* pthread.cc (pthread_mutex::_unlock): Avoid unlocking a mutex if the

recursion_counter is already 0.
(pthread_mutex::_destroy): Don't consider a mutex busy if its recursion_counter
== 0.
(pthread_mutex::_fixup_after_fork): Set recursion_counter to 0 to flag that
we've just forked.  Don't reset the owner of this mutex since the forkee may
think it still owns the mutex.  Reinstate initialization of win32_obj_id.
* fhandler_floppy.cc (fhandler_dev_floppy::raw_read): Initialize a variable to
bypass a C++ warning.

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 5e3ee1c..5e7870a 100644 (file)
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,17 @@
+2008-11-07  Christopher Faylor  <me+cygwin@cgf.cx>
+
+       * pthread.cc (pthread_mutex::_unlock): Avoid unlocking a mutex if the
+       recursion_counter is already 0.
+       (pthread_mutex::_destroy): Don't consider a mutex busy if its
+       recursion_counter == 0.
+       (pthread_mutex::_fixup_after_fork): Set recursion_counter to 0 to flag
+       that we've just forked.  Don't reset the owner of this mutex since the
+       forkee may think it still owns the mutex.  Reinstate initialization of
+       win32_obj_id.
+
+       * fhandler_floppy.cc (fhandler_dev_floppy::raw_read): Initialize a
+       variable to bypass a C++ warning.
+
 2008-11-05  Corinna Vinschen  <corinna@vinschen.de>
 
        * environ.cc (environ_init): Avoid evaluating $CYGWIN twice.

diff --git a/winsup/cygwin/fhandler_floppy.cc b/winsup/cygwin/fhandler_floppy.cc
index 9e19b52..1357515 100644 (file)
--- a/winsup/cygwin/fhandler_floppy.cc
+++ b/winsup/cygwin/fhandler_floppy.cc
@@ -245,7 +245,7 @@ fhandler_dev_floppy::raw_read (void *ptr, size_t& ulen)
 {
   DWORD bytes_read = 0;
   DWORD read2;
-  DWORD bytes_to_read;
+  DWORD bytes_to_read = 0;
   int ret;
   size_t len = ulen;
   char *tgt;

diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 24f4adc..ecf9287 100644 (file)
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -1637,13 +1637,15 @@ pthread_mutex::_unlock (pthread_t self)
   if (!pthread::equal (owner, self))
     return EPERM;
 
-  if (--recursion_counter == 0)
+  /* Don't try to unlock anything if recursion_counter == 0 initially.
+     That means that we've forked. */
+  if (recursion_counter > 0 && --recursion_counter == 0)
     {
       owner = NULL;
 #ifdef DEBUGGING
       tid = 0;
 #endif
-      if (InterlockedDecrement ((long *)&lock_counter))
+      if (InterlockedDecrement ((long *) &lock_counter))
        // Another thread is waiting
        ::ReleaseSemaphore (win32_obj_id, 1, NULL);
     }
@@ -1657,10 +1659,10 @@ pthread_mutex::_destroy (pthread_t self)
   if (condwaits || _trylock (self))
     // Do not destroy a condwaited or locked mutex
     return EBUSY;
-  else if (recursion_counter != 1)
+  else if (recursion_counter > 1)
     {
       // Do not destroy a recursive locked mutex
-      --recursion_counter;
+      recursion_counter--;
       return EBUSY;
     }
 
@@ -1671,19 +1673,20 @@ pthread_mutex::_destroy (pthread_t self)
 void
 pthread_mutex::_fixup_after_fork ()
 {
-  debug_printf ("mutex %x in _fixup_after_fork", this);
+  debug_printf ("mutex %p in _fixup_after_fork", this);
   if (pshared != PTHREAD_PROCESS_PRIVATE)
     api_fatal ("pthread_mutex::_fixup_after_fork () doesn't understand PROCESS_SHARED mutex's");
 
   /* All waiting threads are gone after a fork */
+  recursion_counter = 0;
   lock_counter = 0;
-  owner = NULL;
-  win32_obj_id = NULL;
   condwaits = 0;
 #ifdef DEBUGGING
-  tid = 0xffffffff;        /* Don't know the tid after a fork */
+  tid = 0xffffffff;    /* Don't know the tid after a fork */
 #endif
-
+  win32_obj_id = ::CreateSemaphore (&sec_none_nih, 0, LONG_MAX, NULL);
+  if (!win32_obj_id)
+    api_fatal ("pthread_mutex::_fixup_after_fork () failed to recreate win32 semaphore for mutex");
 }
 
 pthread_mutexattr::pthread_mutexattr ():verifyable_object (PTHREAD_MUTEXATTR_MAGIC),
@@ -2925,7 +2928,7 @@ semaphore::semaphore (unsigned long long shash, LUID sluid, int sfd,
 {
   char name[MAX_PATH];
 
-  __small_sprintf (name, "semaphore/%016X%08x%08x", 
+  __small_sprintf (name, "semaphore/%016X%08x%08x",
                   hash, luid.HighPart, luid.LowPart);
   this->win32_obj_id = ::CreateSemaphore (&sec_all, value, LONG_MAX, name);
   if (!this->win32_obj_id)