On Mon, 1 Aug 2005, Corinna Vinschen wrote:
This patch fixes a seg fault when a thread is created in a detached state
and terminates the first time it is scheduled. pthread::create (the
four-parameter version) calls the three-parameter pthread::create function
which unlocks the mutex, allowing the called thread to be scheduled, then
exits at which point the outer create function calls is_good_objectg(),
but this causes a core dump if pthread::exit() has already been called and
deleted the pthread object.
Thanks for the patch. First, please let me point you to
http://cygwin.com/contrib.html. The important information here is that
you'll need to fill out a copyright assignment form and snail mail it
to Red Hat if you want to get in patches. The only exception are
insignificant patches in terms of changed lines of code. The usual rule of
thumb here is not more than 10 lines. Well, your patch only changes
roughly 12 lines, so I'd let slip it in.
I didn't think that my patch was significant enough that I would need to
do that, but I will if necessary.
However, there are three tiny problems:
[snip]
Here is a corrected ChangeLog and patch:
2005-08-01 Michael Gorse <[EMAIL PROTECTED]>
* thread.cc (pthread::create(3 args)): Make bool.
(pthread_null::create): Ditto.
thread.h: Ditto.
* pthread.cc (pthread_create(4 args)): Check return of inner create
rather than calling is_good_object().
Index: thread.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/thread.cc,v
retrieving revision 1.190
diff -u -p -r1.190 thread.cc
--- thread.cc 6 Jul 2005 20:05:03 -0000 1.190
+++ thread.cc 31 Jul 2005 02:13:14 -0000
@@ -491,13 +491,15 @@ pthread::precreate (pthread_attr *newatt
magic = 0;
}
-void
+bool
pthread::create (void *(*func) (void *), pthread_attr *newattr,
void *threadarg)
{
+ bool retval;
+
precreate (newattr);
if (!magic)
- return;
+ return false;
function = func;
arg = threadarg;
@@ -517,7 +519,9 @@ pthread::create (void *(*func) (void *),
while (!cygtls)
low_priority_sleep (0);
}
+ retval = magic;
mutex.unlock ();
+ return retval;
}
void
@@ -1993,8 +1997,7 @@ pthread::create (pthread_t *thread, cons
return EINVAL;
*thread = new pthread ();
- (*thread)->create (start_routine, attr ? *attr : NULL, arg);
- if (!is_good_object (thread))
+ if (!(*thread)->create (start_routine, attr ? *attr : NULL, arg))
{
delete (*thread);
*thread = NULL;
@@ -3262,9 +3265,10 @@ pthread_null::~pthread_null ()
{
}
-void
+bool
pthread_null::create (void *(*)(void *), pthread_attr *, void *)
{
+ return true;
}
void
Index: thread.h
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/thread.h,v
retrieving revision 1.100
diff -u -p -r1.100 thread.h
--- thread.h 5 Jul 2005 03:16:46 -0000 1.100
+++ thread.h 31 Jul 2005 02:10:52 -0000
@@ -380,7 +380,7 @@ public:
HANDLE cancel_event;
pthread_t joiner;
- virtual void create (void *(*)(void *), pthread_attr *, void *);
+ virtual bool create (void *(*)(void *), pthread_attr *, void *);
pthread ();
virtual ~pthread ();
@@ -473,7 +473,7 @@ class pthread_null : public pthread
/* From pthread These should never get called
* as the ojbect is not verifyable
*/
- void create (void *(*)(void *), pthread_attr *, void *);
+ bool create (void *(*)(void *), pthread_attr *, void *);
void exit (void *value_ptr) __attribute__ ((noreturn));
int cancel ();
void testcancel ();
