Initial commit

Torque/SDK/engine/platformMacCarb/macCarbSemaphore.cc

@@ -0,0 +1,99 @@
+//-----------------------------------------------------------------------------
+// Torque Game Engine 
+// Copyright (C) GarageGames.com, Inc.
+//-----------------------------------------------------------------------------
+
+// platformSemaphore.h does not ask for any inter process communication,
+// and the posix semaphores require a file to be created on disk.
+// which could create annoyances if the appication crashes...
+// so we'll just roll our own semaphore here.
+
+// note: this is not a bulletproof solution to the starving problem...
+
+#include <pthread.h>
+#include "platform/platform.h"
+#include "platform/platformSemaphore.h"
+
+
+
+typedef struct MacCarbSemaphore
+{
+   pthread_mutex_t mDarkroom;
+//   pthread_mutex_t mFoyer; // second lock, to help control starving.
+   pthread_cond_t  mCond;
+   int count;
+};   
+   
+
+void * Semaphore::createSemaphore(U32 initialCount)
+{
+   bool ok;
+   MacCarbSemaphore *semaphore = new MacCarbSemaphore();
+   ok = pthread_mutex_init(&semaphore->mDarkroom,NULL);
+   AssertFatal(ok == 0,"Create semaphore failed at creating mutex mDarkroom.");
+//   ok = pthread_mutex_init(&semaphore->mFoyer,NULL);
+//   AssertFatal(ok != 0,"Create semaphore failed at creating mutex mFoyer.");
+   ok = pthread_cond_init(&semaphore->mCond,NULL);
+   AssertFatal(ok == 0,"Create semaphore failed at creating condition mCond.");
+   
+   semaphore->count = initialCount;
+   
+   return((void*)semaphore);
+}
+
+void Semaphore::destroySemaphore(void * semaphore)
+{
+   MacCarbSemaphore *sem = static_cast<MacCarbSemaphore*>(semaphore);
+   pthread_mutex_destroy(&sem->mDarkroom);
+//   pthread_mutex_destroy(sem->mFoyer);
+   pthread_cond_destroy(&sem->mCond);
+   
+   delete sem;
+}
+
+bool Semaphore::acquireSemaphore(void * semaphore, bool block)
+{ 
+   bool ok;
+   AssertFatal(semaphore, "Semaphore::acquireSemaphore: invalid semaphore");
+   MacCarbSemaphore *sem = static_cast<MacCarbSemaphore*>(semaphore);
+   
+   ok = pthread_mutex_lock(&sem->mDarkroom);
+   AssertFatal(ok == 0,"Mutex Lock failed on mDarkroom in acquireSemaphore().");
+   
+   if(sem->count <= 0 && !block) {
+      ok = pthread_mutex_unlock(&sem->mDarkroom);
+      AssertFatal(ok == 0,"Mutex Unlock failed on mDarkroom when not blocking in acquireSemaphore().");
+      return false;
+   }
+   
+   while( sem->count <= 0 ) {
+      ok = pthread_cond_wait(&sem->mCond, &sem->mDarkroom); // releases mDarkroom while blocked.
+      AssertFatal(ok == 0,"Waiting on mCond failed in acquireSemaphore().");
+   }
+   
+   sem->count--;
+   
+   ok = pthread_mutex_unlock(&sem->mDarkroom);
+   AssertFatal(ok == 0,"Mutex Unlock failed on mDarkroom when leaving acquireSemaphore().");
+   
+   return true;
+}
+
+void Semaphore::releaseSemaphore(void * semaphore)
+{
+   bool ok;
+   AssertFatal(semaphore, "Semaphore::releaseSemaphore: invalid semaphore");
+   MacCarbSemaphore *sem = static_cast<MacCarbSemaphore*>(semaphore);
+   
+   ok = pthread_mutex_lock(&sem->mDarkroom);
+   AssertFatal(ok == 0,"Mutex Lock failed on mDarkroom in releaseSemaphore().");   
+   
+   sem->count++;
+   if(sem->count > 0) {
+      ok = pthread_cond_signal(&sem->mCond);
+      AssertFatal(ok == 0,"Signaling mCond failed in releaseSemaphore().");  
+   }
+   
+   ok = pthread_mutex_unlock(&sem->mDarkroom);
+    AssertFatal(ok == 0,"Mutex Unlock failed on mDarkroom when leaving releaseSemaphore().");
+}