commit 07e3ca9a46801990d662c48d0fddedc63c4c053c
author Nicolas Geoffray <ngeoffray@google.com> Fri Mar 11 09:57:57 2016 +0000
committer Nicolas Geoffray <ngeoffray@google.com> Fri Mar 11 09:57:57 2016 +0000
tree 94fedc96b28c6a46d2b83c80b2cfefd4c2898f4a
parent b7f257f353b1eb2db2732939a0404c118316891d

Fix thread race when fetching the ProfilingInfo object.

Problem is:
1) Compiler fetches the ProfilingInfo of A, it's null.
2) Mutator creates the ProfilingInfo.
3) Compiler notifies it's not using A anymore, calls
   ProfilingInfo::DecrementInlineUse -> Crash as we expected
   ProfilingInfo::IncrementUse to be called before.

Also update some namings to better reflect what is going on.

Change-Id: I55ea4c5d81988131467095e18a0d13a8be9d0ef7

compiler/optimizing/inliner.cc

diff --git a/compiler/optimizing/inliner.cc b/compiler/optimizing/inliner.cc
index bbdac26..d861e39 100644
--- a/compiler/optimizing/inliner.cc
+++ b/compiler/optimizing/inliner.cc
@@ -224,16 +224,29 @@
 
 class ScopedProfilingInfoInlineUse {
  public:
-  explicit ScopedProfilingInfoInlineUse(ArtMethod* method) : method_(method) {
-    Runtime::Current()->GetJit()->GetCodeCache()->NotifyInliningOf(method_, Thread::Current());
+  explicit ScopedProfilingInfoInlineUse(ArtMethod* method, Thread* self)
+      : method_(method),
+        self_(self),
+        // Fetch the profiling info ahead of using it. If it's null when fetching,
+        // we should not call JitCodeCache::DoneInlining.
+        profiling_info_(
+            Runtime::Current()->GetJit()->GetCodeCache()->NotifyCompilerUse(method, self)) {
   }
 
   ~ScopedProfilingInfoInlineUse() {
-    Runtime::Current()->GetJit()->GetCodeCache()->DoneInlining(method_, Thread::Current());
+    if (profiling_info_ != nullptr) {
+      size_t pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
+      DCHECK_EQ(profiling_info_, method_->GetProfilingInfo(pointer_size));
+      Runtime::Current()->GetJit()->GetCodeCache()->DoneCompilerUse(method_, self_);
+    }
   }
 
+  ProfilingInfo* GetProfilingInfo() const { return profiling_info_; }
+
  private:
   ArtMethod* const method_;
+  Thread* const self_;
+  ProfilingInfo* const profiling_info_;
 };
 
 bool HInliner::TryInline(HInvoke* invoke_instruction) {
@@ -287,15 +300,14 @@
 
   // Check if we can use an inline cache.
   ArtMethod* caller = graph_->GetArtMethod();
-  size_t pointer_size = class_linker->GetImagePointerSize();
   if (Runtime::Current()->UseJit()) {
     // Under JIT, we should always know the caller.
     DCHECK(caller != nullptr);
-    ScopedProfilingInfoInlineUse spiis(caller);
-    ProfilingInfo* profiling_info = caller->GetProfilingInfo(pointer_size);
+    ScopedProfilingInfoInlineUse spiis(caller, soa.Self());
+    ProfilingInfo* profiling_info = spiis.GetProfilingInfo();
     if (profiling_info != nullptr) {
       const InlineCache& ic = *profiling_info->GetInlineCache(invoke_instruction->GetDexPc());
-      if (ic.IsUnitialized()) {
+      if (ic.IsUninitialized()) {
         VLOG(compiler) << "Interface or virtual call to "
                        << PrettyMethod(method_index, caller_dex_file)
                        << " is not hit and not inlined";