)
				{
					fprintf(stderr, "%s: undefined variable \"%s\"\n",
							argv[0], argv[2]);
					st->ecnt++;
					return true;
				}
				min = strtoint64(var);
			}
			else
				min = strtoint64(argv[2]);

			if (*argv[3] == ':')
			{
				if ((var = getVariable(st, argv[3] + 1)) == NULL)
				{
					fprintf(stderr, "%s: undefined variable \"%s\"\n",
							argv[0], argv[3]);
					st->ecnt++;
					return true;
				}
				max = strtoint64(var);
			}
			else
				max = strtoint64(argv[3]);

			if (max < min)
			{
				fprintf(stderr, "%s: \\setrandom maximum is less than minimum\n",
						argv[0]);
				st->ecnt++;
				return true;
			}

			/*
			 * Generate random number functions need to be able to subtract
			 * max from min and add one to the result without overflowing.
			 * Since we know max > min, we can detect overflow just by
			 * checking for a negative result. But we must check both that the
			 * subtraction doesn't overflow, and that adding one to the result
			 * doesn't overflow either.
			 */
			if (max - min < 0 || (max - min) + 1 < 0)
			{
				fprintf(stderr, "%s: \\setrandom range is too large\n",
						argv[0]);
				st->ecnt++;
				return true;
			}

			if (argc == 4 ||	/* uniform without or with "uniform" keyword */
				(argc == 5 && pg_strcasecmp(argv[4], "uniform") == 0))
			{
#ifdef DEBUG
				printf("min: " INT64_FORMAT " max: " INT64_FORMAT " random: " INT64_FORMAT "\n", min, max, getrand(thread, min, max));
#endif
				snprintf(res, sizeof(res), INT64_FORMAT, getrand(thread, min, max));
			}
			else if (argc == 6 &&
					 ((pg_strcasecmp(argv[4], "gaussian") == 0) ||
					  (pg_strcasecmp(argv[4], "exponential") == 0)))
			{
				if (*argv[5] == ':')
				{
					if ((var = getVariable(st, argv[5] + 1)) == NULL)
					{
						fprintf(stderr, "%s: invalid threshold number: \"%s\"\n",
								argv[0], argv[5]);
						st->ecnt++;
						return true;
					}
					threshold = strtod(var, NULL);
				}
				else
					threshold = strtod(argv[5], NULL);

				if (pg_strcasecmp(argv[4], "gaussian") == 0)
				{
					if (threshold < MIN_GAUSSIAN_THRESHOLD)
					{
						fprintf(stderr, "gaussian threshold must be at least %f (not \"%s\")\n", MIN_GAUSSIAN_THRESHOLD, argv[5]);
						st->ecnt++;
						return true;
					}
#ifdef DEBUG
					printf("min: " INT64_FORMAT " max: " INT64_FORMAT " random: " INT64_FORMAT "\n", min, max, getGaussianRand(thread, min, max, threshold));
#endif
					snprintf(res, sizeof(res), INT64_FORMAT, getGaussianRand(thread, min, max, threshold));
				}
				else if (pg_strcasecmp(argv[4], "exponential") == 0)
				{
					if (threshold <= 0.0)
					{
						fprintf(stderr, "exponential threshold must be greater than zero (not \"%s\")\n", argv[5]);
						st->ecnt++;
						return true;
					}
#ifdef DEBUG
					printf("min: " INT64_FORMAT " max: " INT64_FORMAT " random: " INT64_FORMAT "\n", min, max, getExponentialRand(thread, min, max, threshold));
#endif
					snprintf(res, sizeof(res), INT64_FORMAT, getExponentialRand(thread, min, max, threshold));
				}
			}
			else	/* this means an error somewhere in the parsing phase... */
			{
				fprintf(stderr, "%s: invalid arguments for \\setrandom\n",
						argv[0]);
				st->ecnt++;
				return true;
			}

			if (!putVariable(st, argv[0], argv[1], res))
			{
				st->ecnt++;
				return true;
			}

			st->listen = 1;
		}
		else if (pg_strcasecmp(argv[0], "set") == 0)
		{
			char		res[64];
			PgBenchExpr *expr = commands[st->state]->expr;
			int64		result;

			if (!evaluateExpr(st, expr, &result))
			{
				st->ecnt++;
				return true;
			}
			sprintf(res, INT64_FORMAT, result);

			if (!putVariable(st, argv[0], argv[1], res))
			{
				st->ecnt++;
				return true;
			}

			st->listen = 1;
		}
		else if (pg_strcasecmp(argv[0], "sleep") == 0)
		{
			char	   *var;
			int			usec;
			instr_time	now;

			if (*argv[1] == ':')
			{
				if ((var = getVariable(st, argv[1] + 1)) == NULL)
				{
					fprintf(stderr, "%s: undefined variable \"%s\"\n",
							argv[0], argv[1]);
					st->ecnt++;
					return true;
				}
				usec = atoi(var);
			}
			else
				usec = atoi(argv[1]);

			if (argc > 2)
			{
				if (pg_strcasecmp(argv[2], "ms") == 0)
					usec *= 1000;
				else if (pg_strcasecmp(argv[2], "s") == 0)
					usec *= 1000000;
			}
			else
				usec *= 1000000;

			INSTR_TIME_SET_CURRENT(now);
			st->txn_scheduled = INSTR_TIME_GET_MICROSEC(now) + usec;
			st->sleeping = 1;

			st->listen = 1;
		}
		else if (pg_strcasecmp(argv[0], "setshell") == 0)
		{
			bool		ret = runShellCommand(st, argv[1], argv + 2, argc - 2);

			if (timer_exceeded) /* timeout */
				return clientDone(st, true);
			else if (!ret)		/* on error */
			{
				st->ecnt++;
				return true;
			}
			else	/* succeeded */
				st->listen = 1;
		}
		else if (pg_strcasecmp(argv[0], "shell") == 0)
		{
			bool		ret = runShellCommand(st, NULL, argv + 1, argc - 1);

			if (timer_exceeded) /* timeout */
				return clientDone(st, true);
			else if (!ret)		/* on error */
			{
				st->ecnt++;
				return true;
			}
			else	/* succeeded */
				st->listen = 1;
		}
		goto top;
	}

	return true;
}

/*
 * print log entry after completing one transaction.
 */
static void
doLog(TState *thread, CState *st, FILE *logfile, instr_time *now, AggVals *agg,
	  bool skipped)
{
	double		lag;
	double		latency;

	/*
	 * Skip the log entry if sampling is enabled and this row doesn't belong
	 * to the random sample.
	 */
	if (sample_rate != 0.0 &&
		pg_erand48(thread->random_state) > sample_rate)
		return;

	if (INSTR_TIME_IS_ZERO(*now))
		INSTR_TIME_SET_CURRENT(*now);

	latency = (double) (INSTR_TIME_GET_MICROSEC(*now) - st->txn_scheduled);
	if (skipped)
		lag = latency;
	else
		lag = (double) (INSTR_TIME_GET_MICROSEC(st->txn_begin) - st->txn_scheduled);

	/* should we aggregate the results or not? */
	if (agg_interval > 0)
	{
		/*
		 * Are we still in the same interval? If yes, accumulate the values
		 * (print them otherwise)
		 */
		if (agg->start_time + agg_interval >= INSTR_TIME_GET_DOUBLE(*now))
		{
			agg->cnt += 1;
			if (skipped)
			{
				/*
				 * there is no latency to record if the transaction was
				 * skipped
				 */
				agg->skipped += 1;
			}
			else
			{
				agg->sum_latency += latency;
				agg->sum2_latency += latency * latency;

				/* first in this aggregation interval */
				if ((agg->cnt == 1) || (latency < agg->min_latency))
					agg->min_latency = latency;

				if ((agg->cnt == 1) || (latency > agg->max_latency))
					agg->max_latency = latency;

				/* and the same for schedule lag */
				if (throttle_delay)
				{
					agg->sum_lag += lag;
					agg->sum2_lag += lag * lag;

					if ((agg->cnt == 1) || (lag < agg->min_lag))
						agg->min_lag = lag;
					if ((agg->cnt == 1) || (lag > agg->max_lag))
						agg->max_lag = lag;
				}
			}
		}
		else
		{
			/*
			 * Loop until we reach the interval of the current transaction
			 * (and print all the empty intervals in between).
			 */
			while (agg->start_time + agg_interval < INSTR_TIME_GET_DOUBLE(*now))
			{
				/*
				 * This is a non-Windows branch (thanks to the ifdef in
				 * usage), so we don't need to handle this in a special way
				 * (see below).
				 */
				fprintf(logfile, "%ld %d %.0f %.0f %.0f %.0f",
						agg->start_time,
						agg->cnt,
						agg->sum_latency,
						agg->sum2_latency,
						agg->min_latency,
						agg->max_latency);
				if (throttle_delay)
				{
					fprintf(logfile, " %.0f %.0f %.0f %.0f",
							agg->sum_lag,
							agg->sum2_lag,
							agg->min_lag,
							agg->max_lag);
					if (latency_limit)
						fprintf(logfile, " %d", agg->skipped);
				}
				fputc('\n', logfile);

