Make locks more reliable

This change switches most of the core locks to be re-entrant, in order
to reduce the chance of deadlocking code that does, clever things with
asynchronous signal handlers. This change implements it it in pthreads
so we're one step closer to having a standardized threading primitives
This commit is contained in:
Justine Tunney 2022-06-11 01:59:26 -07:00
parent 5ea618f0af
commit c260345e06
35 changed files with 369 additions and 258 deletions

View file

@ -16,24 +16,11 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/assert.h"
#include "libc/calls/calls.h"
#include "libc/nexgen32e/threaded.h"
#include "libc/stdio/stdio.h"
/**
* Releases lock on stdio object.
*/
void funlockfile(FILE *f) {
int owner;
bool shouldunlock;
assert(f->reent > 0);
shouldunlock = --f->reent <= 0;
if (__threaded) {
assert(f->lock == gettid());
if (shouldunlock) {
owner = 0;
__atomic_store(&f->lock, &owner, __ATOMIC_RELAXED);
}
}
pthread_mutex_unlock(&f->lock);
}