1 files changed, 0 insertions, 366 deletions
diff --git a/src/backend/port/posix_sema.c b/src/backend/port/posix_sema.c
deleted file mode 100644
index 207a5fba96e..00000000000
--- a/src/backend/port/posix_sema.c
+++ /dev/null
@@ -1,366 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * posix_sema.c
- *	  Implement PGSemaphores using POSIX semaphore facilities
- *
- * We prefer the unnamed style of POSIX semaphore (the kind made with
- * sem_init).  We can cope with the kind made with sem_open, however.
- *
- *
- * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/port/posix_sema.c,v 1.5 2002/06/20 20:29:33 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <unistd.h>
-
-#include "miscadmin.h"
-#include "storage/ipc.h"
-#include "storage/pg_sema.h"
-
-
-#ifdef USE_NAMED_POSIX_SEMAPHORES
-/* PGSemaphore is pointer to pointer to sem_t */
-#define PG_SEM_REF(x)	(*(x))
-#else
-/* PGSemaphore is pointer to sem_t */
-#define PG_SEM_REF(x)	(x)
-#endif
-
-
-#define IPCProtection	(0600)	/* access/modify by user only */
-
-static sem_t **mySemPointers;	/* keep track of created semaphores */
-static int	numSems;			/* number of semas acquired so far */
-static int	maxSems;			/* allocated size of mySemaPointers array */
-static int	nextSemKey;			/* next name to try */
-
-
-static void ReleaseSemaphores(int status, Datum arg);
-
-
-#ifdef USE_NAMED_POSIX_SEMAPHORES
-
-/*
- * PosixSemaphoreCreate
- *
- * Attempt to create a new named semaphore.
- *
- * If we fail with a failure code other than collision-with-existing-sema,
- * print out an error and abort.  Other types of errors suggest nonrecoverable
- * problems.
- */
-static sem_t *
-PosixSemaphoreCreate(void)
-{
-	int			semKey;
-	char		semname[64];
-	sem_t	   *mySem;
-
-	for (;;)
-	{
-		semKey = nextSemKey++;
-
-		snprintf(semname, sizeof(semname), "/pgsql-%d", semKey);
-
-		mySem = sem_open(semname, O_CREAT | O_EXCL,
-						 (mode_t) IPCProtection, (unsigned) 1);
-
-#ifdef SEM_FAILED
-		if (mySem != (sem_t *) SEM_FAILED)
-			break;
-#else
-		if (mySem != (sem_t *) (-1))
-			break;
-#endif
-
-		/* Loop if error indicates a collision */
-		if (errno == EEXIST || errno == EACCES || errno == EINTR)
-			continue;
-
-		/*
-		 * Else complain and abort
-		 */
-		fprintf(stderr, "PosixSemaphoreCreate: sem_open(\"%s\") failed: %s\n",
-				semname, strerror(errno));
-		proc_exit(1);
-	}
-
-	/*
-	 * Unlink the semaphore immediately, so it can't be accessed externally.
-	 * This also ensures that it will go away if we crash.
-	 */
-	sem_unlink(semname);
-
-	return mySem;
-}
-
-#else /* !USE_NAMED_POSIX_SEMAPHORES */
-
-/*
- * PosixSemaphoreCreate
- *
- * Attempt to create a new unnamed semaphore.
- */
-static void
-PosixSemaphoreCreate(sem_t *sem)
-{
-	if (sem_init(sem, 1, 1) < 0)
-	{
-		fprintf(stderr, "PosixSemaphoreCreate: sem_init failed: %s\n",
-				strerror(errno));
-		proc_exit(1);
-	}
-}
-
-#endif /* USE_NAMED_POSIX_SEMAPHORES */
-
-
-/*
- * PosixSemaphoreKill	- removes a semaphore
- */
-static void
-PosixSemaphoreKill(sem_t *sem)
-{
-#ifdef USE_NAMED_POSIX_SEMAPHORES
-	/* Got to use sem_close for named semaphores */
-	if (sem_close(sem) < 0)
-		fprintf(stderr, "PosixSemaphoreKill: sem_close failed: %s\n",
-				strerror(errno));
-#else
-	/* Got to use sem_destroy for unnamed semaphores */
-	if (sem_destroy(sem) < 0)
-		fprintf(stderr, "PosixSemaphoreKill: sem_destroy failed: %s\n",
-				strerror(errno));
-#endif
-}
-
-
-/*
- * PGReserveSemaphores --- initialize semaphore support
- *
- * This is called during postmaster start or shared memory reinitialization.