				/* move to the next inteval */
				agg->start_time = agg->start_time + agg_interval;

				/* reset for "no transaction" intervals */
				agg->cnt = 0;
				agg->skipped = 0;
				agg->min_latency = 0;
				agg->max_latency = 0;
				agg->sum_latency = 0;
				agg->sum2_latency = 0;
				agg->min_lag = 0;
				agg->max_lag = 0;
				agg->sum_lag = 0;
				agg->sum2_lag = 0;
			}

			/* reset the values to include only the current transaction. */
			agg->cnt = 1;
			agg->skipped = skipped ? 1 : 0;
			agg->min_latency = latency;
			agg->max_latency = latency;
			agg->sum_latency = skipped ? 0.0 : latency;
			agg->sum2_latency = skipped ? 0.0 : latency * latency;
			agg->min_lag = lag;
			agg->max_lag = lag;
			agg->sum_lag = lag;
			agg->sum2_lag = lag * lag;
		}
	}
	else
	{
		/* no, print raw transactions */
#ifndef WIN32

		/* This is more than we really ought to know about instr_time */
		if (skipped)
			fprintf(logfile, "%d %d skipped %d %ld %ld",
					st->id, st->cnt, st->use_file,
					(long) now->tv_sec, (long) now->tv_usec);
		else
			fprintf(logfile, "%d %d %.0f %d %ld %ld",
					st->id, st->cnt, latency, st->use_file,
					(long) now->tv_sec, (long) now->tv_usec);
#else

		/* On Windows, instr_time doesn't provide a timestamp anyway */
		if (skipped)
			fprintf(logfile, "%d %d skipped %d 0 0",
					st->id, st->cnt, st->use_file);
		else
			fprintf(logfile, "%d %d %.0f %d 0 0",
					st->id, st->cnt, latency, st->use_file);
#endif
		if (throttle_delay)
			fprintf(logfile, " %.0f", lag);
		fputc('\n', logfile);
	}
}

/* discard connections */
static void
disconnect_all(CState *state, int length)
{
	int			i;

	for (i = 0; i < length; i++)
	{
		if (state[i].con)
		{
			PQfinish(state[i].con);
			state[i].con = NULL;
		}
	}
}

/* create tables and setup data */
static void
init(bool is_no_vacuum)
{
/*
 * The scale factor at/beyond which 32-bit integers are insufficient for
 * storing TPC-B account IDs.
 *
 * Although the actual threshold is 21474, we use 20000 because it is easier to
 * document and remember, and isn't that far away from the real threshold.
 */
#define SCALE_32BIT_THRESHOLD 20000

	/*
	 * Note: TPC-B requires at least 100 bytes per row, and the "filler"
	 * fields in these table declarations were intended to comply with that.
	 * The pgbench_accounts table complies with that because the "filler"
	 * column is set to blank-padded empty string. But for all other tables
	 * the columns default to NULL and so don't actually take any space.  We
	 * could fix that by giving them non-null default values.  However, that
	 * would completely break comparability of pgbench results with prior
	 * versions. Since pgbench has never pretended to be fully TPC-B compliant
	 * anyway, we stick with the historical behavior.
	 */
	struct ddlinfo
	{
		const char *table;		/* table name */
		const char *smcols;		/* column decls if accountIDs are 32 bits */
		const char *bigcols;	/* column decls if accountIDs are 64 bits */
		int			declare_fillfactor;
	};
	static const struct ddlinfo DDLs[] = {
		{
			"pgbench_history",
			"tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
			"tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)",
			0
		},
		{
			"pgbench_tellers",
			"tid int not null,bid int,tbalance int,filler char(84)",
			"tid int not null,bid int,tbalance int,filler char(84)",
			1
		},
		{
			"pgbench_accounts",
			"aid    int not null,bid int,abalance int,filler char(84)",
			"aid bigint not null,bid int,abalance int,filler char(84)",
			1
		},
		{
			"pgbench_branches",
			"bid int not null,bbalance int,filler char(88)",
			"bid int not null,bbalance int,filler char(88)",
			1
		}
	};
	static const char *const DDLINDEXes[] = {
		"alter table pgbench_branches add primary key (bid)",
		"alter table pgbench_tellers add primary key (tid)",
		"alter table pgbench_accounts add primary key (aid)"
	};
	static const char *const DDLKEYs[] = {
		"alter table pgbench_tellers add foreign key (bid) references pgbench_branches",
		"alter table pgbench_accounts add foreign key (bid) references pgbench_branches",
		"alter table pgbench_history add foreign key (bid) references pgbench_branches",
		"alter table pgbench_history add foreign key (tid) references pgbench_tellers",
		"alter table pgbench_history add foreign key (aid) references pgbench_accounts"
	};

	PGconn	   *con;
	PGresult   *res;
	char		sql[256];
	int			i;
	int64		k;

	/* used to track elapsed time and estimate of the remaining time */
	instr_time	start,
				diff;
	double		elapsed_sec,
				remaining_sec;
	int			log_interval = 1;

	if ((con = doConnect()) == NULL)
		exit(1);

	for (i = 0; i < lengthof(DDLs); i++)
	{
		char		opts[256];
		char		buffer[256];
		const struct ddlinfo *ddl = &DDLs[i];
		const char *cols;

		/* Remove old table, if it exists. */
		snprintf(buffer, sizeof(buffer), "drop table if exists %s", ddl->table);
		executeStatement(con, buffer);

		/* Construct new create table statement. */
		opts[0] = '\0';
		if (ddl->declare_fillfactor)
			snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
					 " with (fillfactor=%d)", fillfactor);
		if (tablespace != NULL)
		{
			char	   *escape_tablespace;

			escape_tablespace = PQescapeIdentifier(con, tablespace,
												   strlen(tablespace));
			snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
					 " tablespace %s", escape_tablespace);
			PQfreemem(escape_tablespace);
		}

		cols = (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols;

		snprintf(buffer, sizeof(buffer), "create%s table %s(%s)%s",
				 unlogged_tables ? " unlogged" : "",
				 ddl->table, cols, opts);

		executeStatement(con, buffer);
	}

	executeStatement(con, "begin");

	for (i = 0; i < nbranches * scale; i++)
	{
		/* "filler" column defaults to NULL */
		snprintf(sql, sizeof(sql),
				 "insert into pgbench_branches(bid,bbalance) values(%d,0)",
				 i + 1);
		executeStatement(con, sql);
	}

	for (i = 0; i < ntellers * scale; i++)
	{
		/* "filler" column defaults to NULL */
		snprintf(sql, sizeof(sql),
			"insert into pgbench_tellers(tid,bid,tbalance) values (%d,%d,0)",
				 i + 1, i / ntellers + 1);
		executeStatement(con, sql);
	}

	executeStatement(con, "commit");

	/*
	 * fill the pgbench_accounts table with some data
	 */
	fprintf(stderr, "creating tables...\n");

	executeStatement(con, "begin");
	executeStatement(con, "truncate pgbench_accounts");

	res = PQexec(con, "copy pgbench_accounts from stdin");
	if (PQresultStatus(res) != PGRES_COPY_IN)
	{
		fprintf(stderr, "%s", PQerrorMessage(con));
		exit(1);
	}
	PQclear(res);

	INSTR_TIME_SET_CURRENT(start);

	for (k = 0; k < (int64) naccounts * scale; k++)
	{
		int64		j = k + 1;

		/* "filler" column defaults to blank padded empty string */
		snprintf(sql, sizeof(sql),
				 INT64_FORMAT "\t" INT64_FORMAT "\t%d\t\n",
				 j, k / naccounts + 1, 0);
		if (PQputline(con, sql))
		{
			fprintf(stderr, "PQputline failed\n");
			exit(1);
		}

		/*
		 * If we want to stick with the original logging, print a message each
		 * 100k inserted rows.
		 */
		if ((!use_quiet) && (j % 100000 == 0))
		{
			INSTR_TIME_SET_CURRENT(diff);
			INSTR_TIME_SUBTRACT(diff, start);

			elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
			remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;

			fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)\n",
					j, (int64) naccounts * scale,
					(int) (((int64) j * 100) / (naccounts * (int64) scale)),
					elapsed_sec, remaining_sec);
		}
		/* let's not call the timing for each row, but only each 100 rows */
		else if (use_quiet && (j % 100 == 0))
		{
			INSTR_TIME_SET_CURRENT(diff);
			INSTR_TIME_SUBTRACT(diff, start);

			elapsed_sec = INSTR_TIME_GET_DOUBLE(diff);
			remaining_sec = ((double) scale * naccounts - j) * elapsed_sec / j;

