HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-20 17:16:33 +08:00
Code Issues Packages Projects Releases Wiki Activity

Revert "Recursive lock"

Browse Source 
Joona says that sp_update_pv() does not pass the split point
boundaries, so there is no risk to corrupt data from another
split point. Also the race on thread_should_stop() is harmless
because of this.

So revert the patch and come back to single lock.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2010-02-20 23:56:02 +01:00
parent 2de2b76896
commit 13c096f839
1 changed files with 4 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/search.cpp
View File

@@ -1854,16 +1854,7 @@ namespace {
// New best move?
if (value > sp->bestValue) // Less then 2% of cases
{
// Recursive locking, lock current split point and its ancestors to
// guarantee thread_should_stop() and sp_update_pv() are race free.
SplitPoint* spChain[MAX_THREADS * ACTIVE_SPLIT_POINTS_MAX];
int cnt = 0;
for (spChain[cnt] = sp; spChain[cnt]; )
{
lock_grab(&(spChain[cnt++]->lock));
spChain[cnt] = spChain[cnt - 1]->parent;
}
lock_grab(&(sp->lock));
if (value > sp->bestValue && !TM.thread_should_stop(threadID))
{
sp->bestValue = value;
@@ -1873,10 +1864,7 @@ namespace {
sp_update_pv(sp->parentSstack, ss, sp->ply);
}
}
// Release locks in reverse order
while (cnt > 0)
lock_release(&(spChain[--cnt]->lock));
lock_release(&(sp->lock));
}
}
@@ -1975,16 +1963,7 @@ namespace {
// New best move?
if (value > sp->bestValue) // Less then 2% of cases
{
// Recursive locking, lock current split point and its ancestors to
// guarantee thread_should_stop() and sp_update_pv() are race free.
SplitPoint* spChain[MAX_THREADS * ACTIVE_SPLIT_POINTS_MAX];
int cnt = 0;
for (spChain[cnt] = sp; spChain[cnt]; )
{
lock_grab(&(spChain[cnt++]->lock));
spChain[cnt] = spChain[cnt - 1]->parent;
}
lock_grab(&(sp->lock));
if (value > sp->bestValue && !TM.thread_should_stop(threadID))
{
sp->bestValue = value;
@@ -2001,10 +1980,7 @@ namespace {
ss[sp->ply].mateKiller = move;
}
}
// Release locks in reverse order
while (cnt > 0)
lock_release(&(spChain[--cnt]->lock));
lock_release(&(sp->lock));
}
}