changeset 50192:8bc79d2d1568

8203341: Add a safepoint-aware Semaphore Reviewed-by: pliden, eosterlund
author stefank
date Sun, 20 May 2018 22:10:45 +0200
parents c87fba18f2b9
children 49c3e91c424f
files src/hotspot/share/runtime/handshake.cpp src/hotspot/share/runtime/semaphore.hpp src/hotspot/share/runtime/semaphore.inline.hpp
diffstat 3 files changed, 58 insertions(+), 4 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/runtime/handshake.cpp	Sun May 20 22:08:25 2018 +0200
+++ b/src/hotspot/share/runtime/handshake.cpp	Sun May 20 22:10:45 2018 +0200
@@ -29,7 +29,7 @@
 #include "runtime/handshake.hpp"
 #include "runtime/interfaceSupport.inline.hpp"
 #include "runtime/osThread.hpp"
-#include "runtime/semaphore.hpp"
+#include "runtime/semaphore.inline.hpp"
 #include "runtime/task.hpp"
 #include "runtime/timerTrace.hpp"
 #include "runtime/thread.hpp"
@@ -299,8 +299,7 @@
   CautiouslyPreserveExceptionMark pem(thread);
   ThreadInVMForHandshake tivm(thread);
   if (!_semaphore.trywait()) {
-    ThreadBlockInVM tbivm(thread);
-    _semaphore.wait();
+    _semaphore.wait_with_safepoint_check(thread);
   }
   if (has_operation()) {
     HandshakeOperation* op = _operation;
--- a/src/hotspot/share/runtime/semaphore.hpp	Sun May 20 22:08:25 2018 +0200
+++ b/src/hotspot/share/runtime/semaphore.hpp	Sun May 20 22:10:45 2018 +0200
@@ -37,6 +37,8 @@
 # error "No semaphore implementation provided for this OS"
 #endif
 
+class JavaThread;
+
 // Implements the limited, platform independent Semaphore API.
 class Semaphore : public CHeapObj<mtInternal> {
   SemaphoreImpl _impl;
@@ -54,7 +56,9 @@
   void wait()                 { _impl.wait(); }
 
   bool trywait()              { return _impl.trywait(); }
+
+  void wait_with_safepoint_check();
+  void wait_with_safepoint_check(JavaThread* thread);
 };
 
-
 #endif // SHARE_VM_RUNTIME_SEMAPHORE_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/runtime/semaphore.inline.hpp	Sun May 20 22:10:45 2018 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_RUNTIME_SEMAPHORE_INLINE_HPP
+#define SHARE_VM_RUNTIME_SEMAPHORE_INLINE_HPP
+
+#include "runtime/interfaceSupport.inline.hpp"
+#include "runtime/semaphore.hpp"
+#include "runtime/thread.inline.hpp"
+
+inline void Semaphore::wait_with_safepoint_check(JavaThread* thread) {
+  // Prepare to block and allow safepoints while blocked
+  ThreadBlockInVM tbivm(thread);
+  OSThreadWaitState osts(thread->osthread(), false /* not in Object.wait() */);
+
+  // Wait for value
+  _impl.wait();
+}
+
+inline void Semaphore::wait_with_safepoint_check() {
+  Thread* thread = Thread::current();
+  if (thread->is_Java_thread()) {
+    wait_with_safepoint_check(static_cast<JavaThread*>(thread));
+  } else {
+    // Wait for value
+    _impl.wait();
+  }
+}
+
+#endif // SHARE_VM_RUNTIME_SEMAPHORE_INLINE_HPP