Use a timer to avoid polling

[stockfish] / src / lock.h

diff --git a/src/lock.h b/src/lock.h
index 82726517317764f77abbf5a68020f53e043c45aa..e05db4696c2d4ac46b8cb1c1dbc6264635463426 100644 (file)
--- a/src/lock.h
+++ b/src/lock.h
@@ -17,11 +17,9 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
 #if !defined(LOCK_H_INCLUDED)
 #define LOCK_H_INCLUDED
 
-
 #if !defined(_MSC_VER)
 
 #  include <pthread.h>
@@ -33,14 +31,39 @@ typedef pthread_cond_t WaitCondition;
 #  define lock_grab(x) pthread_mutex_lock(x)
 #  define lock_release(x) pthread_mutex_unlock(x)
 #  define lock_destroy(x) pthread_mutex_destroy(x)
-#  define cond_destroy(x) pthread_cond_destroy(x);
-#  define cond_signal(x) pthread_cond_signal(x);
+#  define cond_destroy(x) pthread_cond_destroy(x)
+#  define cond_init(x) pthread_cond_init(x, NULL)
+#  define cond_signal(x) pthread_cond_signal(x)
+#  define cond_wait(x,y) pthread_cond_wait(x,y)
+#  define cond_timedwait(x,y,z) pthread_cond_timedwait(x,y,z)
 
 #else
 
+#define NOMINMAX // disable macros min() and max()
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #undef WIN32_LEAN_AND_MEAN
+#undef NOMINMAX
+
+// Default fast and race free locks and condition variables
+#if !defined(OLD_LOCKS)
+
+typedef SRWLOCK Lock;
+typedef CONDITION_VARIABLE WaitCondition;
+
+#  define lock_init(x) InitializeSRWLock(x)
+#  define lock_grab(x) AcquireSRWLockExclusive(x)
+#  define lock_release(x) ReleaseSRWLockExclusive(x)
+#  define lock_destroy(x) (x)
+#  define cond_destroy(x) (x)
+#  define cond_init(x) InitializeConditionVariable(x)
+#  define cond_signal(x) WakeConditionVariable(x)
+#  define cond_wait(x,y) SleepConditionVariableSRW(x,y,INFINITE,0)
+#  define cond_timedwait(x,y,z) SleepConditionVariableSRW(x,y,z,0)
+
+// Fallback solution to build for Windows XP and older versions, note that
+// cond_wait() is racy between lock_release() and WaitForSingleObject().
+#else
 
 typedef CRITICAL_SECTION Lock;
 typedef HANDLE WaitCondition;
@@ -49,8 +72,13 @@ typedef HANDLE WaitCondition;
 #  define lock_grab(x) EnterCriticalSection(x)
 #  define lock_release(x) LeaveCriticalSection(x)
 #  define lock_destroy(x) DeleteCriticalSection(x)
-#  define cond_destroy(x) CloseHandle(*x);
-#  define cond_signal(x) SetEvent(*x);
+#  define cond_init(x) { *x = CreateEvent(0, FALSE, FALSE, 0); }
+#  define cond_destroy(x) CloseHandle(*x)
+#  define cond_signal(x) SetEvent(*x)
+#  define cond_wait(x,y) { lock_release(y); WaitForSingleObject(*x, INFINITE); lock_grab(y); }
+#  define cond_timedwait(x,y,z) { lock_release(y); WaitForSingleObject(*x,z); lock_grab(y); }
+
+#endif
 
 #endif