			/* have we reached the next interval (or end)? */
			if ((j == scale * naccounts) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
			{
				fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) done (elapsed %.2f s, remaining %.2f s)\n",
						j, (int64) naccounts * scale,
						(int) (((int64) j * 100) / (naccounts * (int64) scale)), elapsed_sec, remaining_sec);

				/* skip to the next interval */
				log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
			}
		}

	}
	if (PQputline(con, "\\.\n"))
	{
		fprintf(stderr, "very last PQputline failed\n");
		exit(1);
	}
	if (PQendcopy(con))
	{
		fprintf(stderr, "PQendcopy failed\n");
		exit(1);
	}
	executeStatement(con, "commit");

	/* vacuum */
	if (!is_no_vacuum)
	{
		fprintf(stderr, "vacuum...\n");
		executeStatement(con, "vacuum analyze pgbench_branches");
		executeStatement(con, "vacuum analyze pgbench_tellers");
		executeStatement(con, "vacuum analyze pgbench_accounts");
		executeStatement(con, "vacuum analyze pgbench_history");
	}

	/*
	 * create indexes
	 */
	fprintf(stderr, "set primary keys...\n");
	for (i = 0; i < lengthof(DDLINDEXes); i++)
	{
		char		buffer[256];

		strlcpy(buffer, DDLINDEXes[i], sizeof(buffer));

		if (index_tablespace != NULL)
		{
			char	   *escape_tablespace;

			escape_tablespace = PQescapeIdentifier(con, index_tablespace,
												   strlen(index_tablespace));
			snprintf(buffer + strlen(buffer), sizeof(buffer) - strlen(buffer),
					 " using index tablespace %s", escape_tablespace);
			PQfreemem(escape_tablespace);
		}

		executeStatement(con, buffer);
	}

	/*
	 * create foreign keys
	 */
	if (foreign_keys)
	{
		fprintf(stderr, "set foreign keys...\n");
		for (i = 0; i < lengthof(DDLKEYs); i++)
		{
			executeStatement(con, DDLKEYs[i]);
		}
	}

	fprintf(stderr, "done.\n");
	PQfinish(con);
}

/*
 * Parse the raw sql and replace :param to $n.
 */
static bool
parseQuery(Command *cmd, const char *raw_sql)
{
	char	   *sql,
			   *p;

	sql = pg_strdup(raw_sql);
	cmd->argc = 1;

	p = sql;
	while ((p = strchr(p, ':')) != NULL)
	{
		char		var[12];
		char	   *name;
		int			eaten;

		name = parseVariable(p, &eaten);
		if (name == NULL)
		{
			while (*p == ':')
			{
				p++;
			}
			continue;
		}

		if (cmd->argc >= MAX_ARGS)
		{
			fprintf(stderr, "statement has too many arguments (maximum is %d): %s\n", MAX_ARGS - 1, raw_sql);
			pg_free(name);
			return false;
		}

		sprintf(var, "$%d", cmd->argc);
		p = replaceVariable(&sql, p, eaten, var);

		cmd->argv[cmd->argc] = name;
		cmd->argc++;
	}

	cmd->argv[0] = sql;
	return true;
}

void
syntax_error(const char *source, const int lineno,
			 const char *line, const char *command,
			 const char *msg, const char *more, const int column)
{
	fprintf(stderr, "%s:%d: %s", source, lineno, msg);
	if (more != NULL)
		fprintf(stderr, " (%s)", more);
	if (column != -1)
		fprintf(stderr, " at column %d", column);
	fprintf(stderr, " in command \"%s\"\n", command);
	if (line != NULL)
	{
		fprintf(stderr, "%s\n", line);
		if (column != -1)
		{
			int			i;

			for (i = 0; i < column - 1; i++)
				fprintf(stderr, " ");
			fprintf(stderr, "^ error found here\n");
		}
	}
	exit(1);
}

/* Parse a command; return a Command struct, or NULL if it's a comment */
static Command *
process_commands(char *buf, const char *source, const int lineno)
{
	const char	delim[] = " \f\n\r\t\v";

	Command    *my_commands;
	int			j;
	char	   *p,
			   *tok;

	/* Make the string buf end at the next newline */
	if ((p = strchr(buf, '\n')) != NULL)
		*p = '\0';

	/* Skip leading whitespace */
	p = buf;
	while (isspace((unsigned char) *p))
		p++;

	/* If the line is empty or actually a comment, we're done */
	if (*p == '\0' || strncmp(p, "--", 2) == 0)
		return NULL;

	/* Allocate and initialize Command structure */
	my_commands = (Command *) pg_malloc(sizeof(Command));
	my_commands->line = pg_strdup(buf);
	my_commands->command_num = num_commands++;
	my_commands->type = 0;		/* until set */
	my_commands->argc = 0;

	if (*p == '\\')
	{
		int			max_args = -1;

		my_commands->type = META_COMMAND;

		j = 0;
		tok = strtok(++p, delim);

		if (tok != NULL && pg_strcasecmp(tok, "set") == 0)
			max_args = 2;

		while (tok != NULL)
		{
			my_commands->cols[j] = tok - buf + 1;
			my_commands->argv[j++] = pg_strdup(tok);
			my_commands->argc++;
			if (max_args >= 0 && my_commands->argc >= max_args)
				tok = strtok(NULL, "");
			else
				tok = strtok(NULL, delim);
		}

		if (pg_strcasecmp(my_commands->argv[0], "setrandom") == 0)
		{
			/*
			 * parsing: \setrandom variable min max [uniform] \setrandom
			 * variable min max (gaussian|exponential) threshold
			 */

			if (my_commands->argc < 4)
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "missing arguments", NULL, -1);
			}

			/* argc >= 4 */

			if (my_commands->argc == 4 ||		/* uniform without/with
												 * "uniform" keyword */
				(my_commands->argc == 5 &&
				 pg_strcasecmp(my_commands->argv[4], "uniform") == 0))
			{
				/* nothing to do */
			}
			else if (			/* argc >= 5 */
					 (pg_strcasecmp(my_commands->argv[4], "gaussian") == 0) ||
				   (pg_strcasecmp(my_commands->argv[4], "exponential") == 0))
			{
				if (my_commands->argc < 6)
				{
					syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
					 "missing threshold argument", my_commands->argv[4], -1);
				}
				else if (my_commands->argc > 6)
				{
					syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
								 "too many arguments", my_commands->argv[4],
								 my_commands->cols[6]);
				}
			}
			else	/* cannot parse, unexpected arguments */
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "unexpected argument", my_commands->argv[4],
							 my_commands->cols[4]);
			}
		}
		else if (pg_strcasecmp(my_commands->argv[0], "set") == 0)
		{
			if (my_commands->argc < 3)
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "missing argument", NULL, -1);
			}

			expr_scanner_init(my_commands->argv[2], source, lineno,
							  my_commands->line, my_commands->argv[0],
							  my_commands->cols[2] - 1);

			if (expr_yyparse() != 0)
			{
				/* dead code: exit done from syntax_error called by yyerror */
				exit(1);
			}

			my_commands->expr = expr_parse_result;

			expr_scanner_finish();
		}
		else if (pg_strcasecmp(my_commands->argv[0], "sleep") == 0)
		{
			if (my_commands->argc < 2)
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "missing argument", NULL, -1);
			}

			/*
			 * Split argument into number and unit to allow "sleep 1ms" etc.
			 * We don't have to terminate the number argument with null
			 * because it will be parsed with atoi, which ignores trailing
			 * non-digit characters.
			 */
			if (my_commands->argv[1][0] != ':')
			{
				char	   *c = my_commands->argv[1];

				while (isdigit((unsigned char) *c))
					c++;
				if (*c)
				{
					my_commands->argv[2] = c;
					if (my_commands->argc < 3)
						my_commands->argc = 3;
				}
			}

			if (my_commands->argc >= 3)
			{
				if (pg_strcasecmp(my_commands->argv[2], "us") != 0 &&
					pg_strcasecmp(my_commands->argv[2], "ms") != 0 &&
					pg_strcasecmp(my_commands->argv[2], "s") != 0)
				{
					syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
								 "unknown time unit, must be us, ms or s",
								 my_commands->argv[2], my_commands->cols[2]);
				}
			}

