added conditional variables for win/linux/sdl, switched sql thread worker to conditional to avoid busy looping, corrected a spikeism

git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@2991 fc73d0e0-1445-4013-8a0c-d673dee63da5

engine/client/cl_screen.c

@@ -1360,7 +1360,7 @@ void SCR_DrawClock(void)
 void SCR_DrawGameClock(void)
 {
 	float showtime;
-	int minuites;
+	int minutes;
 	int seconds;
 	char str[16];
 	int flags;
@@ -1380,17 +1380,17 @@ void SCR_DrawGameClock(void)
 	if (showtime < 0)
 	{
 		showtime *= -1;
-		minuites = showtime/60;
+		minutes = showtime/60;
-		seconds = (int)showtime - (minuites*60);
+		seconds = (int)showtime - (minutes*60);
-		minuites *= -1;
+		minutes *= -1;
 	}
 	else
 	{
-		minuites = showtime/60;
+		minutes = showtime/60;
-		seconds = (int)showtime - (minuites*60);
+		seconds = (int)showtime - (minutes*60);
 	}
 
-	sprintf(str, " %02i:%02i", minuites, seconds);
+	sprintf(str, " %02i:%02i", minutes, seconds);
 
 	SCR_StringXY(str, show_gameclock_x.value, show_gameclock_y.value);
 }

engine/client/sys_linux.c

@@ -621,7 +621,7 @@ void Sys_WaitOnThread(void *thread)
 }
 
 /* Mutex calls */
-void *Sys_CreateMutex()
+void *Sys_CreateMutex(void)
 {
 	pthread_mutex_t *mutex = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
 	
@@ -650,4 +650,84 @@ void Sys_DestroyMutex(void *mutex)
 	pthread_mutex_destroy(mutex);
 	free(mutex);
 }
+
+/* Conditional wait calls */
+typedef struct condvar_s
+{
+	pthread_mutex_t *mutex;
+	pthread_cond_t *cond;
+} condvar_t;
+
+void *Sys_CreateConditional(void)
+{
+	condvar_t *condv;
+	pthread_mutex_t *mutex;
+	pthread_cond_t *cond;
+	
+	condv = (condvar_t *)malloc(sizeof(condvar_t));
+	if (!condv)
+		return NULL;
+	
+	mutex = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
+	if (!mutex)
+		return NULL;
+		
+	cond = (pthread_cond_t *)malloc(sizeof(pthread_cond_t));
+	if (!cond)
+		return NULL;
+		
+	if (!pthread_mutex_init(mutex, NULL))
+	{
+		if (!pthread_cond_init(cond, NULL))
+		{
+			condv->cond = cond;
+			condv->mutex = mutex;
+			
+			return (void *)condv;
+		}
+		else
+			pthread_mutex_destroy(mutex);
+	}
+	
+	free(cond);
+	free(mutex);
+	free(condv);
+	return NULL;	
+}
+
+qboolean Sys_LockConditional(void *condv)
+{
+	return !pthread_mutex_lock(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_UnlockConditional(void *condv)
+{
+	return !pthread_mutex_unlock(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionWait(void *condv)
+{
+	return !pthread_cond_wait(((condvar_t *)condv)->cond, ((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionSignal(void *condv)
+{
+	return !pthread_cond_signal(((condvar_t *)condv)->cond);
+}
+
+qboolean Sys_ConditionBroadcast(void *condv)
+{
+	return !pthread_cond_broadcast(((condvar_t *)condv)->cond);
+}
+
+void Sys_DestroyConditional(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+	
+	pthread_cond_destroy(cv->cond);
+	pthread_mutex_destroy(cv->mutex);
+	free(cv->cond);
+	free(cv->mutex);
+	free(cv);
+}
 #endif

