Use fast SRWLOCK locks under Windows

They are fast and also have the same semantic of Linux ones.

This allow to simplify the code and especially to use
SleepConditionVariableSRW() to wait on a condition releaseing the lock,
this has the same semantic as pthread_cond_wait().

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/lock.h b/src/lock.h
index 82726517317764f77abbf5a68020f53e043c45aa..489a5663ab123071d5bb468d1301a620a33f3a5f 100644 (file)
--- a/src/lock.h
+++ b/src/lock.h
@@ -34,7 +34,9 @@ typedef pthread_cond_t WaitCondition;
 #  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_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);
 
 #else
 
@@ -42,15 +44,17 @@ typedef pthread_cond_t WaitCondition;
 #include <windows.h>
 #undef WIN32_LEAN_AND_MEAN
 
-typedef CRITICAL_SECTION Lock;
-typedef HANDLE WaitCondition;
-
-#  define lock_init(x) InitializeCriticalSection(x)
-#  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);
+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);
 
 #endif
 

diff --git a/src/search.cpp b/src/search.cpp
index b3d54fb0c71328b8ca337c485589088106358683..b303d31f521e61a6bf61f690cc9b3de3391401fd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -2224,8 +2224,7 @@ split_point_start: // At split points actual search starts from here
 
         // If we are not thinking, wait for a condition to be signaled
         // instead of wasting CPU time polling for work.
-        while (   threadID >= ActiveThreads
-               || threads[threadID].state == THREAD_INITIALIZING)
+        while (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
         {
             assert(!sp);
             assert(threadID != 0);
@@ -2235,14 +2234,12 @@ split_point_start: // At split points actual search starts from here
 
             threads[threadID].state = THREAD_AVAILABLE;
 
-#if !defined(_MSC_VER)
             lock_grab(&WaitLock);
-            if (threadID >= ActiveThreads)
-                pthread_cond_wait(&WaitCond[threadID], &WaitLock);
+
+            if (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
+                cond_wait(&WaitCond[threadID], &WaitLock);
+
             lock_release(&WaitLock);
-#else
-            WaitForSingleObject(WaitCond[threadID], INFINITE);
-#endif
         }
 
         // If this thread has been assigned work, launch a search
@@ -2305,11 +2302,7 @@ split_point_start: // At split points actual search starts from here
     lock_init(&WaitLock);
 
     for (i = 0; i < MAX_THREADS; i++)
-#if !defined(_MSC_VER)
-        pthread_cond_init(&WaitCond[i], NULL);
-#else
-        WaitCond[i] = CreateEvent(0, FALSE, FALSE, 0);
-#endif
+        cond_init(&WaitCond[i]);
 
     // Initialize splitPoints[] locks
     for (i = 0; i < MAX_THREADS; i++)