Semaphore Used for Critical Section

#include "m2m_type.h"

#include "m2m_os_lock_api.h"

M2M_T_OS_LOCK semaphore

    .

    /* Initialize a semaphore for a Critical Section: "val" value is equal to M2M_OS_LOCK_CS, it is

        the initial semaphore count = 1*/

        semaphore = m2m_os_lock_init(M2M_OS_LOCK_CS);

    /* The retrieved semaphore count is one, then the semaphore count is decreased. The control is returned to the calling

        task */

        m2m_os_lock_lock(semaphore);

    /* The current task executes its critical code section, any task trying to use m2m_os_lock_lock(semaphore) gets stuck */

    /* Increase the semaphore count by one to unlock the semaphore. */

    /* Pay attention: unlock the semaphore more times than it is locked changes its behaviour: it works as a counting 

        semaphore, (counter > 1). So its use is no more suited for Critical Sections which need binary semaphore */

        m2m_os_lock_unlock(semaphore);

    /* Destroy the semaphore */

        m2m_os_lock_destroy(semaphore);

    .