Diff: mbed-os/rtos/Mutex.h

Revision:

0:8fdf9a60065b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/rtos/Mutex.h	Wed Oct 10 00:33:53 2018 +0000
@@ -0,0 +1,181 @@
+/* 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"
+#include "platform/mbed_toolchain.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.
+
+      @return  status code that indicates the execution status of the function:
+               @a osOK the mutex has been obtained.
+
+      @note You cannot call this function from ISR context.
+      @note This function treats RTOS errors as fatal system errors, so can only return osOK.
+            Use of the return value is deprecated, as the return is expected to become void in the future.
+     */
+    osStatus lock(void);
+
+    /**
+      For backwards compatibility.
+      @deprecated Do not use this function. This function has been replaced with lock(), trylock() and trylock_for() functions.
+
+      Wait until a Mutex becomes available.
+      @param   millisec  timeout value or 0 in case of no time-out.
+      @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 osErrorResource the mutex could not be obtained when no timeout was specified.
+
+      @note You cannot call this function from ISR context.
+      @note This function treats RTOS errors as fatal system errors, so can only return osOK or
+            osErrorResource in case when millisec is 0 or osErrorTimeout if millisec is not osWaitForever.
+     */
+    MBED_DEPRECATED_SINCE("mbed-os-5.10.0", "Replaced with lock(), trylock() and trylock_for() functions")
+    osStatus lock(uint32_t millisec);
+
+    /** 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.
+
+      @note You cannot call this function from ISR context.
+      @note This function treats RTOS errors as fatal system errors, so can only return osOK.
+            Use of the return value is deprecated, as the return is expected to become void in the future.
+     */
+    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
+
+