			/* this should be an error?! */
			for (j = 3; j < my_commands->argc; j++)
				fprintf(stderr, "%s: extra argument \"%s\" ignored\n",
						my_commands->argv[0], my_commands->argv[j]);
		}
		else if (pg_strcasecmp(my_commands->argv[0], "setshell") == 0)
		{
			if (my_commands->argc < 3)
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "missing argument", NULL, -1);
			}
		}
		else if (pg_strcasecmp(my_commands->argv[0], "shell") == 0)
		{
			if (my_commands->argc < 1)
			{
				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
							 "missing command", NULL, -1);
			}
		}
		else
		{
			syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
						 "invalid command", NULL, -1);
		}
	}
	else
	{
		my_commands->type = SQL_COMMAND;

		switch (querymode)
		{
			case QUERY_SIMPLE:
				my_commands->argv[0] = pg_strdup(p);
				my_commands->argc++;
				break;
			case QUERY_EXTENDED:
			case QUERY_PREPARED:
				if (!parseQuery(my_commands, p))
					exit(1);
				break;
			default:
				exit(1);
		}
	}

	return my_commands;
}

/*
 * Read a line from fd, and return it in a malloc'd buffer.
 * Return NULL at EOF.
 *
 * The buffer will typically be larger than necessary, but we don't care
 * in this program, because we'll free it as soon as we've parsed the line.
 */
static char *
read_line_from_file(FILE *fd)
{
	char		tmpbuf[BUFSIZ];
	char	   *buf;
	size_t		buflen = BUFSIZ;
	size_t		used = 0;

	buf = (char *) palloc(buflen);
	buf[0] = '\0';

	while (fgets(tmpbuf, BUFSIZ, fd) != NULL)
	{
		size_t		thislen = strlen(tmpbuf);

		/* Append tmpbuf to whatever we had already */
		memcpy(buf + used, tmpbuf, thislen + 1);
		used += thislen;

		/* Done if we collected a newline */
		if (thislen > 0 && tmpbuf[thislen - 1] == '\n')
			break;

		/* Else, enlarge buf to ensure we can append next bufferload */
		buflen += BUFSIZ;
		buf = (char *) pg_realloc(buf, buflen);
	}

	if (used > 0)
		return buf;

	/* Reached EOF */
	free(buf);
	return NULL;
}

static int
process_file(char *filename)
{
#define COMMANDS_ALLOC_NUM 128

	Command   **my_commands;
	FILE	   *fd;
	int			lineno,
				index;
	char	   *buf;
	int			alloc_num;

	if (num_files >= MAX_FILES)
	{
		fprintf(stderr, "at most %d SQL files are allowed\n", MAX_FILES);
		exit(1);
	}

	alloc_num = COMMANDS_ALLOC_NUM;
	my_commands = (Command **) pg_malloc(sizeof(Command *) * alloc_num);

	if (strcmp(filename, "-") == 0)
		fd = stdin;
	else if ((fd = fopen(filename, "r")) == NULL)
	{
		fprintf(stderr, "could not open file \"%s\": %s\n",
				filename, strerror(errno));
		pg_free(my_commands);
		return false;
	}

	lineno = 0;
	index = 0;

	while ((buf = read_line_from_file(fd)) != NULL)
	{
		Command    *command;

		lineno += 1;

		command = process_commands(buf, filename, lineno);

		free(buf);

		if (command == NULL)
			continue;

		my_commands[index] = command;
		index++;

		if (index >= alloc_num)
		{
			alloc_num += COMMANDS_ALLOC_NUM;
			my_commands = pg_realloc(my_commands, sizeof(Command *) * alloc_num);
		}
	}
	fclose(fd);

	my_commands[index] = NULL;

	sql_files[num_files++] = my_commands;

	return true;
}

static Command **
process_builtin(char *tb, const char *source)
{
#define COMMANDS_ALLOC_NUM 128

	Command   **my_commands;
	int			lineno,
				index;
	char		buf[BUFSIZ];
	int			alloc_num;

	alloc_num = COMMANDS_ALLOC_NUM;
	my_commands = (Command **) pg_malloc(sizeof(Command *) * alloc_num);

	lineno = 0;
	index = 0;

	for (;;)
	{
		char	   *p;
		Command    *command;

		p = buf;
		while (*tb && *tb != '\n')
			*p++ = *tb++;

		if (*tb == '\0')
			break;

		if (*tb == '\n')
			tb++;

		*p = '\0';

		lineno += 1;

		command = process_commands(buf, source, lineno);
		if (command == NULL)
			continue;

		my_commands[index] = command;
		index++;

		if (index >= alloc_num)
		{
			alloc_num += COMMANDS_ALLOC_NUM;
			my_commands = pg_realloc(my_commands, sizeof(Command *) * alloc_num);
		}
	}

	my_commands[index] = NULL;

	return my_commands;
}

/* print out results */
static void
printResults(int ttype, int64 normal_xacts, int nclients,
			 TState *threads, int nthreads,
			 instr_time total_time, instr_time conn_total_time,
			 int64 total_latencies, int64 total_sqlats,
			 int64 throttle_lag, int64 throttle_lag_max,
			 int64 throttle_latency_skipped, int64 latency_late)
{
	double		time_include,
				tps_include,
				tps_exclude;
	char	   *s;

	time_include = INSTR_TIME_GET_DOUBLE(total_time);
	tps_include = normal_xacts / time_include;
	tps_exclude = normal_xacts / (time_include -
						(INSTR_TIME_GET_DOUBLE(conn_total_time) / nthreads));

	if (ttype == 0)
		s = "TPC-B (sort of)";
	else if (ttype == 2)
		s = "Update only pgbench_accounts";
	else if (ttype == 1)
		s = "SELECT only";
	else
		s = "Custom query";

	printf("transaction type: %s\n", s);
	printf("scaling factor: %d\n", scale);
	printf("query mode: %s\n", QUERYMODE[querymode]);
	printf("number of clients: %d\n", nclients);
	printf("number of threads: %d\n", nthreads);
	if (duration <= 0)
	{
		printf("number of transactions per client: %d\n", nxacts);
		printf("number of transactions actually processed: " INT64_FORMAT "/" INT64_FORMAT "\n",
			   normal_xacts, (int64) nxacts * nclients);
	}
	else
	{
		printf("duration: %d s\n", duration);
		printf("number of transactions actually processed: " INT64_FORMAT "\n",
			   normal_xacts);
	}

	/* Remaining stats are nonsensical if we failed to execute any xacts */
	if (normal_xacts <= 0)
		return;

	if (throttle_delay && latency_limit)
		printf("number of transactions skipped: " INT64_FORMAT " (%.3f %%)\n",
			   throttle_latency_skipped,
			   100.0 * throttle_latency_skipped / (throttle_latency_skipped + normal_xacts));

	if (latency_limit)
		printf("number of transactions above the %.1f ms latency limit: " INT64_FORMAT " (%.3f %%)\n",
			   latency_limit / 1000.0, latency_late,
		   100.0 * latency_late / (throttle_latency_skipped + normal_xacts));

	if (throttle_delay || progress || latency_limit)
	{
		/* compute and show latency average and standard deviation */
		double		latency = 0.001 * total_latencies / normal_xacts;
		double		sqlat = (double) total_sqlats / normal_xacts;

		printf("latency average: %.3f ms\n"
			   "latency stddev: %.3f ms\n",
			   latency, 0.001 * sqrt(sqlat - 1000000.0 * latency * latency));
	}
	else
	{
		/* only an average latency computed from the duration is available */
		printf("latency average: %.3f ms\n",
			   1000.0 * duration * nclients / normal_xacts);
	}

	if (throttle_delay)
	{
		/*
		 * Report average transaction lag under rate limit throttling.  This
		 * is the delay between scheduled and actual start times for the
		 * transaction.  The measured lag may be caused by thread/client load,
		 * the database load, or the Poisson throttling process.
		 */
		printf("rate limit schedule lag: avg %.3f (max %.3f) ms\n",
			   0.001 * throttle_lag / normal_xacts, 0.001 * throttle_lag_max);
	}

	printf("tps = %f (including connections establishing)\n", tps_include);
	printf("tps = %f (excluding connections establishing)\n", tps_exclude);

	/* Report per-command latencies */
	if (is_latencies)
	{
		int			i;

		for (i = 0; i < num_files; i++)
		{
			Command   **commands;

			if (num_files > 1)
				printf("statement latencies in milliseconds, file %d:\n", i + 1);
			else
				printf("statement latencies in milliseconds:\n");

			for (commands = sql_files[i]; *commands != NULL; commands++)
			{
				Command    *command = *commands;
				int			cnum = command->command_num;
				double		total_time;
				instr_time	total_exec_elapsed;
				int			total_exec_count;
				int			t;

