8246265: ZGC: Introduce ZConditionLock

Reviewed-by: eosterlund, stefank

src/hotspot/share/gc/z/zLock.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, 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
@@ -52,6 +52,20 @@ class ZReentrantLock {
   bool is_owned() const;
 };
 
+class ZConditionLock {
+private:
+  os::PlatformMonitor _lock;
+
+public:
+  void lock();
+  bool try_lock();
+  void unlock();
+
+  bool wait(uint64_t millis = 0);
+  void notify();
+  void notify_all();
+};
+
 template <typename T>
 class ZLocker : public StackObj {
 private:

src/hotspot/share/gc/z/zLock.inline.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, 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
@@ -77,6 +77,30 @@ inline bool ZReentrantLock::is_owned() const {
   return owner == thread;
 }
 
+inline void ZConditionLock::lock() {
+  _lock.lock();
+}
+
+inline bool ZConditionLock::try_lock() {
+  return _lock.try_lock();
+}
+
+inline void ZConditionLock::unlock() {
+  _lock.unlock();
+}
+
+inline bool ZConditionLock::wait(uint64_t millis) {
+  return _lock.wait(millis) == OS_OK;
+}
+
+inline void ZConditionLock::notify() {
+  _lock.notify();
+}
+
+inline void ZConditionLock::notify_all() {
+  _lock.notify_all();
+}
+
 template <typename T>
 inline ZLocker<T>::ZLocker(T* lock) :
     _lock(lock) {