- * It should do whatever is needed to be able to support up to maxSemas
- * subsequent PGSemaphoreCreate calls.  Also, if any system resources
- * are acquired here or in PGSemaphoreCreate, register an on_shmem_exit
- * callback to release them.
- *
- * The port number is passed for possible use as a key (for Posix, we use
- * it to generate the starting semaphore name).  In a standalone backend,
- * zero will be passed.
- *
- * In the Posix implementation, we acquire semaphores on-demand; the
- * maxSemas parameter is just used to size the array that keeps track of
- * acquired semas for subsequent releasing.
- */
-void
-PGReserveSemaphores(int maxSemas, int port)
-{
-	mySemPointers = (sem_t **) malloc(maxSemas * sizeof(sem_t *));
-	if (mySemPointers == NULL)
-		elog(PANIC, "Out of memory in PGReserveSemaphores");
-	numSems = 0;
-	maxSems = maxSemas;
-	nextSemKey = port * 1000;
-
-	on_shmem_exit(ReleaseSemaphores, 0);
-}
-
-/*
- * Release semaphores at shutdown or shmem reinitialization
- *
- * (called as an on_shmem_exit callback, hence funny argument list)
- */
-static void
-ReleaseSemaphores(int status, Datum arg)
-{
-	int			i;
-
-	for (i = 0; i < numSems; i++)
-		PosixSemaphoreKill(mySemPointers[i]);
-	free(mySemPointers);
-}
-
-/*
- * PGSemaphoreCreate
- *
- * Initialize a PGSemaphore structure to represent a sema with count 1
- */
-void
-PGSemaphoreCreate(PGSemaphore sema)
-{
-	sem_t  *newsem;
-
-	/* Can't do this in a backend, because static state is postmaster's */
-	Assert(!IsUnderPostmaster);
-
-	if (numSems >= maxSems)
-		elog(PANIC, "PGSemaphoreCreate: too many semaphores created");
-
-#ifdef USE_NAMED_POSIX_SEMAPHORES
-	*sema = newsem = PosixSemaphoreCreate();
-#else
-	PosixSemaphoreCreate(sema);
-	newsem = sema;
-#endif
-
-	/* Remember new sema for ReleaseSemaphores */
-	mySemPointers[numSems++] = newsem;
-}
-
-/*
- * PGSemaphoreReset
- *
- * Reset a previously-initialized PGSemaphore to have count 0
- */
-void
-PGSemaphoreReset(PGSemaphore sema)
-{
-	/*
-	 * There's no direct API for this in POSIX, so we have to ratchet the
-	 * semaphore down to 0 with repeated trywait's.
-	 */
-	for (;;)
-	{
-		if (sem_trywait(PG_SEM_REF(sema)) < 0)
-		{
-			if (errno == EAGAIN || errno == EDEADLK)
-				break;			/* got it down to 0 */
-			if (errno == EINTR)
-				continue;		/* can this happen? */
-			fprintf(stderr, "PGSemaphoreReset: sem_trywait failed: %s\n",
-					strerror(errno));
-			proc_exit(1);
-		}
-	}
-}
-
-/*
- * PGSemaphoreLock
- *
- * Lock a semaphore (decrement count), blocking if count would be < 0
- */
-void
-PGSemaphoreLock(PGSemaphore sema, bool interruptOK)
-{
-	int			errStatus;
-
-	/*
-	 * Note: if errStatus is -1 and errno == EINTR then it means we
-	 * returned from the operation prematurely because we were sent a
-	 * signal.	So we try and lock the semaphore again.