				/* Accumulate per-thread data for command */
				INSTR_TIME_SET_ZERO(total_exec_elapsed);
				total_exec_count = 0;
				for (t = 0; t < nthreads; t++)
				{
					TState	   *thread = &threads[t];

					INSTR_TIME_ADD(total_exec_elapsed,
								   thread->exec_elapsed[cnum]);
					total_exec_count += thread->exec_count[cnum];
				}

				if (total_exec_count > 0)
					total_time = INSTR_TIME_GET_MILLISEC(total_exec_elapsed) / (double) total_exec_count;
				else
					total_time = 0.0;

				printf("\t%f\t%s\n", total_time, command->line);
			}
		}
	}
}


int
main(int argc, char **argv)
{
	static struct option long_options[] = {
		/* systematic long/short named options */
		{"client", required_argument, NULL, 'c'},
		{"connect", no_argument, NULL, 'C'},
		{"debug", no_argument, NULL, 'd'},
		{"define", required_argument, NULL, 'D'},
		{"file", required_argument, NULL, 'f'},
		{"fillfactor", required_argument, NULL, 'F'},
		{"host", required_argument, NULL, 'h'},
		{"initialize", no_argument, NULL, 'i'},
		{"jobs", required_argument, NULL, 'j'},
		{"log", no_argument, NULL, 'l'},
		{"no-vacuum", no_argument, NULL, 'n'},
		{"port", required_argument, NULL, 'p'},
		{"progress", required_argument, NULL, 'P'},
		{"protocol", required_argument, NULL, 'M'},
		{"quiet", no_argument, NULL, 'q'},
		{"report-latencies", no_argument, NULL, 'r'},
		{"scale", required_argument, NULL, 's'},
		{"select-only", no_argument, NULL, 'S'},
		{"skip-some-updates", no_argument, NULL, 'N'},
		{"time", required_argument, NULL, 'T'},
		{"transactions", required_argument, NULL, 't'},
		{"username", required_argument, NULL, 'U'},
		{"vacuum-all", no_argument, NULL, 'v'},
		/* long-named only options */
		{"foreign-keys", no_argument, &foreign_keys, 1},
		{"index-tablespace", required_argument, NULL, 3},
		{"tablespace", required_argument, NULL, 2},
		{"unlogged-tables", no_argument, &unlogged_tables, 1},
		{"sampling-rate", required_argument, NULL, 4},
		{"aggregate-interval", required_argument, NULL, 5},
		{"rate", required_argument, NULL, 'R'},
		{"latency-limit", required_argument, NULL, 'L'},
		{NULL, 0, NULL, 0}
	};

	int			c;
	int			nclients = 1;	/* default number of simulated clients */
	int			nthreads = 1;	/* default number of threads */
	int			is_init_mode = 0;		/* initialize mode? */
	int			is_no_vacuum = 0;		/* no vacuum at all before testing? */
	int			do_vacuum_accounts = 0; /* do vacuum accounts before testing? */
	int			ttype = 0;		/* transaction type. 0: TPC-B, 1: SELECT only,
								 * 2: skip update of branches and tellers */
	int			optindex;
	char	   *filename = NULL;
	bool		scale_given = false;

	bool		benchmarking_option_set = false;
	bool		initialization_option_set = false;

	CState	   *state;			/* status of clients */
	TState	   *threads;		/* array of thread */

	instr_time	start_time;		/* start up time */
	instr_time	total_time;
	instr_time	conn_total_time;
	int64		total_xacts = 0;
	int64		total_latencies = 0;
	int64		total_sqlats = 0;
	int64		throttle_lag = 0;
	int64		throttle_lag_max = 0;
	int64		throttle_latency_skipped = 0;
	int64		latency_late = 0;

	int			i;
	int			nclients_dealt;

#ifdef HAVE_GETRLIMIT
	struct rlimit rlim;
#endif

	PGconn	   *con;
	PGresult   *res;
	char	   *env;

	char		val[64];

	progname = get_progname(argv[0]);

	if (argc > 1)
	{
		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
		{
			usage();
			exit(0);
		}
		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
		{
			puts("pgbench (PostgreSQL) " PG_VERSION);
			exit(0);
		}
	}

#ifdef WIN32
	/* stderr is buffered on Win32. */
	setvbuf(stderr, NULL, _IONBF, 0);
#endif

	if ((env = getenv("PGHOST")) != NULL && *env != '\0')
		pghost = env;
	if ((env = getenv("PGPORT")) != NULL && *env != '\0')
		pgport = env;
	else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
		login = env;

	state = (CState *) pg_malloc(sizeof(CState));
	memset(state, 0, sizeof(CState));

	while ((c = getopt_long(argc, argv, "ih:nvp:dqSNc:j:Crs:t:T:U:lf:D:F:M:P:R:L:", long_options, &optindex)) != -1)
	{
		switch (c)
		{
			case 'i':
				is_init_mode++;
				break;
			case 'h':
				pghost = pg_strdup(optarg);
				break;
			case 'n':
				is_no_vacuum++;
				break;
			case 'v':
				do_vacuum_accounts++;
				break;
			case 'p':
				pgport = pg_strdup(optarg);
				break;
			case 'd':
				debug++;
				break;
			case 'S':
				ttype = 1;
				benchmarking_option_set = true;
				break;
			case 'N':
				ttype = 2;
				benchmarking_option_set = true;
				break;
			case 'c':
				benchmarking_option_set = true;
				nclients = atoi(optarg);
				if (nclients <= 0 || nclients > MAXCLIENTS)
				{
					fprintf(stderr, "invalid number of clients: \"%s\"\n",
							optarg);
					exit(1);
				}
#ifdef HAVE_GETRLIMIT
#ifdef RLIMIT_NOFILE			/* most platforms use RLIMIT_NOFILE */
				if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
#else							/* but BSD doesn't ... */
				if (getrlimit(RLIMIT_OFILE, &rlim) == -1)
#endif   /* RLIMIT_NOFILE */
				{
					fprintf(stderr, "getrlimit failed: %s\n", strerror(errno));
					exit(1);
				}
				if (rlim.rlim_cur < nclients + 3)
				{
					fprintf(stderr, "need at least %d open files, but system limit is %ld\n",
							nclients + 3, (long) rlim.rlim_cur);
					fprintf(stderr, "Reduce number of clients, or use limit/ulimit to increase the system limit.\n");
					exit(1);
				}
#endif   /* HAVE_GETRLIMIT */
				break;
			case 'j':			/* jobs */
				benchmarking_option_set = true;
				nthreads = atoi(optarg);
				if (nthreads <= 0)
				{
					fprintf(stderr, "invalid number of threads: \"%s\"\n",
							optarg);
					exit(1);
				}
#ifndef ENABLE_THREAD_SAFETY
				if (nthreads != 1)
				{
					fprintf(stderr, "threads are not supported on this platform; use -j1\n");
					exit(1);
				}
#endif   /* !ENABLE_THREAD_SAFETY */
				break;
			case 'C':
				benchmarking_option_set = true;
				is_connect = true;
				break;
			case 'r':
				benchmarking_option_set = true;
				is_latencies = true;
				break;
			case 's':
				scale_given = true;
				scale = atoi(optarg);
				if (scale <= 0)
				{
					fprintf(stderr, "invalid scaling factor: \"%s\"\n", optarg);
					exit(1);
				}
				break;
			case 't':
				benchmarking_option_set = true;
				if (duration > 0)
				{
					fprintf(stderr, "specify either a number of transactions (-t) or a duration (-T), not both\n");
					exit(1);
				}
				nxacts = atoi(optarg);
				if (nxacts <= 0)
				{
					fprintf(stderr, "invalid number of transactions: \"%s\"\n",
							optarg);
					exit(1);
				}
				break;
			case 'T':
				benchmarking_option_set = true;
				if (nxacts > 0)
				{
					fprintf(stderr, "specify either a number of transactions (-t) or a duration (-T), not both\n");
					exit(1);
				}
				duration = atoi(optarg);
				if (duration <= 0)
				{
					fprintf(stderr, "invalid duration: \"%s\"\n", optarg);
					exit(1);
				}
				break;
			case 'U':
				login = pg_strdup(optarg);
				break;
			case 'l':
				benchmarking_option_set = true;
				use_log = true;
				break;
			case 'q':
				initialization_option_set = true;
				use_quiet = true;
				break;
			case 'f':
				benchmarking_option_set = true;
				ttype = 3;
				filename = pg_strdup(optarg);
				if (process_file(filename) == false || *sql_files[num_files - 1] == NULL)
					exit(1);
				break;
			case 'D':
				{
					char	   *p;

					benchmarking_option_set = true;

					if ((p = strchr(optarg, '=')) == NULL || p == optarg || *(p + 1) == '\0')
					{
						fprintf(stderr, "invalid variable definition: \"%s\"\n",
								optarg);
						exit(1);
					}

