commit b98063a4d54c5a741152a1eebc262d8e223b3b25
author Sebastien Hertz <shertz@google.com> Wed Mar 26 10:57:20 2014 +0100
committer Sebastien Hertz <shertz@google.com> Wed Mar 26 11:05:11 2014 +0100
tree 4a5b3bf342db4a28ead0772746017566a6eab723
parent 909f133bc938928a2403baccc983701cb9ebb17f

Fix alloc tracker locking issue

Fixes a lock level violation where we attempt to take the thread list lock
while already holding the alloc tracker lock. We now avoid holding the alloc
tracker lock when updating allocation entrypoints.

Bug: 13646642
Change-Id: Iab505dae67d0c754031fe30d50a7cbd5e4ba5785

runtime/debugger.cc

diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index c18d5c6e..1ff2003 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -3767,22 +3767,27 @@
 }
 
 void Dbg::SetAllocTrackingEnabled(bool enabled) {
-  MutexLock mu(Thread::Current(), *alloc_tracker_lock_);
   if (enabled) {
-    if (recent_allocation_records_ == NULL) {
-      alloc_record_max_ = GetAllocTrackerMax();
-      LOG(INFO) << "Enabling alloc tracker (" << alloc_record_max_ << " entries of "
-                << kMaxAllocRecordStackDepth << " frames, taking "
-                << PrettySize(sizeof(AllocRecord) * alloc_record_max_) << ")";
-      alloc_record_head_ = alloc_record_count_ = 0;
-      recent_allocation_records_ = new AllocRecord[alloc_record_max_];
-      CHECK(recent_allocation_records_ != NULL);
+    {
+      MutexLock mu(Thread::Current(), *alloc_tracker_lock_);
+      if (recent_allocation_records_ == NULL) {
+        alloc_record_max_ = GetAllocTrackerMax();
+        LOG(INFO) << "Enabling alloc tracker (" << alloc_record_max_ << " entries of "
+            << kMaxAllocRecordStackDepth << " frames, taking "
+            << PrettySize(sizeof(AllocRecord) * alloc_record_max_) << ")";
+        alloc_record_head_ = alloc_record_count_ = 0;
+        recent_allocation_records_ = new AllocRecord[alloc_record_max_];
+        CHECK(recent_allocation_records_ != NULL);
+      }
     }
     Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints();
   } else {
     Runtime::Current()->GetInstrumentation()->UninstrumentQuickAllocEntryPoints();
-    delete[] recent_allocation_records_;
-    recent_allocation_records_ = NULL;
+    {
+      MutexLock mu(Thread::Current(), *alloc_tracker_lock_);
+      delete[] recent_allocation_records_;
+      recent_allocation_records_ = NULL;
+    }
   }
 }