namespace { extern "C" {
// start_routine() is the C function which is called when a new thread
- // is launched. It simply calls idle_loop() with the supplied threadID.
+ // is launched. It simply calls idle_loop() of the supplied thread.
// There are two versions of this function; one for POSIX threads and
// one for Windows threads.
#if defined(_MSC_VER)
- DWORD WINAPI start_routine(LPVOID threadID) {
+ DWORD WINAPI start_routine(LPVOID thread) {
- Threads[*(int*)threadID].idle_loop(NULL);
+ ((Thread*)thread)->idle_loop(NULL);
return 0;
}
#else
- void* start_routine(void* threadID) {
+ void* start_routine(void* thread) {
- Threads[*(int*)threadID].idle_loop(NULL);
+ ((Thread*)thread)->idle_loop(NULL);
return NULL;
}
}
-// cutoff_occurred() checks whether a beta cutoff has occurred in
-// the thread's currently active split point, or in some ancestor of
-// the current split point.
+// cutoff_occurred() checks whether a beta cutoff has occurred in the current
+// active split point, or in some ancestor of the split point.
bool Thread::cutoff_occurred() const {
activeThreads = cnt;
for (int i = 0; i < MAX_THREADS; i++)
- threads[i].do_sleep = !(i < activeThreads);
+ if (i < activeThreads)
+ {
+ // Dynamically allocate pawn and material hash tables according to the
+ // number of active threads. This avoids preallocating memory for all
+ // possible threads if only few are used as, for instance, on mobile
+ // devices where memory is scarce and allocating for MAX_THREADS could
+ // even result in a crash.
+ threads[i].pawnTable.init();
+ threads[i].materialTable.init();
+
+ threads[i].do_sleep = false;
+ }
+ else
+ threads[i].do_sleep = true;
}
void ThreadsManager::init() {
- // Threads will sent to sleep as soon as created, only main thread is kept alive
- set_size(1);
- threads[0].state = Thread::SEARCHING;
- threads[0].threadID = 0;
-
- // Allocate pawn and material hash tables for main thread
- init_hash_tables();
-
// Initialize threads lock, used when allocating slaves during splitting
lock_init(&threadsLock);
lock_init(&(threads[i].splitPoints[j].lock));
}
- // Create and startup all the threads but the main that is already running
+ // Initialize main thread's associated data
+ threads[0].state = Thread::SEARCHING;
+ threads[0].threadID = 0;
+ set_size(1); // This makes all the threads but the main to go to sleep
+
+ // Create and launch all the threads but the main that is already running,
+ // threads will go immediately to sleep.
for (int i = 1; i < MAX_THREADS; i++)
{
- threads[i].state = Thread::INITIALIZING;
+ threads[i].state = Thread::AVAILABLE;
threads[i].threadID = i;
#if defined(_MSC_VER)
- bool ok = (CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i].threadID , 0, NULL) != NULL);
+ threads[i].handle = CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i], 0, NULL);
+ bool ok = (threads[i].handle != NULL);
#else
- pthread_t pthreadID;
- bool ok = (pthread_create(&pthreadID, NULL, start_routine, (void*)&threads[i].threadID) == 0);
- pthread_detach(pthreadID);
+ bool ok = (pthread_create(&threads[i].handle, NULL, start_routine, (void*)&threads[i]) == 0);
#endif
+
if (!ok)
{
- std::cout << "Failed to create thread number " << i << std::endl;
+ std::cerr << "Failed to create thread number " << i << std::endl;
::exit(EXIT_FAILURE);
}
-
- // Wait until the thread has finished launching and is gone to sleep
- while (threads[i].state == Thread::INITIALIZING) {}
}
}
{
threads[i].do_terminate = true;
threads[i].wake_up();
- while (threads[i].state != Thread::TERMINATED) {}
+
+#if defined(_MSC_VER)
+ WaitForSingleObject(threads[i].handle, 0);
+ CloseHandle(threads[i].handle);
+#else
+ pthread_join(threads[i].handle, NULL);
+#endif
}
// Now we can safely destroy locks and wait conditions
}
-// init_hash_tables() dynamically allocates pawn and material hash tables
-// according to the number of active threads. This avoids preallocating
-// memory for all possible threads if only few are used as, for instance,
-// on mobile devices where memory is scarce and allocating for MAX_THREADS
-// threads could even result in a crash.
-
-void ThreadsManager::init_hash_tables() {
-
- for (int i = 0; i < activeThreads; i++)
- {
- threads[i].pawnTable.init();
- threads[i].materialTable.init();
- }
-}
-
-
// available_slave_exists() tries to find an idle thread which is available as
// a slave for the thread with threadID "master".
threads[i].splitPoint = sp;
// This makes the slave to exit from idle_loop()
- threads[i].state = Thread::WORKISWAITING;
+ threads[i].state = Thread::SEARCHING;
if (useSleepingThreads)
threads[i].wake_up();
masterThread.splitPoint = sp;
masterThread.activeSplitPoints++;
- masterThread.state = Thread::WORKISWAITING;
// Everything is set up. The master thread enters the idle loop, from
// which it will instantly launch a search, because its state is