					*p++ = '\0';
					if (!putVariable(&state[0], "option", optarg, p))
						exit(1);
				}
				break;
			case 'F':
				initialization_option_set = true;
				fillfactor = atoi(optarg);
				if (fillfactor < 10 || fillfactor > 100)
				{
					fprintf(stderr, "invalid fillfactor: \"%s\"\n", optarg);
					exit(1);
				}
				break;
			case 'M':
				benchmarking_option_set = true;
				if (num_files > 0)
				{
					fprintf(stderr, "query mode (-M) should be specified before any transaction scripts (-f)\n");
					exit(1);
				}
				for (querymode = 0; querymode < NUM_QUERYMODE; querymode++)
					if (strcmp(optarg, QUERYMODE[querymode]) == 0)
						break;
				if (querymode >= NUM_QUERYMODE)
				{
					fprintf(stderr, "invalid query mode (-M): \"%s\"\n",
							optarg);
					exit(1);
				}
				break;
			case 'P':
				benchmarking_option_set = true;
				progress = atoi(optarg);
				if (progress <= 0)
				{
					fprintf(stderr, "invalid thread progress delay: \"%s\"\n",
							optarg);
					exit(1);
				}
				break;
			case 'R':
				{
					/* get a double from the beginning of option value */
					double		throttle_value = atof(optarg);

					benchmarking_option_set = true;

					if (throttle_value <= 0.0)
					{
						fprintf(stderr, "invalid rate limit: \"%s\"\n", optarg);
						exit(1);
					}
					/* Invert rate limit into a time offset */
					throttle_delay = (int64) (1000000.0 / throttle_value);
				}
				break;
			case 'L':
				{
					double		limit_ms = atof(optarg);

					if (limit_ms <= 0.0)
					{
						fprintf(stderr, "invalid latency limit: \"%s\"\n",
								optarg);
						exit(1);
					}
					benchmarking_option_set = true;
					latency_limit = (int64) (limit_ms * 1000);
				}
				break;
			case 0:
				/* This covers long options which take no argument. */
				if (foreign_keys || unlogged_tables)
					initialization_option_set = true;
				break;
			case 2:				/* tablespace */
				initialization_option_set = true;
				tablespace = pg_strdup(optarg);
				break;
			case 3:				/* index-tablespace */
				initialization_option_set = true;
				index_tablespace = pg_strdup(optarg);
				break;
			case 4:
				benchmarking_option_set = true;
				sample_rate = atof(optarg);
				if (sample_rate <= 0.0 || sample_rate > 1.0)
				{
					fprintf(stderr, "invalid sampling rate: \"%s\"\n", optarg);
					exit(1);
				}
				break;
			case 5:
#ifdef WIN32
				fprintf(stderr, "--aggregate-interval is not currently supported on Windows\n");
				exit(1);
#else
				benchmarking_option_set = true;
				agg_interval = atoi(optarg);
				if (agg_interval <= 0)
				{
					fprintf(stderr, "invalid number of seconds for aggregation: \"%s\"\n",
							optarg);
					exit(1);
				}
#endif
				break;
			default:
				fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
				exit(1);
				break;
		}
	}

	/*
	 * Don't need more threads than there are clients.  (This is not merely an
	 * optimization; throttle_delay is calculated incorrectly below if some
	 * threads have no clients assigned to them.)
	 */
	if (nthreads > nclients)
		nthreads = nclients;

	/* compute a per thread delay */
	throttle_delay *= nthreads;

	if (argc > optind)
		dbName = argv[optind];
	else
	{
		if ((env = getenv("PGDATABASE")) != NULL && *env != '\0')
			dbName = env;
		else if (login != NULL && *login != '\0')
			dbName = login;
		else
			dbName = "";
	}

	if (is_init_mode)
	{
		if (benchmarking_option_set)
		{
			fprintf(stderr, "some of the specified options cannot be used in initialization (-i) mode\n");
			exit(1);
		}

		init(is_no_vacuum);
		exit(0);
	}
	else
	{
		if (initialization_option_set)
		{
			fprintf(stderr, "some of the specified options cannot be used in benchmarking mode\n");
			exit(1);
		}
	}

	/* Use DEFAULT_NXACTS if neither nxacts nor duration is specified. */
	if (nxacts <= 0 && duration <= 0)
		nxacts = DEFAULT_NXACTS;

	/* --sampling-rate may be used only with -l */
	if (sample_rate > 0.0 && !use_log)
	{
		fprintf(stderr, "log sampling (--sampling-rate) is allowed only when logging transactions (-l)\n");
		exit(1);
	}

	/* --sampling-rate may must not be used with --aggregate-interval */
	if (sample_rate > 0.0 && agg_interval > 0)
	{
		fprintf(stderr, "log sampling (--sampling-rate) and aggregation (--aggregate-interval) cannot be used at the same time\n");
		exit(1);
	}

	if (agg_interval > 0 && !use_log)
	{
		fprintf(stderr, "log aggregation is allowed only when actually logging transactions\n");
		exit(1);
	}

	if (duration > 0 && agg_interval > duration)
	{
		fprintf(stderr, "number of seconds for aggregation (%d) must not be higher than test duration (%d)\n", agg_interval, duration);
		exit(1);
	}

	if (duration > 0 && agg_interval > 0 && duration % agg_interval != 0)
	{
		fprintf(stderr, "duration (%d) must be a multiple of aggregation interval (%d)\n", duration, agg_interval);
		exit(1);
	}

	/*
	 * save main process id in the global variable because process id will be
	 * changed after fork.
	 */
	main_pid = (int) getpid();
	progress_nclients = nclients;
	progress_nthreads = nthreads;

	if (nclients > 1)
	{
		state = (CState *) pg_realloc(state, sizeof(CState) * nclients);
		memset(state + 1, 0, sizeof(CState) * (nclients - 1));

		/* copy any -D switch values to all clients */
		for (i = 1; i < nclients; i++)
		{
			int			j;

			state[i].id = i;
			for (j = 0; j < state[0].nvariables; j++)
			{
				if (!putVariable(&state[i], "startup", state[0].variables[j].name, state[0].variables[j].value))
					exit(1);
			}
		}
	}

	if (debug)
	{
		if (duration <= 0)
			printf("pghost: %s pgport: %s nclients: %d nxacts: %d dbName: %s\n",
				   pghost, pgport, nclients, nxacts, dbName);
		else
			printf("pghost: %s pgport: %s nclients: %d duration: %d dbName: %s\n",
				   pghost, pgport, nclients, duration, dbName);
	}

	/* opening connection... */
	con = doConnect();
	if (con == NULL)
		exit(1);

	if (PQstatus(con) == CONNECTION_BAD)
	{
		fprintf(stderr, "connection to database \"%s\" failed\n", dbName);
		fprintf(stderr, "%s", PQerrorMessage(con));
		exit(1);
	}

	if (ttype != 3)
	{
		/*
		 * get the scaling factor that should be same as count(*) from
		 * pgbench_branches if this is not a custom query
		 */
		res = PQexec(con, "select count(*) from pgbench_branches");
		if (PQresultStatus(res) != PGRES_TUPLES_OK)
		{
			fprintf(stderr, "%s", PQerrorMessage(con));
			exit(1);
		}
		scale = atoi(PQgetvalue(res, 0, 0));
		if (scale < 0)
		{
			fprintf(stderr, "invalid count(*) from pgbench_branches: \"%s\"\n",
					PQgetvalue(res, 0, 0));
			exit(1);
		}
		PQclear(res);

		/* warn if we override user-given -s switch */
		if (scale_given)
			fprintf(stderr,
					"scale option ignored, using count from pgbench_branches table (%d)\n",
					scale);
	}

	/*
	 * :scale variables normally get -s or database scale, but don't override
	 * an explicit -D switch
	 */
	if (getVariable(&state[0], "scale") == NULL)
	{
		snprintf(val, sizeof(val), "%d", scale);
		for (i = 0; i < nclients; i++)
		{
			if (!putVariable(&state[i], "startup", "scale", val))
				exit(1);
		}
	}

	/*
	 * Define a :client_id variable that is unique per connection. But don't
	 * override an explicit -D switch.
	 */
	if (getVariable(&state[0], "client_id") == NULL)
	{
		for (i = 0; i < nclients; i++)
		{
			snprintf(val, sizeof(val), "%d", i);
			if (!putVariable(&state[i], "startup", "client_id", val))
				exit(1);
		}
	}

	if (!is_no_vacuum)
	{
		fprintf(stderr, "starting vacuum...");
		tryExecuteStatement(con, "vacuum pgbench_branches");
		tryExecuteStatement(con, "vacuum pgbench_tellers");
		tryExecuteStatement(con, "truncate pgbench_history");
		fprintf(stderr, "end.\n");

		if (do_vacuum_accounts)
		{
			fprintf(stderr, "starting vacuum pgbench_accounts...");
			tryExecuteStatement(con, "vacuum analyze pgbench_accounts");
			fprintf(stderr, "end.\n");
		}
	}
	PQfinish(con);