engine/client/sys_morphos.c

@@ -440,9 +440,17 @@ void Sys_LowFPPrecision (void)
 void *Sys_CreateThread(int (*func)(void *), void *args, int stacksize) { return NULL; }
 void Sys_WaitOnThread(void *thread) {}
 /* Mutex calls */
-void *Sys_CreateMutex() { return NULL; }
+void *Sys_CreateMutex(void) { return NULL; }
-qboolean Sys_TryLockMutex(void *mutex) { return FALSE; }
+qboolean Sys_TryLockMutex(void *mutex) { return false; }
-qboolean Sys_LockMutex(void *mutex) { return FALSE; }
+qboolean Sys_LockMutex(void *mutex) { return false; }
-qboolean Sys_UnlockMutex(void *mutex) { return FALSE; }
+qboolean Sys_UnlockMutex(void *mutex) { return false; }
 void Sys_DestroyMutex(void *mutex) {}
+/* Conditional wait calls */
+void *Sys_CreateConditional(void) { return NULL; }
+qboolean Sys_LockConditional(void *condv) { return false; }
+qboolean Sys_UnlockConditional(void *condv) { return false; }
+qboolean Sys_ConditionWait(void *condv) { return false; }
+qboolean Sys_ConditionSignal(void *condv) { return false; }
+qboolean Sys_ConditionBroadcast(void *condv) { return false; }
+void Sys_DestroyConditional(void *condv) {}
 #endif

engine/client/sys_sdl.c

@@ -366,7 +366,7 @@ void Sys_WaitOnThread(void *thread)
 
 /* Mutex calls */
 // SDL mutexes don't have try-locks for mutexes in the spec so we stick with 1-value semaphores
-void *Sys_CreateMutex()
+void *Sys_CreateMutex(void)
 {
 	return (void *)SDL_CreateSemaphore(1);
 }
@@ -388,7 +388,78 @@ qboolean Sys_UnlockMutex(void *mutex)
 
 void Sys_DestroyMutex(void *mutex)
 {
-	return SDL_DestroySemaphore(mutex);
+	SDL_DestroySemaphore(mutex);
+}
+
+/* Conditional wait calls */
+typedef struct condvar_s
+{
+	SDL_mutex *mutex;
+	SDL_cond *cond;
+} condvar_t;
+
+void *Sys_CreateConditional(void)
+{
+	condvar_t *condv;
+	SDL_mutex *mutex;
+	SDL_cond *cond;
+	
+	condv = (condvar_t *)malloc(sizeof(condvar_t));
+	if (!condv)
+		return NULL;
+		
+	mutex = SDL_CreateMutex();
+	cond = SDL_CreateCond();
+	
+	if (mutex)
+	{
+		if (cond)
+		{
+			condv->cond = cond;
+			condv->mutex = mutex;
+		
+			return (void *)condv;
+		}
+		else
+			SDL_DestroyMutex(mutex);
+	}
+	
+	free(condv);
+	return NULL;	
+}
+
+qboolean Sys_LockConditional(void *condv)
+{
+	return !SDL_mutexP(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_UnlockConditional(void *condv)
+{
+	return !SDL_mutexV(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionWait(void *condv)
+{
+	return !SDL_CondWait(((condvar_t *)condv)->cond, ((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionSignal(void *condv)
+{
+	return !SDL_CondSignal(((condvar_t *)condv)->cond);
+}
+
+qboolean Sys_ConditionBroadcast(void *condv)
+{
+	return !SDL_CondBroadcast(((condvar_t *)condv)->cond);
+}
+
+void Sys_DestroyConditional(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+	
+	SDL_DestroyCond(cv->cond);
+	SDL_DestroyMutex(cv->mutex);
+	free(cv);
 }
 #endif
 

