Diff: mbed-os/rtos/Semaphore.h

Revision:

0:6ad07c9019fd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/rtos/Semaphore.h	Wed May 30 00:01:50 2018 +0000
@@ -0,0 +1,109 @@
+/* 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 SEMAPHORE_H
+#define SEMAPHORE_H
+
+#include <stdint.h>
+#include "cmsis_os2.h"
+#include "mbed_rtos1_types.h"
+#include "mbed_rtos_storage.h"
+#include "platform/NonCopyable.h"
+
+namespace rtos {
+/** \addtogroup rtos */
+/** @{*/
+/**
+ * \defgroup rtos_Semaphore Semaphore class
+ * @{
+ */
+
+/** The Semaphore class is used to manage and protect access to a set of shared resources.
+ *
+ * @note
+ * Memory considerations: The semaphore 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 Semaphore : private mbed::NonCopyable<Semaphore> {
+public:
+    /** Create and Initialize a Semaphore object used for managing resources.
+      @param count      number of available resources; maximum index value is (count-1). (default: 0).
+
+      @note You cannot call this function from ISR context.
+    */
+    Semaphore(int32_t count=0);
+
+    /** Create and Initialize a Semaphore object used for managing resources.
+      @param  count     number of available resources
+      @param  max_count maximum number of available resources
+
+      @note You cannot call this function from ISR context.
+    */
+    Semaphore(int32_t count, uint16_t max_count);
+
+    /** Wait until a Semaphore resource becomes available.
+      @param   millisec  timeout value or 0 in case of no time-out. (default: osWaitForever).
+      @return  number of available tokens, before taking one; or -1 in case of incorrect parameters
+
+      @note You may call this function from ISR context if the millisec parameter is set to 0.
+    */
+    int32_t wait(uint32_t millisec=osWaitForever);
+
+    /** Wait until a Semaphore resource becomes available.
+      @param   millisec  absolute timeout time, referenced to Kernel::get_ms_count()
+      @return  number of available tokens, before taking one; or -1 in case of incorrect parameters
+      @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 acquire attempt will time out earlier than specified.
+
+      @note You cannot call this function from ISR context.
+    */
+    int32_t wait_until(uint64_t millisec);
+
+    /** Release a Semaphore resource that was obtain with Semaphore::wait.
+      @return status code that indicates the execution status of the function:
+              @a osOK the token has been correctly released.
+              @a osErrorResource the maximum token count has been reached.
+              @a osErrorParameter internal error.
+
+      @note You may call this function from ISR context.
+    */
+    osStatus release(void);
+
+    /** Semaphore destructor
+     *
+     * @note You cannot call this function from ISR context.
+     */
+    ~Semaphore();
+
+private:
+    void constructor(int32_t count, uint16_t max_count);
+
+    osSemaphoreId_t               _id;
+    mbed_rtos_storage_semaphore_t _obj_mem;
+};
+/** @}*/
+/** @}*/
+}
+#endif
+
+