| .. _module-pw_sync_embos: |
| |
| ============= |
| pw_sync_embos |
| ============= |
| This is a set of backends for pw_sync based on embOS v4. |
| |
| -------------------------------- |
| Critical Section Lock Primitives |
| -------------------------------- |
| |
| Mutex & TimedMutex |
| ================== |
| The embOS v4 backend for the Mutex and TimedMutex use ``OS_RSEMA`` as the |
| underlying type. It is created using ``OS_CreateRSema`` as part of the |
| constructors and cleaned up using ``OS_DeleteRSema`` in the destructors. |
| |
| InterruptSpinLock |
| ================= |
| The embOS v4 backend for InterruptSpinLock is backed by a ``bool`` which permits |
| these objects to detect accidental recursive locking. |
| |
| This object uses ``OS_IncDI`` and ``OS_DecRI`` to mask interrupts which enables |
| the critical section. In addition, ``OS_SuspendAllTasks`` and |
| ``OS_ResumeAllSuspendedTasks`` are used to to prevent accidental thread context |
| switches while the InterruptSpinLock is locked. |
| |
| -------------------- |
| Signaling Primitives |
| -------------------- |
| |
| ThreadNotification & TimedThreadNotification |
| ============================================ |
| The native embOS v4 implementation of its semaphores (``OS_CSEMA``) is very |
| efficient, ergo we recommend using the binary semaphore backends for |
| ThreadNotifications: |
| - ``pw_sync:binary_semaphore_thread_notification_backend`` |
| - ``pw_sync:binary_semaphore_timed_thread_notification_backend`` |
| |
| BinarySemaphore & CountingSemaphore |
| =================================== |
| The embOS v4 backends for the BinarySemaphore and CountingSemaphore use |
| ``OS_CSEMA`` as the underlying type. It is created using ``OS_CreateCSema`` as |
| part of the constructor and cleaned up using ``OS_DeleteCSema`` in the |
| destructor. |
