Integrate r28203 from MRI.

eval.c

@@ -12609,6 +12609,8 @@ static struct timer_thread {
     pthread_t thread;
 } time_thread = {PTHREAD_COND_INITIALIZER, PTHREAD_MUTEX_INITIALIZER};
 
+static int timer_stopping;
+
 #define safe_mutex_lock(lock) \
     pthread_mutex_lock(lock); \
     pthread_cleanup_push((void (*)_((void *)))pthread_mutex_unlock, lock)
@@ -12633,6 +12635,9 @@ thread_timer(dummy)
 #define WAIT_FOR_10MS() \
     pthread_cond_timedwait(&running->cond, &running->lock, get_ts(&to, PER_NANO/100))
     while ((err = WAIT_FOR_10MS()) == EINTR || err == ETIMEDOUT) {
+      if (timer_stopping)
+        break;
+
 	if (!rb_thread_critical) {
 	    rb_thread_pending = 1;
 	    if (rb_trap_immediate) {
@@ -12660,7 +12665,9 @@ rb_thread_start_timer()
     safe_mutex_lock(&time_thread.lock);
     if (pthread_create(&time_thread.thread, 0, thread_timer, args) == 0) {
 	thread_init = 1;
+#if !defined(__NetBSD__) && !defined(__APPLE__) && !defined(linux)
 	pthread_atfork(0, 0, rb_thread_stop_timer);
+#endif
 	pthread_cond_wait(&start, &time_thread.lock);
     }
     pthread_cleanup_pop(1);
@@ -12671,10 +12678,12 @@ rb_thread_stop_timer()
 {
     if (!thread_init) return;
     safe_mutex_lock(&time_thread.lock);
+    timer_stopping = 1;
     pthread_cond_signal(&time_thread.cond);
     thread_init = 0;
     pthread_cleanup_pop(1);
     pthread_join(time_thread.thread, NULL);
+    timer_stopping = 0;
 }
 #elif defined(HAVE_SETITIMER)
 static void

io.c

@@ -3248,6 +3248,9 @@ pipe_open(pstr, pname, mode)
     }
 
   retry:
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+    rb_thread_stop_timer();
+#endif
     switch ((pid = fork())) {
       case 0:			/* child */
 	if (modef & FMODE_READABLE) {
@@ -3275,11 +3278,17 @@ pipe_open(pstr, pname, mode)
 		    ruby_sourcefile, ruby_sourceline, pname);
 	    _exit(127);
 	}
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+	rb_thread_start_timer();
+#endif
 	rb_io_synchronized(RFILE(orig_stdout)->fptr);
 	rb_io_synchronized(RFILE(orig_stderr)->fptr);
 	return Qnil;
 
       case -1:			/* fork failed */
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+        rb_thread_start_timer();
+#endif
 	if (errno == EAGAIN) {
 	    rb_thread_sleep(1);
 	    goto retry;
@@ -3300,6 +3309,9 @@ pipe_open(pstr, pname, mode)
 	break;
 
       default:			/* parent */
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+        rb_thread_start_timer();
+#endif
 	if (pid < 0) rb_sys_fail(pname);
 	else {
 	    VALUE port = io_alloc(rb_cIO);

process.c

@@ -1330,7 +1330,14 @@ rb_f_fork(obj)
     fflush(stderr);
 #endif
 
-    switch (pid = fork()) {
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+    before_exec();
+#endif
+    pid = fork();
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+    after_exec();
+#endif
+    switch (pid) {
       case 0:
 #ifdef linux
 	after_exec();
@@ -1570,13 +1577,19 @@ rb_f_system(argc, argv)
 
     chfunc = signal(SIGCHLD, SIG_DFL);
   retry:
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+    before_exec();
+#endif
     pid = fork();
     if (pid == 0) {
 	/* child process */
 	rb_thread_atfork();
 	rb_protect(proc_exec_args, (VALUE)&earg, NULL);
 	_exit(127);
     }
+#if defined(__NetBSD__) || defined(__APPLE__) || defined(linux)
+    after_exec();
+#endif
     if (pid < 0) {
 	if (errno == EAGAIN) {
 	    rb_thread_sleep(1);