-	 *
-	 * Each time around the loop, we check for a cancel/die interrupt. We
-	 * assume that if such an interrupt comes in while we are waiting, it
-	 * will cause the sem_wait() call to exit with errno == EINTR, so that we
-	 * will be able to service the interrupt (if not in a critical section
-	 * already).
-	 *
-	 * Once we acquire the lock, we do NOT check for an interrupt before
-	 * returning.  The caller needs to be able to record ownership of the
-	 * lock before any interrupt can be accepted.
-	 *
-	 * There is a window of a few instructions between CHECK_FOR_INTERRUPTS
-	 * and entering the sem_wait() call.  If a cancel/die interrupt occurs in
-	 * that window, we would fail to notice it until after we acquire the
-	 * lock (or get another interrupt to escape the sem_wait()).  We can
-	 * avoid this problem by temporarily setting ImmediateInterruptOK to
-	 * true before we do CHECK_FOR_INTERRUPTS; then, a die() interrupt in
-	 * this interval will execute directly.  However, there is a huge
-	 * pitfall: there is another window of a few instructions after the
-	 * sem_wait() before we are able to reset ImmediateInterruptOK.  If an
-	 * interrupt occurs then, we'll lose control, which means that the
-	 * lock has been acquired but our caller did not get a chance to
-	 * record the fact. Therefore, we only set ImmediateInterruptOK if the
-	 * caller tells us it's OK to do so, ie, the caller does not need to
-	 * record acquiring the lock.  (This is currently true for lockmanager
-	 * locks, since the process that granted us the lock did all the
-	 * necessary state updates. It's not true for Posix semaphores used to
-	 * implement LW locks or emulate spinlocks --- but the wait time for
-	 * such locks should not be very long, anyway.)
-	 */
-	do
-	{
-		ImmediateInterruptOK = interruptOK;
-		CHECK_FOR_INTERRUPTS();
-		errStatus = sem_wait(PG_SEM_REF(sema));
-		ImmediateInterruptOK = false;
-	} while (errStatus < 0 && errno == EINTR);
-
-	if (errStatus < 0)
-	{
-		fprintf(stderr, "PGSemaphoreLock: sem_wait failed: %s\n",
-				strerror(errno));
-		proc_exit(255);
-	}
-}
-
-/*
- * PGSemaphoreUnlock
- *
- * Unlock a semaphore (increment count)
- */
-void
-PGSemaphoreUnlock(PGSemaphore sema)
-{
-	int			errStatus;
-
-	/*
-	 * Note: if errStatus is -1 and errno == EINTR then it means we
-	 * returned from the operation prematurely because we were sent a
-	 * signal.	So we try and unlock the semaphore again. Not clear this
-	 * can really happen, but might as well cope.
-	 */
-	do
-	{
-		errStatus = sem_post(PG_SEM_REF(sema));
-	} while (errStatus < 0 && errno == EINTR);
-
-	if (errStatus < 0)
-	{
-		fprintf(stderr, "PGSemaphoreUnlock: sem_post failed: %s\n",
-				strerror(errno));
-		proc_exit(255);
-	}
-}
-
-/*
- * PGSemaphoreTryLock
- *
- * Lock a semaphore only if able to do so without blocking
- */
-bool
-PGSemaphoreTryLock(PGSemaphore sema)
-{
-	int			errStatus;
-
-	/*
-	 * Note: if errStatus is -1 and errno == EINTR then it means we
-	 * returned from the operation prematurely because we were sent a
-	 * signal.	So we try and lock the semaphore again.
-	 */
-	do
-	{
-		errStatus = sem_trywait(PG_SEM_REF(sema));
-	} while (errStatus < 0 && errno == EINTR);
-
-	if (errStatus < 0)
-	{
-		if (errno == EAGAIN || errno == EDEADLK)
-			return false;		/* failed to lock it */
-		/* Otherwise we got trouble */
-		fprintf(stderr, "PGSemaphoreTryLock: sem_trywait failed: %s\n",
-				strerror(errno));
-		proc_exit(255);
-	}
-
-	return true;
-}