| // -*-c++-*- |
| // vim: set ft=cpp: |
| |
| /* Distributed under the OSI-approved BSD 3-Clause License. See accompanying |
| file Copyright.txt or https://cmake.org/licensing for details. */ |
| #ifndef cm_shared_mutex |
| #define cm_shared_mutex |
| |
| #if __cplusplus >= 201402L || defined(_MSVC_LANG) && _MSVC_LANG >= 201402L |
| # define CMake_HAVE_CXX_SHARED_LOCK |
| #endif |
| #if __cplusplus >= 201703L || defined(_MSVC_LANG) && _MSVC_LANG >= 201703L |
| # define CMake_HAVE_CXX_SHARED_MUTEX |
| #endif |
| |
| #if defined(CMake_HAVE_CXX_SHARED_LOCK) |
| # include <shared_mutex> // IWYU pragma: export |
| #endif |
| #if !defined(CMake_HAVE_CXX_SHARED_MUTEX) |
| # include "cm_uv.h" |
| #endif |
| |
| namespace cm { |
| #if defined(CMake_HAVE_CXX_SHARED_MUTEX) |
| using std::shared_mutex; |
| #else |
| class shared_mutex |
| { |
| uv_rwlock_t _M_; |
| |
| public: |
| using native_handle_type = uv_rwlock_t*; |
| |
| shared_mutex() { uv_rwlock_init(&_M_); } |
| ~shared_mutex() { uv_rwlock_destroy(&_M_); } |
| |
| shared_mutex(shared_mutex const&) = delete; |
| shared_mutex& operator=(shared_mutex const&) = delete; |
| |
| void lock() { uv_rwlock_wrlock(&_M_); } |
| bool try_lock() { return uv_rwlock_trywrlock(&_M_) == 0; } |
| void unlock() { uv_rwlock_wrunlock(&_M_); } |
| |
| void lock_shared() { uv_rwlock_rdlock(&_M_); } |
| void unlock_shared() { uv_rwlock_rdunlock(&_M_); } |
| |
| native_handle_type native_handle() { return &_M_; } |
| }; |
| #endif |
| |
| #if defined(CMake_HAVE_CXX_SHARED_LOCK) |
| using std::shared_lock; |
| #else |
| template <typename T> |
| class shared_lock |
| { |
| T& _mutex; |
| |
| public: |
| using mutex_type = T; |
| |
| shared_lock(T& m) |
| : _mutex(m) |
| { |
| _mutex.lock_shared(); |
| } |
| |
| ~shared_lock() { _mutex.unlock_shared(); } |
| |
| shared_lock(shared_lock const&) = delete; |
| shared_lock& operator=(shared_lock const&) = delete; |
| }; |
| #endif |
| } |
| |
| #endif |