Difference between revisions of "DosQueryQueue (OS/2 1.x)"
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This call determines the number of elements in a queue. | This call determines the number of elements in a queue. | ||
==Syntax== | ==Syntax== | ||
| − | + | DosQueryQueue (QueueHandle, NumberElements) | |
| − | DosQueryQueue | + | |
| − | |||
| − | |||
==Parameters== | ==Parameters== | ||
| − | ; | + | ;QueueHandle (HQUEUE) - input : Handle of the queue to find size. |
| + | ;NumberElements (PUSHORT) - output : Address of the number of entries in the queue waiting to be processed. | ||
| − | |||
==Return Code== | ==Return Code== | ||
rc (USHORT) - return | rc (USHORT) - return | ||
| − | |||
Return code descriptions are: | Return code descriptions are: | ||
| − | + | * 0 NO_ERROR | |
| − | * 0 | + | * 337 ERROR_QUE_INVALID_HANDLE |
| − | * 337 | + | |
==Remarks== | ==Remarks== | ||
Any thread of a process that has access to the queue (because of a DosCreateQueue or a DosOpenQueue request) may issue DosQueryQueue to determine the number of elements currently in the queue. | Any thread of a process that has access to the queue (because of a DosCreateQueue or a DosOpenQueue request) may issue DosQueryQueue to determine the number of elements currently in the queue. | ||
| − | If the process that created the queue closes it before this request is issued, ERROR_QUE_INVALID_HANDLE is returned. | + | If the process that created the queue closes it before this request is issued, ERROR_QUE_INVALID_HANDLE is returned. |
==Example Code== | ==Example Code== | ||
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Returns WORD | Returns WORD | ||
</PRE> | </PRE> | ||
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| − | [[Category: | + | [[Category:Dos]] |
Revision as of 12:14, 1 March 2017
This call determines the number of elements in a queue.
Contents
Syntax
DosQueryQueue (QueueHandle, NumberElements)
Parameters
- QueueHandle (HQUEUE) - input
- Handle of the queue to find size.
- NumberElements (PUSHORT) - output
- Address of the number of entries in the queue waiting to be processed.
Return Code
rc (USHORT) - return
Return code descriptions are:
- 0 NO_ERROR
- 337 ERROR_QUE_INVALID_HANDLE
Remarks
Any thread of a process that has access to the queue (because of a DosCreateQueue or a DosOpenQueue request) may issue DosQueryQueue to determine the number of elements currently in the queue.
If the process that created the queue closes it before this request is issued, ERROR_QUE_INVALID_HANDLE is returned.
Example Code
C Binding
#define INCL_DOSQUEUES USHORT rc = DosQueryQueue(QueueHandle, NumberElements); HQUEUE QueueHandle; /* Queue handle */ PUSHORT NumberElements; /* Size of the queue (returned) */ USHORT rc; /* return code */
MASM Binding
EXTRN DosQueryQueue:FAR INCL_DOSQUEUES EQU 1 PUSH WORD QueueHandle ;Queue handle PUSH@ WORD NumberElements ;Size of the queue (returned) CALL DosQueryQueue Returns WORD
