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Use re-entrant locks on stdio

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This commit is contained in:
Justine Tunney 2022-05-22 08:13:13 -07:00
parent 4e9662cbc7
commit 1f229e4efc
78 changed files with 427 additions and 179 deletions
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18
libc/stdio/ftrylockfile.c
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@ -16,13 +16,23 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/spinlock.h"
#include "libc/calls/calls.h"
#include "libc/intrin/lockcmpxchgp.h"
#include "libc/nexgen32e/threaded.h"
#include "libc/stdio/stdio.h"
/**
* Tries to acquire stdio object lock.
* @return 0 for success or non-zero if someone else has the lock
* Tries to acquire reentrant stdio object lock.
*
* @return 0 on success, or non-zero if another thread owns the lock
*/
int ftrylockfile(FILE *f) {
return _trylock(&f->lock);
int me, owner = 0;
if (__threaded) {
me = gettid();
if (!_lockcmpxchgp(&f->lock, &owner, me) && owner == me) {
owner = 0;
}
}
return owner;
}