xref: /third_party/musl/src/stdio/putc.h (revision 570af302)
1#include "stdio_impl.h"
2#include "pthread_impl.h"
3
4#ifdef __GNUC__
5__attribute__((__noinline__))
6#endif
7static int locking_putc(int c, FILE *f)
8{
9	if (a_cas(&f->lock, 0, MAYBE_WAITERS-1)) __lockfile(f);
10	c = putc_unlocked(c, f);
11	if (a_swap(&f->lock, 0) & MAYBE_WAITERS)
12		__wake(&f->lock, 1, 1);
13	return c;
14}
15
16static inline int do_putc(int c, FILE *f)
17{
18	int l = f->lock;
19	if (l < 0 || l && (l & ~MAYBE_WAITERS) == __pthread_self()->tid)
20		return putc_unlocked(c, f);
21	return locking_putc(c, f);
22}
23