#include <iostream>
+#include "search.h"
#include "thread.h"
#include "ucioption.h"
namespace { extern "C" {
// start_routine() is the C function which is called when a new thread
- // 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.
+ // is launched. It simply calls idle_loop() of the supplied thread. The
+ // last two threads are dedicated to read input from GUI and to mimic a
+ // timer, so they run in listener_loop() and timer_loop() respectively.
#if defined(_MSC_VER)
-
DWORD WINAPI start_routine(LPVOID thread) {
-
- ((Thread*)thread)->idle_loop(NULL);
- return 0;
- }
-
#else
-
void* start_routine(void* thread) {
+#endif
- ((Thread*)thread)->idle_loop(NULL);
- return NULL;
- }
+ if (((Thread*)thread)->threadID == MAX_THREADS)
+ ((Thread*)thread)->listener_loop();
-#endif
+ else if (((Thread*)thread)->threadID == MAX_THREADS + 1)
+ ((Thread*)thread)->timer_loop();
+ else
+ ((Thread*)thread)->idle_loop(NULL);
+
+ return 0;
+ }
} }
void ThreadsManager::init() {
+ // Initialize sleep condition used to block waiting for GUI input
+ cond_init(&sleepCond);
+
// Initialize threads lock, used when allocating slaves during splitting
lock_init(&threadsLock);
// Initialize sleep and split point locks
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 0; i < MAX_THREADS + 2; i++)
{
lock_init(&threads[i].sleepLock);
cond_init(&threads[i].sleepCond);
// 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++)
+ for (int i = 1; i < MAX_THREADS + 2; i++)
{
threads[i].is_searching = false;
threads[i].threadID = i;
void ThreadsManager::exit() {
- // Wake up all the slave threads at once. This is faster than "wake and wait"
- // for each thread and avoids a rare crash once every 10K games under Linux.
- for (int i = 1; i < MAX_THREADS; i++)
- {
- threads[i].do_terminate = true;
- threads[i].wake_up();
- }
-
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 0; i < MAX_THREADS + 2; i++)
{
if (i != 0)
{
+ threads[i].do_terminate = true;
+ threads[i].wake_up();
+
// Wait for slave termination
#if defined(_MSC_VER)
WaitForSingleObject(threads[i].handle, 0);
}
lock_destroy(&threadsLock);
+ cond_destroy(&sleepCond);
}
}
+// split_point_finished() checks if all the slave threads of a given split
+// point have finished searching.
+
+bool ThreadsManager::split_point_finished(SplitPoint* sp) const {
+
+ for (int i = 0; i < activeThreads; i++)
+ if (sp->is_slave[i])
+ return false;
+
+ return true;
+}
+
+
// split() does the actual work of distributing the work at a node between
// several available threads. If it does not succeed in splitting the
// node (because no idle threads are available, or because we have no unused
// Explicit template instantiations
template Value ThreadsManager::split<false>(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<true>(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
+
+
+// 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.
+ if (cmd == "quit")
+ 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);
+}