## Presentation Device Driver Reference for OS/2

[prev][next][parent][TOC]

### GreLockDevice

Select an item:

    Syntax
    Parameters
    Returns
    Remarks
    Glossary

Simulation support:

None. This function is mandatory for all drivers.

Description:

GreLockDevice locks a device for use by a single thread.

This function must be supported by all presentation drivers. GreLockDevice prevents two separate processes from accessing the resource (device context ) at the same time. Hardcopy drivers need do nothing except return TRUE ( Successful).

    #define INCL_GRE_DEVMISC3

    #include <os2.h>

    HDC      hdc;        /*  Device context handle. */

    PVOID    pInstance;  /*  Pointer to instance data. */

    ULONG    lFunction;  /*  High-order WORD=flags; low-order WORD=NGreLockDevice. */

    BOOL     rc;         /*  Return Code. */

    rc = GreLockDevice(hdc, pInstance, lFunction);