git
/
gcc
mirror of git://gcc.gnu.org/git/gcc.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Use atomic load/store to access static backtrace state pointer 

As the static backtrace state pointer can be accessed from multiple
threads, use atomics to access it.

Regtested on x86_64-pc-linux-gnu.

libgfortran/ChangeLog:

2018-12-02  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/88137
	* runtime/backtrace.c (show_backtrace): Use atomic load/store to
	access the static lbstate pointer.

From-SVN: r266724
This commit is contained in:
Janne Blomqvist 2018-12-02 17:12:44 +02:00
parent 4a82df9a38
commit df996c3fd2
2 changed files with 17 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
libgfortran/ChangeLog
View File

@ -1,3 +1,9 @@
2018-12-02 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/88137
* runtime/backtrace.c (show_backtrace): Use atomic load/store to
access the static lbstate pointer.
2018-11-30 Janne Blomqvist <jb@gcc.gnu.org> 2018-11-30 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/88137 PR libfortran/88137

17
libgfortran/runtime/backtrace.c
View File

@ -149,15 +149,20 @@ show_backtrace (bool in_signal_handler)
/* Note that libbacktrace allows the state to be accessed from /* Note that libbacktrace allows the state to be accessed from
multiple threads, so we don't need to use a TLS variable for the multiple threads, so we don't need to use a TLS variable for the
state here. */ state here. */
static struct backtrace_state *lbstate; static struct backtrace_state *lbstate_saved;
struct backtrace_state *lbstate;
struct mystate state = { 0, false, in_signal_handler }; struct mystate state = { 0, false, in_signal_handler };
lbstate = __atomic_load_n (&lbstate_saved, __ATOMIC_RELAXED);
if (!lbstate) if (!lbstate)
lbstate = backtrace_create_state (NULL, __gthread_active_p (), {
error_callback, NULL); lbstate = backtrace_create_state (NULL, __gthread_active_p (),
error_callback, NULL);
if (lbstate == NULL) if (lbstate)
return; __atomic_store_n (&lbstate_saved, lbstate, __ATOMIC_RELAXED);
else
return;
}
if (!BACKTRACE_SUPPORTED || (in_signal_handler && BACKTRACE_USES_MALLOC)) if (!BACKTRACE_SUPPORTED || (in_signal_handler && BACKTRACE_USES_MALLOC))
{ {