engine/client/sys_win.c

@@ -1403,7 +1403,7 @@ void Sys_WaitOnThread(void *thread)
 }
 
 /* Mutex calls */
-void *Sys_CreateMutex()
+void *Sys_CreateMutex(void)
 {
 	return (void *)CreateMutex(NULL, 0, NULL);
 }
@@ -1427,4 +1427,154 @@ void Sys_DestroyMutex(void *mutex)
 {
 	CloseHandle(mutex);
 }
+
+/* Conditional wait calls */
+/*
+TODO: Windows Vista has condition variables as documented here:
+http://msdn.microsoft.com/en-us/library/ms682052(VS.85).aspx
+Note this uses Slim Reader/Writer locks (Vista+ exclusive)
+or critical sections.
+
+The condition variable implementation is based on the libSDL implementation.
+This code could probably be made more efficient with the use of events or
+different mechanisms but for now the main concern is a correct and
+complete solution.
+*/
+typedef struct condvar_s
+{
+    int waiting;
+    int signals;
+    CRITICAL_SECTION countlock;
+	CRITICAL_SECTION mainlock;
+    HANDLE wait_sem;
+    HANDLE wait_done;
+} condvar_t;
+
+void *Sys_CreateConditional(void) 
+{ 
+	condvar_t *cv;
+
+	cv = (condvar_t *)malloc(sizeof(condvar_t));
+	if (!cv)
+		return NULL;
+
+	cv->waiting = 0;
+	cv->signals = 0;
+	InitializeCriticalSection (&cv->mainlock);
+	InitializeCriticalSection (&cv->countlock);
+	cv->wait_sem = CreateSemaphore (NULL, 0, 0x7fffffff, NULL);
+	cv->wait_done = CreateSemaphore (NULL, 0, 0x7fffffff, NULL);
+
+	if (cv->wait_sem && cv->wait_done)
+		return (void *)cv;
+
+	// something failed so deallocate everything
+	if (cv->wait_done)
+		CloseHandle(cv->wait_done);
+	if (cv->wait_sem)
+		CloseHandle(cv->wait_sem);
+	DeleteCriticalSection(&cv->countlock);
+	DeleteCriticalSection(&cv->mainlock);
+	free(cv);
+
+	return NULL;
+}
+
+qboolean Sys_LockConditional(void *condv) 
+{ 
+	EnterCriticalSection(&((condvar_t *)condv)->mainlock);
+	return true; 
+}
+
+qboolean Sys_UnlockConditional(void *condv) 
+{ 
+	LeaveCriticalSection(&((condvar_t *)condv)->mainlock);
+	return true; 
+}
+
+qboolean Sys_ConditionWait(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+	qboolean success;
+
+	// increase count for non-signaled waiting threads
+	EnterCriticalSection(&cv->countlock);
+	cv->waiting++;
+	LeaveCriticalSection(&cv->countlock);
+
+	LeaveCriticalSection(&cv->mainlock); // unlock as per condition variable definition
+
+	// wait on a signal
+	success = (WaitForSingleObject(cv->wait_sem, INFINITE) != WAIT_FAILED);
+
+	// update waiting count and alert signaling thread that we're done to avoid the deadlock condition
+	EnterCriticalSection(&cv->countlock);
+	if (cv->signals > 0) 
+	{
+		ReleaseSemaphore(cv->wait_done, cv->signals, NULL);
+		cv->signals = 0;
+	}
+	cv->waiting--;
+	LeaveCriticalSection(&cv->countlock);
+
+	EnterCriticalSection(&cv->mainlock); // lock as per condition variable definition
+
+	return success;
+}
+
+qboolean Sys_ConditionSignal(void *condv) 
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	// if there are non-signaled waiting threads, we signal one and wait on the response
+	EnterCriticalSection(&cv->countlock);
+	if (cv->waiting > cv->signals)
+	{
+		cv->signals++;
+		ReleaseSemaphore(cv->wait_sem, 1, NULL);
+		LeaveCriticalSection(&cv->countlock);
+		WaitForSingleObject(cv->wait_done, INFINITE);
+	}
+	else
+		LeaveCriticalSection(&cv->countlock);
+
+    return true;
+}
+
+qboolean Sys_ConditionBroadcast(void *condv) 
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	// if there are non-signaled waiting threads, we signal all of them and wait on all the responses back
+	EnterCriticalSection(&cv->countlock);
+	if (cv->waiting > cv->signals) 
+	{
+		int i, num_waiting;
+
+		num_waiting = (cv->waiting - cv->signals);
+		cv->signals = cv->waiting;
+		
+		ReleaseSemaphore(cv->wait_sem, num_waiting, NULL);
+		LeaveCriticalSection(&cv->countlock);
+		// there's no call to wait for the same object multiple times so we need to loop through
+		// and burn up the semaphore count
+		for (i = 0; i < num_waiting; i++) 
+			WaitForSingleObject(cv->wait_done, INFINITE);
+	}
+	else
+		LeaveCriticalSection(&cv->countlock);
+
+	return true;
+}
+
+void Sys_DestroyConditional(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	CloseHandle(cv->wait_done);
+	CloseHandle(cv->wait_sem);
+	DeleteCriticalSection(&cv->countlock);
+	DeleteCriticalSection(&cv->mainlock);
+	free(cv);
+}
 #endif

