[cairo-commit] src/cairoint.h

Carl Worth cworth at kemper.freedesktop.org
Thu Mar 1 23:51:59 PST 2007


 src/cairoint.h |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletion(-)

New commits:
diff-tree d48bb4fbe876a93199ba48fcf5f32734fbe18ba9 (from df2d42ac7fb71997abd406fb5716c0bd85037c04)
Author: Carl Worth <cworth at cworth.org>
Date:   Thu Mar 1 23:34:34 2007 -0800

    Implement CAIRO_MUTEX_INIT with memcpy instead of pthread_mutex_init
    
    The trick here is that with the weak symbol support for pthreads,
    pthread_mutex_init can be a NOP leaving the mutex uninitialized.
    Then, if some pthread-using library is dynamically loaded, the
    non-NOP pthread functions get used and we end up trying to lock
    an uninitialized mutex.
    
    This should fix the bugs reported here:
    
    	Cairo 1.3.14 deadlocks in cairo_scaled_font_glyph_extents or _cairo_ft_unscaled_font_lock_face
    	https://bugs.freedesktop.org/show_bug.cgi?id=10035

diff --git a/src/cairoint.h b/src/cairoint.h
index 890929f..3a2d845 100755
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -141,7 +141,10 @@ CAIRO_BEGIN_DECLS
 # define CAIRO_MUTEX_LOCK(name) pthread_mutex_lock (&name)
 # define CAIRO_MUTEX_UNLOCK(name) pthread_mutex_unlock (&name)
 typedef pthread_mutex_t cairo_mutex_t;
-# define CAIRO_MUTEX_INIT(mutex) pthread_mutex_init ((mutex), NULL)
+#define CAIRO_MUTEX_INIT(mutex) do {				\
+    pthread_mutex_t tmp_mutex = PTHREAD_MUTEX_INITIALIZER;      \
+    memcpy (mutex, &tmp_mutex, sizeof (tmp_mutex));             \
+} while (0)
 # define CAIRO_MUTEX_FINI(mutex) pthread_mutex_destroy (mutex)
 # define CAIRO_MUTEX_NIL_INITIALIZER PTHREAD_MUTEX_INITIALIZER
 #endif


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