FILE_MAILSLOT_QUERY_INFORMATION structure (ntifs.h)

The FILE_MAILSLOT_QUERY_INFORMATION structure contains information about a mailslot.

Syntax

typedef struct _FILE_MAILSLOT_QUERY_INFORMATION {
  ULONG         MaximumMessageSize;
  ULONG         MailslotQuota;
  ULONG         NextMessageSize;
  ULONG         MessagesAvailable;
  LARGE_INTEGER ReadTimeout;
} FILE_MAILSLOT_QUERY_INFORMATION, *PFILE_MAILSLOT_QUERY_INFORMATION;

Members

MaximumMessageSize

The maximum size, in bytes, of a single message that can be written to the mailslot, or 0 for a message of any size.

MailslotQuota

The size, in bytes, of the in-memory pool that is reserved for writes to this mailslot.

NextMessageSize

The next message size, in bytes.

MessagesAvailable

The total number of messages waiting to be read from the mailslot.

ReadTimeout

The time, in milliseconds, that a read operation can wait for a message to be written to the mailslot before a time-out occurs. A value of –1 requests that the read wait forever for a message, without timing out. A value of 0 requests that the read not wait and return immediately whether a pending message is available to be read or not.

Remarks

For more information, see Mailslots.

Requirements

Requirement	Value
Minimum supported client	Windows 2000
Header	ntifs.h (include FltKernel.h, Ntifs.h)