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

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rev 47413 : Introduce SafepointMechanism
rev 47415 : Add Thread Local handshakes and thread local polling

@@ -25,23 +25,68 @@
 #ifndef SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP
 #define SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP
 
 #include "runtime/safepointMechanism.hpp"
 #include "runtime/safepoint.hpp"
-#include "runtime/thread.hpp"
+#include "runtime/thread.inline.hpp"
 
+bool SafepointMechanism::local_poll_armed(JavaThread* thread) {
+  const intptr_t poll_word = reinterpret_cast<intptr_t>(thread->get_polling_page());
+  return mask_bits_are_true(poll_word, poll_bit());
+}
 
 bool SafepointMechanism::global_poll() {
   return SafepointSynchronize::do_call_back();
 }
 
-bool SafepointMechanism::poll() {
+bool SafepointMechanism::local_poll(Thread* thread) {
+  // Mutexes can be taken but none JavaThread. These cannot have handshakes
+  // operation but they must stop for safepoints.
+  if (thread->is_Java_thread()) {
+    return local_poll_armed((JavaThread*)thread);
+  } else {
+    return global_poll();
+  }
+}
+
+bool SafepointMechanism::poll(Thread* thread) {
+  if (uses_thread_local_poll()) {
+    return local_poll(thread);
+  } else {
   return global_poll();
+  }
+}
+
+void SafepointMechanism::block_if_requested_local_poll(JavaThread *thread) {
+  bool armed = local_poll_armed(thread); // load acquire, polling page -> op / global state
+  if(armed) {
+    // We could be armed for either a handshake operation or a safepoint
+    if (thread->has_handshake()) {
+      thread->handshake_process_by_self();
+    } else {
+      if (global_poll()) {
+        SafepointSynchronize::block(thread);
+      }
+    }
+  }
 }
 
 void SafepointMechanism::block_if_requested(JavaThread *thread) {
+  if (uses_thread_local_poll()) {
+    block_if_requested_local_poll(thread);
+  } else {
+    // If we don't have per thread poll this could a handshake or a safepoint
   if (global_poll()) {
     SafepointSynchronize::block(thread);
   }
+  }
+}
+
+void SafepointMechanism::arm_local_poll(JavaThread* thread) {
+  thread->set_polling_page(poll_armed_value());
+}
+
+void SafepointMechanism::disarm_local_poll(JavaThread* thread) {
+  thread->set_polling_page(poll_disarmed_value());
 }
 
 #endif // SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP
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