Function Overview

CMSIS-RTOS v2 provides multiple API interfaces:

• CMSIS-RTOS2 is the new C function API that supports dynamic object creation and ARMv8-M (ARM Cortex-M23 and Cortex-M33).
• CMSIS-RTOS C API v1 is a C function API that is backward compatible with CMSIS-RTOS v1.
• CMSIS-RTOS C++ API is a C++ class function API.

It is possible to intermix the different API variants in the same application and even in the same C/C++ source module. However, the functions of the C API Version 1 may be deprecated in future versions of CMSIS-RTOS.

CMSIS-RTOS2

Overview of all CMSIS-RTOS C API v2 functions that are implemented in the cmsis_os2.h header file.

• Kernel Information and Control
  • osKernelGetInfo : Get RTOS Kernel Information.
  • osKernelGetState : Get the current RTOS Kernel state.
  • osKernelGetSysTimerCount : Get the RTOS kernel system timer count.
  • osKernelGetSysTimerFreq : Get the RTOS kernel system timer frequency.
  • osKernelInitialize : Initialize the RTOS Kernel.
  • osKernelLock : Lock the RTOS Kernel scheduler.
  • osKernelUnlock : Unlock the RTOS Kernel scheduler.
  • osKernelRestoreLock : Restore the RTOS Kernel scheduler lock state.
  • osKernelResume : Resume the RTOS Kernel scheduler.
  • osKernelStart : Start the RTOS Kernel scheduler.
  • osKernelSuspend : Suspend the RTOS Kernel scheduler.
  • osKernelGetTickCount : Get the RTOS kernel tick count.
  • osKernelGetTickFreq : Get the RTOS kernel tick frequency.
• Thread Management
  • osThreadDetach : Detach a thread (thread storage can be reclaimed when thread terminates).
  • osThreadEnumerate : Enumerate active threads.
  • osThreadExit : Terminate execution of current running thread.
  • osThreadGetCount : Get number of active threads.
  • osThreadGetId : Return the thread ID of the current running thread.
  • osThreadGetName : Get name of a thread.
  • osThreadGetPriority : Get current priority of a thread.
  • osThreadGetStackSize : Get stack size of a thread.
  • osThreadGetStackSpace : Get available stack space of a thread based on stack watermark recording during execution.
  • osThreadGetState : Get current thread state of a thread.
  • osThreadJoin : Wait for specified thread to terminate.
  • osThreadNew : Create a thread and add it to Active Threads.
  • osThreadResume : Resume execution of a thread.
  • osThreadSetPriority : Change priority of a thread.
  • osThreadSuspend : Suspend execution of a thread.
  • osThreadTerminate : Terminate execution of a thread.
  • osThreadYield : Pass control to next thread that is in state READY.
• Thread Flags
  • osThreadFlagsSet : Set the specified Thread Flags of a thread.
  • osThreadFlagsClear : Clear the specified Thread Flags of current running thread.
  • osThreadFlagsGet : Get the current Thread Flags of current running thread.
  • osThreadFlagsWait : Wait for one or more Thread Flags of the current running thread to become signaled.
• Event Flags
  • osEventFlagsGetName : Get name of an Event Flags object.
  • osEventFlagsNew : Create and Initialize an Event Flags object.
  • osEventFlagsDelete : Delete an Event Flags object.
  • osEventFlagsSet : Set the specified Event Flags.
  • osEventFlagsClear : Clear the specified Event Flags.
  • osEventFlagsGet : Get the current Event Flags.
  • osEventFlagsWait : Wait for one or more Event Flags to become signaled.
• Generic Wait Functions
  • osDelay : Wait for Timeout (Time Delay).
  • osDelayUntil : Wait until specified time.
• Timer Management
