Changeset 320

Timestamp:

Mar 15, 2011, 8:59:48 PM (14 years ago)

Author:

katerina

Message:

Fix for ticket #237: Potential deadlock in sh_hash_hashdelete()

Location:

trunk

Files:

• include/sh_pthread.h (modified) (2 diffs)
• src/sh_hash.c (modified) (2 diffs)

trunk/include/sh_pthread.h

@@ -23 +23 @@
         do {                                                               \
                 int oldtype;                                               \
+                int executeStack = 1;                                      \
                 pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype);  \
                 pthread_cleanup_push(sh_pthread_mutex_unlock, (void*)&(M));\
                 pthread_mutex_lock(&(M))
 
+#define SH_MUTEX_TRYLOCK(M)                                                \
+        do {                                                               \
+                int oldtype;                                               \
+                int executeStack = 0;                                      \
+                pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype);  \
+                pthread_cleanup_push(sh_pthread_mutex_unlock, (void*)&(M));\
+                pthread_mutex_trylock(&(M));                               \
+                executeStack = 1
 
 #define SH_MUTEX_UNLOCK(M)                                                 \
-                pthread_cleanup_pop(1);                                    \
+                pthread_cleanup_pop(executeStack);                         \
                 pthread_setcanceltype(oldtype, NULL);                      \
         } while (0)
@@ -147 +156 @@
 #define SH_MUTEX_EXTERN(M)                      extern void *SH_MUTEX_DUMMY_ ## M
 #define SH_MUTEX_LOCK(M)                        ((void)0)
+#define SH_MUTEX_TRYLOCK(M)                     ((void)0)
 #define SH_MUTEX_UNLOCK(M)                      ((void)0)
 #define SH_MUTEX_LOCK_UNSAFE(M)                 ((void)0)

trunk/src/sh_hash.c

@@ -1554 +1554 @@
 
   SL_ENTER(_("sh_hash_hashdelete"));
-  SH_MUTEX_LOCK(mutex_hash);
+
+  /* need deadlock detection here if called from exit handler 
+   */
+  SH_MUTEX_TRYLOCK(mutex_hash);
 
   if (IsInit == 0) 
@@ -1570 +1573 @@
   ; /* 'label at end of compound statement */
   SH_MUTEX_UNLOCK(mutex_hash);
+
   SL_RET0(_("sh_hash_hashdelete"));
 }