DosQueryQueue (OS/2 1.x)

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This call determines the number of elements in a queue.

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.

Bindings

C

#define INCL_DOSQUEUES

USHORT  rc = DosQueryQueue(QueueHandle, NumberElements);

HQUEUE  QueueHandle;    /* Queue handle */
PUSHORT NumberElements; /* Size of the queue (returned) */

USHORT  rc;             /* return code */

MASM

EXTRN  DosQueryQueue:FAR
INCL_DOSQUEUES      EQU 1

PUSH   WORD    QueueHandle    ;Queue handle
PUSH@  WORD    NumberElements ;Size of the queue (returned)
CALL   DosQueryQueue

Returns WORD