nsz Git - musl/blob - src/stdio/flockfile.c

   1 #include "stdio_impl.h"
   2 #include "pthread_impl.h"
   3
   4 #define MAYBE_WAITERS 0x40000000
   5
   6 void flockfile(FILE *f)
   7 {
   8         while (ftrylockfile(f)) {
   9                 int owner = f->lock;
  10                 if (!owner) continue;
  11                 a_cas(&f->lock, owner, owner|MAYBE_WAITERS);
  12                 __futexwait(&f->lock, owner|MAYBE_WAITERS, 1);
  13         }
  14 }