From: Christopher Faylor <me@cgf.cx>
Date: Wed, 22 Dec 2004 16:59:03 +0000 (+0000)
Subject: * pinfo.cc (proc_waiter): Zero wait_thread in child to avoid races with process
X-Git-Tag: binutils-2_16-branchpoint~268
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=9bc36097c9a1aaeb2665a5bb28c4b84246970f60;p=newlib-cygwin.git

* pinfo.cc (proc_waiter): Zero wait_thread in child to avoid races with process
termination.
* cygthread.cc (cygthread::terminate): Clumsily detect when h has gone away and
attempt no further action.
---

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 88148bf55..364f8c398 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,10 @@
+2004-12-22  Christopher Faylor  <cgf@timesys.com>
+
+	* pinfo.cc (proc_waiter): Zero wait_thread in child to avoid races with
+	process termination.
+	* cygthread.cc (cygthread::terminate): Clumsily detect when h has gone away
+	and attempt no further action.
+
 2004-12-22  Christopher Faylor  <cgf@timesys.com>
 
 	* cygthread.h (cygthread::release): Just declare here.
diff --git a/winsup/cygwin/cygthread.cc b/winsup/cygwin/cygthread.cc
index d20bf6853..80fc5e0cc 100644
--- a/winsup/cygwin/cygthread.cc
+++ b/winsup/cygwin/cygthread.cc
@@ -226,18 +226,33 @@ cygthread::release ()
 void
 cygthread::terminate_thread ()
 {
+  /* FIXME: The if (!h) stuff below should be handled better.  The
+     problem is that terminate_thread could be called while a thread
+     is terminating and either the thread could be handling its own
+     release or, if this is being called during exit, some other
+     thread may be attempting to free up this resource.  In the former
+     case, setting some kind of "I deal with my own exit" type of
+     flag may be the way to handle this. */
   if (!is_freerange)
     {
       ResetEvent (*this);
       ResetEvent (thread_sync);
     }
+  if (!h)
+    return;
   (void) TerminateThread (h, 0);
   (void) WaitForSingleObject (h, INFINITE);
+  if (!h)
+    return;
+
   CloseHandle (h);
 
-  while (!stack_ptr)
+  while (h && !stack_ptr)
     low_priority_sleep (0);
 
+  if (!h)
+    return;
+
   MEMORY_BASIC_INFORMATION m;
   memset (&m, 0, sizeof (m));
   (void) VirtualQuery (stack_ptr, &m, sizeof m);
diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc
index a26336c98..508ed5cb6 100644
--- a/winsup/cygwin/pinfo.cc
+++ b/winsup/cygwin/pinfo.cc
@@ -763,6 +763,7 @@ proc_waiter (void *arg)
     }
 
   sigproc_printf ("exiting wait thread for pid %d", pid);
+  vchild.wait_thread = NULL;
   _my_tls._ctinfo->release ();	/* return the cygthread to the cygthread pool */
   return 0;
 }