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QHdr

Header: OSUtils.h

struct QHdr {
    SInt16 qFlags; 
    SInt16 pad; 
    SInt32 MutexID; 
    QElemPtr qHead; 
    QElemPtr qTail;
};
typedef QHdr QHdrPtr;

Field descriptions

qFlags

Queue flags. This field contains information that is different for each queue type. Ordinarily, these flags are reserved for use by system software.

pad

A pointer to the first element in the queue. If a queue has no elements, this field is set to NULL.

MutexID

A pointer to the last element in the queue. If a queue has no elements, this field is set to NULL.

qHead
qTail

A queue header is a block of data that contains information about a queue. Each operating-system queue created and maintained by the Macintosh Operating System consists of a queue header and a linked list of queue elements.

The QHdr data type defines the structure of a queue header.


© 2000 Apple Computer, Inc. — (Last Updated 4/6/2000)