IoMgrLockEnter (FUN)

FUNCTION IoMgrLockEnter : RTS_IEC_RESULT

This function acquires the mutual-exclusion locks for the given operations for critical sections inside the I/O driver’s implementation of IoDrvReadInputs(), IoDrvWriteOutputs(), and IoDrvStartBusCycle(). The locks can be released with the function IoMgrLockLeave(). While a lock is held, any other thread is blocked from acquiring the lock and waits until the lock is released.

IMPLEMENTATION NOTE: The behavior of the dwLockScope parameter can’t be implemented on all platforms. Platforms without synchronization functionality may not be able to implement this behavior. IoMgrEmbedded of the CODESYSControlEmbedded runtime system for example can only disable and enable all interrupts.

InOut:

Scope

Name

Type

Comment

Return

IoMgrLockEnter

RTS_IEC_RESULT
error code

  • ERR_OK: Locks were successfully acquired.

  • ERR_PARAMETER: The pbyIoDrv parameter is NULL (only implementations that use this parameter), or the dwLockScope parameter has none of the GVL LockScopes set (only implementations that use this parameter).

  • ERR_FAILED: No driver entry for pbyIoDrv found in device pool.

Input

hIoDrv

RTS_IEC_HANDLE

Handle to the driver instance which is returned by the function IoMgrRegisterInstance2().

dwLockScope

DWORD

The operations for which to acquire locks. See GVL LockScopes for detailed information.