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Retire Thread::BOOKED

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>
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1 parent 68583f4 commit 4a71c862702c05b3c56e902f4675fdf68041710b @mcostalba committed Aug 7, 2011
Showing with 16 additions and 25 deletions.
  1. +15 −23 src/thread.cpp
  2. +1 −2 src/thread.h
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@@ -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);
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@@ -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
};

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