* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
+#include "config.h"
+
#include "gbitlock.h"
#include <glib/gmessages.h>
#include <glib/gatomic.h>
#include <glib/gslist.h>
#include <glib/gthread.h>
+#include <glib/gslice.h>
#include "gthreadprivate.h"
-#include "config.h"
-
#ifdef G_BIT_LOCK_FORCE_FUTEX_EMULATION
#undef HAVE_FUTEX
#endif
#ifndef HAVE_FUTEX
+static GMutex g_futex_mutex;
static GSList *g_futex_address_list = NULL;
-static GMutex *g_futex_mutex = NULL;
-#endif
-
-void
-_g_futex_thread_init (void) {
-#ifndef HAVE_FUTEX
- g_futex_mutex = g_mutex_new ();
#endif
-}
#ifdef HAVE_FUTEX
/*
{
const volatile gint *address;
gint ref_count;
- GCond *wait_queue;
+ GCond wait_queue;
} WaitAddress;
static WaitAddress *
g_futex_wait (const volatile gint *address,
gint value)
{
- g_mutex_lock (g_futex_mutex);
+ g_mutex_lock (&g_futex_mutex);
if G_LIKELY (g_atomic_int_get (address) == value)
{
WaitAddress *waiter;
{
waiter = g_slice_new (WaitAddress);
waiter->address = address;
- waiter->wait_queue = g_cond_new ();
+ g_cond_init (&waiter->wait_queue);
waiter->ref_count = 0;
g_futex_address_list =
g_slist_prepend (g_futex_address_list, waiter);
}
waiter->ref_count++;
- g_cond_wait (waiter->wait_queue, g_futex_mutex);
+ g_cond_wait (&waiter->wait_queue, &g_futex_mutex);
if (!--waiter->ref_count)
{
g_futex_address_list =
g_slist_remove (g_futex_address_list, waiter);
- g_cond_free (waiter->wait_queue);
+ g_cond_clear (&waiter->wait_queue);
g_slice_free (WaitAddress, waiter);
}
}
- g_mutex_unlock (g_futex_mutex);
+ g_mutex_unlock (&g_futex_mutex);
}
static void
* 2) need to -stay- locked until the end to ensure a wake()
* in another thread doesn't cause 'waiter' to stop existing
*/
- g_mutex_lock (g_futex_mutex);
+ g_mutex_lock (&g_futex_mutex);
if ((waiter = g_futex_find_address (address)))
- g_cond_signal (waiter->wait_queue);
- g_mutex_unlock (g_futex_mutex);
+ g_cond_signal (&waiter->wait_queue);
+ g_mutex_unlock (&g_futex_mutex);
}
#endif
#define CONTENTION_CLASSES 11
static volatile gint g_bit_lock_contended[CONTENTION_CLASSES];
+#if (defined (i386) || defined (__amd64__))
+ #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+ #define USE_ASM_GOTO 1
+ #endif
+#endif
+
/**
* g_bit_lock:
* @address: a pointer to an integer
g_bit_lock (volatile gint *address,
gint lock_bit)
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
retry:
- asm volatile goto ("lock bts %1, (%0)\n"
- "jc %l[contended]"
- : /* no output */
- : "r" (address), "r" (lock_bit)
- : "cc", "memory"
- : contended);
+ __asm__ volatile goto ("lock bts %1, (%0)\n"
+ "jc %l[contended]"
+ : /* no output */
+ : "r" (address), "r" (lock_bit)
+ : "cc", "memory"
+ : contended);
return;
contended:
* g_bit_trylock:
* @address: a pointer to an integer
* @lock_bit: a bit value between 0 and 31
- * @returns: %TRUE if the lock was acquired
*
* Sets the indicated @lock_bit in @address, returning %TRUE if
* successful. If the bit is already set, returns %FALSE immediately.
* @address must be atomic in order for this function to work
* reliably.
*
+ * Returns: %TRUE if the lock was acquired
+ *
* Since: 2.24
**/
gboolean
g_bit_trylock (volatile gint *address,
gint lock_bit)
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
gboolean result;
- asm volatile ("lock bts %2, (%1)\n"
- "setnc %%al\n"
- "movzx %%al, %0"
- : "=r" (result)
- : "r" (address), "r" (lock_bit)
- : "cc", "memory");
+ __asm__ volatile ("lock bts %2, (%1)\n"
+ "setnc %%al\n"
+ "movzx %%al, %0"
+ : "=r" (result)
+ : "r" (address), "r" (lock_bit)
+ : "cc", "memory");
return result;
#else
g_bit_unlock (volatile gint *address,
gint lock_bit)
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
asm volatile ("lock btr %1, (%0)"
: /* no output */
: "r" (address), "r" (lock_bit)
{
const volatile gint *int_address = address;
+ /* this implementation makes these (reasonable) assumptions: */
+ G_STATIC_ASSERT (G_BYTE_ORDER == G_LITTLE_ENDIAN ||
+ (G_BYTE_ORDER == G_BIG_ENDIAN &&
+ sizeof (int) == 4 &&
+ (sizeof (gpointer) == 4 || sizeof (gpointer) == 8)));
+
#if G_BYTE_ORDER == G_BIG_ENDIAN && GLIB_SIZEOF_VOID_P == 8
int_address++;
#endif
g_return_if_fail (lock_bit < 32);
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
retry:
asm volatile goto ("lock bts %1, (%0)\n"
"jc %l[contended]"
* g_pointer_bit_trylock:
* @address: a pointer to a #gpointer-sized value
* @lock_bit: a bit value between 0 and 31
- * @returns: %TRUE if the lock was acquired
*
* This is equivalent to g_bit_trylock, but working on pointers (or
* other pointer-sized values).
* For portability reasons, you may only lock on the bottom 32 bits of
* the pointer.
*
+ * Returns: %TRUE if the lock was acquired
+ *
* Since: 2.30
**/
gboolean
g_return_val_if_fail (lock_bit < 32, FALSE);
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
gboolean result;
asm volatile ("lock bts %2, (%1)\n"
g_return_if_fail (lock_bit < 32);
{
-#if defined (__GNUC__) && (defined (i386) || defined (__amd64__))
+#ifdef USE_ASM_GOTO
asm volatile ("lock btr %1, (%0)"
: /* no output */
: "r" (address), "r" ((gsize) lock_bit)