Change Mutex lock and unlock API return value to void

Author: rajkan01

rtos/Mutex.h

@@ -84,18 +84,9 @@ class Mutex : private mbed::NonCopyable<Mutex> {
     /**
       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 it can only return osOK.
-            Use of the return value is deprecated, as the return is expected to become void in the future.
      */
-#if MBED_CONF_RTOS_PRESENT
-    osStatus lock();
-#else
-    void lock(); // Value return backwards compatibility not required for non-RTOS
-#endif
+    void lock();
 
     /** Try to lock the mutex, and return immediately
       @return true if the mutex was acquired, false otherwise.
@@ -132,18 +123,9 @@ class Mutex : private mbed::NonCopyable<Mutex> {
     /**
       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 it can only return osOK.
-            Use of the return value is deprecated, as the return is expected to become void in the future.
      */
-#if MBED_CONF_RTOS_PRESENT
-    osStatus unlock();
-#else
-    void unlock(); // Value return backwards compatibility not required for non-RTOS
-#endif
+    void unlock();
 
     /** Get the owner the this mutex
       @return  the current owner of this mutex.

rtos/source/Mutex.cpp

@@ -57,7 +57,7 @@ void Mutex::constructor(const char *name)
     MBED_ASSERT(_id || mbed_get_error_in_progress());
 }
 
-osStatus Mutex::lock(void)
+void Mutex::lock(void)
 {
     osStatus status = osMutexAcquire(_id, osWaitForever);
     if (osOK == status) {
@@ -67,8 +67,6 @@ osStatus Mutex::lock(void)
     if (status != osOK && !mbed_get_error_in_progress()) {
         MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_LOCK_FAILED), "Mutex lock failed", status);
     }
-
-    return osOK;
 }
 
 bool Mutex::trylock()
@@ -109,7 +107,7 @@ bool Mutex::trylock_until(uint64_t millisec)
     }
 }
 
-osStatus Mutex::unlock()
+void Mutex::unlock()
 {
     osStatus status = osMutexRelease(_id);
     if (osOK == status) {
@@ -119,8 +117,6 @@ osStatus Mutex::unlock()
     if (status != osOK && !mbed_get_error_in_progress()) {
         MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_UNLOCK_FAILED), "Mutex unlock failed", status);
     }
-
-    return status;
 }
 
 osThreadId Mutex::get_owner()