CriticalSectionLock class improvement

mbed.h

@@ -89,6 +89,7 @@
 #include "platform/FileSystemHandle.h"
 #include "platform/FileHandle.h"
 #include "platform/DirHandle.h"
+#include "platform/ScopedLock.h"
 #include "platform/CriticalSectionLock.h"
 #include "platform/DeepSleepLock.h"
 

platform/CriticalSectionLock.h

@@ -19,6 +19,7 @@
 #define MBED_CRITICALSECTIONLOCK_H
 
 #include "platform/mbed_critical.h"
+#include "platform/ScopedLock.h"
 
 namespace mbed {
 
@@ -30,48 +31,112 @@ namespace mbed {
  */
 
 /** RAII object for disabling, then restoring, interrupt state
-  * Usage:
-  * @code
-  *
-  * void f() {
-  *     // some code here
-  *     {
-  *         CriticalSectionLock lock;
-  *         // Code in this block will run with interrupts disabled
-  *     }
-  *     // interrupts will be restored to their previous state
-  * }
-  * @endcode
-  */
+ *
+ * @deprecated
+ * The CriticalSectionLock has been superseded by the ScopedCriticalSectionLock
+ *
+ * Usage:
+ * @code
+ *
+ * void f() {
+ *     // some code here
+ *     {
+ *         CriticalSectionLock lock;
+ *         // Code in this block will run with interrupts disabled
+ *     }
+ *     // interrupts will be restored to their previous state
+ * }
+ * @endcode
+ */
 class CriticalSectionLock {
 public:
-    CriticalSectionLock() 
+    MBED_DEPRECATED_SINCE("mbed-os-5.7",
+    "The CriticalSectionLock has been superseded by the ScopedCriticalSectionLock.")
+    CriticalSectionLock()
     {
         core_util_critical_section_enter();
     }
 
-    ~CriticalSectionLock() 
+    ~CriticalSectionLock()
     {
         core_util_critical_section_exit();
     }
 
     /** Mark the start of a critical section
-     *     
+     *
      */
     void lock()
     {
         core_util_critical_section_enter();
     }
 
     /** Mark the end of a critical section
-     *     
+     *
      */
     void unlock()
     {
         core_util_critical_section_exit();
     }
 };
 
+
+/** Class for disabling and restoring interrupt state
+  * Usage:
+  * @code
+  *
+  * void foo() {
+  *     // some code here
+  *     CriticalSectionLock::lock();
+  *         // Code in this block will run with interrupts disabled
+  *     CriticalSectionLock::unlock();
+  *     // interrupts will be restored to their previous state
+  * }
+  * @endcode
+  */
+class CriticalSection : private NonCopyable<CriticalSection> {
+public:
+    /** Mark the start of a critical section
+     */
+    static void lock()
+    {
+        core_util_critical_section_enter();
+    }
+    /** Mark the end of a critical section
+     */
+    static void unlock()
+    {
+        core_util_critical_section_exit();
+    }
+};
+
+/**@}*/
+
+/**@}*/
+
+/** RAII object for disabling, then restoring, interrupt state
+  *
+  * Usage:
+  * @code
+  *
+  * void foo() {
+  *     // some code here
+  *     {
+  *         ScopedCriticalSectionLock lock;
+  *         // Code in this block will run with interrupts disabled
+  *     }
+  *     // interrupts will be restored to their previous state
+  * }
+  * @endcode
+  */
+class ScopedCriticalSectionLock : private CriticalSection, private ScopedLock<CriticalSection> {
+    // Note: inherit from CriticalSection and ScopedLock to use empty base optimisation
+public:
+    ScopedCriticalSectionLock() :
+        CriticalSection(),
+        ScopedLock<CriticalSection>(static_cast<CriticalSection&>(*this)) {
+    }
+};
+
 /**@}*/
 
 /**@}*/

platform/ScopedLock.h

@@ -0,0 +1,87 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_SCOPEDLOCK_H
+#define MBED_SCOPEDLOCK_H
+
+#include "platform/NonCopyable.h"
+
+namespace mbed {
+
+/** \addtogroup platform */
+/** @{*/
+/**
+ * \defgroup platform_ScopedLock ScopedLock functions
+ * @{
+ */
+
+/** RAII-style mechanism for owning a lock of Lockable object for the duration of a scoped block
+ *
+ * @tparam Lockable The type implementing BasicLockable concept
+ *
+ * @note For type Lockable to be BasicLockable the following conditions have to be satisfied:
+ *        - has public member function @a lock which blocks until a lock can be obtained for the current execution context
+ *        - has public member function @a unlock which releases the lock
+ *
+ * Usage:
+ *
+ * Example with rtos::Mutex
+ *
+ * @code
+ * void foo(Mutex &m) {
+ *     ScopedLock<Mutex> lock(m);
+ *     // Code in this block will be protected by Mutex lock
+ * }
+ * @endcode
+ *
+ *
+ * More generic example
+ *
+ * @code
+ * template<typename Lockable>
+ * void foo(Lockable& lockable) {
+ *     ScopedLock<Lockable> lock(lockable);
+ *     // Code in this block will run under lock
+ * }
+ * @endcode
+ */
+template <typename Lockable>
+class ScopedLock : private NonCopyable<ScopedLock<Lockable> > {
+public:
+    /** Locks given locable object
+     *
+     * @param lockable reference to the instance of Lockable object
+     * @note lockable object should outlive the ScopedLock object
+     */
+    ScopedLock(Lockable& lockable): _lockable(lockable)
+    {
+        _lockable.lock();
+    }
+
+    ~ScopedLock()
+    {
+        _lockable.unlock();
+    }
+private:
+    Lockable& _lockable;
+};
+
+/**@}*/
+
+/**@}*/
+
+} // embed
+
+#endif // MBED_SCOPEDLOCK_H

rtos/Mutex.h

@@ -28,15 +28,30 @@
 #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);
+ *     // Code in this block will be protected by Mutex lock
+ * }
+ * @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.