FILE_MAILSLOT_SET_INFORMATION - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTIOAPI_H

/**
 * The FILE_MAILSLOT_SET_INFORMATION structure is used to set a value on a mailslot.
 *
 * \remarks https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/ns-ntifs-_file_mailslot_set_information
 */
typedef struct _FILE_MAILSLOT_SET_INFORMATION
{
    PLARGE_INTEGER 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. 
} FILE_MAILSLOT_SET_INFORMATION, *PFILE_MAILSLOT_SET_INFORMATION;

#endif

View code on GitHub

This structure is documented in Windows Driver Kit.