source: asp3_tinet_ecnl_arm/trunk/musl-1.1.18/src/stdio/ftrylockfile.c@ 352

#include "stdio_impl.h"
#include "pthread_impl.h"
#include <limits.h>

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;
        }
}

int ftrylockfile(FILE *f)
{
        pthread_t self = __pthread_self();
        int tid = self->tid;
        if (f->lock == tid) {
                if (f->lockcount == LONG_MAX)
                        return -1;
                f->lockcount++;
                return 0;
        }
        if (f->lock < 0) f->lock = 0;
        if (f->lock || a_cas(&f->lock, 0, tid))
                return -1;
        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;
        return 0;
}