But only when needed, after a split point. This behaviour
does not apply when useSleepingThreads is false, becuase
in this case threads are not woken up at split points so
must be already running.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This method belongs to Thread, not to ThreadsManager.
Reshuffle stuff in thread.cpp while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Release split point lock before to wake up
master thread. This seems to increase speed
in case "sleeping threads" are used:
After 7792 games with 4 threads at very fast TC (2"+0.05)
Mod vs Orig 1722 - 1627 - 4443 ELO +4 (+- 5.1)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
When allocating a slave we set both is_searching
and splitPoint under lock protection.
Unfortunatly the order in which the variables are
set is not defined. This article was very clarifying:
http://software.intel.com/en-us/blogs/2007/11/30/volatile-almost-useless-for-multi-threaded-programming/
So when in idle loop we test for is_searching and then
access splitPoint, it could happen that splitPoint is still
not updated leading to a possible crash.
Fix the race lock protecting splitPoint access.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Apart from some renaming the biggest change
is the retire of split_point_finished()
replaced by slavesMask flags. As a side
effect we now take also split point lock
when allocation available threads.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of Posix threads. This seems to fix time
losses of the gcc compiled version for Windows.
The patch replaces the MSVC specific _MSC_VER flag
with _WIN32 and _WIN64 that are defined both by
MSVC and mingw-gcc.
Workaround found by Jim Ablett.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
pass references (Windows style) instead of
pointers (Posix style) as function arguments.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
And directly pass RootMoves instead of SearchMoves
to main thread. A class declaration is better suited
in a header and slims a bit the fatty search.cpp
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We just need to verify if a legal move is among the
SearchMoves, so we don't need a vector for this.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
New gcc 4.7 complains about casting a volatile pointer
to void* so assign the variables directly.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
We try hard not to lose on time even under extreme
time pressure. We achieve this through 3 different but
coordinated steps:
1) Increase max frequency of timer events
2) Quickly return after a stop signal
3) Take in account timer resolution
With these SF played under LittleBlitzer at 1"+0.02 and 3"+0
without losing on time even one game.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Before creating main thread we set its do_sleep flag to true,
then thread is created and it will go to sleep in main_loop()
after resetting do_sleep.
But if after the setting of do_sleep and before its resetting
the UI thread calls start_thinking() it will not wait on:
if (!asyncMode)
while (!main.do_sleep)
cond_wait(&sleepCond, &main.sleepLock);
as it should but will immediately return before the main thread has
started the search. This very rare race show itself during bench,
when the first position is erroneusly skipped so that bench node count
results of 5309038 instead of the correct 5457475.
The patch is somewhat tricky, but is simple and it works!
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems it yields to missing wake-up events with the
result of SF loosing on time as reported by many people.
So revert the patch and use a more robust approach: assume
there can be spurious wake ups events and make the code to
work also in those cases.
While debugging I found that WaitForSingleObject() had wrong
parameter 0 instead of INFINITE yielding to a crash while
exiting under Windows, strangely unnoticed til now.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Currently after a 'quit' command UI thread raises stop
signal, exits from uci_loop() and calls Threads.exit()
while the search threads are still active.
In Threads.exit() main thread is asked to terminate, but
if it is parked in idle_loop() it will exit and free its
resources (in particular the shared Movepicker object) while
sibling slaves are still active and this leads to a crash.
The fix is to let the UI thread always wait for main thread
to finish the search before to return from uci_loop().
Found by Valgrind when running with 8 threads.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Greatly improves the usage. User defined conversions
are a novelity for SF, another amazing C++ facility
at work !
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Make a better use of C++ operators overloading to
streamline the APIs.
Also sync polyglot.ini file while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Diretcly use the underlying std::vector<Move> and the
STL algorithms. Also a bit of cleanup while there.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Detach from the UI thread the input arguments used by
the search threads so that the UI thread is able to receive
and process any command sent by the GUI while other threads
keep searching.
