GetMailslotInfo

The GetMailslotInfo function retrieves information about the specified mailslot.

BOOL GetMailslotInfo(
  HANDLE hMailslot,          // mailslot handle
  LPDWORD lpMaxMessageSize,  // maximum message size
  LPDWORD lpNextSize,        // size of next message
  LPDWORD lpMessageCount,    // number of messages
  LPDWORD lpReadTimeout      // read time-out interval
);

Parameters

hMailslot

[in] Handle to a mailslot. The CreateMailslot function must create this handle.

lpMaxMessageSize

[in] Pointer to a buffer specifying the maximum message size, in bytes, allowed for this mailslot, when the function returns. This value can be greater than or equal to the value specified in the cbMaxMsg parameter of the CreateMailslot function that created the mailslot. This parameter can be NULL.

lpNextSize

[in] Pointer to a buffer specifying the size, in bytes, of the next message, when the function returns. The following value has special meaning.

Value	Meaning
MAILSLOT_NO_MESSAGE	There is no next message.

This parameter can be NULL.

lpMessageCount

[in] Pointer to a buffer specifying the total number of messages waiting to be read, when the function returns. This parameter can be NULL.

lpReadTimeout

[in] Pointer to a buffer specifying the amount of time, in milliseconds, a read operation can wait for a message to be written to the mailslot before a time-out occurs. This parameter is filled in when the function returns. This parameter can be NULL.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Kernel32.lib.

See Also

Mailslots Overview, Mailslot Functions, CreateMailslot, SetMailslotInfo