	/* set random seed */
	INSTR_TIME_SET_CURRENT(start_time);
	srandom((unsigned int) INSTR_TIME_GET_MICROSEC(start_time));

	/* process builtin SQL scripts */
	switch (ttype)
	{
		case 0:
			sql_files[0] = process_builtin(tpc_b,
										   "<builtin: TPC-B (sort of)>");
			num_files = 1;
			break;

		case 1:
			sql_files[0] = process_builtin(select_only,
										   "<builtin: select only>");
			num_files = 1;
			break;

		case 2:
			sql_files[0] = process_builtin(simple_update,
										   "<builtin: simple update>");
			num_files = 1;
			break;

		default:
			break;
	}

	/* set up thread data structures */
	threads = (TState *) pg_malloc(sizeof(TState) * nthreads);
	nclients_dealt = 0;

	for (i = 0; i < nthreads; i++)
	{
		TState	   *thread = &threads[i];

		thread->tid = i;
		thread->state = &state[nclients_dealt];
		thread->nstate =
			(nclients - nclients_dealt + nthreads - i - 1) / (nthreads - i);
		thread->random_state[0] = random();
		thread->random_state[1] = random();
		thread->random_state[2] = random();
		thread->throttle_latency_skipped = 0;
		thread->latency_late = 0;

		nclients_dealt += thread->nstate;

		if (is_latencies)
		{
			/* Reserve memory for the thread to store per-command latencies */
			int			t;

			thread->exec_elapsed = (instr_time *)
				pg_malloc(sizeof(instr_time) * num_commands);
			thread->exec_count = (int *)
				pg_malloc(sizeof(int) * num_commands);

			for (t = 0; t < num_commands; t++)
			{
				INSTR_TIME_SET_ZERO(thread->exec_elapsed[t]);
				thread->exec_count[t] = 0;
			}
		}
		else
		{
			thread->exec_elapsed = NULL;
			thread->exec_count = NULL;
		}
	}

	/* all clients must be assigned to a thread */
	Assert(nclients_dealt == nclients);

	/* get start up time */
	INSTR_TIME_SET_CURRENT(start_time);

	/* set alarm if duration is specified. */
	if (duration > 0)
		setalarm(duration);

	/* start threads */
#ifdef ENABLE_THREAD_SAFETY
	for (i = 0; i < nthreads; i++)
	{
		TState	   *thread = &threads[i];

		INSTR_TIME_SET_CURRENT(thread->start_time);

		/* the first thread (i = 0) is executed by main thread */
		if (i > 0)
		{
			int			err = pthread_create(&thread->thread, NULL, threadRun, thread);

			if (err != 0 || thread->thread == INVALID_THREAD)
			{
				fprintf(stderr, "could not create thread: %s\n", strerror(err));
				exit(1);
			}
		}
		else
		{
			thread->thread = INVALID_THREAD;
		}
	}
#else
	INSTR_TIME_SET_CURRENT(threads[0].start_time);
	threads[0].thread = INVALID_THREAD;
#endif   /* ENABLE_THREAD_SAFETY */

	/* wait for threads and accumulate results */
	INSTR_TIME_SET_ZERO(conn_total_time);
	for (i = 0; i < nthreads; i++)
	{
		TState	   *thread = &threads[i];
		int			j;

#ifdef ENABLE_THREAD_SAFETY
		if (threads[i].thread == INVALID_THREAD)
			/* actually run this thread directly in the main thread */
			(void) threadRun(thread);
		else
			/* wait of other threads. should check that 0 is returned? */
			pthread_join(thread->thread, NULL);
#else
		(void) threadRun(thread);
#endif   /* ENABLE_THREAD_SAFETY */

		/* thread level stats */
		throttle_lag += thread->throttle_lag;
		throttle_latency_skipped += threads->throttle_latency_skipped;
		latency_late += thread->latency_late;
		if (throttle_lag_max > thread->throttle_lag_max)
			throttle_lag_max = thread->throttle_lag_max;
		INSTR_TIME_ADD(conn_total_time, thread->conn_time);

		/* client-level stats */
		for (j = 0; j < thread->nstate; j++)
		{
			total_xacts += thread->state[j].cnt;
			total_latencies += thread->state[j].txn_latencies;
			total_sqlats += thread->state[j].txn_sqlats;
		}
	}
	disconnect_all(state, nclients);

	/*
	 * XXX We compute results as though every client of every thread started
	 * and finished at the same time.  That model can diverge noticeably from
	 * reality for a short benchmark run involving relatively many threads.
	 * The first thread may process notably many transactions before the last
	 * thread begins.  Improving the model alone would bring limited benefit,
	 * because performance during those periods of partial thread count can
	 * easily exceed steady state performance.  This is one of the many ways
	 * short runs convey deceptive performance figures.
	 */
	INSTR_TIME_SET_CURRENT(total_time);
	INSTR_TIME_SUBTRACT(total_time, start_time);
	printResults(ttype, total_xacts, nclients, threads, nthreads,
				 total_time, conn_total_time, total_latencies, total_sqlats,
				 throttle_lag, throttle_lag_max, throttle_latency_skipped,
				 latency_late);

	return 0;
}

static void *
threadRun(void *arg)
{
	TState	   *thread = (TState *) arg;
	CState	   *state = thread->state;
	FILE	   *logfile = NULL; /* per-thread log file */
	instr_time	start,
				end;
	int			nstate = thread->nstate;
	int			remains = nstate;		/* number of remaining clients */
	int			i;

	/* for reporting progress: */
	int64		thread_start = INSTR_TIME_GET_MICROSEC(thread->start_time);
	int64		last_report = thread_start;
	int64		next_report = last_report + (int64) progress * 1000000;
	int64		last_count = 0,
				last_lats = 0,
				last_sqlats = 0,
				last_lags = 0,
				last_skipped = 0;

	AggVals		aggs;

	/*
	 * Initialize throttling rate target for all of the thread's clients.  It
	 * might be a little more accurate to reset thread->start_time here too.
	 * The possible drift seems too small relative to typical throttle delay
	 * times to worry about it.
	 */
	INSTR_TIME_SET_CURRENT(start);
	thread->throttle_trigger = INSTR_TIME_GET_MICROSEC(start);
	thread->throttle_lag = 0;
	thread->throttle_lag_max = 0;

	INSTR_TIME_SET_ZERO(thread->conn_time);

	/* open log file if requested */
	if (use_log)
	{
		char		logpath[64];

		if (thread->tid == 0)
			snprintf(logpath, sizeof(logpath), "pgbench_log.%d", main_pid);
		else
			snprintf(logpath, sizeof(logpath), "pgbench_log.%d.%d", main_pid, thread->tid);
		logfile = fopen(logpath, "w");

		if (logfile == NULL)
		{
			fprintf(stderr, "could not open logfile \"%s\": %s\n",
					logpath, strerror(errno));
			goto done;
		}
	}

	if (!is_connect)
	{
		/* make connections to the database */
		for (i = 0; i < nstate; i++)
		{
			if ((state[i].con = doConnect()) == NULL)
				goto done;
		}
	}

	/* time after thread and connections set up */
	INSTR_TIME_SET_CURRENT(thread->conn_time);
	INSTR_TIME_SUBTRACT(thread->conn_time, thread->start_time);

	agg_vals_init(&aggs, thread->start_time);

	/* send start up queries in async manner */
	for (i = 0; i < nstate; i++)
	{
		CState	   *st = &state[i];
		Command   **commands = sql_files[st->use_file];
		int			prev_ecnt = st->ecnt;

		st->use_file = getrand(thread, 0, num_files - 1);
		if (!doCustom(thread, st, &thread->conn_time, logfile, &aggs))
			remains--;			/* I've aborted */

		if (st->ecnt > prev_ecnt && commands[st->state]->type == META_COMMAND)
		{
			fprintf(stderr, "client %d aborted in state %d; execution of meta-command failed\n",
					i, st->state);
			remains--;			/* I've aborted */
			PQfinish(st->con);
			st->con = NULL;
		}
	}

	while (remains > 0)
	{
		fd_set		input_mask;
		int			maxsock;	/* max socket number to be waited */
		int64		now_usec = 0;
		int64		min_usec;

