Load shadow frame's this object only upon instrumentation.

We used to load the shadow frame's this object when entering the interpreter
and push it into thread's SIRT to make it visible to garbage collector. But
it is only used by instrumentation listeners.

We now move this load at each place an instrumentation listener is called. This
avoids loading it when instrumentation is disabled. This also allows to remove
the SIRT reference and the push/pop management it implies when entering/exiting
the interpreter.

The performance improvement is 6% in average on our benchmarks suite.

This CL also makes method Instrumentation::ExceptionCaughtEvent const so we can
use a "const instrumentation::Instrumentation*" object in interpreter.

Change-Id: I2caccba9a906f244c8057b24031250f9824cc711

1 files changed, 15 insertions, 21 deletions

diff --git a/runtime/interpreter/interpreter_goto_table_impl.cc b/runtime/interpreter/interpreter_goto_table_impl.cc
index 7f4c7c8..4bef770 100644
--- a/runtime/interpreter/interpreter_goto_table_impl.cc
+++ b/runtime/interpreter/interpreter_goto_table_impl.cc
@@ -24,7 +24,6 @@ namespace interpreter {
 // - "inst" : the current Instruction*.
 // - "dex_pc": the current pc.
 // - "shadow_frame": the current shadow frame.
-// - "insns": the start of current method's code item.
 // - "mh": the current MethodHelper.
 // - "currentHandlersTable": the current table of pointer to each instruction handler.
 
@@ -78,22 +77,16 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
     return JValue();
   }
   self->VerifyStack();
-  instrumentation::Instrumentation* const instrumentation = Runtime::Current()->GetInstrumentation();
-
-  // As the 'this' object won't change during the execution of current code, we
-  // want to cache it in local variables. Nevertheless, in order to let the
-  // garbage collector access it, we store it into sirt references.
-  SirtRef<Object> this_object_ref(self, shadow_frame.GetThisObject(code_item->ins_size_));
 
   uint32_t dex_pc = shadow_frame.GetDexPC();
+  const instrumentation::Instrumentation* const instrumentation = Runtime::Current()->GetInstrumentation();
   if (LIKELY(dex_pc == 0)) {  // We are entering the method as opposed to deoptimizing..
     if (UNLIKELY(instrumentation->HasMethodEntryListeners())) {
-      instrumentation->MethodEnterEvent(self, this_object_ref.get(),
+      instrumentation->MethodEnterEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                         shadow_frame.GetMethod(), 0);
     }
   }
-  const uint16_t* const insns = code_item->insns_;
-  const Instruction* inst = Instruction::At(insns + dex_pc);
+  const Instruction* inst = Instruction::At(code_item->insns_ + dex_pc);
 
   // Define handlers table.
   static const void* handlersTable[kNumPackedOpcodes] = {
@@ -212,7 +205,7 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
       CheckSuspend(self);
     }
     if (UNLIKELY(instrumentation->HasMethodExitListeners())) {
-      instrumentation->MethodExitEvent(self, this_object_ref.get(),
+      instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                        shadow_frame.GetMethod(), dex_pc,
                                        result);
     }
@@ -227,7 +220,7 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
       CheckSuspend(self);
     }
     if (UNLIKELY(instrumentation->HasMethodExitListeners())) {
-      instrumentation->MethodExitEvent(self, this_object_ref.get(),
+      instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                        shadow_frame.GetMethod(), dex_pc,
                                        result);
     }
@@ -243,7 +236,7 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
       CheckSuspend(self);
     }
     if (UNLIKELY(instrumentation->HasMethodExitListeners())) {
-      instrumentation->MethodExitEvent(self, this_object_ref.get(),
+      instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                        shadow_frame.GetMethod(), dex_pc,
                                        result);
     }
@@ -258,7 +251,7 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
       CheckSuspend(self);
     }
     if (UNLIKELY(instrumentation->HasMethodExitListeners())) {
-      instrumentation->MethodExitEvent(self, this_object_ref.get(),
+      instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                        shadow_frame.GetMethod(), dex_pc,
                                        result);
     }
@@ -274,7 +267,7 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
       CheckSuspend(self);
     }
     if (UNLIKELY(instrumentation->HasMethodExitListeners())) {
-      instrumentation->MethodExitEvent(self, this_object_ref.get(),
+      instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),
                                        shadow_frame.GetMethod(), dex_pc,
                                        result);
     }
@@ -2324,8 +2317,9 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
     if (UNLIKELY(self->TestAllFlags())) {
       CheckSuspend(self);
     }
+    Object* this_object = shadow_frame.GetThisObject(code_item->ins_size_);
     uint32_t found_dex_pc = FindNextInstructionFollowingException(self, shadow_frame, dex_pc,
-                                                                  this_object_ref,
+                                                                  this_object,
                                                                   instrumentation);
     if (found_dex_pc == DexFile::kDexNoIndex) {
       return JValue(); /* Handled in caller. */
@@ -2336,11 +2330,11 @@ JValue ExecuteGotoImpl(Thread* self, MethodHelper& mh, const DexFile::CodeItem*
   }
 
   // Create alternative instruction handlers dedicated to instrumentation.
-#define INSTRUMENTATION_INSTRUCTION_HANDLER(o, code, n, f, r, i, a, v)    \
-  instrumentation_op_##code: {                                            \
-    instrumentation->DexPcMovedEvent(self, this_object_ref.get(),         \
-                                     shadow_frame.GetMethod(), dex_pc);   \
-    goto *handlersTable[Instruction::code];                               \
+#define INSTRUMENTATION_INSTRUCTION_HANDLER(o, code, n, f, r, i, a, v)                        \
+  instrumentation_op_##code: {                                                                \
+    instrumentation->DexPcMovedEvent(self, shadow_frame.GetThisObject(code_item->ins_size_),  \
+                                     shadow_frame.GetMethod(), dex_pc);                       \
+    goto *handlersTable[Instruction::code];                                                   \
   }
 #include "dex_instruction_list.h"
       DEX_INSTRUCTION_LIST(INSTRUMENTATION_INSTRUCTION_HANDLER)