Revert^4 "Rewrite JVMTI method tracing to use trampolines"

Since we are unable to change the semantics of ClassLoaded and
ClassPrepared due to b/111394423 for the moment changes were made in
libjdwp to remove the deadlock between the jit being stopped and
jit-threads trying to lock JVMTI monitors in libjdwp.

Until some resolution for b/111394423 is implemented agents should be
very careful about gaining locks in the ClassLoaded, ClassPrepared or
VMObjectAlloc events if said lock is held over a call to
SetEventNotificationMode, SetExtensionEventCallback,
RetransformClasses, or RedefineClasses. These locks can only be
safely held if the object argument to the event is not an array-class
object or the thread is known not to be a jit thread.

This reverts commit bf2ca05ccf658a9f626d1cb3f1adca6087ece7b8.

Bug: 111394423
Test: ./art/tools/run-libjdwp-tests.sh --mode=host --debug

Reason for revert: Fixed issue with libjdwp deadlocking on jit threads

Change-Id: I8baeb8311f67062cbc26286eb221da34e1972f27

1 files changed, 15 insertions, 0 deletions

diff --git a/runtime/jit/jit_code_cache.cc b/runtime/jit/jit_code_cache.cc
index eeb35156b5..70a717154b 100644
--- a/runtime/jit/jit_code_cache.cc
+++ b/runtime/jit/jit_code_cache.cc
@@ -362,6 +362,21 @@ const void* JitCodeCache::GetJniStubCode(ArtMethod* method) {
   return nullptr;
 }
 
+void JitCodeCache::ClearAllCompiledDexCode() {
+  MutexLock mu(Thread::Current(), lock_);
+  // Get rid of OSR code waiting to be put on a thread.
+  osr_code_map_.clear();
+
+  // We don't clear out or even touch method_code_map_ since that is what we use to go the other
+  // way, move from code currently-running to the method it's from. Getting rid of it would break
+  // the jit-gc, stack-walking and signal handling. Since we never look through it to go the other
+  // way (from method -> code) everything is fine.
+
+  for (ProfilingInfo* p : profiling_infos_) {
+    p->SetSavedEntryPoint(nullptr);
+  }
+}
+
 const void* JitCodeCache::FindCompiledCodeForInstrumentation(ArtMethod* method) {
   // If jit-gc is still on we use the SavedEntryPoint field for doing that and so cannot use it to
   // find the instrumentation entrypoint.