Fix thread destruction

Releasing a thread reference uses a mutex, which means the kernel
resources used for synchronization must be available until late during
the destruction process. For simplicity, merge __pthread_thread_dealloc
into __pthread_thread_terminate.

* Makefile (libpthread-routines): Remove pt-thread-dealloc.
* pthread/pt-create.c (__pthread_create_internal): Remove call to
__pthread_thread_dealloc.
* pthread/pt-exit.c (__pthread_exit): Likewise.
* pthread/pt-internal.h (__pthread_thread_dealloc): Remove declaration.
(__pthread_thread_terminate): Update description.
* sysdeps/mach/pt-thread-dealloc.c: Remove file.
* sysdeps/mach/pt-thread-terminate.c (__pthread_thread_terminate):
Destroy the wake up port.

6 files changed, 10 insertions, 53 deletions

diff --git a/Makefile b/Makefile
index 61e59fc..8ef990e 100644
--- a/Makefile
+++ b/Makefile
@@ -119,7 +119,6 @@ libpthread-routines := pt-attr pt-attr-destroy pt-attr-getdetachstate	    \
 									    \
 	pt-stack-alloc							    \
 	pt-thread-alloc							    \
-	pt-thread-dealloc						    \
 	pt-thread-start							    \
 	pt-thread-terminate						    \
 	pt-startup							    \
diff --git a/pthread/pt-create.c b/pthread/pt-create.c
index 99d1b47..5358b08 100644
--- a/pthread/pt-create.c
+++ b/pthread/pt-create.c
@@ -217,7 +217,6 @@ __pthread_create_internal (struct __pthread **thread,
   pthread->tcb = NULL;
  failed_thread_tls_alloc:
 #endif /* ENABLE_TLS */
-  __pthread_thread_dealloc (pthread);
   __pthread_thread_terminate (pthread);
 
   /* __pthread_thread_terminate has taken care of deallocating the stack and
diff --git a/pthread/pt-exit.c b/pthread/pt-exit.c
index ea61732..6d827db 100644
--- a/pthread/pt-exit.c
+++ b/pthread/pt-exit.c
@@ -98,15 +98,11 @@ __pthread_exit (void *status)
   /* Destroy any signal state.  */
   __pthread_sigstate_destroy (self);
 
-  /* Kernel resources may be used to implement synchronization objects,
-     release them late.  */
-  __pthread_thread_dealloc (self);
-
   /* Self terminating requires TLS, so defer the release of the TCB until
      the thread structure is reused.  */
 
-  /* Terminate the kernel thread, release the stack and drop the
-     self reference.  */
+  /* Release kernel resources, including the kernel thread and the stack,
+     and drop the self reference.  */
   __pthread_thread_terminate (self);
 
   /* NOTREACHED */
diff --git a/pthread/pt-internal.h b/pthread/pt-internal.h
index 9747f1f..7465761 100644
--- a/pthread/pt-internal.h
+++ b/pthread/pt-internal.h
@@ -245,14 +245,12 @@ extern int __pthread_setup (struct __pthread *__restrict thread,
    resources) for THREAD; it must not be placed on the run queue.  */
 extern int __pthread_thread_alloc (struct __pthread *thread);
 
-/* Deallocate any kernel resources associated with THREAD.  */
-extern void __pthread_thread_dealloc (struct __pthread *thread);
-
 /* Start THREAD making it eligible to run.  */
 extern int __pthread_thread_start (struct __pthread *thread);
 
 /* Terminate the kernel thread associated with THREAD, and deallocate its
-   stack.  In addition, THREAD loses one reference.
+   stack as well as any other kernel resource associated with it.
+   In addition, THREAD looses one reference.
 
    This function can be called by any thread, including the target thread.
    Since some resources that are destroyed along the kernel thread are
diff --git a/sysdeps/mach/pt-thread-dealloc.c b/sysdeps/mach/pt-thread-dealloc.c
deleted file mode 100644
index e977c3f..0000000
--- a/sysdeps/mach/pt-thread-dealloc.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/* Deallocate the kernel thread resources.  Mach version.
-   Copyright (C) 2005 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Library General Public License as
-   published by the Free Software Foundation; either version 2 of the
-   License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Library General Public License for more details.
-
-   You should have received a copy of the GNU Library General Public
-   License along with the GNU C Library; see the file COPYING.LIB.  If not,
-   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
-#include <assert.h>
-#include <errno.h>
-#include <mach.h>
-
-#include <pt-internal.h>
-
-/* Deallocate any kernel resources associated with THREAD except don't
-   terminate the thread itself.  */
-void
-__pthread_thread_dealloc (struct __pthread *thread)
-{
-  /* Why no assert?  Easy.  When Mach kills a task, it starts by
-     invalidating the task port and then terminating the threads one
-     by one.  But while it is terminating them, they are still
-     eligible to be scheduled.  Imagine we have two threads, one calls
-     exit, one calls pthread_exit.  The second one may run this after
-     the mask port can been destroyed thus gratuitously triggering the
-     assert.  */
-  __mach_port_destroy (__mach_task_self (),
-		       thread->wakeupmsg.msgh_remote_port);
-}
diff --git a/sysdeps/mach/pt-thread-terminate.c b/sysdeps/mach/pt-thread-terminate.c
index b9d08fc..6672065 100644
--- a/sysdeps/mach/pt-thread-terminate.c
+++ b/sysdeps/mach/pt-thread-terminate.c
@@ -32,7 +32,7 @@ void
 __pthread_thread_terminate (struct __pthread *thread)
 {
   thread_t kernel_thread, self_ktid;
-  mach_port_t reply_port;
+  mach_port_t wakeup_port, reply_port;
   void *stackaddr;
   size_t stacksize;
   error_t err;
@@ -50,6 +50,8 @@ __pthread_thread_terminate (struct __pthread *thread)
       stacksize = 0;
     }
 
+  wakeup_port = thread->wakeupmsg.msgh_remote_port;
+
   /* Each thread has its own reply port, allocated from MiG stub code calling
      __mig_get_reply_port.  Destroying it is a bit tricky because the calls
      involved are also RPCs, causing the creation of a new reply port if
@@ -64,6 +66,9 @@ __pthread_thread_terminate (struct __pthread *thread)
   /* Finally done with the thread structure.  */
   __pthread_dealloc (thread);
 
+  /* The wake up port is now no longer needed.  */
+  __mach_port_destroy (__mach_task_self (), wakeup_port);
+
   /* Terminate and release all that's left.  */
   err = __thread_terminate_release (kernel_thread, mach_task_self (),
 				    kernel_thread, reply_port,