engine/common/sys.h

@@ -91,11 +91,20 @@ qboolean Sys_GetDesktopParameters(int *width, int *height, int *bpp, int *refres
 void *Sys_CreateThread(int (*func)(void *), void *args, int stacksize);
 void Sys_WaitOnThread(void *thread);
 
-void *Sys_CreateMutex();
+void *Sys_CreateMutex(void);
 qboolean Sys_TryLockMutex(void *mutex);
 qboolean Sys_LockMutex(void *mutex);
 qboolean Sys_UnlockMutex(void *mutex);
 void Sys_DestroyMutex(void *mutex);
+
+/* Conditional wait calls */
+void *Sys_CreateConditional(void);
+qboolean Sys_LockConditional(void *condv);
+qboolean Sys_UnlockConditional(void *condv);
+qboolean Sys_ConditionWait(void *condv);
+qboolean Sys_ConditionSignal(void *condv);
+qboolean Sys_ConditionBroadcast(void *condv);
+void Sys_DestroyConditional(void *condv);
 #endif
 
 #ifdef _WIN32

engine/server/pr_cmds.c

@@ -6349,7 +6349,7 @@ typedef struct sqlserver_s
 	void *thread; // worker thread for server
 	MYSQL *mysql; // mysql server
 	volatile qboolean active; // set to false to kill thread
-	void *requestlock; // mutex for queue read/write
+	void *requestcondv; // lock and conditional variable for queue read/write
 	void *resultlock; // mutex for queue read/write
 	int querynum; // next reference number for queries
 	queryrequest_t *requests; // query requests queue
@@ -6390,19 +6390,20 @@ queryresult_t *SQL_PullResult(sqlserver_t *server)
 
 void SQL_PushRequest(sqlserver_t *server, queryrequest_t *qreq)
 {
-	Sys_LockMutex(server->requestlock);
+	Sys_LockConditional(server->requestcondv);
 	qreq->next = NULL;
 	if (!server->requestslast)
 		server->requests = server->requestslast = qreq;
 	else
 		server->requestslast = server->requestslast->next = qreq;
-	Sys_UnlockMutex(server->requestlock);
+	Sys_UnlockConditional(server->requestcondv);
 }
 
