''

2 files changed, 123 insertions, 103 deletions

diff --git a/manual/pthread_key_create.html b/manual/pthread_key_create.html
index 9d9e004..5ecca69 100644
--- a/manual/pthread_key_create.html
+++ b/manual/pthread_key_create.html
@@ -5,7 +5,7 @@
 	<TITLE>PTHREAD_SPECIFIC(3) manual page</TITLE>
 	<META NAME="GENERATOR" CONTENT="OpenOffice.org 1.1.3  (Linux)">
 	<META NAME="CREATED" CONTENT="20050504;18425400">
-	<META NAME="CHANGED" CONTENT="20050505;18330000">
+	<META NAME="CHANGED" CONTENT="20050509;18220200">
 	<!-- manual page source format generated by PolyglotMan v3.2, -->
 	<!-- available at http://polyglotman.sourceforge.net/ -->
 </HEAD>
@@ -60,9 +60,9 @@ in all currently executing threads.
 a destructor function associated with the key. When a thread
 terminates via <B>pthread_exit</B> or by cancellation, <I>destr_function</I>
 is called with arguments the value associated with the key in that
-thread. The <I>destr_function</I> is not called if that value is
-<B>NULL</B>. The order in which destructor functions are called at
-thread termination time is unspecified. 
+thread. The <I>destr_function</I> is not called if that value is <B>NULL</B><SPAN STYLE="font-weight: medium">
+or the key has been deleted</SPAN>. The order in which destructor
+functions are called at thread termination time is unspecified. 
 </P>
 <P>Before the destructor function is called, the <B>NULL</B> value is
 associated with the key in the current thread. A destructor function
@@ -70,11 +70,7 @@ might, however, re-associate non- <B>NULL</B> values to that key or
 some other key. To deal with this, if after all the destructors have
 been called for all non- <B>NULL</B> values, there are still some
 non- <B>NULL</B> values with associated destructors, then the process
-is repeated. The <B>Pthreads-w32</B> implementation stops the process after
-<B>PTHREAD_DESTRUCTOR_ITERATIONS</B> iterations, even if some non-
-<B>NULL</B> values with associated descriptors remain. Other
-implementations may loop indefinitely. 
-</P>
+is repeated.</P>
 <P><B>pthread_key_delete</B> deallocates a TSD key. It does not check
 whether non- <B>NULL</B> values are associated with that key in the
 currently executing threads, nor call the destructor function
@@ -86,6 +82,24 @@ in the calling thread, storing the given <I>pointer</I> instead.
 <P><B>pthread_getspecific</B> returns the value currently associated
 with <I>key</I> in the calling thread. 
 </P>
+<P>The routines <B>pthread_setspecific</B>, <B>pthread_getspecific</B>,
+and <B>pthread_key_delete</B> can be called from <I>destr_function</I>
+targeting any valid key including the key on which <I>destr_function</I>
+is currently operating. If <B>pthread_getspecific</B> is called on
+the key whose thread specific data is being destroyed, the value NULL
+is returned, unless <B>pthread_setspecific</B> was called previously
+on that key from within <I>destr_function</I> to set the value to
+non-NULL. For some implementations the effect of calling
+<B>pthread_setspecific</B> from within <I>destr_function</I> can be
+either memory leakage or infinite loops if <I>destr_function</I> has
+already been called at least <B>PTHREAD_DESTRUCTOR_ITERATIONS</B>
+times.</P>
+<P STYLE="font-weight: medium"><B>Pthreads-w32</B> stops running key
+<I>destr_function</I> routines after <B>PTHREAD_DESTRUCTOR_ITERATIONS</B>
+iterations, even if some non- <B>NULL</B> values with associated
+descriptors remain. If memory is allocated and associated with a key
+from within <I>destr_function</I>, that memory may not be reclaimed
+because that key's <I>destr_function</I>, may not run again.</P>
 <H2><A HREF="#toc3" NAME="sect3">Return Value</A></H2>
 <P><B>pthread_key_create</B>, <B>pthread_key_delete</B>, and
 <B>pthread_setspecific</B> return 0 on success and a non-zero error
@@ -105,7 +119,7 @@ error:
 		<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>EAGAIN</B> 
 		</DT></DL>
 </DL>
-<BLOCKQUOTE STYLE="margin-left: 3cm">
+<BLOCKQUOTE STYLE="margin-left: 5cm">
 <B>PTHREAD_KEYS_MAX</B> keys are already allocated 
 </BLOCKQUOTE>
 <DL>
@@ -113,7 +127,7 @@ error:
 		<DT STYLE="margin-right: 1cm; margin-bottom: 0.5cm"><B>ENOMEM</B> 
 		</DT></DL>
 </DL>
-<BLOCKQUOTE STYLE="margin-left: 3cm">
+<BLOCKQUOTE STYLE="margin-left: 5cm">
 Insufficient memory to allocate the key. 
 </BLOCKQUOTE>
 <P><B>pthread_key_delete</B> and <B>pthread_setspecific</B> return
@@ -171,8 +185,8 @@ static void buffer_destroy(void * buf)
   free(buf);
 }</PRE>
 <HR>
-<BLOCKQUOTE STYLE="margin-left: 0cm"><A NAME="toc"></A><B>Table of
-Contents</B></BLOCKQUOTE>
+<BLOCKQUOTE STYLE="margin-left: 0cm; margin-right: 0cm"><A NAME="toc"></A>
+<B>Table of Contents</B></BLOCKQUOTE>
 <UL>
 	<LI><BLOCKQUOTE STYLE="margin-bottom: 0cm"><A HREF="#sect0" NAME="toc0">Name</A>
 		</BLOCKQUOTE>
@@ -194,4 +208,4 @@ Contents</B></BLOCKQUOTE>
 	</BLOCKQUOTE>
 </UL>
 </BODY>
-</HTML>
+</HTML>
\ No newline at end of file
diff --git a/ptw32_callUserDestroyRoutines.c b/ptw32_callUserDestroyRoutines.c
index cdec87e..a583f18 100644
--- a/ptw32_callUserDestroyRoutines.c
+++ b/ptw32_callUserDestroyRoutines.c
@@ -77,10 +77,6 @@ ptw32_callUserDestroyRoutines (pthread_t thread)
        * for the current thread.
        *
        * Do this process at most PTHREAD_DESTRUCTOR_ITERATIONS times.
-       *
-       * First we need to serialise with pthread_key_delete by locking
-       * both assoc guards, but in the reverse order to normal, and so
-       * we must be careful to avoid deadlock.
        */
       do
 	{
@@ -89,125 +85,135 @@ ptw32_callUserDestroyRoutines (pthread_t thread)
 
