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#include "stdio_impl.h"
#include "pthread_impl.h"
#include <limits.h>
#define MAYBE_WAITERS 0x40000000
void __do_orphaned_stdio_locks()
{
FILE *f;
for (f=__pthread_self()->stdio_locks; f; f=f->next_locked)
a_store(&f->lock, 0x40000000);
}
void __unlist_locked_file(FILE *f)
{
if (f->lockcount) {
if (f->next_locked) f->next_locked->prev_locked = f->prev_locked;
if (f->prev_locked) f->prev_locked->next_locked = f->next_locked;
else __pthread_self()->stdio_locks = f->next_locked;
}
}
void __register_locked_file(FILE *f, pthread_t self)
{
f->lockcount = 1;
f->prev_locked = 0;
f->next_locked = self->stdio_locks;
if (f->next_locked) f->next_locked->prev_locked = f;
self->stdio_locks = f;
}
int ftrylockfile(FILE *f)
{
pthread_t self = __pthread_self();
int tid = self->tid;
int owner = f->lock;
if ((owner & ~MAYBE_WAITERS) == tid) {
if (f->lockcount == LONG_MAX)
return -1;
f->lockcount++;
return 0;
}
if (owner < 0) f->lock = owner = 0;
if (owner || a_cas(&f->lock, 0, tid))
return -1;
__register_locked_file(f, self);
return 0;
}
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