-queryrequest_t *SQL_PullRequest(sqlserver_t *server)
+queryrequest_t *SQL_PullRequest(sqlserver_t *server, qboolean lock)
 {
 	queryrequest_t *qreq;
-	Sys_LockMutex(server->requestlock);
+	if (lock)
+		Sys_LockConditional(server->requestcondv);
 	qreq = server->requests;
 	if (qreq)
 	{
@@ -6410,7 +6411,7 @@ queryrequest_t *SQL_PullRequest(sqlserver_t *server)
 		if (!server->requests)
 			server->requestslast = NULL;
 	}
-	Sys_UnlockMutex(server->requestlock);
+	Sys_UnlockConditional(server->requestcondv);
 
 	return qreq;
 }
@@ -6424,6 +6425,7 @@ int sql_serverworker(void *sref)
 	char *error = NULL;
 	my_bool reconnect = 1;
 	int tinit;
+	qboolean needlock = false;
 
 	if (tinit = mysql_thread_init())
 		error = "MYSQL thread init failed";
@@ -6439,9 +6441,9 @@ int sql_serverworker(void *sref)
 
 	while (server->active)
 	{	
-		// TODO: replace this with a conditional
+		Sys_LockConditional(server->requestcondv);
-		if (!server->requests)
+		Sys_ConditionWait(server->requestcondv);
-			continue;
+		needlock = false; // so we don't try to relock first round
 
 		while (1)
 		{
@@ -6453,9 +6455,13 @@ int sql_serverworker(void *sref)
 			int columns = -1;
 			int qesize = 0;
 
-			if (!(qreq = SQL_PullRequest(server)))
+			if (!(qreq = SQL_PullRequest(server, needlock)))
 				break;
 
+			// pullrequest makes sure our condition is unlocked but we'll need
+			// a lock next round
+			needlock = true;
+
 			// perform the query and fill out the result structure
 			if (mysql_query(server->mysql, qreq->query))
 				qerror = mysql_error(server->mysql);
@@ -6501,7 +6507,6 @@ int sql_serverworker(void *sref)
 				break;
 			}
 		}
-
 	}
 
 	if (server->mysql)
@@ -6560,13 +6565,13 @@ void PF_sqlconnect (progfuncs_t *prinst, struct globalvars_s *pr_globals)
 	sqlservers[serverref] = server;
 
 	server->active = true;
-	server->requestlock = Sys_CreateMutex();
+	server->requestcondv = Sys_CreateConditional();
 	server->resultlock = Sys_CreateMutex();
 
-	if (!server->requestlock || !server->resultlock)
+	if (!server->requestcondv || !server->resultlock)
 	{
-		if (server->requestlock)
+		if (server->requestcondv)
-			Sys_DestroyMutex(server->requestlock);
+			Sys_DestroyConditional(server->requestcondv);
 		if (server->resultlock)
 			Sys_DestroyMutex(server->resultlock);
 		Z_Free(server);
@@ -6597,7 +6602,8 @@ void PF_sqldisconnect (progfuncs_t *prinst, struct globalvars_s *pr_globals)
 
 	sqlservers[serverref]->active = false;
 
-	// TODO: conditional broadcast here
+	// force the threads to reiterate requests and hopefully terminate
+	Sys_ConditionBroadcast(sqlservers[serverref]->requestcondv);
 }
 
 void PF_sqlopenquery (progfuncs_t *prinst, struct globalvars_s *pr_globals)
@@ -6624,8 +6630,7 @@ void PF_sqlopenquery (progfuncs_t *prinst, struct globalvars_s *pr_globals)
 	Q_strncpy(qreq->query, querystr, qsize);
 
 	SQL_PushRequest(sqlservers[serverref], qreq);
-
+	Sys_ConditionSignal(sqlservers[serverref]->requestcondv);
-	// TODO: conditional trip here
 
 	G_FLOAT(OFS_RETURN) = querynum;
 }
@@ -6892,7 +6897,7 @@ void SQL_DeInit()
 		Sys_WaitOnThread(server->thread);
 
 		// server resource deallocation (TODO: should this be done in the thread itself?)
-		Sys_DestroyMutex(server->requestlock);
+		Sys_DestroyConditional(server->requestcondv);
 		Sys_DestroyMutex(server->resultlock);
 		
 		qreq = server->requests;

engine/server/sv_sys_unix.c

@@ -901,7 +901,7 @@ void Sys_WaitOnThread(void *thread)
 }
 
 /* Mutex calls */
-void *Sys_CreateMutex()
+void *Sys_CreateMutex(void)
 {
 	pthread_mutex_t *mutex = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
 	
