[PATCH] Cannot wait for user lock in sync_while_locked
keithp at keithp.com
Sat Mar 3 02:08:03 PST 2012
sync_while_locked grabs the user lock before performing the sync
operation. Telling InternalLockDisplay to wait for the user lock will
thus deadlock, so don't do that.
Signed-off-by: Keith Packard <keithp at keithp.com>
I don't know how this could ever have failed to deadlock --
sync_while_locked has called _XUserLockDisplay, and so locking_level
is non-zero. When _XInternalLockDisplay finds locking_level > 0, it
then calls _XDisplayLockWait, which is going to hang around for a
*very long time* as the lock is held by the current thread.
This patch fixes my application nicely, but I'd love to have someone
sanity check this...
src/XlibInt.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/XlibInt.c b/src/XlibInt.c
index a8f5d08..12b816f 100644
@@ -214,7 +214,7 @@ void sync_while_locked(Display *dpy)
- InternalLockDisplay(dpy, /* don't skip user locks */ 0);
+ InternalLockDisplay(dpy, /* skip user locks */ 1);
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