[Opalvoip-svn] SF.net SVN: opalvoip:[21345] ptlib/trunk/src/ptlib/unix/tlibthrd.cxx

[<hfr...@us...>]

Revision: 21345
          http://opalvoip.svn.sourceforge.net/opalvoip/?rev=21345&view=rev
Author:   hfriederich
Date:     2008-10-15 22:18:46 +0000 (Wed, 15 Oct 2008)

Log Message:
-----------
Fix another deadlock occurring when calling PTRACE while
process.activeThreads is locked

Modified Paths:
--------------
    ptlib/trunk/src/ptlib/unix/tlibthrd.cxx

Modified: ptlib/trunk/src/ptlib/unix/tlibthrd.cxx
===================================================================
--- ptlib/trunk/src/ptlib/unix/tlibthrd.cxx	2008-10-15 11:46:05 UTC (rev 21344)
+++ ptlib/trunk/src/ptlib/unix/tlibthrd.cxx	2008-10-15 22:18:46 UTC (rev 21345)
@@ -127,11 +127,23 @@
     process.breakBlock.Wait(delay);
 
     process.activeThreadMutex.Wait();
-    for (PINDEX i = 0; i < process.activeThreads.GetSize(); ++i) {
-      PThread & thread = process.activeThreads.GetDataAt(i);
-      if (thread.autoDelete && thread.IsTerminated())
-        delete process.activeThreads.RemoveAt(process.activeThreads.GetKeyAt(i));
-    }
+    PBoolean found;
+    do {
+      found = PFalse;
+      for (PINDEX i = 0; i < process.activeThreads.GetSize(); ++i) {
+        PThread & thread = process.activeThreads.GetDataAt(i);
+        if (thread.autoDelete && thread.IsTerminated()) {
+          // unlock the activeThreadMutex to avoid deadlocks:
+          // if somewhere in the destructor a call to PTRACE() is made,
+          // which itself calls PThread::Current(), deadlocks are possible
+          process.activeThreadMutex.Signal();
+          delete process.activeThreads.RemoveAt(process.activeThreads.GetKeyAt(i));
+          process.activeThreadMutex.Wait();
+          found = PTrue;
+          break;
+        }
+      }
+    } while (found == PTrue); 
     process.activeThreadMutex.Signal();
 
     process.PXCheckSignals();


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