nsz Git - musl/blob - src/thread/forkall.c

   1 #if 0
   2 #include "pthread_impl.h"
   3 #include <setjmp.h>
   4
   5 struct thread {
   6         struct thread *next;
   7         pthread_t td;
   8         jmp_buf jb;
   9         void *tmp, *stack;
  10 };
  11
  12 struct ctx {
  13         struct thread *list;
  14         pthread_t caller;
  15         pid_t pid;
  16         size_t cnt;
  17         pthread_barrier_t barrier;
  18 };
  19
  20 static void restart_thread(pthread_t self)
  21 {
  22         struct thread *t = self->start_arg;
  23         self->start_arg = t->tmp;
  24         self->pid = getpid();
  25         longjmp(t->jb, 1);
  26 }
  27
  28 static void do_forkall(void *p)
  29 {
  30         struct ctx *c = p, *volatile cv = c;
  31         char tmpstack[2048];
  32         struct thread *tp, t = {
  33                 .td = __pthread_self(),
  34                 .next = c->list,
  35                 .stack = tmpstack+1024
  36         };
  37
  38         if (t.td != c->caller) {
  39                 c->cnt++;
  40                 t.tmp = t.td->start_arg;
  41                 t.td->start_arg = &t;
  42                 if (setjmp(t.jb)) {
  43                         c = cv;
  44                         if (c->pid) return;
  45                         pthread_barrier_wait(&c->barrier);
  46                         return;
  47                 }
  48                 c->list = &t;
  49                 __synccall_wait();
  50                 return;
  51         }
  52         c->pid = syscall(SYS_fork);
  53         if (c->pid) return;
  54
  55         pthread_barrier_init(&c->barrier, 0, c->cnt);
  56         for (tp=c->list; tp; tp=tp->next)
  57                 if (__uniclone(tp->stack, restart_thread, tp->td) < 0)
  58                         _exit(127);
  59         pthread_barrier_wait(&c->barrier);
  60 }
  61
  62 pid_t forkall()
  63 {
  64         struct ctx c = { .caller = pthread_self() };
  65         __synccall(do_forkall, &c);
  66         return c.pid;
  67 }
  68 #endif