+
+
+// Thread::timer_loop() is where the timer thread waits maxPly milliseconds
+// and then calls do_timer_event().
+
+void Thread::timer_loop() {
+
+ while (!do_terminate)
+ {
+ lock_grab(&sleepLock);
+ timed_wait(&sleepCond, &sleepLock, maxPly ? maxPly : INT_MAX);
+ lock_release(&sleepLock);
+ do_timer_event();
+ }
+}
+
+
+// ThreadsManager::set_timer() is used to set the timer to trigger after msec
+// milliseconds. If msec is 0 then timer is stopped.
+
+void ThreadsManager::set_timer(int msec) {
+
+ Thread& timer = threads[MAX_THREADS + 1];
+
+ lock_grab(&timer.sleepLock);
+ timer.maxPly = msec;
+ cond_signal(&timer.sleepCond); // Wake up and restart the timer
+ lock_release(&timer.sleepLock);
+}
+
+
+// Thread::listener_loop() is where the listener thread, used for I/O, waits for
+// input. When is_searching is false then input is read in sync with main thread
+// (that blocks), otherwise the listener thread reads any input asynchronously
+// and processes the input line calling do_uci_async_cmd().
+
+void Thread::listener_loop() {
+
+ std::string cmd;
+
+ while (true)
+ {
+ lock_grab(&sleepLock);
+
+ Threads.inputLine = cmd;
+ do_sleep = !is_searching;
+
+ // Here the thread is parked in sync mode after a line has been read
+ while (do_sleep && !do_terminate) // Catches spurious wake ups
+ {
+ cond_signal(&Threads.sleepCond); // Wake up main thread
+ cond_wait(&sleepCond, &sleepLock); // Sleep here
+ }
+
+ lock_release(&sleepLock);
+
+ if (do_terminate)
+ return;
+
+ if (!std::getline(std::cin, cmd)) // Block waiting for input
+ cmd = "quit";
+
+ lock_grab(&sleepLock);
+
+ // If we are in async mode then process the command now
+ if (is_searching)
+ {
+ // Command "quit" is the last one received by the GUI, so park the
+ // thread waiting for exiting. Also, after a "stop", for instance on a
+ // ponder miss, GUI can immediately send the new position to search,
+ // so return to in-sync mode to avoid discarding good data.
+ if (cmd == "quit" || cmd == "stop")
+ is_searching = false;
+
+ do_uci_async_cmd(cmd);
+ cmd = ""; // Input has been consumed
+ }
+
+ lock_release(&sleepLock);
+ }
+}
+
+
+// ThreadsManager::getline() is used by main thread to block and wait for input,
+// the behaviour mimics std::getline().
+
+void ThreadsManager::getline(std::string& cmd) {
+
+ Thread& listener = threads[MAX_THREADS];
+
+ lock_grab(&listener.sleepLock);
+
+ listener.is_searching = false; // Set sync mode
+
+ // If there is already some input to grab then skip without to wake up the
+ // listener. This can happen if after we send the "bestmove", the GUI sends
+ // a command that the listener buffers in inputLine before going to sleep.
+ if (inputLine.empty())
+ {
+ listener.do_sleep = false;
+ cond_signal(&listener.sleepCond); // Wake up listener thread
+
+ while (!listener.do_sleep)
+ cond_wait(&sleepCond, &listener.sleepLock); // Wait for input
+ }
+
+ cmd = inputLine;
+ inputLine = ""; // Input has been consumed
+
+ lock_release(&listener.sleepLock);
+}
+
+
+// ThreadsManager::start_listener() is called at the beginning of the search to
+// swith from sync behaviour (default) to async and so be able to read from UCI
+// while other threads are searching. This avoids main thread polling for input.
+
+void ThreadsManager::start_listener() {
+
+ Thread& listener = threads[MAX_THREADS];
+
+ lock_grab(&listener.sleepLock);
+ listener.is_searching = true;
+ listener.do_sleep = false;
+ cond_signal(&listener.sleepCond); // Wake up listener thread
+ lock_release(&listener.sleepLock);
+}
+
+
+// ThreadsManager::stop_listener() is called before to send "bestmove" to GUI to
+// return to in-sync behaviour. This is needed because while in async mode any
+// command is discarded without being processed (except for a very few ones).
+
+void ThreadsManager::stop_listener() {
+
+ Thread& listener = threads[MAX_THREADS];
+
+ lock_grab(&listener.sleepLock);
+ listener.is_searching = false;
+ lock_release(&listener.sleepLock);
+}