commit 733b0202736dde8508f7764bbf98e92684002acc
author Mythri Alle <mythria@google.com> Fri Jan 13 13:32:21 2023 +0000
committer Mythri Alle <mythria@google.com> Mon Jan 16 13:32:54 2023 +0000
tree 4d6b6f6ff503b6639c36a281246780ee4637340d
parent ae12f96965dd1fb1cf5fefb0188b749e921ba88b

Reland "Limited deopt request from jvmti should enable entry / exit hooks""

This reverts commit b69a3ebf5a4a4ef8ae25db170fce9e25844a2f1b.

Reason for revert: Re-landing with a fix.
It is OK to use resolution stubs when entry / exit stubs are required.
Resolution stubs fetch code that supports entry / exit hooks when required.

Change-Id: I0e7d807df2c92249cd17e2a5df324ac47e248874

openjdkjvmti/deopt_manager.cc

diff --git a/openjdkjvmti/deopt_manager.cc b/openjdkjvmti/deopt_manager.cc
index 129aa0f..99acb87 100644
--- a/openjdkjvmti/deopt_manager.cc
+++ b/openjdkjvmti/deopt_manager.cc
@@ -496,6 +496,15 @@
   art::ScopedThreadStateChange stsc(self, art::ThreadState::kSuspended);
   deoptimization_status_lock_.ExclusiveLock(self);
   deopter_count_++;
+  if (deopter_count_ == 1) {
+    // When we add a deoptimization requester, we should enable entry / exit hooks. We only call
+    // this in debuggable runtimes and hence it won't be necessary to update entrypoints but we
+    // still need to inform instrumentation that we need to actually run entry / exit hooks. Though
+    // entrypoints are capable of running entry / exit hooks they won't run them unless enabled.
+    ScopedDeoptimizationContext sdc(self, this);
+    art::Runtime::Current()->GetInstrumentation()->EnableEntryExitHooks(kInstrumentationKey);
+    return;
+  }
   deoptimization_status_lock_.ExclusiveUnlock(self);
 }
 

runtime/instrumentation.cc

diff --git a/runtime/instrumentation.cc b/runtime/instrumentation.cc
index 60511b5..62a2d8f 100644
--- a/runtime/instrumentation.cc
+++ b/runtime/instrumentation.cc
@@ -223,8 +223,11 @@
     return false;
   }
 
-  // Code running in the interpreter doesn't need entry/exit stubs.
-  if (Runtime::Current()->GetClassLinker()->IsQuickToInterpreterBridge(entry_point)) {
+  ClassLinker* linker = Runtime::Current()->GetClassLinker();
+  // Interpreter supports entry / exit hooks. Resolution stubs fetch code that supports entry / exit
+  // hooks when required. So return true for both cases.
+  if (linker->IsQuickToInterpreterBridge(entry_point) ||
+      linker->IsQuickResolutionStub(entry_point)) {
     return true;
   }
 
@@ -238,7 +241,7 @@
   }
 
   // GenericJni trampoline can handle entry / exit hooks.
-  if (Runtime::Current()->GetClassLinker()->IsQuickGenericJniStub(entry_point)) {
+  if (linker->IsQuickGenericJniStub(entry_point)) {
     return true;
   }
 
@@ -881,6 +884,11 @@
   instrumentation_level_ = requested_level;
 }
 
+void Instrumentation::EnableEntryExitHooks(const char* key) {
+  DCHECK(Runtime::Current()->IsJavaDebuggable());
+  ConfigureStubs(key, InstrumentationLevel::kInstrumentWithInstrumentationStubs);
+}
+
 void Instrumentation::MaybeRestoreInstrumentationStack() {
   // Restore stack only if there is no method currently deoptimized.
   if (!IsDeoptimizedMethodsEmpty()) {

runtime/instrumentation.h

diff --git a/runtime/instrumentation.h b/runtime/instrumentation.h
index 3d868eb..626ff8e 100644
--- a/runtime/instrumentation.h
+++ b/runtime/instrumentation.h
@@ -243,6 +243,11 @@
   void DisableDeoptimization(const char* key)
       REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_);
 
+  // Enables entry exit hooks support. This is called in preparation for debug requests that require
+  // calling method entry / exit hooks.
+  void EnableEntryExitHooks(const char* key)
+      REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_);
+
   bool AreAllMethodsDeoptimized() const {
     return InterpreterStubsInstalled();
   }