svn commit: r514249 - in /harmony/enhanced/drlvm/trunk/vm: thread/src/thread_init.c vmcore/src/class_support/C_Interface.cpp

[wj...@apache.org]

Author: wjwashburn
Date: Sat Mar  3 13:42:34 2007
New Revision: 514249

URL: http://svn.apache.org/viewvc?view=rev&rev=514249
Log:
H3203, fixes deadlock in vm_gc_lock_enum
build, build test passes on winxp 32 and linux rhel4.0 32 gcc 4.0.2


Modified:
    harmony/enhanced/drlvm/trunk/vm/thread/src/thread_init.c
    harmony/enhanced/drlvm/trunk/vm/vmcore/src/class_support/C_Interface.cpp

Modified: harmony/enhanced/drlvm/trunk/vm/thread/src/thread_init.c
URL: http://svn.apache.org/viewvc/harmony/enhanced/drlvm/trunk/vm/thread/src/thread_init.c?view=diff&rev=514249&r1=514248&r2=514249
==============================================================================
--- harmony/enhanced/drlvm/trunk/vm/thread/src/thread_init.c (original)
+++ harmony/enhanced/drlvm/trunk/vm/thread/src/thread_init.c Sat Mar  3 13:42:34 2007
@@ -229,7 +229,38 @@
  * The lock blocks new thread creation and thread exit operations. 
  */
 IDATA VMCALL hythread_global_lock() {
-    return hymutex_lock(TM_LIBRARY->TM_LOCK);
+    IDATA r = 0;
+    hythread_t self = tm_self_tls;
+    int saved_count;
+
+    // we need not care about suspension if the thread
+    // is not even tattached to hythread
+    if (self == NULL)
+        return hymutex_lock(TM_LIBRARY->TM_LOCK);
+
+    // suspend_disable_count must be 0 on potentially
+    // blocking operation to prevent suspension deadlocks,
+    // meaning that the thread is safe for suspension
+    saved_count = reset_suspend_disable();
+    r = hymutex_lock(TM_LIBRARY->TM_LOCK);
+    if (r) return r;
+
+    // make sure we do not get a global thread lock
+    // while being requested to suspend
+    while (self->suspend_request) {
+        // give up global thread lock before safepoint,
+        // because this thread can be suspended at a safepoint
+        r = hymutex_unlock(TM_LIBRARY->TM_LOCK);
+        if (r) return r;
+        hythread_safe_point();
+        r = hymutex_lock(TM_LIBRARY->TM_LOCK);
+        if (r) return r;
+    }
+
+    // do not use set_suspend_disable() as we do not
+    // want safe points happening under global lock
+    self->suspend_disable_count = saved_count;
+    return 0;
 }
 
 /**

Modified: harmony/enhanced/drlvm/trunk/vm/vmcore/src/class_support/C_Interface.cpp
URL: http://svn.apache.org/viewvc/harmony/enhanced/drlvm/trunk/vm/vmcore/src/class_support/C_Interface.cpp?view=diff&rev=514249&r1=514248&r2=514249
==============================================================================
--- harmony/enhanced/drlvm/trunk/vm/vmcore/src/class_support/C_Interface.cpp (original)
+++ harmony/enhanced/drlvm/trunk/vm/vmcore/src/class_support/C_Interface.cpp Sat Mar  3 13:42:34 2007
@@ -2296,9 +2296,7 @@
 
 void vm_gc_lock_enum()
 {
-    tmn_suspend_enable();
     hythread_global_lock();
-    tmn_suspend_disable();
 } // vm_gc_lock_enum