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* dcrt0.cc (child_info_fork::alloc_stack_hard_way): Change sense of guard test.

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Increase size of stack reserved and increase size before the current stack
pointer.  Use pointers when doing arithmetic.
(dll_crt0_1): Initialize exception handler when we notice we're the child of a
fork from non-main thread.
* fork.cc (frok::parent): Make argument volatile.
(frok::child): Ditto.
(lock_signals): New class.
(lock_pthread): Ditto.
(hold_everhthing): Ditto.
(frok::parent): Move atforkprepare and atforkparent to lock_pthread class.
(fork): Make ischild boolean.  Use hold_everything variable within limited
scope to set various mutexes in such a way as to avoid deadlocks.
* thread.h (pthread_mutex::tid): New variable, active when debugging for
tracking thread id of owner.
(pthread_mutex::set_owner): Set tid when debugging.
* thread.cc (pthread_mutex::pthread_mutex): Clear tid.
(pthread_mutex::_unlock): Ditto when unlocking.
(pthread_mutex::fixup_after_fork): Set tid to special value after forking since
owner is unknown.
This commit is contained in:
Christopher Faylor
2007-02-22 12:34:55 +00:00
parent bd8f891e8a
commit 39fc0d36ae
5 changed files with 171 additions and 55 deletions
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33
winsup/cygwin/thread.cc
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@ -1,9 +1,7 @@
/* thread.cc: Locking and threading module functions
Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Red Hat, Inc.
Originally written by Marco Fuykschot <marco@ddi.nl>
Substantialy enhanced by Robert Collins <rbtcollins@hotmail.com>
Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
2006, 2007 Red Hat, Inc.
This file is part of Cygwin.
@ -1599,7 +1597,11 @@ pthread_mutex::pthread_mutex (pthread_mutexattr *attr) :
verifyable_object (PTHREAD_MUTEX_MAGIC),
lock_counter (0),
win32_obj_id (NULL), recursion_counter (0),
condwaits (0), owner (NULL), type (PTHREAD_MUTEX_ERRORCHECK),
condwaits (0), owner (NULL),
#ifdef DEBUGGING
tid (0),
#endif
type (PTHREAD_MUTEX_ERRORCHECK),
pshared (PTHREAD_PROCESS_PRIVATE)
{
win32_obj_id = ::CreateSemaphore (&sec_none_nih, 0, LONG_MAX, NULL);
@ -1680,6 +1682,9 @@ pthread_mutex::_unlock (pthread_t self)
if (--recursion_counter == 0)
{
owner = NULL;
#ifdef DEBUGGING
tid = 0;
#endif
if (InterlockedDecrement ((long *)&lock_counter))
// Another thread is waiting
::ReleaseSemaphore (win32_obj_id, 1, NULL);
@ -1713,11 +1718,21 @@ pthread_mutex::_fixup_after_fork ()
api_fatal ("pthread_mutex::_fixup_after_fork () doesn'tunderstand PROCESS_SHARED mutex's");
if (owner == NULL)
/* mutex has no owner, reset to initial */
lock_counter = 0;
{
/* mutex has no owner, reset to initial */
lock_counter = 0;
#ifdef DEBUGGING
tid = 0;
#endif
}
else if (lock_counter != 0)
/* All waiting threads are gone after a fork */
lock_counter = 1;
{
/* All waiting threads are gone after a fork */
lock_counter = 1;
#ifdef DEBUGGING
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)