 	  (void) pthread_mutex_lock(&(sp->threadLock));
 	  /*
-	   * The next assoc pointer is stored in the thread struct so that
+	   * The pointer to the next assoc is stored in the thread struct so that
 	   * the assoc destructor in pthread_key_delete can adjust it
 	   * if it deletes this assoc. This can happen if we fail to acquire
 	   * both locks below, and are forced to release all of our locks,
-	   * leaving open the opportunity.
+	   * leaving open the opportunity for pthread_key_delete to get in
+	   * before us.
 	   */
 	  sp->nextAssoc = sp->keys;
 	  (void) pthread_mutex_unlock(&(sp->threadLock));
 
-      for (;;)
-	{
-	  void * value;
-	  pthread_key_t k;
-	  void (*destructor) (void *);
-
-	  (void) pthread_mutex_lock(&(sp->threadLock));
-
-	  if ((assoc = (ThreadKeyAssoc *)sp->nextAssoc) == NULL)
-	    {
-	      /* Finished */
-	      pthread_mutex_unlock(&(sp->threadLock));
-	      break;
-	    }
-	  else
+	  for (;;)
 	    {
+	      void * value;
+	      pthread_key_t k;
+	      void (*destructor) (void *);
+
 	      /*
-	       * assoc->key must be valid because assoc can't change or be
-	       * removed from our chain while we hold at least one lock. If
-	       * the assoc was on our key chain then the key has not been
-	       * deleted yet.
-	       *
-	       * Try to acquire both locks without deadlocking.
+	       * First we need to serialise with pthread_key_delete by locking
+	       * both assoc guards, but in the reverse order to our convention,
+	       * so we must be careful to avoid deadlock.
 	       */
-	      if (pthread_mutex_trylock(&(assoc->key->keyLock)) == EBUSY)
+	      (void) pthread_mutex_lock(&(sp->threadLock));
+
+	      if ((assoc = (ThreadKeyAssoc *)sp->nextAssoc) == NULL)
 		{
+		  /* Finished */
 		  pthread_mutex_unlock(&(sp->threadLock));
-		  Sleep(1); // Ugly.
+		  break;
+		}
+	      else
+		{
 		  /*
-		   * Go around again.
-		   * If pthread_key_delete has removed this assoc in the meantime,
-		   * sp->keys will point to a new assoc.
+		   * assoc->key must be valid because assoc can't change or be
+		   * removed from our chain while we hold at least one lock. If
+		   * the assoc was on our key chain then the key has not been
+		   * deleted yet.
+		   *
+		   * Now try to acquire the second lock without deadlocking.
+		   * If we fail, we need to relinquish the first lock and the
+		   * processor and then try to acquire them all again.
 		   */
-		  continue;
+		  if (pthread_mutex_trylock(&(assoc->key->keyLock)) == EBUSY)
+		    {
+		      pthread_mutex_unlock(&(sp->threadLock));
+		      Sleep(1); // Ugly but necessary to avoid priority effects.
+		      /*
+		       * Go around again.
+		       * If pthread_key_delete has removed this assoc in the meantime,
+		       * sp->nextAssoc will point to a new assoc.
+		       */
+		      continue;
+		    }
 		}
-	    }
-
-	  /* We now hold both locks */
 
