commit 310008008c90fea246efd00cb99ee7ded97c5209
author Mathieu Chartier <mathieuc@google.com> Sun Jun 14 14:14:37 2015 -0700
committer Mathieu Chartier <mathieuc@google.com> Mon Jun 22 15:45:13 2015 -0700
tree 93ef04470ec9c883e003b0a8043b370b8f05718f
parent f7012291ed9c984e2b50d83d7a2d5758cd64c99a

New experimental GC stress mode

Tries to do a GC for every unique call stack (up to 16 frames).
The goal is to catch moving GC bugs and lock violations without being
rediculously slow. Some tests fail on 64 bits, 32 bit host doesn't
work. N5 is booting.

Added runtime -Xgc options: gcstress and nogcstress.

Bug: 21664466

Change-Id: Icb8e420f2048e8ee83bcca7937563166a2638f5c

runtime/gc/heap.h

diff --git a/runtime/gc/heap.h b/runtime/gc/heap.h
index 18244c8..8f4bd2a 100644
--- a/runtime/gc/heap.h
+++ b/runtime/gc/heap.h
@@ -19,6 +19,7 @@
 
 #include <iosfwd>
 #include <string>
+#include <unordered_set>
 #include <vector>
 
 #include "allocator_type.h"
@@ -181,7 +182,8 @@
                 bool ignore_max_footprint, bool use_tlab,
                 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap,
                 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc,
-                bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction,
+                bool verify_post_gc_rosalloc, bool gc_stress_mode,
+                bool use_homogeneous_space_compaction,
                 uint64_t min_interval_homogeneous_space_compaction_by_oom);
 
   ~Heap();
@@ -909,6 +911,10 @@
 
   void UpdateGcCountRateHistograms() EXCLUSIVE_LOCKS_REQUIRED(gc_complete_lock_);
 
+  // GC stress mode attempts to do one GC per unique backtrace.
+  void CheckGcStressMode(Thread* self, mirror::Object** obj)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   // All-known continuous spaces, where objects lie within fixed bounds.
   std::vector<space::ContinuousSpace*> continuous_spaces_;
 
@@ -1064,6 +1070,7 @@
   bool verify_pre_gc_rosalloc_;
   bool verify_pre_sweeping_rosalloc_;
   bool verify_post_gc_rosalloc_;
+  const bool gc_stress_mode_;
 
   // RAII that temporarily disables the rosalloc verification during
   // the zygote fork.
@@ -1219,6 +1226,14 @@
   std::unique_ptr<AllocRecordObjectMap> allocation_records_
       GUARDED_BY(Locks::alloc_tracker_lock_);
 
+  // GC stress related data structures.
+  Mutex* backtrace_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
+  // Debugging variables, seen backtraces vs unique backtraces.
+  Atomic<uint64_t> seen_backtrace_count_;
+  Atomic<uint64_t> unique_backtrace_count_;
+  // Stack trace hashes that we already saw,
+  std::unordered_set<uint64_t> seen_backtraces_ GUARDED_BY(backtrace_lock_);
+
   friend class CollectorTransitionTask;
   friend class collector::GarbageCollector;
   friend class collector::MarkCompact;