ok. David
On Tue, May 1, 2012 at 3:47 PM, <asha...@chromium.org> wrote: > Reviewers: xur, davidxl, > > Message: > Please take a look at this. > > Description: > This fixes an issue with profile collection when multiple threads call > fork() around the same time. > > 2012-03-12 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. > > > Please review this at http://codereview.appspot.com/6151043/ > > Affected files: > M . > M libgcc/ChangeLog > M libgcc/ChangeLog.google-4_7 > M libgcc/gthr-posix.h > M libgcc/gthr-single.h > M libgcc/gthr.h > M libgcc/libgcov.c > M libgcc/unwind-dw2-fde.c > > > Index: . > =================================================================== > --- . (revision 187027) > +++ . (working copy) > > Property changes on: . > ___________________________________________________________________ > Modified: svn:mergeinfo > Merged /trunk:r185231 > Index: libgcc/ChangeLog > =================================================================== > --- libgcc/ChangeLog (revision 187027) > +++ libgcc/ChangeLog (working copy) > @@ -1,3 +1,19 @@ > +2012-03-12 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. > + > 2012-04-20 Thomas Schwinge <tho...@codesourcery.com> > > struct siginfo vs. siginfo_t > Index: libgcc/ChangeLog.google-4_7 > =================================================================== > --- libgcc/ChangeLog.google-4_7 (revision 187027) > +++ libgcc/ChangeLog.google-4_7 (working copy) > @@ -1,3 +1,20 @@ > +2012-05-01 Ahmad Sharif <asha...@google.com> > + 2012-03-12 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. > + > 2012-04-17 Teresa Johnson <tejohn...@google.com> > > Backport from google/main rev r186550 > Index: libgcc/gthr-single.h > =================================================================== > --- libgcc/gthr-single.h (revision 187027) > +++ libgcc/gthr-single.h (working copy) > @@ -36,6 +36,7 @@ > > #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/libgcov.c > =================================================================== > --- libgcc/libgcov.c (revision 187027) > +++ libgcc/libgcov.c (working copy) > @@ -48,6 +48,7 @@ > #include "tm.h" > #endif /* __KERNEL__ */ > #include "libgcc_tm.h" > +#include "gthr.h" > > #if 1 > #define THREAD_PREFIX __thread > @@ -668,6 +669,25 @@ > 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. */ > @@ -677,6 +697,9 @@ > { > const struct gcov_info *gi_ptr; > > + init_mx_once (); > + __gthread_mutex_lock (&__gcov_flush_mx); > + > __gcov_stop_pmu_profiler (); > gcov_exit (); > for (gi_ptr = __gcov_list; gi_ptr; gi_ptr = gi_ptr->next) > @@ -700,6 +723,7 @@ > } > } > __gcov_start_pmu_profiler (); > + __gthread_mutex_unlock (&__gcov_flush_mx); > } > > #else /* __GCOV_KERNEL__ */ > @@ -1721,8 +1745,13 @@ > pid_t > __gcov_fork (void) > { > + pid_t pid; > + extern __gthread_mutex_t __gcov_flush_mx; > __gcov_flush (); > - return fork (); > + 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 187027) > +++ libgcc/unwind-dw2-fde.c (working copy) > @@ -47,11 +47,10 @@ > > #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; > -#endif > > -#ifdef __GTHREAD_MUTEX_INIT_FUNCTION > static void > init_object_mutex (void) > { > @@ -64,8 +63,6 @@ > 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. */ > Index: libgcc/gthr-posix.h > =================================================================== > --- libgcc/gthr-posix.h (revision 187027) > +++ libgcc/gthr-posix.h (working copy) > @@ -63,6 +63,7 @@ > #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 > @@ -754,6 +755,14 @@ > #endif > > 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.h > =================================================================== > --- libgcc/gthr.h (revision 187027) > +++ libgcc/gthr.h (working copy) > @@ -52,11 +52,12 @@ > 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. > >
