[checkmk-commits] Tweak SharedMutex for C++14, will probably die soon anyway.

Module: check_mk Branch: master Commit: b02e20067bce96cde593db23a451d236cd5dd092 URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=b02e20067bce96… Author: Sven Panne &lt;sp(a)mathias-kettner.de&gt; Date: Mon Mar 7 10:56:47 2016 +0100 Tweak SharedMutex for C++14, will probably die soon anyway. --- livestatus/src/mk/SharedMutex.h | 86 ++++++++++++++++++--------------------- 1 file changed, 40 insertions(+), 46 deletions(-) diff --git a/livestatus/src/mk/SharedMutex.h b/livestatus/src/mk/SharedMutex.h index 8cfd1ce..ca16e35 100644 --- a/livestatus/src/mk/SharedMutex.h +++ b/livestatus/src/mk/SharedMutex.h @@ -25,45 +25,54 @@ #ifndef mk_SharedMutex_h #define mk_SharedMutex_h -#include "config.h" // IWYU pragma: keep +#include "config.h" // IWYU pragma: keep #include <pthread.h> -#include "Mutex.h" +#include <string.h> +#include <mutex> +#include <system_error> // A more or less drop-in replacement for C++14's <shared_mutex> (partial) namespace mk { -// Note: This is not in the standard, but close enough to shared_mutex for our purposes. +inline void throw_system_error(int err) { + throw std::system_error(std::error_code(err, std::generic_category())); +} + +inline void check_status(int status) { + if (status != 0) throw_system_error(status); +} + +// Note: This is not in the standard, but close enough to shared_mutex for our +// purposes. class rw_mutex { public: typedef pthread_rwlock_t *native_handle_type; rw_mutex() { check_status(pthread_rwlock_init(&_mutex, 0)); } ~rw_mutex() { check_status(pthread_rwlock_destroy(&_mutex)); } void lock() { check_status(pthread_rwlock_wrlock(&_mutex)); } - bool try_lock() - { + bool try_lock() { int status = pthread_rwlock_trywrlock(&_mutex); if (status != EBUSY) check_status(status); return status == 0; } void unlock() { check_status(pthread_rwlock_unlock(&_mutex)); } void lock_shared() { check_status(pthread_rwlock_rdlock(&_mutex)); } - bool try_lock_shared() - { + bool try_lock_shared() { int status = pthread_rwlock_tryrdlock(&_mutex); if (status != EBUSY) check_status(status); return status == 0; } void unlock_shared() { check_status(pthread_rwlock_unlock(&_mutex)); } native_handle_type native_handle() { return &_mutex; } + private: - rw_mutex(const rw_mutex &); // = delete - rw_mutex &operator=(const rw_mutex &); // = delete + rw_mutex(const rw_mutex &); // = delete + rw_mutex &operator=(const rw_mutex &); // = delete pthread_rwlock_t _mutex; }; - template <typename Mutex> class shared_lock { public: @@ -71,26 +80,19 @@ public: shared_lock() : _mutex(0), _owns_lock(false) {} explicit shared_lock(mutex_type &m) - : _mutex(addressOf(m)), _owns_lock(false) - { + : _mutex(addressOf(m)), _owns_lock(false) { lock(); _owns_lock = true; } - shared_lock(mutex_type &m, defer_lock_t) - : _mutex(addressOf(m)), _owns_lock(false) - { - } + shared_lock(mutex_type &m, std::defer_lock_t) + : _mutex(addressOf(m)), _owns_lock(false) {} - shared_lock(mutex_type &m, try_to_lock_t) - : _mutex(addressOf(m)), _owns_lock(_mutex->try_lock_shared()) - { - } + shared_lock(mutex_type &m, std::try_to_lock_t) + : _mutex(addressOf(m)), _owns_lock(_mutex->try_lock_shared()) {} - shared_lock(mutex_type &m, adopt_lock_t) - : _mutex(addressOf(m)), _owns_lock(true) - { - } + shared_lock(mutex_type &m, std::adopt_lock_t) + : _mutex(addressOf(m)), _owns_lock(true) {} // template<typename Clock, typename Duration> // shared_lock(mutex_type& m, @@ -100,24 +102,21 @@ public: // shared_lock(mutex_type& m, // const chrono::duration<Rep, Period>& rtime); - ~shared_lock() - { + ~shared_lock() { if (_owns_lock) unlock(); } // shared_lock(shared_lock&& other) // shared_lock& operator=(shared_lock&& other) - void lock() - { + void lock() { if (!_mutex) throw_system_error(EPERM); if (_owns_lock) throw_system_error(EDEADLK); _mutex->lock_shared(); _owns_lock = true; } - bool try_lock() - { + bool try_lock() { if (!_mutex) throw_system_error(EPERM); if (_owns_lock) throw_system_error(EDEADLK); _owns_lock = _mutex->try_lock_shared(); @@ -130,8 +129,7 @@ public: // template<typename Rep, typename Period> // bool try_lock_for(const chrono::duration<Rep, Period>& rtime) - void unlock() - { + void unlock() { if (!_owns_lock) throw_system_error(EPERM); if (_mutex) { _mutex->unlock_shared(); @@ -139,14 +137,12 @@ public: } } - void swap(shared_lock &other) - { + void swap(shared_lock &other) { std::swap(_mutex, other._mutex); std::swap(_owns_lock, other._owns_lock); } - mutex_type *release() - { + mutex_type *release() { mutex_type *ret = _mutex; _mutex = 0; _owns_lock = false; @@ -154,31 +150,29 @@ public: } bool owns_lock() const { return _owns_lock; } - operator bool() const { return owns_lock(); } // explicit + operator bool() const { return owns_lock(); } // explicit mutex_type *mutex() const { return _mutex; } + private: - shared_lock(const shared_lock &); // = delete; - shared_lock &operator=(const shared_lock &); // = delete; + shared_lock(const shared_lock &); // = delete; + shared_lock &operator=(const shared_lock &); // = delete; mutex_type *_mutex; bool _owns_lock; // basically std::addressof from C++11's <memory> template <typename T> - inline T *addressOf(T &x) - { + inline T *addressOf(T &x) { return reinterpret_cast<T *>( &const_cast<char &>(reinterpret_cast<const volatile char &>(x))); } }; - template <typename Mutex> -void swap(shared_lock<Mutex> &x, shared_lock<Mutex> &y) -{ +void swap(shared_lock<Mutex> &x, shared_lock<Mutex> &y) { x.swap(y); } -} // namespace mk +} // namespace mk -#endif // mk_SharedMutex_h +#endif // mk_SharedMutex_h