With this patch there is no more need to block the UI
thread after a "stop", so it is a more reliable and
robust solution than the previous patch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Unfortunatly xboard sends immediately the new position to
search after sending "stop" when we have a ponder miss.
Becuase main thread position is not copied but is referenced
directly from root position and the latter is modified by
the "position.." UCI command we end up with the working position
that changes under our feet while the search is still recovering
after the "stop" and this causes a crash.
This happens only with the (broken) xboard, native UCI does not
have this problem.
Reported by otello1984
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Fixes an hang when playing with ponder ON. Perhaps there is still
a very small race but now it seems engine does not hang anymore.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Move global search-related variables under "Search" namespace.
As a side effect we can move uci_async_command() and
wait_for_stop_or_ponderhit() away from search.cpp
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use the starting thread to wait for GUI input and instead use
the other threads to search. The consequence is that now think()
is alwasy started on a differnt thread than the caller that
returns immediately waiting for input. This reformat greatly
simplifies the code and is more in line with the common way
to implement this feature.
As a side effect now we don't need anymore Makefile tricks
with sleep() to allow profile builds.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
After a "stop" due to a ponder miss Xboard sends
immediately the new position to search, without
waiting for engine to effectively stop the search.
It is not clear if this is a GUI bug (as I suspect)
or allowed behaviour, but because it won't be fixed
anyway workaround this issue making listener thread
to switch to in-sync mode as soon as a "stop" command
is received.
Thanks to Mike Whiteley for reporting this.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
The timer will be fired asynchronously to handle
time management flags, while other threads are
searching.
This implementation uses a thread waiting on a
timed condition variable instead of real timers.
This approach allow to reduce platform dependant
code to a minimum and also is the most portable given
that timers libraries are very different among platforms
and also the best ones are not compatible with olds
Windows.
Also retire the now unused polling code.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Instead of polling for input use a dedicated listener
thread to read commands from the GUI independently
from other threads.
To do this properly we have to delegate to the listener
all the reading from the GUI: while searching but also
while waiting for a command, like in std::getline().
So we have two possible behaviours: in-sync mode, in which
the thread mimics std::getline() and the caller blocks until
something is read from GUI, and async mode where the listener
continuously reads and processes GUI commands while other
threads are searching.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Build broken by commit 3141490374
where we renamed move_is_ok() in is_ok() and this clashes
with the same named method in Position that overrides the
move's one causing compile errors.
The fix is to rename the method in Position.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
It seems we have a very rare crash under Linux, once
every 10K games without this patch.
Is faster to wake up all the threads, especially on SMP,
where the threads can then exit in parallel while the main
thread is waiting for the next one to terminate.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Now that we have just two mutually exclusive thread's states
we can repleace them by a simple boolean.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Allocation of pawn and material hash tables should
be strictly bounded to the change of the number of
activeThreads, so move the code inside set_size().
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Use proper way to detect for thread terimnation instead of
our homegrown flag.
It adds more code than it removes and adds also platform specific
code, neverthless I think is the way to go becuase Thread::TERMINATED
flag is intrinsecly racy given that when we raise it thread is still
_not_ terminated nor it can be, and also we don't want to reinvent
the (broken) wheel of thread termination detection when there is
already available the proper one.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Was used to prevent issues when creating multiple threads
on Windows, but now it seems we can remove it safely.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
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>
When calling split or we immediately return because unable to
find available slaves, or we start searching on _all_ the moves
of the node or until a cut-off occurs, so that when returning
from split we immediately leave the moves loop.
Because of this we don't need to change alpha inside split() and
we can use a signature similar to search() so to better clarify
that split() is actually a search on the remaining node's moves.
No functional change with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Allocate and initialize a new split point
out of lock becuase modified data is local to
master thread only.
Also better document why we need a lock at
the end of split().
No functional change with faked split.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Another great success by Joona !
After 5876 games at 10"+0.1
Mod vs Orig: 1073 - 849 - 3954 ELO +13 (+- 5.2)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
