Revert^4 "JVMTI PopFrame support"
This reverts commit 202b617acf477e8e8e11915f467120a0bd518e74.
This unreverts commit 202b617acf.
This unreverts commit 88a2a9d7a1.
There were several bugs with the implementation of pop-frame related
to interactions between the jit, exception handling, class-loading,
and deoptimization.
- We were instrumenting the target thread stack in cases where it was
unnecessary which caused the exception handler to incorrectly
determine that a method was not deoptimizable. This caused the
pop-frame to be ignored.
- We were incorrectly sending ExceptionCatch events if an exception
suppressed by pop-frame would have been caught in the current frame.
- We were allowing pop-frame to be used on threads suspended in the
ClassLoad or ClassPrepare events despite having surprising semantics
in that situation (see b/117615146).
Needed to modify test 1953 slightly for inclusion in CTS. I needed to
make the CTS entrypoint not run the class-load tests (since the cts
configuration means the classes are loaded by the verifier and not the
interpreter). I updated the expected.txt and check script to reflect
this.
Reason for revert: Fixed issue causing Exception events to sometimes
eat PopFrame and other issues.
Test: ./test.py --host
Test: ./art/tools/run-libjdwp-tests.sh --mode=host
Bug: 73255278
Bug: 111357976
Bug: 117533193
Bug: 117615146
Change-Id: I655c4fe769938cf41d7589f931d6710cf2001506
diff --git a/openjdkjvmti/ti_stack.cc b/openjdkjvmti/ti_stack.cc
index 220ad22..5a98755 100644
--- a/openjdkjvmti/ti_stack.cc
+++ b/openjdkjvmti/ti_stack.cc
@@ -112,6 +112,23 @@
size_t stop;
};
+art::ShadowFrame* FindFrameAtDepthVisitor::GetOrCreateShadowFrame(bool* created_frame) {
+ art::ShadowFrame* cur = GetCurrentShadowFrame();
+ if (cur == nullptr) {
+ *created_frame = true;
+ art::ArtMethod* method = GetMethod();
+ const uint16_t num_regs = method->DexInstructionData().RegistersSize();
+ cur = GetThread()->FindOrCreateDebuggerShadowFrame(GetFrameId(),
+ num_regs,
+ method,
+ GetDexPc());
+ DCHECK(cur != nullptr);
+ } else {
+ *created_frame = false;
+ }
+ return cur;
+}
+
template <typename FrameFn>
GetStackTraceVisitor<FrameFn> MakeStackTraceVisitor(art::Thread* thread_in,
size_t start,
@@ -1065,16 +1082,7 @@
// From here we are sure to succeed.
bool needs_instrument = false;
// Get/create a shadow frame
- art::ShadowFrame* shadow_frame = visitor.GetCurrentShadowFrame();
- if (shadow_frame == nullptr) {
- needs_instrument = true;
- const size_t frame_id = visitor.GetFrameId();
- const uint16_t num_regs = method->DexInstructionData().RegistersSize();
- shadow_frame = target->FindOrCreateDebuggerShadowFrame(frame_id,
- num_regs,
- method,
- visitor.GetDexPc());
- }
+ art::ShadowFrame* shadow_frame = visitor.GetOrCreateShadowFrame(&needs_instrument);
{
art::WriterMutexLock lk(self, tienv->event_info_mutex_);
// Mark shadow frame as needs_notify_pop_
@@ -1089,4 +1097,88 @@
} while (true);
}
+jvmtiError StackUtil::PopFrame(jvmtiEnv* env ATTRIBUTE_UNUSED, jthread thread) {
+ art::Thread* self = art::Thread::Current();
+ art::Thread* target;
+ do {
+ ThreadUtil::SuspendCheck(self);
+ art::MutexLock ucsl_mu(self, *art::Locks::user_code_suspension_lock_);
+ // Make sure we won't be suspended in the middle of holding the thread_suspend_count_lock_ by a
+ // user-code suspension. We retry and do another SuspendCheck to clear this.
