nsz Git - musl/blob - src/process/fork.c

   1 #include <unistd.h>
   2 #include <string.h>
   3 #include <signal.h>
   4 #include "syscall.h"
   5 #include "libc.h"
   6 #include "pthread_impl.h"
   7
   8 static void dummy(int x)
   9 {
  10 }
  11
  12 weak_alias(dummy, __fork_handler);
  13 weak_alias(dummy, __aio_atfork);
  14
  15 pid_t fork(void)
  16 {
  17         pid_t ret;
  18         sigset_t set;
  19         __fork_handler(-1);
  20         __block_all_sigs(&set);
  21         __aio_atfork(-1);
  22 #ifdef SYS_fork
  23         ret = __syscall(SYS_fork);
  24 #else
  25         ret = __syscall(SYS_clone, SIGCHLD, 0);
  26 #endif
  27         if (!ret) {
  28                 pthread_t self = __pthread_self();
  29                 self->tid = __syscall(SYS_gettid);
  30                 self->robust_list.off = 0;
  31                 self->robust_list.pending = 0;
  32                 self->next = self->prev = self;
  33                 __thread_list_lock = 0;
  34                 libc.threads_minus_1 = 0;
  35                 if (libc.need_locks) libc.need_locks = -1;
  36         }
  37         __aio_atfork(!ret);
  38         __restore_sigs(&set);
  39         __fork_handler(!ret);
  40         return __syscall_ret(ret);
  41 }