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 "lock.h"
   7 #include "pthread_impl.h"
   8
   9 static void dummy(int x)
  10 {
  11 }
  12
  13 weak_alias(dummy, __fork_handler);
  14 weak_alias(dummy, __aio_atfork);
  15
  16 pid_t fork(void)
  17 {
  18         pid_t ret;
  19         sigset_t set;
  20         __fork_handler(-1);
  21         __block_all_sigs(&set);
  22         __aio_atfork(-1);
  23         LOCK(__abort_lock);
  24 #ifdef SYS_fork
  25         ret = __syscall(SYS_fork);
  26 #else
  27         ret = __syscall(SYS_clone, SIGCHLD, 0);
  28 #endif
  29         if (!ret) {
  30                 pthread_t self = __pthread_self();
  31                 self->tid = __syscall(SYS_gettid);
  32                 self->robust_list.off = 0;
  33                 self->robust_list.pending = 0;
  34                 self->next = self->prev = self;
  35                 __thread_list_lock = 0;
  36                 libc.threads_minus_1 = 0;
  37                 if (libc.need_locks) libc.need_locks = -1;
  38         }
  39         UNLOCK(__abort_lock);
  40         __aio_atfork(!ret);
  41         __restore_sigs(&set);
  42         __fork_handler(!ret);
  43         return __syscall_ret(ret);
  44 }