Marco Costalba [Wed, 7 Dec 2011 06:45:44 +0000 (07:45 +0100)]
Retire all extensions (but checks) for non-PV nodes
It seems we don't have any added value. Note that the
moves that were used to be extended are still flagged
as dangerous so to avoid at least pruning them.
After 9555 games
Mod vs Orig 1562 - 1540 - 6453 ELO +0 (+- 4)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sat, 3 Dec 2011 09:54:44 +0000 (10:54 +0100)]
Don't disable IO buffering at startup
It was never clear to me why we needed this trick, and now
that we rely only on C++ std::getline() and std::cout for
input / output it is even more a mistery what this code does.
So disable it and wait to see if someone screams ;-)
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sun, 27 Nov 2011 16:07:17 +0000 (17:07 +0100)]
Detach search arguments from UI thread
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>
Marco Costalba [Sun, 27 Nov 2011 11:16:23 +0000 (12:16 +0100)]
After a "stop" do not read new input until search finishes
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>
Marco Costalba [Wed, 23 Nov 2011 19:07:29 +0000 (20:07 +0100)]
Rewrite async I/O
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>
Marco Costalba [Sat, 19 Nov 2011 10:30:32 +0000 (11:30 +0100)]
Don't check for early stop when StopOnPonderhit is set
If we are pondering we will stop the search only when
GUI sends "ponderhit" or "stop" commands or when we reach
maximum depth. In all the other cases we continue to search
so there is no need to verify for available time.
Also better clarify why wait_for_stop_or_ponderhit() before
to exit in some cases.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sat, 8 Oct 2011 12:01:18 +0000 (13:01 +0100)]
Rewrite early stop logic
In the "easy move" paradigm we verify if the best move has
ever changed over a good number of iterations and if the
biggest part of the searched nodes are consumed on it.
This is a kind of hacky ad indirect heuristic to deduce
if one move is much better than others.
Rewrite the early stop condition to verify directly if one
move is much better than others performing an exclusion
search.
Idea to use exclusion search for time management if form Critter.
After 12245 games at 30"+0.1
Mod vs Orig 1776 - 1775 - 8694 ELO +0 (+-3.4)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sat, 12 Nov 2011 09:10:01 +0000 (10:10 +0100)]
Rewrite link time optimization in Makefile
Instead of binding link time optimization to the choice of
popcount support, do the right thing and add -flto option
when gcc 4.5 or later is detected.
Although it should be supported also under mingw, it happens
that it doesn't, at least on my 4.6.1 due to some known bugs.
Thanks to Mike for helping me with this patch.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Thu, 10 Nov 2011 08:20:41 +0000 (09:20 +0100)]
Fix regression: engine hangs while pondering
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>
Marco Costalba [Wed, 9 Nov 2011 04:03:46 +0000 (05:03 +0100)]
Another fix to profile-build on gcc 4.6
Oliver reports profile builds error with new gcc 4.6, he says:
"We need to add -lgov with profile-generate AND profile-use.
So it has to be added to the second stage of building too.
The problem occurred first with the introduction of gcc4.6 and
I think this is because the previous version did find the gcov
library automatically. gcc4.6 needs more precise options and
does less guesses. I have seen it in debian, Ubuntu and also with
mingw on Windows. And all use gcc4.6."
This patch fixes the issue.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Tue, 8 Nov 2011 06:34:44 +0000 (07:34 +0100)]
Fix profile-build
After async I/O patches 'bench' changed behaviour and now waits for
input at the end of the test run. This is due to listener thread stay
blocked on std::getline() even after test run is finished, as soon as
we feed something the thread unblocks and then quickly exits.
This is not a big problem, but has the bad side effect of breaking
profile builds that hang forever at the end of the test run.
The tricky workaround is to create a pipe that connects to stockfish
input and then, when test run is finished, breaking the pipe: this
makes std::getline() immediately return.
So this patch adds a 'sleep 10' piped into 'stockfish bench' test run
command. After 10 seconds sleep ends, the pipe breaks and 'bench'
finishes as usual.
Thanks to Oliver Korff for reporting the issue, and to Mike Whiteley
for having co-authored this solution.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sun, 6 Nov 2011 10:59:07 +0000 (11:59 +0100)]
Better define wait_for_stop_or_ponderhit()
Use do_uci_async_cmd() instead of process input commands
directly and clarify that what we are waiting for is
something that is able to raise StopRequest flag.
Also fix some stale comments in do_uci_async_cmd(). Here
we need to reset Limits.ponder only upon receiving "ponderhit".
In the case of "quit" or "stop" resetting Limits.ponder has no
effect because the search is going to be stopped anyway.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sat, 5 Nov 2011 10:19:21 +0000 (11:19 +0100)]
Use a timer to avoid polling
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>
Marco Costalba [Sat, 5 Nov 2011 06:53:19 +0000 (07:53 +0100)]
Rewrite how commands from GUI are read
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>
Marco Costalba [Sun, 30 Oct 2011 10:26:06 +0000 (11:26 +0100)]
Sync do_move() and undo_move()
It is not possible to unify due to the fact that the
sequence steps are reversed. What we can do is to try
to sync comments and code as much as we can to easy
reading and documentation.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Sun, 16 Oct 2011 22:56:25 +0000 (23:56 +0100)]
Fix compile error in debug mode
Build broken by commit 3141490374182551ed2
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>
Marco Costalba [Sun, 9 Oct 2011 07:22:13 +0000 (08:22 +0100)]
Link Time Optimization doesn't needs -static
Justin reports that it breaks the compilation on Fedore 15 and as Tom says:
-static is only needed to work around the gcc on ubuntu 11.10 beta bug.
If -static introduces issues on its own then it is better to remove it.
It will not be needed in most environments.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Also unify flto, popcount and msse3 optimization under "modern"
target, note that this can break the "modern" build on old gcc that
do not support -flto option: in this case update gcc ;-) or default
to the standard build.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Mon, 26 Sep 2011 05:07:11 +0000 (06:07 +0100)]
When exiting wake up all threads at once
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>
Marco Costalba [Fri, 12 Aug 2011 08:53:32 +0000 (10:53 +0200)]
Fix silly icc remark #2259
Another stupid remark to quiet out:
remark #2259: non-pointer conversion from "int" to "UINT16={unsigned short}"
may lose significant bits
In this case icc always converts to an integer the result of a shift operation
if the bit size of the operand is smaller, hence the warning when assignin
back to n.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Thu, 4 Aug 2011 13:14:56 +0000 (14:14 +0100)]
Retire Rml full PV search at depth == 1
Now that Rml ordering is based on normal MovePicker logic,
apart for the ttMove that is given, we can avoid to score
all the root moves at depth 1. We only need it for easy move
detection logic, but in this case we just need to score the
first two best moves and not all the Rml set.
No regression after 6400 games
Mod vs Orig 1052 1012 4336 ELO +2 (+- 4.9)
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
Marco Costalba [Mon, 8 Aug 2011 22:07:09 +0000 (23:07 +0100)]
Retire ThreadsManager::init_hash_tables()
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>
Marco Costalba [Mon, 8 Aug 2011 20:25:37 +0000 (21:25 +0100)]
Retire Thread::TERMINATED
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>
Marco Costalba [Mon, 8 Aug 2011 09:08:41 +0000 (10:08 +0100)]
Retire broken SendSearchedNodes
Now that we can split at root it happens that SendSearchedNodes
works only once at the end of the iteration, but this is useless
becuase speed info is sent anyhow toghter with the pv line.
So retire for now, waiting to find something SMP compatible.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>