diff options
Diffstat (limited to 'sfntly/port/lock.h')
-rw-r--r-- | sfntly/port/lock.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sfntly/port/lock.h b/sfntly/port/lock.h new file mode 100644 index 0000000..b2e29bf --- /dev/null +++ b/sfntly/port/lock.h @@ -0,0 +1,76 @@ +/* + * Copyright 2011 Google Inc. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ +#define SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ + +#if defined (WIN32) +#include <windows.h> +#else // Assume pthread. +#include <pthread.h> +#include <errno.h> +#endif + +#include "sfntly/port/type.h" + +namespace sfntly { + +#if defined (WIN32) + typedef CRITICAL_SECTION OSLockType; +#else // Assume pthread. + typedef pthread_mutex_t OSLockType; +#endif + +class Lock { + public: + Lock(); + ~Lock(); + + // If the lock is not held, take it and return true. If the lock is already + // held by something else, immediately return false. + bool Try(); + + // Take the lock, blocking until it is available if necessary. + void Acquire(); + + // Release the lock. This must only be called by the lock's holder: after + // a successful call to Try, or a call to Lock. + void Unlock(); + + private: + OSLockType os_lock_; + NO_COPY_AND_ASSIGN(Lock); +}; + +// A helper class that acquires the given Lock while the AutoLock is in scope. +class AutoLock { + public: + explicit AutoLock(Lock& lock) : lock_(lock) { + lock_.Acquire(); + } + + ~AutoLock() { + lock_.Unlock(); + } + + private: + Lock& lock_; + NO_COPY_AND_ASSIGN(AutoLock); +}; + +} // namespace sfntly + +#endif // SFNTLY_CPP_SRC_SFNTLY_PORT_LOCK_H_ |