libc-top-half/musl/src/process/_Fork.c

   1 #include <unistd.h>
   2 #include <signal.h>
   3 #include "syscall.h"
   4 #include "libc.h"
   5 #include "lock.h"
   6 #include "pthread_impl.h"
   7 #include "aio_impl.h"
   8
   9 static void dummy(int x) { }
  10 weak_alias(dummy, __aio_atfork);
  11
  12 pid_t _Fork(void)
  13 {
  14         pid_t ret;
  15         sigset_t set;
  16         __block_all_sigs(&set);
  17         __aio_atfork(-1);
  18         LOCK(__abort_lock);
  19 #ifdef SYS_fork
  20         ret = __syscall(SYS_fork);
  21 #else
  22         ret = __syscall(SYS_clone, SIGCHLD, 0);
  23 #endif
  24         if (!ret) {
  25                 pthread_t self = __pthread_self();
  26                 self->tid = __syscall(SYS_gettid);
  27                 self->robust_list.off = 0;
  28                 self->robust_list.pending = 0;
  29                 self->next = self->prev = self;
  30                 __thread_list_lock = 0;
  31                 libc.threads_minus_1 = 0;
  32                 if (libc.need_locks) libc.need_locks = -1;
  33         }
  34         UNLOCK(__abort_lock);
  35         __aio_atfork(!ret);
  36         __restore_sigs(&set);
  37         return __syscall_ret(ret);
  38 }