From: Sylvain Joyeux <sylvain.joyeux@...4x.org>
Date: 2007-03-15T00:15:57+09:00
Subject: [PATCH] grave bug in 1.8.6's thread implementation

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In ext/thread/thread.c, remove_one leaves the list in an inconsistent state. 
The fix is in thread-mutex-remove_one.diff. 

Is it me or there is no testsuite for multithread-related stuff ? That's a 
pity, fastthread did include one :-(

Other patches:
thread-mutex-not_owner.diff makes lock_mutex check that the mutex is actually 
    owned by the caller. 
thread-mutex-recursive_lock.diff raises if we are trying to recursively lock 
    the mutex. (Note that I can as easily add a recursive mutex behaviour)

Best regards
Sylvain Joyeux

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--- /home/sjoyeux/system/ruby-1.8.6/ext/thread/thread.c	2007-03-03 11:08:06.000000000 +0100
+++ thread.c	2007-03-14 15:36:58.000000000 +0100
@@ -429,8 +443,13 @@ unlock_mutex_inner(Mutex *mutex)
     VALUE waking;
 
     if (!RTEST(mutex->owner)) {
-        return Qundef;
+	rb_raise(rb_eThreadError, "not owner");
+    }
+
+    if (mutex->owner != rb_thread_current()) {
+	rb_raise(rb_eThreadError, "not owner");
     }
+
     mutex->owner = Qnil;
     waking = wake_one(&mutex->waiting);
 

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--- /home/sjoyeux/system/ruby-1.8.6/ext/thread/thread.c	2007-03-03 11:08:06.000000000 +0100
+++ thread.c	2007-03-14 15:45:24.000000000 +0100
@@ -399,6 +410,9 @@ lock_mutex(Mutex *mutex)
     rb_thread_critical = 1;
 
     while (RTEST(mutex->owner)) {
+	if (mutex->owner == current)
+	    rb_raise(rb_eThreadError, "recursive mutex lock");
+
         wait_list(&mutex->waiting);
         rb_thread_critical = 1;
     }

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--- /home/sjoyeux/system/ruby-1.8.6/ext/thread/thread.c	2007-03-03 11:08:06.000000000 +0100
+++ thread.c	2007-03-14 15:36:58.000000000 +0100
@@ -429,8 +433,13 @@ unlock_mutex_inner(Mutex *mutex)
     VALUE waking;
 
     if (!RTEST(mutex->owner)) {
-        return Qundef;
+	rb_raise(rb_eThreadError, "Not owner");
     }
+
+    if (mutex->owner != rb_thread_current()) {
+	rb_raise(rb_eThreadError, "Not owner");
+    }
+
     mutex->owner = Qnil;
     waking = wake_one(&mutex->waiting);
 

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