* ext/pty/pty.c (get_device_once): abandon asynchronous exception

  that might cause serious problem if a program terminated early.
  asynchronous exception is a very bad thing anyway.  use
  Process.waitpid(pid) or PTY.check(pid) to poll program
  termination. if PTY.check is called with optional second
  argument being true, it raises an exception same as one from
  previous behavior.  [incompatible] fix: [ruby-core:19583]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@20298 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 46 insertions, 71 deletions

diff --git a/ext/pty/pty.c b/ext/pty/pty.c
index e0d571a581..f0b8e66595 100644
--- a/ext/pty/pty.c
+++ b/ext/pty/pty.c
@@ -127,51 +127,8 @@ echild_status(VALUE self)
 struct pty_info {
     int fd;
     rb_pid_t child_pid;
-    VALUE thread;
 };
 
-static void
-raise_from_wait(const char *state, const struct pty_info *info)
-{
-    char buf[1024];
-    VALUE exc;
-
-    snprintf(buf, sizeof(buf), "pty - %s: %ld", state, (long)info->child_pid);
-    exc = rb_exc_new2(eChildExited, buf);
-    rb_iv_set(exc, "status", rb_last_status_get());
-    rb_funcall(info->thread, rb_intern("raise"), 1, exc);
-}
-
-static VALUE
-pty_syswait(void *arg)
-{
-    const struct pty_info *const info = arg;
-    rb_pid_t cpid;
-    int status;
-
-    for (;;) {
-	cpid = rb_waitpid(info->child_pid, &status, WUNTRACED);
-	if (cpid == -1) return Qnil;
-
-#if defined(WIFSTOPPED)
-#elif defined(IF_STOPPED)
-#define WIFSTOPPED(status) IF_STOPPED(status)
-#else
----->> Either IF_STOPPED or WIFSTOPPED is needed <<----
-#endif /* WIFSTOPPED | IF_STOPPED */
-	if (WIFSTOPPED(status)) { /* suspend */
-	    raise_from_wait("stopped", info);
-	}
-	else if (kill(info->child_pid, 0) == 0) {
-	    raise_from_wait("changed", info);
-	}
-	else {
-	    raise_from_wait("exited", info);
-	    return Qnil;
-	}
-    }
-}
-
 static void getDevice(int*, int*, char [DEVICELEN]);
 
 struct exec_info {
@@ -217,7 +174,6 @@ establishShell(int argc, VALUE *argv, struct pty_info *info,
     }
     getDevice(&master, &slave, SlaveName);
 
-    info->thread = rb_thread_current();
     if ((pid = fork()) < 0) {
 	close(master);
 	close(slave);
@@ -288,15 +244,6 @@ establishShell(int argc, VALUE *argv, struct pty_info *info,
     info->fd = master;
 }
 
-static VALUE
-pty_finalize_syswait(struct pty_info *info)
-{
-    rb_thread_kill(info->thread);
-    rb_funcall(info->thread, rb_intern("value"), 0);
-    rb_detach_process(info->child_pid);
-    return Qnil;
-}
-
 static int
 get_device_once(int *master, int *slave, char SlaveName[DEVICELEN], int fail)
 {
@@ -396,13 +343,19 @@ getDevice(int *master, int *slave, char SlaveName[DEVICELEN])
     }
 }
 
+static VALUE
+pty_detach_process(struct pty_info *info)
+{
+    rb_detach_process(info->child_pid);
+    return Qnil;
+}
+
 /* ruby function: getpty */
 static VALUE
 pty_getpty(int argc, VALUE *argv, VALUE self)
 {
     VALUE res;
     struct pty_info info;
-    struct pty_info thinfo;
     rb_io_t *wfptr,*rfptr;
     VALUE rport = rb_obj_alloc(rb_cFile);
     VALUE wport = rb_obj_alloc(rb_cFile);
@@ -426,32 +379,55 @@ pty_getpty(int argc, VALUE *argv, VALUE self)
     rb_ary_store(res,1,(VALUE)wport);
     rb_ary_store(res,2,PIDT2NUM(info.child_pid));
 
-    thinfo.thread = rb_thread_create(pty_syswait, (void*)&info);
-    thinfo.child_pid = info.child_pid;
-    rb_thread_schedule();
-
     if (rb_block_given_p()) {
-	rb_ensure(rb_yield, res, pty_finalize_syswait, (VALUE)&thinfo);
+	rb_ensure(rb_yield, res, pty_detach_process, (VALUE)&info);
 	return Qnil;
     }
     return res;
 }
 
-/* ruby function: protect_signal - obsolete */
-static VALUE
-pty_protect(VALUE self)
+static void
+raise_from_check(pid_t pid, int status)
 {
-    rb_warn("PTY::protect_signal is no longer needed");
-    rb_yield(Qnil);
-    return self;
+    const char *state;
+    char buf[1024];
+    VALUE exc;
+
+#if defined(WIFSTOPPED)
+#elif defined(IF_STOPPED)
+#define WIFSTOPPED(status) IF_STOPPED(status)
+#else
+---->> Either IF_STOPPED or WIFSTOPPED is needed <<----
+#endif /* WIFSTOPPED | IF_STOPPED */
+    if (WIFSTOPPED(status)) { /* suspend */
+	state = "stopped";
+    }
+    else if (kill(pid, 0) == 0) {
+	state = "changed";
+    }
+    else {
+	state = "exited";
+    }
+    snprintf(buf, sizeof(buf), "pty - %s: %ld", state, (long)pid);
+    exc = rb_exc_new2(eChildExited, buf);
+    rb_iv_set(exc, "status", rb_last_status_get());
+    rb_exc_raise(exc);
 }
 
-/* ruby function: reset_signal - obsolete */
 static VALUE
-pty_reset_signal(VALUE self)
+pty_check(int argc, VALUE *argv, VALUE self)
 {
-    rb_warn("PTY::reset_signal is no longer needed");
-    return self;
+    VALUE pid, exc;
+    pid_t cpid;
+    int status;
+
+    rb_scan_args(argc, argv, "11", &pid, &exc);
+    cpid = rb_waitpid(NUM2PIDT(pid), &status, WUNTRACED);
+    if (cpid == -1) return Qnil;
+
+    if (!RTEST(exc)) return status;
+    raise_from_check(pid, status);
+    return Qnil;		/* not reached */
 }
 
 static VALUE cPTY;
@@ -462,8 +438,7 @@ Init_pty()
     cPTY = rb_define_module("PTY");
     rb_define_module_function(cPTY,"getpty",pty_getpty,-1);
     rb_define_module_function(cPTY,"spawn",pty_getpty,-1);
-    rb_define_module_function(cPTY,"protect_signal",pty_protect,0);
-    rb_define_module_function(cPTY,"reset_signal",pty_reset_signal,0);
+    rb_define_singleton_function(cPTY,"check",pty_check,-1);
 
     eChildExited = rb_define_class_under(cPTY,"ChildExited",rb_eRuntimeError);
     rb_define_method(eChildExited,"status",echild_status,0);