This function unlocks the specified locked HIGEAR.
Declaration:
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AT_ERRCOUNT EXPORT ACCUAPI IG_thread_image_unlock( HIGEAR hIGear, AT_MODE nLockMode ); |
Arguments:
Name | Type | Description |
hIGear | HIGEAR | ImageGear Image handle. |
nLockMode | AT_MODE | The lock mode (IG_THREAD_LOCK_READ or IG_THREAD_LOCK_WRITE) indicator. Several threads can perform read lock concurrently, but only one thread is allowed to do write lock. |
Return Value:
Returns the number of ImageGear errors that occurred during this function call.
Supported Raster Image Formats:
This function does not process image pixels.
Sample:
MFC Threads
Example:
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hIGear = pDoc->hMainGear; nErrCnt = IG_thread_image_lock( pDoc->hMainGear, IG_THREAD_LOCK_WRITE ); if (nErrCnt == 0) { // locked successfully IG_IP_rotate_multiple_90( hIGear, IG_ROTATE_90 ); IG_thread_image_unlock( pDoc->hMainGear, IG_THREAD_LOCK_WRITE ); ... } |
Remarks:
Two APIs (IG_thread_image_lock() and IG_thread_image_unlock()) are required for those situations in which two or more threads-at least one of which is modifying or deleting an image-are simultaneously accessing the same HIGEAR. For example, one thread can save HIGEAR to a JPEG file (read access to a HIGEAR), while another is performing rotation in the asynchronous mode (write access to a HIGEAR). Thus the "saving" thread would be required to call lock/unlock with the read mode as a parameter, and the "rotation" thread would be required to call lock/unlock with the write mode as a parameter.