Add Win32 unlink/rename file.

src/port/dirmod.c

+#ifndef TEST_VERSION
+
+#undef rename
+#undef unlink
+
+int pgrename(const char *from, const char *to)
+{
+	int loops = 0;
+
+	while (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING))
+	{
+		if (GetLastError() != ERROR_ACCESS_DENIED)
+			/* set errno? */
+			return -1;
+		Sleep(100);	/* ms */
+		if (loops == 10)
+#ifndef FRONTEND
+			elog(LOG, "Unable to rename %s to %s, continuing to try", from, to);
+#else
+			fprintf(stderr, "Unable to rename %s to %s, continuing to try\n", from, to);
+#endif
+		loops++;
+	}
+
+	if (loops > 10)
+#ifndef FRONTEND
+		elog(LOG, "Completed rename of %s to %s", from, to);
+#else
+		fprintf(stderr, "Completed rename of %s to %s\n", from, to);
+#endif
+	return 0;
+}
+
+
+int pgunlink(const char *path)
+{
+	int loops = 0;
+
+	while (unlink(path))
+	{
+		if (errno != EACCES)
+			/* set errno? */
+			return -1;
+		Sleep(100);	/* ms */
+		if (loops == 10)
+#ifndef FRONTEND
+			elog(LOG, "Unable to unlink %s, continuing to try", path);
+#else
+			fprintf(stderr, "Unable to unlink %s, continuing to try\n", path);
+#endif
+		loops++;
+	}
+
+	if (loops > 10)
+#ifndef FRONTEND
+		elog(LOG, "Completed unlink of %s", path);
+#else
+		fprintf(stderr, "Completed unlink of %s\n", path);
+#endif
+	return 0;
+}
+
+
+#else
+
+
+/*
+ *  Illustrates problem with Win32 rename() and unlink()
+ *	under concurrent access.
+ *
+ *	Run with arg '1', then less than 5 seconds later, run with
+ *	 arg '2' (rename) or '3'(unlink) to see the problem.
+ */
+ 
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <windows.h>
+
+#define halt(str) \
+do { \
+	fputs(str, stderr); \
+	exit(1); \
+} while (0)
+
+int
+main(int argc, char* argv[])
+{
+	FILE *fd;
+
+	if (argc != 2)
+		halt("Arg must be '1' (test), '2' (rename), or '3' (unlink)\n"
+			 "Run '1' first, then less than 5 seconds later, run\n"
+			 "'2' to test rename, or '3' to test unlink.\n");
+
+	if (atoi(argv[1]) == 1)
+	{
+		if ((fd = fopen("/rtest.txt", "w")) == NULL)
+			halt("Can not create file\n");
+		fclose(fd);
+		if ((fd = fopen("/rtest.txt", "r")) == NULL)
+			halt("Can not open file\n");
+		Sleep(5000);
+	}
+	else if (atoi(argv[1]) == 2)
+	{
+		unlink("/rtest.new");
+		if ((fd = fopen("/rtest.new", "w")) == NULL)
+			halt("Can not create file\n");
+		fclose(fd);
+		while (!MoveFileEx("/rtest.new", "/rtest.txt", MOVEFILE_REPLACE_EXISTING))
+		{
+			if (GetLastError() != ERROR_ACCESS_DENIED)
+				halt("Unknown failure\n");
+			else
+				fprintf(stderr, "move failed\n");
+			Sleep(500);
+		}
+		halt("move successful\n");
+	}
+	else if (atoi(argv[1]) == 3)
+	{
+		while (unlink("/rtest.txt"))
+		{
+			if (errno != EACCES)
+				halt("Unknown failure\n");
+			else
+				fprintf(stderr, "unlink failed\n");
+			Sleep(500);
+		}
+		halt("unlink successful\n");
+	}
+	else	
+		halt("invalid arg\n");
+
+	return 0;
+}
+#endif