/*-------------------------------------------------------------------------
 *
 * proc.h--
 *    
 *
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 * $Id: proc.h,v 1.5 1997/08/19 21:39:58 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef _PROC_H_
#define _PROC_H_

#include <storage/lock.h>

typedef struct {
  int	 		sleeplock;
  int			semNum;
  IpcSemaphoreId	semId;
  IpcSemaphoreKey	semKey;
} SEMA;

/*
 * Each backend has:
 */
typedef struct proc {

  /* proc->links MUST BE THE FIRST ELEMENT OF STRUCT (see ProcWakeup()) */

  SHM_QUEUE         links;	/* proc can be waiting for one event(lock) */
  SEMA              sem;	/* ONE semaphore to sleep on */
  int               errType; 	/* error code tells why we woke up */

  int               procId;  	/* unique number for this structure
			 	 * NOT unique per backend, these things
				 * are reused after the backend dies.
				 */

  int               critSects;	/* If critSects > 0, we are in sensitive
				 * routines that cannot be recovered when
				 * the process fails.
				 */

  int               prio;	/* priority for sleep queue */

  TransactionId     xid;	/* transaction currently being executed
				 * by this proc
				 */

  LOCK *            waitLock;	/* Lock we're sleeping on */
  int               token;	/* info for proc wakeup routines */	
  int		    pid;	/* This procs process id */
  short		    sLocks[MAX_SPINS];	/* Spin lock stats */
  SHM_QUEUE	    lockQueue;	/* locks associated with current transaction */
} PROC;


/*
 * MAX_PROC_SEMS is the maximum number of per-process semaphores (those used
 * by the lock mgr) we can keep track of. PROC_NSEMS_PER_SET is the number
 * of semaphores in each (sys-V) semaphore set allocated. (Be careful not
 * to set it to greater 32. Otherwise, the bitmap will overflow.)
 */
#define  MAX_PROC_SEMS		128
#define  PROC_NSEMS_PER_SET	16

typedef struct procglobal {
    SHMEM_OFFSET	freeProcs;
    int			numProcs;
    IPCKey		currKey;
    int32		freeSemMap[MAX_PROC_SEMS/PROC_NSEMS_PER_SET];
} PROC_HDR;

extern PROC *MyProc;

#define PROC_INCR_SLOCK(lock) if (MyProc) (MyProc->sLocks[(lock)])++
#define PROC_DECR_SLOCK(lock) if (MyProc) (MyProc->sLocks[(lock)])--

/*
 * flags explaining why process woke up
 */
#define NO_ERROR 	0
#define ERR_TIMEOUT	1
#define ERR_BUFFER_IO	2

#define MAX_PRIO	50
#define MIN_PRIO	(-1)

extern SPINLOCK ProcStructLock;

/*
 * Function Prototypes
 */
extern void InitProcess(IPCKey key);
extern void ProcReleaseLocks(void);
extern bool ProcRemove(int pid);
/* extern bool ProcKill(int exitStatus, int pid); */
/* make static in storage/lmgr/proc.c -- jolly */

extern void ProcQueueInit(PROC_QUEUE *queue);
extern int ProcSleep(PROC_QUEUE *queue, SPINLOCK spinlock, int token, 
	      int prio, LOCK *lock);
extern int ProcLockWakeup(PROC_QUEUE *queue, char * ltable, char * lock);
extern void ProcAddLock(SHM_QUEUE *elem);
extern void ProcReleaseSpins(PROC *proc);
extern void ProcFreeAllSemaphores(void);

#endif /* PROC_H */