@@ -930,5 +930,85 @@ void Sys_DestroyMutex(void *mutex)
 	pthread_mutex_destroy(mutex);
 	free(mutex);
 }
+
+/* Conditional wait calls */
+typedef struct condvar_s
+{
+	pthread_mutex_t *mutex;
+	pthread_cond_t *cond;
+} condvar_t;
+
+void *Sys_CreateConditional(void)
+{
+	condvar_t *condv;
+	pthread_mutex_t *mutex;
+	pthread_cond_t *cond;
+	
+	condv = (condvar_t *)malloc(sizeof(condvar_t));
+	if (!condv)
+		return NULL;
+	
+	mutex = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
+	if (!mutex)
+		return NULL;
+		
+	cond = (pthread_cond_t *)malloc(sizeof(pthread_cond_t));
+	if (!cond)
+		return NULL;
+		
+	if (!pthread_mutex_init(mutex, NULL))
+	{
+		if (!pthread_cond_init(cond, NULL))
+		{
+			condv->cond = cond;
+			condv->mutex = mutex;
+			
+			return (void *)condv;
+		}
+		else
+			pthread_mutex_destroy(mutex);
+	}
+	
+	free(cond);
+	free(mutex);
+	free(condv);
+	return NULL;	
+}
+
+qboolean Sys_LockConditional(void *condv)
+{
+	return !pthread_mutex_lock(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_UnlockConditional(void *condv)
+{
+	return !pthread_mutex_unlock(((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionWait(void *condv)
+{
+	return !pthread_cond_wait(((condvar_t *)condv)->cond, ((condvar_t *)condv)->mutex);
+}
+
+qboolean Sys_ConditionSignal(void *condv)
+{
+	return !pthread_cond_signal(((condvar_t *)condv)->cond);
+}
+
+qboolean Sys_ConditionBroadcast(void *condv)
+{
+	return !pthread_cond_broadcast(((condvar_t *)condv)->cond);
+}
+
+void Sys_DestroyConditional(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+	
+	pthread_cond_destroy(cv->cond);
+	pthread_mutex_destroy(cv->mutex);
+	free(cv->cond);
+	free(cv->mutex);
+	free(cv);
+}
 #endif
 