		FD_ZERO(&input_mask);

		maxsock = -1;
		min_usec = PG_INT64_MAX;
		for (i = 0; i < nstate; i++)
		{
			CState	   *st = &state[i];
			Command   **commands = sql_files[st->use_file];
			int			sock;

			if (st->con == NULL)
			{
				continue;
			}
			else if (st->sleeping)
			{
				if (st->throttling && timer_exceeded)
				{
					/* interrupt client which has not started a transaction */
					remains--;
					st->sleeping = 0;
					st->throttling = false;
					PQfinish(st->con);
					st->con = NULL;
					continue;
				}
				else	/* just a nap from the script */
				{
					int			this_usec;

					if (min_usec == PG_INT64_MAX)
					{
						instr_time	now;

						INSTR_TIME_SET_CURRENT(now);
						now_usec = INSTR_TIME_GET_MICROSEC(now);
					}

					this_usec = st->txn_scheduled - now_usec;
					if (min_usec > this_usec)
						min_usec = this_usec;
				}
			}
			else if (commands[st->state]->type == META_COMMAND)
			{
				min_usec = 0;	/* the connection is ready to run */
				break;
			}

			sock = PQsocket(st->con);
			if (sock < 0)
			{
				fprintf(stderr, "bad socket: %s\n", strerror(errno));
				goto done;
			}

			FD_SET(sock, &input_mask);

			if (maxsock < sock)
				maxsock = sock;
		}

		/* also wake up to print the next progress report on time */
		if (progress && min_usec > 0 && thread->tid == 0)
		{
			/* get current time if needed */
			if (now_usec == 0)
			{
				instr_time	now;

				INSTR_TIME_SET_CURRENT(now);
				now_usec = INSTR_TIME_GET_MICROSEC(now);
			}

			if (now_usec >= next_report)
				min_usec = 0;
			else if ((next_report - now_usec) < min_usec)
				min_usec = next_report - now_usec;
		}

		/*
		 * Sleep until we receive data from the server, or a nap-time
		 * specified in the script ends, or it's time to print a progress
		 * report.
		 */
		if (min_usec > 0 && maxsock != -1)
		{
			int			nsocks; /* return from select(2) */

			if (min_usec != PG_INT64_MAX)
			{
				struct timeval timeout;

				timeout.tv_sec = min_usec / 1000000;
				timeout.tv_usec = min_usec % 1000000;
				nsocks = select(maxsock + 1, &input_mask, NULL, NULL, &timeout);
			}
			else
				nsocks = select(maxsock + 1, &input_mask, NULL, NULL, NULL);
			if (nsocks < 0)
			{
				if (errno == EINTR)
					continue;
				/* must be something wrong */
				fprintf(stderr, "select() failed: %s\n", strerror(errno));
				goto done;
			}
		}

		/* ok, backend returns reply */
		for (i = 0; i < nstate; i++)
		{
			CState	   *st = &state[i];
			Command   **commands = sql_files[st->use_file];
			int			prev_ecnt = st->ecnt;

			if (st->con && (FD_ISSET(PQsocket(st->con), &input_mask)
							|| commands[st->state]->type == META_COMMAND))
			{
				if (!doCustom(thread, st, &thread->conn_time, logfile, &aggs))
					remains--;	/* I've aborted */
			}

			if (st->ecnt > prev_ecnt && commands[st->state]->type == META_COMMAND)
			{
				fprintf(stderr, "client %d aborted in state %d; execution of meta-command failed\n",
						i, st->state);
				remains--;		/* I've aborted */
				PQfinish(st->con);
				st->con = NULL;
			}
		}

		/* progress report by thread 0 for all threads */
		if (progress && thread->tid == 0)
		{
			instr_time	now_time;
			int64		now;

			INSTR_TIME_SET_CURRENT(now_time);
			now = INSTR_TIME_GET_MICROSEC(now_time);
			if (now >= next_report)
			{
				/* generate and show report */
				int64		count = 0,
							lats = 0,
							sqlats = 0,
							lags = 0,
							skipped = 0;
				int64		run = now - last_report;
				double		tps,
							total_run,
							latency,
							sqlat,
							lag,
							stdev;

				/*
				 * Add up the statistics of all threads.
				 *
				 * XXX: No locking. There is no guarantee that we get an
				 * atomic snapshot of the transaction count and latencies, so
				 * these figures can well be off by a small amount. The
				 * progress is report's purpose is to give a quick overview of
				 * how the test is going, so that shouldn't matter too much.
				 * (If a read from a 64-bit integer is not atomic, you might
				 * get a "torn" read and completely bogus latencies though!)
				 */
				for (i = 0; i < progress_nclients; i++)
				{
					count += state[i].cnt;
					lats += state[i].txn_latencies;
					sqlats += state[i].txn_sqlats;
				}

				for (i = 0; i < progress_nthreads; i++)
				{
					skipped += thread[i].throttle_latency_skipped;
					lags += thread[i].throttle_lag;
				}

				total_run = (now - thread_start) / 1000000.0;
				tps = 1000000.0 * (count - last_count) / run;
				latency = 0.001 * (lats - last_lats) / (count - last_count);
				sqlat = 1.0 * (sqlats - last_sqlats) / (count - last_count);
				stdev = 0.001 * sqrt(sqlat - 1000000.0 * latency * latency);
				lag = 0.001 * (lags - last_lags) / (count - last_count);

				fprintf(stderr,
						"progress: %.1f s, %.1f tps, "
						"lat %.3f ms stddev %.3f",
						total_run, tps, latency, stdev);
				if (throttle_delay)
				{
					fprintf(stderr, ", lag %.3f ms", lag);
					if (latency_limit)
						fprintf(stderr, ", " INT64_FORMAT " skipped",
								skipped - last_skipped);
				}
				fprintf(stderr, "\n");

				last_count = count;
				last_lats = lats;
				last_sqlats = sqlats;
				last_lags = lags;
				last_report = now;
				last_skipped = skipped;

				/*
				 * Ensure that the next report is in the future, in case
				 * pgbench/postgres got stuck somewhere.
				 */
				do
				{
					next_report += (int64) progress *1000000;
				} while (now >= next_report);
			}
		}
	}

done:
	INSTR_TIME_SET_CURRENT(start);
	disconnect_all(state, nstate);
	INSTR_TIME_SET_CURRENT(end);
	INSTR_TIME_ACCUM_DIFF(thread->conn_time, end, start);
	if (logfile)
		fclose(logfile);
	return NULL;
}

/*
 * Support for duration option: set timer_exceeded after so many seconds.
 */

#ifndef WIN32

static void
handle_sig_alarm(SIGNAL_ARGS)
{
	timer_exceeded = true;
}

static void
setalarm(int seconds)
{
	pqsignal(SIGALRM, handle_sig_alarm);
	alarm(seconds);
}

#else							/* WIN32 */

static VOID CALLBACK
win32_timer_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
{
	timer_exceeded = true;
}

static void
setalarm(int seconds)
{
	HANDLE		queue;
	HANDLE		timer;

	/* This function will be called at most once, so we can cheat a bit. */
	queue = CreateTimerQueue();
	if (seconds > ((DWORD) -1) / 1000 ||
		!CreateTimerQueueTimer(&timer, queue,
							   win32_timer_callback, NULL, seconds * 1000, 0,
							   WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE))
	{
		fprintf(stderr, "failed to set timer\n");
		exit(1);
	}
}

/* partial pthread implementation for Windows */

typedef struct win32_pthread
{
	HANDLE		handle;
	void	   *(*routine) (void *);
	void	   *arg;
	void	   *result;
} win32_pthread;

static unsigned __stdcall
win32_pthread_run(void *arg)
{
	win32_pthread *th = (win32_pthread *) arg;

	th->result = th->routine(th->arg);

	return 0;
}

static int
pthread_create(pthread_t *thread,
			   pthread_attr_t *attr,
			   void *(*start_routine) (void *),
			   void *arg)
{
	int			save_errno;
	win32_pthread *th;

	th = (win32_pthread *) pg_malloc(sizeof(win32_pthread));
	th->routine = start_routine;
	th->arg = arg;
	th->result = NULL;

	th->handle = (HANDLE) _beginthreadex(NULL, 0, win32_pthread_run, th, 0, NULL);
	if (th->handle == NULL)
	{
		save_errno = errno;
		free(th);
		return save_errno;
	}

	*thread = th;
	return 0;
}

static int
pthread_join(pthread_t th, void **thread_return)
{
	if (th == NULL || th->handle == NULL)
		return errno = EINVAL;

	if (WaitForSingleObject(th->handle, INFINITE) != WAIT_OBJECT_0)
	{
		_dosmaperr(GetLastError());
		return errno;
	}

	if (thread_return)
		*thread_return = th->result;

	CloseHandle(th->handle);
	free(th);
	return 0;
}

#endif   /* WIN32 */
