* thread.c (rb_mutex_trylock): return false if Mutex owned

by current thread.  [ruby-core:20943]
* thread.c (rb_mutex_lock): check dead lock (recursive lock) here.
* test/ruby/test_thread.rb: add a test.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21148 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Mon Dec 29 11:58:39 2008  Koichi Sasada  <ko1@atdot.net>
+
+	* thread.c (rb_mutex_trylock): return false if Mutex owned
+	  by current thread.  [ruby-core:20943]
+
+	* thread.c (rb_mutex_lock): check dead lock (recursive lock) here.
+
+	* test/ruby/test_thread.rb: add a test.
+
 Mon Dec 29 10:58:54 2008  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* file.c (rb_get_path): move encoding conversion of file path

test/ruby/test_thread.rb

@@ -438,6 +438,18 @@ class TestThread < Test::Unit::TestCase
     assert_equal(false, m3.locked?)
   end
 
+  def test_mutex_trylock
+    m = Mutex.new
+    assert_equal(true, m.try_lock)
+    assert_equal(false, m.try_lock, '[ruby-core:20943]')
+
+    Thread.new{
+      assert_equal(false, m.try_lock)
+    }.join
+
+    m.unlock
+  end
+
   def test_recursive_error
     o = Object.new
     def o.inspect

thread.c

@@ -2796,10 +2796,6 @@ rb_mutex_trylock(VALUE self)
     VALUE locked = Qfalse;
     GetMutexPtr(self, mutex);
 
-    if (mutex->th == GET_THREAD()) {
-	rb_raise(rb_eThreadError, "deadlock; recursive locking");
-    }
-
     native_mutex_lock(&mutex->lock);
     if (mutex->th == 0) {
 	mutex->th = GET_THREAD();
@@ -2871,11 +2867,16 @@ lock_interrupt(void *ptr)
 VALUE
 rb_mutex_lock(VALUE self)
 {
+
     if (rb_mutex_trylock(self) == Qfalse) {
 	mutex_t *mutex;
 	rb_thread_t *th = GET_THREAD();
 	GetMutexPtr(self, mutex);
 
+	if (mutex->th == GET_THREAD()) {
+	    rb_raise(rb_eThreadError, "deadlock; recursive locking");
+	}
+
 	while (mutex->th != th) {
 	    int interrupted;
 	    enum rb_thread_status prev_status = th->status;