GreUnlockDevice

GreUnlockDevice allows all pending screen input or output operations blocked by GreLockDevice to continue.

This function must be supported by all presentation drivers. For hardcopy devices, the hardcopy driver need do nothing except return TRUE (Successful). GreUnlockDevice is used to enable another process to access a resource (device context) that had been previously locked to prevent simultaneous update.


 * Simulation support: None. This function is mandatory for all drivers.

Syntax
GreUnlockDevice(hdc, pInstance, lFunction)

Parameters

 * hdc (HDC) - input:Device context handle.
 * pInstance (PVOID) - input:Pointer to instance data.
 * lFunction (ULONG) - input:High-order WORD=flags; low-order WORD=NGreUnlockDevice.

Return Code

 * rc (BOOL) - returns:Return codes.
 * On completion, the handling routine must return a BOOLEAN value to indicate success or an error.
 * TRUE Successful
 * FALSE Error
 * Possible Errors Detected: When an error is detected, the handling routine must call WinSetErrorInfo to post the condition. An error code for conditions that the handling routine is expected to check is:
 * PMERR_DEV_FUNC_NOT_INSTALLED
 * Refer to the "Error Explanations" section in the Presentation Manager Programming Reference for further explanation.

Remarks
This function is used to synchronize the use and update of the visible region.