-	   sp->nextAssoc = assoc->nextKey;
+	      /* We now hold both locks */
 
-	  /*
-	   * Key still active; pthread_key_delete
-	   * will block on these same mutexes before
-	   * it can release actual key; therefore,
-	   * key is valid and we can call the destroy
-	   * routine;
-	   */
-	  k = assoc->key;
-	  destructor = k->destructor;
-	  value = TlsGetValue(k->key);
-	  TlsSetValue (k->key, NULL);
+	      sp->nextAssoc = assoc->nextKey;
 
-	  // Every assoc->key exists and has a destructor
-	  if (value != NULL && iterations <= PTHREAD_DESTRUCTOR_ITERATIONS)
-	    {
 	      /*
-	       * Unlock both locks before the destructor runs.
-	       * POSIX says pthread_key_delete can be run from destructors,
-	       * and that probably includes with this key as target.
+	       * Key still active; pthread_key_delete
+	       * will block on these same mutexes before
+	       * it can release actual key; therefore,
+	       * key is valid and we can call the destroy
+	       * routine;
 	       */
-	      (void) pthread_mutex_unlock(&(sp->threadLock));
-	      (void) pthread_mutex_unlock(&(k->keyLock));
+	      k = assoc->key;
+	      destructor = k->destructor;
+	      value = TlsGetValue(k->key);
+	      TlsSetValue (k->key, NULL);
+
+	      // Every assoc->key exists and has a destructor
+	      if (value != NULL && iterations <= PTHREAD_DESTRUCTOR_ITERATIONS)
+		{
+		  /*
+		   * Unlock both locks before the destructor runs.
+		   * POSIX says pthread_key_delete can be run from destructors,
+		   * and that probably includes with this key as target.
+		   * pthread_setspecific can also be run from destructors and
+		   * also needs to be able to access the assocs.
+		   */
+		  (void) pthread_mutex_unlock(&(sp->threadLock));
+		  (void) pthread_mutex_unlock(&(k->keyLock));
 
-	      assocsRemaining++;
+		  assocsRemaining++;
 
 #ifdef __cplusplus
 
-	      try
-		{
+		  try
+		    {
+		      /*
+		       * Run the caller's cleanup routine.
+		       */
+		      destructor (value);
+		    }
+		  catch (...)
+		    {
+		      /*
+		       * A system unexpected exception has occurred
+		       * running the user's destructor.
+		       * We get control back within this block in case
+		       * the application has set up it's own terminate
+		       * handler. Since we are leaving the thread we
+		       * should not get any internal pthreads
+		       * exceptions.
+		       */
+		      terminate ();
+		    }
+
+#else /* __cplusplus */
+
 		  /*
 		   * Run the caller's cleanup routine.
 		   */
 		  destructor (value);
+
+#endif /* __cplusplus */
+
 		}
-	      catch (...)
+	      else
 		{
 		  /*
-		   * A system unexpected exception has occurred
-		   * running the user's destructor.
-		   * We get control back within this block in case
-		   * the application has set up it's own terminate
-		   * handler. Since we are leaving the thread we
-		   * should not get any internal pthreads
-		   * exceptions.
+		   * Remove association from both the key and thread chains
+		   * and reclaim it's memory resources.
 		   */
-		  terminate ();
+		  ptw32_tkAssocDestroy (assoc);
+		  (void) pthread_mutex_unlock(&(sp->threadLock));
+		  (void) pthread_mutex_unlock(&(k->keyLock));
 		}
-
-#else /* __cplusplus */
-
-	      /*
-	       * Run the caller's cleanup routine.
-	       */
-	      destructor (value);
-
-#endif /* __cplusplus */
-
 	    }
-	  else
-	    {
-	      /*
-	       * Remove association from both the key and thread chains
-	       * and reclaim it's memory resources.
-	       */
-	      ptw32_tkAssocDestroy (assoc);
-	      (void) pthread_mutex_unlock(&(sp->threadLock));
-	      (void) pthread_mutex_unlock(&(k->keyLock));
-	    }
-	}
 	}
       while (assocsRemaining);
     }