8255384: Remove special_runtime_exit_condition() check from SS::block()

Reviewed-by: dholmes, rrich, dcubed

Author: pchilano

src/hotspot/share/interpreter/zero/bytecodeInterpreter.cpp

@@ -102,11 +102,14 @@
   There really shouldn't be any handles remaining to trash but this is cheap
   in relation to a safepoint.
 */
-#define SAFEPOINT                                                                 \
-    {                                                                             \
-       /* zap freed handles rather than GC'ing them */                            \
-       HandleMarkCleaner __hmc(THREAD);                                           \
-       CALL_VM(SafepointMechanism::process_if_requested(THREAD), handle_exception); \
+#define SAFEPOINT                                                                                            \
+    {                                                                                                        \
+       /* zap freed handles rather than GC'ing them */                                                       \
+       HandleMarkCleaner __hmc(THREAD);                                                                      \
+       if (SafepointMechanism::should_process(THREAD)) {                                                     \
+         CALL_VM(SafepointMechanism::process_if_requested_with_exit_check(THREAD, true /* check asyncs */),  \
+                 handle_exception);                                                                          \
+       }                                                                                                     \
     }
 
 /*

src/hotspot/share/runtime/safepoint.cpp

@@ -737,29 +737,6 @@ void SafepointSynchronize::block(JavaThread *thread) {
   guarantee(thread->safepoint_state()->get_safepoint_id() == InactiveSafepointCounter,
             "The safepoint id should be set only in block path");
 
-  // Check for pending. async. exceptions or suspends - except if the
-  // thread was blocked inside the VM. has_special_runtime_exit_condition()
-  // is called last since it grabs a lock and we only want to do that when
-  // we must.
-  //
-  // Note: we never deliver an async exception at a polling point as the
-  // compiler may not have an exception handler for it. The polling
-  // code will notice the async and deoptimize and the exception will
-  // be delivered. (Polling at a return point is ok though). Sure is
-  // a lot of bother for a deprecated feature...
-  //
-  // We don't deliver an async exception if the thread state is
-  // _thread_in_native_trans so JNI functions won't be called with
-  // a surprising pending exception. If the thread state is going back to java,
-  // async exception is checked in check_special_condition_for_native_trans().
-
-  if (state != _thread_blocked_trans &&
-      state != _thread_in_vm_trans &&
-      thread->has_special_runtime_exit_condition()) {
-    thread->handle_special_runtime_exit_condition(
-      !thread->is_at_poll_safepoint() && (state != _thread_in_native_trans));
-  }
-
   // cross_modify_fence is done by SafepointMechanism::process_if_requested
   // which is the only caller here.
 }
@@ -955,12 +932,7 @@ void ThreadSafepointState::handle_polling_page_exception() {
     StackWatermarkSet::after_unwind(self);
 
     // Process pending operation
-    SafepointMechanism::process_if_requested(self);
-    // We have to wait if we are here because of a handshake for object deoptimization.
-    if (self->is_obj_deopt_suspend()) {
-      self->wait_for_object_deoptimization();
-    }
-    self->check_and_handle_async_exceptions();
+    SafepointMechanism::process_if_requested_with_exit_check(self, true /* check asyncs */);
 
     // restore oop result, if any
     if (return_oop) {
@@ -970,17 +942,18 @@ void ThreadSafepointState::handle_polling_page_exception() {
 
   // This is a safepoint poll. Verify the return address and block.
   else {
-    set_at_poll_safepoint(true);
 
     // verify the blob built the "return address" correctly
     assert(real_return_addr == caller_fr.pc(), "must match");
 
+    set_at_poll_safepoint(true);
     // Process pending operation
-    SafepointMechanism::process_if_requested(self);
-    // We have to wait if we are here because of a handshake for object deoptimization.
-    if (self->is_obj_deopt_suspend()) {
-      self->wait_for_object_deoptimization();
-    }
+    // We never deliver an async exception at a polling point as the
+    // compiler may not have an exception handler for it. The polling
+    // code will notice the pending async exception, deoptimize and
+    // the exception will be delivered. (Polling at a return point
+    // is ok though). Sure is a lot of bother for a deprecated feature...
+    SafepointMechanism::process_if_requested_with_exit_check(self, false /* check asyncs */);
     set_at_poll_safepoint(false);
 
     // If we have a pending async exception deoptimize the frame

src/hotspot/share/runtime/safepointMechanism.cpp

@@ -80,7 +80,7 @@ void SafepointMechanism::process(JavaThread *thread) {
     // Any load in ::block must not pass the global poll load.
     // Otherwise we might load an old safepoint counter (for example).
     OrderAccess::loadload();
-    SafepointSynchronize::block(thread); // Recursive
+    SafepointSynchronize::block(thread);
   }
 
   // The call to on_safepoint fixes the thread's oops and the first few frames.

src/hotspot/share/runtime/safepointMechanism.hpp

@@ -83,6 +83,7 @@ class SafepointMechanism : public AllStatic {
 
   // Processes a pending requested operation.
   static inline void process_if_requested(JavaThread* thread);
+  static inline void process_if_requested_with_exit_check(JavaThread* thread, bool check_asyncs);
   // Compute what the poll values should be and install them.
   static void update_poll_values(JavaThread* thread);
 

src/hotspot/share/runtime/safepointMechanism.inline.hpp

@@ -80,6 +80,13 @@ void SafepointMechanism::process_if_requested(JavaThread *thread) {
   process_if_requested_slow(thread);
 }
 
+void SafepointMechanism::process_if_requested_with_exit_check(JavaThread* thread, bool check_asyncs) {
+  process_if_requested(thread);
+  if (thread->has_special_runtime_exit_condition()) {
+    thread->handle_special_runtime_exit_condition(check_asyncs);
+  }
+}
+
 void SafepointMechanism::arm_local_poll(JavaThread* thread) {
   thread->poll_data()->set_polling_word(_poll_word_armed_value);
   thread->poll_data()->set_polling_page(_poll_page_armed_value);

src/hotspot/share/runtime/thread.cpp

@@ -2409,11 +2409,11 @@ void JavaThread::java_suspend_self_with_safepoint_check() {
     // might return to _thread_in_Java and execute bytecodes for an arbitrary
     // long time.
     set_thread_state_fence(state);
-  } while (is_external_suspend());
 
-  if (state != _thread_in_native) {
-    SafepointMechanism::process_if_requested(this);
-  }
+    if (state != _thread_in_native) {
+      SafepointMechanism::process_if_requested(this);
+    }
+  } while (is_external_suspend());
 }
 
 // Wait for another thread to perform object reallocation and relocking on behalf of
@@ -2493,20 +2493,9 @@ void JavaThread::verify_not_published() {
 // directly and when thread state is _thread_in_native_trans
 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
   assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
-
   assert(!thread->has_last_Java_frame() || thread->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
 
-  if (thread->is_external_suspend()) {
-    thread->java_suspend_self_with_safepoint_check();
-  } else {
-    SafepointMechanism::process_if_requested(thread);
-  }
-
-  if (thread->is_obj_deopt_suspend()) {
-    thread->wait_for_object_deoptimization();
-  }
-
-  JFR_ONLY(SUSPEND_THREAD_CONDITIONAL(thread);)
+  SafepointMechanism::process_if_requested_with_exit_check(thread, false /* check asyncs */);
 }
 
 // Slow path when the native==>VM/Java barriers detect a safepoint is in