  • osTimerDelete : Delete a timer.
  • osTimerGetName : Get name of a timer.
  • osTimerIsRunning : Check if a timer is running.
  • osTimerNew : Create and Initialize a timer.
  • osTimerStart : Start or restart a timer.
  • osTimerStop : Stop a timer.
• Mutex Management
  • osMutexAcquire : Acquire a Mutex or timeout if it is locked.
  • osMutexDelete : Delete a Mutex object.
  • osMutexGetName : Get name of a Mutex object.
  • osMutexGetOwner : Get Thread which owns a Mutex object.
  • osMutexNew : Create and Initialize a Mutex object.
  • osMutexRelease : Release a Mutex that was acquired by osMutexAcquire.
• Semaphores
  • osSemaphoreAcquire : Acquire a Semaphore token or timeout if no tokens are available.
  • osSemaphoreDelete : Delete a Semaphore object.
  • osSemaphoreGetCount : Get current Semaphore token count.
  • osSemaphoreGetName : Get name of a Semaphore object.
  • osSemaphoreNew : Create and Initialize a Semaphore object.
  • osSemaphoreRelease : Release a Semaphore token that was acquired by osSemaphoreAcquire.
• Memory Pool
  • osMemoryPoolAlloc : Allocate a memory block from a Memory Pool.
  • osMemoryPoolDelete : Delete a Memory Pool object.
  • osMemoryPoolFree : Return an allocated memory block back to a Memory Pool.
  • osMemoryPoolGetBlockSize : Get memory block size in a Memory Pool.
  • osMemoryPoolGetCapacity : Get maximum number of memory blocks in a Memory Pool.
  • osMemoryPoolGetCount : Get number of memory blocks used in a Memory Pool.
  • osMemoryPoolGetName : Get name of a Memory Pool object.
  • osMemoryPoolGetSpace : Get number of memory blocks available in a Memory Pool.
  • osMemoryPoolNew : Create and Initialize a Memory Pool object.
• Message Queue
  • osMessageQueueDelete : Delete a Message Queue object.
  • osMessageQueueGet : Get a Message from a Queue or timeout if Queue is empty.
  • osMessageQueueGetCapacity : Get maximum number of messages in a Message Queue.
  • osMessageQueueGetCount : Get number of queued messages in a Message Queue.
  • osMessageQueueGetMsgSize : Get maximum message size in a Memory Pool.
  • osMessageQueueGetName : Get name of a Message Queue object.
  • osMessageQueueGetSpace : Get number of available slots for messages in a Message Queue.
  • osMessageQueueNew : Create and Initialize a Message Queue object.
  • osMessageQueuePut : Put a Message into a Queue or timeout if Queue is full.
  • osMessageQueueReset : Reset a Message Queue to initial empty state.
• RTX5 Specific API
  • osRtxErrorNotify : OS Error Callback function.
  • osRtxIdleThread : OS Idle Thread.
  • osRtxSysTimerSetup : OS System Timer functions (default implementation uses SysTick)
  • osRtxSysTimerEnable : Enable System Timer.
  • osRtxSysTimerDisable : Disable System Timer.
  • osRtxSysTimerAckIRQ : Acknowledge System Timer IRQ.
  • osRtxSysTimerGetCount : Get System Timer count.
  • osRtxSysTimerGetFreq : Get System Timer frequency.

The following CMSIS-RTOS2 functions can be called from threads and Interrupt Service Routines (ISR):

• osKernelGetSysTimerCount, osKernelGetSysTimerFreq
• osThreadFlagsSet
• osEventFlagsSet, osEventFlagsClear, osEventFlagsGet, osEventFlagsWait
• osSemaphoreAcquire, osSemaphoreRelease, osSemaphoreGetCount
• osMemoryPoolAlloc, osMemoryPoolFree, osMemoryPoolGetCapacity, osMemoryPoolGetBlockSize, osMemoryPoolGetCount, osMemoryPoolGetSpace
• osMessageQueuePut, osMessageQueueGet, osMessageQueueGetCapacity, osMessageQueueGetMsgSize, osMessageQueueGetCount, osMessageQueueGetSpace