deepcrayon/stockfish
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Retire Thread::BOOKED

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Start a slave as soon as is allocated.

No functional change with faked split.

Regression tested the full split() series and after
2000 games no regression and no crash.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2011-08-07 19:56:53 +01:00
parent 68583f4d48
commit 4a71c86270
2 changed files with 16 additions and 25 deletions
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38
src/thread.cpp
View file

@ -283,18 +283,23 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
int workersCnt = 1; // At least the master is included
// Try to allocate available threads setting state to Thread::BOOKED, this
// must be done under lock protection to avoid concurrent allocation of
// the same slave by another master.
// Try to allocate available threads and ask them to start searching setting
// the state to Thread::WORKISWAITING, this must be done under lock protection
// to avoid concurrent allocation of the same slave by another master.
lock_grab(&threadsLock);
for (i = 0; !Fake && i < activeThreads && workersCnt < maxThreadsPerSplitPoint; i++)
if (i != master && threads[i].is_available_to(master))
{
threads[i].state = Thread::BOOKED;
threads[i].splitPoint = &splitPoint;
splitPoint.is_slave[i] = true;
workersCnt++;
splitPoint.is_slave[i] = true;
threads[i].splitPoint = &splitPoint;
// This makes the slave to exit from idle_loop()
threads[i].state = Thread::WORKISWAITING;
if (useSleepingThreads)
threads[i].wake_up();
}
lock_release(&threadsLock);
@ -303,27 +308,14 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
if (!Fake && workersCnt == 1)
return bestValue;
masterThread.activeSplitPoints++;
masterThread.splitPoint = &splitPoint;
// Tell the threads that they have some work to do. This will make them leave
// their idle loop.
for (i = 0; i < activeThreads; i++)
if (i == master || splitPoint.is_slave[i])
{
assert(i == master || threads[i].state == Thread::BOOKED);
// This makes the slave to exit from idle_loop()
threads[i].state = Thread::WORKISWAITING;
if (useSleepingThreads && i != master)
threads[i].wake_up();
}
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
// THREAD_WORKISWAITING. We send the split point as a second parameter to the
// idle loop, which means that the main thread will return from the idle
// Thread::WORKISWAITING. We send the split point as a second parameter to
// the idle loop, which means that the main thread will return from the idle
// loop when all threads have finished their work at this split point.
idle_loop(master, &splitPoint);

3
src/thread.h
View file

@ -70,8 +70,7 @@ struct Thread {
INITIALIZING, // Thread is initializing itself
SEARCHING, // Thread is performing work
AVAILABLE, // Thread is waiting for work
BOOKED, // Other thread (master) has booked us as a slave
WORKISWAITING, // Master has ordered us to start
WORKISWAITING, // Master has ordered us to start searching
TERMINATED // We are quitting and thread is terminated
};