#include <time.h>
#include <sys/time.h>
#include <unistd.h>
+#include <string.h>
#ifdef WIN32
#define FSYNC_FILENAME "./test_fsync.out"
#define FSYNC_FILENAME "/var/tmp/test_fsync.out"
#endif
-/* O_SYNC and O_FSYNC are the same */
+/* This logic comes from src/backend/access/transam/xlog.c where it's
+ better documented */
+#ifdef O_DIRECT
+#define PG_O_DIRECT O_DIRECT
+#else
+#define PG_O_DIRECT 0
+#endif
+
#if defined(O_SYNC)
-#define OPEN_SYNC_FLAG O_SYNC
+#define BARE_OPEN_SYNC_FLAG O_SYNC
#elif defined(O_FSYNC)
-#define OPEN_SYNC_FLAG O_FSYNC
-#elif defined(O_DSYNC)
-#define OPEN_DATASYNC_FLAG O_DSYNC
+#define BARE_OPEN_SYNC_FLAG O_FSYNC
+#endif
+#ifdef BARE_OPEN_SYNC_FLAG
+#define OPEN_SYNC_FLAG (BARE_OPEN_SYNC_FLAG | PG_O_DIRECT)
#endif
+#if defined(O_DSYNC)
#if defined(OPEN_SYNC_FLAG)
-#if defined(O_DSYNC) && (O_DSYNC != OPEN_SYNC_FLAG)
-#define OPEN_DATASYNC_FLAG O_DSYNC
+#if O_DSYNC != BARE_OPEN_SYNC_FLAG
+#define OPEN_DATASYNC_FLAG (O_DSYNC | PG_O_DIRECT)
+#endif
+#else
+#define OPEN_DATASYNC_FLAG (O_DSYNC | PG_O_DIRECT)
#endif
#endif
+
#define WAL_FILE_SIZE (16 * 1024 * 1024)
void die(char *str);