This fixes PR49484 by protecting __gcov_flush against concurrent
execution. To be able to use the gthread facility I have to
introduce the requirement that __GTHREAD_MUTEX_INIT_FUNCTION
is always available, even if __GTHREAD_MUTEX_INIT is available as
otherwise no dynamic initialization of a mutex is possible.
I have adjusted gthr-posix.h and gthr-single.h only - target
maintainers, please update your ports accordingly in advance.
Boostrap and regtest on x86_64-unknown-linux-gnu is ongoing,
but this looks like something for stage1 anyway.
Richard.
2012-01-18 Richard Guenther <rguent...@suse.de>
* gthr.h (__GTHREAD_MUTEX_INIT_FUNCTION): Adjust specification.
* gthr-posix.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
(__gthread_mutex_init_function): New function.
* gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
PR gcov/49484
* libgcov.c: Include gthr.h.
(__gcov_flush_mx): New global variable.
(init_mx, init_mx_once): New functions.
(__gcov_flush): Protect self with a mutex.
(__gcov_fork): Re-initialize mutex after forking.
* unwind-dw2-fde.c: Change condition under which to use
__GTHREAD_MUTEX_INIT_FUNCTION.
Index: libgcc/libgcov.c
===================================================================
*** libgcc/libgcov.c (revision 183270)
--- libgcc/libgcov.c (working copy)
*************** see the files COPYING3 and COPYING.RUNTI
*** 30,35 ****
--- 30,36 ----
#include "coretypes.h"
#include "tm.h"
#include "libgcc_tm.h"
+ #include "gthr.h"
#if defined(inhibit_libc)
#define IN_LIBGCOV (-1)
*************** __gcov_init (struct gcov_info *info)
*** 705,710 ****
--- 706,730 ----
info->version = 0;
}
+ #ifdef __GTHREAD_MUTEX_INIT
+ ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx = __GTHREAD_MUTEX_INIT;
+ #define init_mx_once()
+ #else
+ __gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
+
+ static void
+ init_mx (void)
+ {
+ __GTHREAD_MUTEX_INIT_FUNCTION (&mx);
+ }
+ static void
+ init_mx_once (void)
+ {
+ static __gthread_once_t once = __GTHREAD_ONCE_INIT;
+ __gthread_once (&once, init_mx);
+ }
+ #endif
+
/* Called before fork or exec - write out profile information gathered so
far and reset it to zero. This avoids duplication or loss of the
profile information gathered so far. */
*************** __gcov_flush (void)
*** 714,719 ****
--- 734,742 ----
{
const struct gcov_info *gi_ptr;
+ init_mx_once ();
+ __gthread_mutex_lock (&__gcov_flush_mx);
+
gcov_exit ();
for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
{
*************** __gcov_flush (void)
*** 737,742 ****
--- 760,767 ----
}
}
}
+
+ __gthread_mutex_unlock (&__gcov_flush_mx);
}
#endif /* L_gcov */
*************** __gcov_ior_profiler (gcov_type *counters
*** 975,982 ****
pid_t
__gcov_fork (void)
{
__gcov_flush ();
! return fork ();
}
#endif
--- 1000,1012 ----
pid_t
__gcov_fork (void)
{
+ pid_t pid;
+ extern __gthread_mutex_t __gcov_flush_mx;
__gcov_flush ();
! pid = fork ();
! if (pid == 0)
! __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
! return pid;
}
#endif
Index: libgcc/unwind-dw2-fde.c
===================================================================
*** libgcc/unwind-dw2-fde.c (revision 183270)
--- libgcc/unwind-dw2-fde.c (working copy)
*************** static struct object *seen_objects;
*** 47,57 ****
#ifdef __GTHREAD_MUTEX_INIT
static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT;
#else
static __gthread_mutex_t object_mutex;
- #endif
- #ifdef __GTHREAD_MUTEX_INIT_FUNCTION
static void
init_object_mutex (void)
{
--- 47,56 ----
#ifdef __GTHREAD_MUTEX_INIT
static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT;
+ #define init_object_mutex_once()
#else
static __gthread_mutex_t object_mutex;
static void
init_object_mutex (void)
{
*************** init_object_mutex_once (void)
*** 64,71 ****
static __gthread_once_t once = __GTHREAD_ONCE_INIT;
__gthread_once (&once, init_object_mutex);
}
- #else
- #define init_object_mutex_once()
#endif
/* Called from crtbegin.o to register the unwind info for an object. */
--- 63,68 ----
Index: libgcc/gthr-posix.h
===================================================================
*** libgcc/gthr-posix.h (revision 183270)
--- libgcc/gthr-posix.h (working copy)
*************** typedef struct timespec __gthread_time_t
*** 63,68 ****
--- 63,69 ----
#define __GTHREAD_HAS_COND 1
#define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
+ #define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function
#define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
#if defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
#define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER
*************** __gthread_setspecific (__gthread_key_t _
*** 731,736 ****
--- 732,745 ----
}
static inline int
+ __gthread_mutex_init_function (__gthread_mutex_t *__mutex)
+ {
+ if (__gthread_active_p ())
+ return __gthrw_(pthread_mutex_init) (__mutex, NULL);
+ return 0;
+ }
+
+ static inline int
__gthread_mutex_destroy (__gthread_mutex_t *__mutex)
{
if (__gthread_active_p ())
Index: libgcc/gthr-single.h
===================================================================
*** libgcc/gthr-single.h (revision 183270)
--- libgcc/gthr-single.h (working copy)
*************** typedef int __gthread_recursive_mutex_t;
*** 36,41 ****
--- 36,42 ----
#define __GTHREAD_ONCE_INIT 0
#define __GTHREAD_MUTEX_INIT 0
+ #define __GTHREAD_MUTEX_INIT_FUNCTION (mx)
#define __GTHREAD_RECURSIVE_MUTEX_INIT 0
#define UNUSED __attribute__((unused))
Index: libgcc/gthr.h
===================================================================
--- libgcc/gthr.h (revision 183270)
+++ libgcc/gthr.h (working copy)
@@ -52,11 +52,12 @@ see the files COPYING3 and COPYING.RUNTI
to initialize __gthread_mutex_t to get a fast
non-recursive mutex.
__GTHREAD_MUTEX_INIT_FUNCTION
- some systems can't initialize a mutex without a
- function call. On such systems, define this to a
- function which looks like this:
+ to initialize __gthread_mutex_t to get a fast
+ non-recursive mutex.
+ Define this to a function which looks like this:
void __GTHREAD_MUTEX_INIT_FUNCTION (__gthread_mutex_t *)
- Don't define __GTHREAD_MUTEX_INIT in this case
+ Some systems can't initialize a mutex without a
+ function call. Don't define __GTHREAD_MUTEX_INIT in this case.
__GTHREAD_RECURSIVE_MUTEX_INIT
__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION
as above, but for a recursive mutex.
