Nicolas Borla
/
BBR_1Ebene
BBR 1 Ebene
Diff: mbed-os/rtos/Mutex.h
- Revision:
- 0:fbdae7e6d805
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed-os/rtos/Mutex.h Mon May 14 11:29:06 2018 +0000 @@ -0,0 +1,163 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2012 ARM Limited + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#ifndef MUTEX_H +#define MUTEX_H + +#include <stdint.h> +#include "cmsis_os2.h" +#include "mbed_rtos1_types.h" +#include "mbed_rtos_storage.h" + +#include "platform/NonCopyable.h" +#include "platform/ScopedLock.h" + +namespace rtos { +/** \addtogroup rtos */ +/** @{*/ + +class Mutex; +/** Typedef for the mutex lock + * + * Usage: + * @code + * void foo(Mutex &m) { + * ScopedMutexLock lock(m); + * // Mutex lock protects code in this block + * } + * @endcode + */ +typedef mbed::ScopedLock<Mutex> ScopedMutexLock; + +/** + * \defgroup rtos_Mutex Mutex class + * @{ + */ + +/** The Mutex class is used to synchronize the execution of threads. + This is for example used to protect access to a shared resource. + + @note You cannot use member functions of this class in ISR context. If you require Mutex functionality within + ISR handler, consider using @a Semaphore. + + @note + Memory considerations: The mutex control structures will be created on current thread's stack, both for the Mbed OS + and underlying RTOS objects (static or dynamic RTOS memory pools are not being used). +*/ +class Mutex : private mbed::NonCopyable<Mutex> { +public: + /** Create and Initialize a Mutex object + * + * @note You cannot call this function from ISR context. + */ + Mutex(); + + /** Create and Initialize a Mutex object + + @param name name to be used for this mutex. It has to stay allocated for the lifetime of the thread. + + @note You cannot call this function from ISR context. + */ + Mutex(const char *name); + + /** Wait until a Mutex becomes available. + @param millisec timeout value or 0 in case of no time-out. (default: osWaitForever) + @return status code that indicates the execution status of the function: + @a osOK the mutex has been obtained. + @a osErrorTimeout the mutex could not be obtained in the given time. + @a osErrorParameter internal error. + @a osErrorResource the mutex could not be obtained when no timeout was specified. + @a osErrorISR this function cannot be called from the interrupt service routine. + + @note You cannot call this function from ISR context. + */ + osStatus lock(uint32_t millisec=osWaitForever); + + /** Try to lock the mutex, and return immediately + @return true if the mutex was acquired, false otherwise. + @note equivalent to trylock_for(0) + + @note You cannot call this function from ISR context. + */ + bool trylock(); + + /** Try to lock the mutex for a specified time + @param millisec timeout value or 0 in case of no time-out. + @return true if the mutex was acquired, false otherwise. + @note the underlying RTOS may have a limit to the maximum wait time + due to internal 32-bit computations, but this is guaranteed to work if the + wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded, + the lock attempt will time out earlier than specified. + + @note You cannot call this function from ISR context. + */ + bool trylock_for(uint32_t millisec); + + /** Try to lock the mutex until specified time + @param millisec absolute timeout time, referenced to Kernel::get_ms_count() + @return true if the mutex was acquired, false otherwise. + @note the underlying RTOS may have a limit to the maximum wait time + due to internal 32-bit computations, but this is guaranteed to work if the + wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded, + the lock attempt will time out earlier than specified. + + @note You cannot call this function from ISR context. + */ + bool trylock_until(uint64_t millisec); + + /** Unlock the mutex that has previously been locked by the same thread + @return status code that indicates the execution status of the function: + @a osOK the mutex has been released. + @a osErrorParameter internal error. + @a osErrorResource the mutex was not locked or the current thread wasn't the owner. + @a osErrorISR this function cannot be called from the interrupt service routine. + + @note You cannot call this function from ISR context. + */ + osStatus unlock(); + + /** Get the owner the this mutex + @return the current owner of this mutex. + + @note You cannot call this function from ISR context. + */ + osThreadId get_owner(); + + /** Mutex destructor + * + * @note You cannot call this function from ISR context. + */ + ~Mutex(); + +private: + void constructor(const char *name = NULL); + friend class ConditionVariable; + + osMutexId_t _id; + mbed_rtos_storage_mutex_t _obj_mem; + uint32_t _count; +}; +/** @}*/ +/** @}*/ +} +#endif + +