engine/server/sv_sys_win.c

@@ -1274,7 +1274,7 @@ void Sys_WaitOnThread(void *thread)
 }
 
 /* Mutex calls */
-void *Sys_CreateMutex()
+void *Sys_CreateMutex(void)
 {
 	return (void *)CreateMutex(NULL, 0, NULL);
 }
@@ -1298,6 +1298,156 @@ void Sys_DestroyMutex(void *mutex)
 {
 	CloseHandle(mutex);
 }
+
+/* Conditional wait calls */
+/*
+TODO: Windows Vista has condition variables as documented here:
+http://msdn.microsoft.com/en-us/library/ms682052(VS.85).aspx
+Note this uses Slim Reader/Writer locks (Vista+ exclusive)
+or critical sections.
+
+The condition variable implementation is based on the libSDL implementation.
+This code could probably be made more efficient with the use of events or
+different mechanisms but for now the main concern is a correct and
+complete solution.
+*/
+typedef struct condvar_s
+{
+    int waiting;
+    int signals;
+    CRITICAL_SECTION countlock;
+	CRITICAL_SECTION mainlock;
+    HANDLE wait_sem;
+    HANDLE wait_done;
+} condvar_t;
+
+void *Sys_CreateConditional(void) 
+{ 
+	condvar_t *cv;
+
+	cv = (condvar_t *)malloc(sizeof(condvar_t));
+	if (!cv)
+		return NULL;
+
+	cv->waiting = 0;
+	cv->signals = 0;
+	InitializeCriticalSection (&cv->mainlock);
+	InitializeCriticalSection (&cv->countlock);
+	cv->wait_sem = CreateSemaphore (NULL, 0, 0x7fffffff, NULL);
+	cv->wait_done = CreateSemaphore (NULL, 0, 0x7fffffff, NULL);
+
+	if (cv->wait_sem && cv->wait_done)
+		return (void *)cv;
+
+	// something failed so deallocate everything
+	if (cv->wait_done)
+		CloseHandle(cv->wait_done);
+	if (cv->wait_sem)
+		CloseHandle(cv->wait_sem);
+	DeleteCriticalSection(&cv->countlock);
+	DeleteCriticalSection(&cv->mainlock);
+	free(cv);
+
+	return NULL;
+}
+
+qboolean Sys_LockConditional(void *condv) 
+{ 
+	EnterCriticalSection(&((condvar_t *)condv)->mainlock);
+	return true; 
+}
+
+qboolean Sys_UnlockConditional(void *condv) 
+{ 
+	LeaveCriticalSection(&((condvar_t *)condv)->mainlock);
+	return true; 
+}
+
+qboolean Sys_ConditionWait(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+	qboolean success;
+
+	// increase count for non-signaled waiting threads
+	EnterCriticalSection(&cv->countlock);
+	cv->waiting++;
+	LeaveCriticalSection(&cv->countlock);
+
+	LeaveCriticalSection(&cv->mainlock); // unlock as per condition variable definition
+
+	// wait on a signal
+	success = (WaitForSingleObject(cv->wait_sem, INFINITE) != WAIT_FAILED);
+
+	// update waiting count and alert signaling thread that we're done to avoid the deadlock condition
+	EnterCriticalSection(&cv->countlock);
+	if (cv->signals > 0) 
+	{
+		ReleaseSemaphore(cv->wait_done, cv->signals, NULL);
+		cv->signals = 0;
+	}
+	cv->waiting--;
+	LeaveCriticalSection(&cv->countlock);
+
+	EnterCriticalSection(&cv->mainlock); // lock as per condition variable definition
+
+	return success;
+}
+
+qboolean Sys_ConditionSignal(void *condv) 
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	// if there are non-signaled waiting threads, we signal one and wait on the response
+	EnterCriticalSection(&cv->countlock);
+	if (cv->waiting > cv->signals)
+	{
+		cv->signals++;
+		ReleaseSemaphore(cv->wait_sem, 1, NULL);
+		LeaveCriticalSection(&cv->countlock);
+		WaitForSingleObject(cv->wait_done, INFINITE);
+	}
+	else
+		LeaveCriticalSection(&cv->countlock);
+
+    return true;
+}
+
+qboolean Sys_ConditionBroadcast(void *condv) 
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	// if there are non-signaled waiting threads, we signal all of them and wait on all the responses back
+	EnterCriticalSection(&cv->countlock);
+	if (cv->waiting > cv->signals) 
+	{
+		int i, num_waiting;
+
+		num_waiting = (cv->waiting - cv->signals);
+		cv->signals = cv->waiting;
+		
+		ReleaseSemaphore(cv->wait_sem, num_waiting, NULL);
+		LeaveCriticalSection(&cv->countlock);
+		// there's no call to wait for the same object multiple times so we need to loop through
+		// and burn up the semaphore count
+		for (i = 0; i < num_waiting; i++) 
+			WaitForSingleObject(cv->wait_done, INFINITE);
+	}
+	else
+		LeaveCriticalSection(&cv->countlock);
+
+	return true;
+}
+
+void Sys_DestroyConditional(void *condv)
+{
+	condvar_t *cv = (condvar_t *)condv;
+
+	CloseHandle(cv->wait_done);
+	CloseHandle(cv->wait_sem);
+	DeleteCriticalSection(&cv->countlock);
+	DeleteCriticalSection(&cv->mainlock);
+	free(cv);
+}
 #endif
 
 #endif