commit 9ef78b59da51080882e47505896b420977fd79ae
author Mathieu Chartier <mathieuc@google.com> Thu Sep 25 17:03:12 2014 -0700
committer Mathieu Chartier <mathieuc@google.com> Fri Sep 26 16:04:56 2014 -0700
tree 6c568756e4e16e68d5d3346261009350969d5b77
parent 95f03e6a4737f90685fab86e98709f1c4393d5ef

Fix broken runtime SetStatsEnabled logic

Previously, Runtime::SetStatsEnabled wouldn't take stats_enabled_
into account when deciding whether or not to increment / decrement
teh stats enabled counter. This resulted in counter underflows and
other errors which caused some CTS tests to fail.

Also added some locking to prevent race conditions.

Bug: 17360878

(cherry picked from commit a98ffd745bbecb2e84a492194950c0b94966546b)

Change-Id: I21d241a58d35bd6a607aa2305c6da81720bd0886

runtime/base/mutex.cc

diff --git a/runtime/base/mutex.cc b/runtime/base/mutex.cc
index 2c95ede..4383a7c 100644
--- a/runtime/base/mutex.cc
+++ b/runtime/base/mutex.cc
@@ -37,6 +37,7 @@
 ReaderWriterMutex* Locks::classlinker_classes_lock_ = nullptr;
 Mutex* Locks::deoptimization_lock_ = nullptr;
 ReaderWriterMutex* Locks::heap_bitmap_lock_ = nullptr;
+Mutex* Locks::instrument_entrypoints_lock_ = nullptr;
 Mutex* Locks::intern_table_lock_ = nullptr;
 Mutex* Locks::jni_libraries_lock_ = nullptr;
 Mutex* Locks::logging_lock_ = nullptr;
@@ -876,6 +877,10 @@
       } \
       current_lock_level = new_level;
 
+    UPDATE_CURRENT_LOCK_LEVEL(kInstrumentEntrypointsLock);
+    DCHECK(instrument_entrypoints_lock_ == nullptr);
+    instrument_entrypoints_lock_ = new Mutex("instrument entrypoint lock", current_lock_level);
+
     UPDATE_CURRENT_LOCK_LEVEL(kMutatorLock);
     DCHECK(mutator_lock_ == nullptr);
     mutator_lock_ = new ReaderWriterMutex("mutator lock", current_lock_level);

runtime/base/mutex.h

diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index 8d2cdce..516fa07 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -100,6 +100,7 @@
   kTraceLock,
   kHeapBitmapLock,
   kMutatorLock,
+  kInstrumentEntrypointsLock,
   kThreadListSuspendThreadLock,
   kZygoteCreationLock,
 
@@ -491,6 +492,9 @@
   // potential deadlock cycle.
   static Mutex* thread_list_suspend_thread_lock_;
 
+  // Guards allocation entrypoint instrumenting.
+  static Mutex* instrument_entrypoints_lock_ ACQUIRED_AFTER(thread_list_suspend_thread_lock_);
+
   // The mutator_lock_ is used to allow mutators to execute in a shared (reader) mode or to block
   // mutators by having an exclusive (writer) owner. In normal execution each mutator thread holds
   // a share on the mutator_lock_. The garbage collector may also execute with shared access but
@@ -549,7 +553,7 @@
   // else                                          |  .. running ..
   //   Goto x                                      |  .. running ..
   //  .. running ..                                |  .. running ..
-  static ReaderWriterMutex* mutator_lock_ ACQUIRED_AFTER(thread_list_suspend_thread_lock_);
+  static ReaderWriterMutex* mutator_lock_ ACQUIRED_AFTER(instrument_entrypoints_lock_);
 
   // Allow reader-writer mutual exclusion on the mark and live bitmaps of the heap.
   static ReaderWriterMutex* heap_bitmap_lock_ ACQUIRED_AFTER(mutator_lock_);