+ if (ThreadUtil::WouldSuspendForUserCodeLocked(self)) {
+ continue;
+ }
+ // From now on we know we cannot get suspended by user-code.
+ // NB This does a SuspendCheck (during thread state change) so we need to make sure we don't
+ // have the 'suspend_lock' locked here.
+ art::ScopedObjectAccess soa(self);
+ art::MutexLock tll_mu(self, *art::Locks::thread_list_lock_);
+ jvmtiError err = ERR(INTERNAL);
+ if (!ThreadUtil::GetAliveNativeThread(thread, soa, &target, &err)) {
+ return err;
+ }
+ {
+ art::MutexLock tscl_mu(self, *art::Locks::thread_suspend_count_lock_);
+ if (target == self || target->GetUserCodeSuspendCount() == 0) {
+ // We cannot be the current thread for this function.
+ return ERR(THREAD_NOT_SUSPENDED);
+ }
+ }
+ JvmtiGlobalTLSData* tls_data = ThreadUtil::GetGlobalTLSData(target);
+ constexpr art::StackVisitor::StackWalkKind kWalkKind =
+ art::StackVisitor::StackWalkKind::kIncludeInlinedFrames;
+ if (tls_data != nullptr &&
+ tls_data->disable_pop_frame_depth != JvmtiGlobalTLSData::kNoDisallowedPopFrame &&
+ tls_data->disable_pop_frame_depth == art::StackVisitor::ComputeNumFrames(target,
+ kWalkKind)) {
+ LOG(WARNING) << "Disallowing frame pop due to in-progress class-load/prepare. Frame at depth "
+ << tls_data->disable_pop_frame_depth << " was marked as un-poppable by the "
+ << "jvmti plugin. See b/117615146 for more information.";
+ return ERR(OPAQUE_FRAME);
+ }
+ // We hold the user_code_suspension_lock_ so the target thread is staying suspended until we are
+ // done.
+ std::unique_ptr<art::Context> context(art::Context::Create());
+ FindFrameAtDepthVisitor final_frame(target, context.get(), 0);
+ FindFrameAtDepthVisitor penultimate_frame(target, context.get(), 1);
+ final_frame.WalkStack();
+ penultimate_frame.WalkStack();
+
+ if (!final_frame.FoundFrame() || !penultimate_frame.FoundFrame()) {
+ // Cannot do it if there is only one frame!
+ return ERR(NO_MORE_FRAMES);
+ }
+
+ art::ArtMethod* called_method = final_frame.GetMethod();
+ art::ArtMethod* calling_method = penultimate_frame.GetMethod();
+ if (calling_method->IsNative() || called_method->IsNative()) {
+ return ERR(OPAQUE_FRAME);
+ }
+ // From here we are sure to succeed.
+
+ // Get/create a shadow frame
+ bool created_final_frame = false;
+ bool created_penultimate_frame = false;
+ art::ShadowFrame* called_shadow_frame =
+ final_frame.GetOrCreateShadowFrame(&created_final_frame);
+ art::ShadowFrame* calling_shadow_frame =
+ penultimate_frame.GetOrCreateShadowFrame(&created_penultimate_frame);
+
+ CHECK_NE(called_shadow_frame, calling_shadow_frame)
+ << "Frames at different depths not different!";
+
+ // Tell the shadow-frame to return immediately and skip all exit events.
+ called_shadow_frame->SetForcePopFrame(true);
+ calling_shadow_frame->SetForceRetryInstruction(true);
+
+ // Make sure can we will go to the interpreter and use the shadow frames. The early return for
+ // the final frame will force everything to the interpreter so we only need to instrument if it
+ // was not present.
+ if (created_final_frame) {
+ DeoptManager::Get()->DeoptimizeThread(target);
+ }
+ return OK;
+ } while (true);
+}
+
} // namespace openjdkjvmti