1#include "stdio_impl.h"
2#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
3#include "pthread_impl.h"
4
5#ifdef __GNUC__
6__attribute__((__noinline__))
7#endif
8static int locking_getc(FILE *f)
9{
10 if (a_cas(&f->lock, 0, MAYBE_WAITERS-1)) __lockfile(f);
11 int c = getc_unlocked(f);
12 if (a_swap(&f->lock, 0) & MAYBE_WAITERS)
13 __wake(&f->lock, 1, 1);
14 return c;
15}
16#endif
17
18static inline int do_getc(FILE *f)
19{
20#if defined(__wasilibc_unmodified_upstream) || defined(_REENTRANT)
21 int l = f->lock;
22 if (l < 0 || l && (l & ~MAYBE_WAITERS) == __pthread_self()->tid)
23 return getc_unlocked(f);
24 return locking_getc(f);
25#else
26 // With no threads, locking is unnecessary.
27 return getc_unlocked(f);
28#endif
29}