Safe Haskell	Safe-Inferred
Language	Haskell2010

Named pipe server APIs

createNamedPipe Source

Creates an instance of a named pipe and returns a handle for subsequent pipe operations. A named pipe server process uses this function either to create the first instance of a specific named pipe and establish its basic attributes or to create a new instance of an existing named pipe.

For full details see https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-createnamedpipea

To create a named pipe which can be associate with IO completion port on needs to pass fILE_FLAG_OVERLAPPED to OpenMode argument, e.g.

 Win32.createNamedPipe pipeName
                       (pIPE_ACCESS_DUPLEX .|. fILE_FLAG_OVERLAPPED)
                       (pIPE_TYPE_BYTE .|. pIPE_READMODE_BYTE)
                       pIPE_UNLIMITED_INSTANCES
                       512
                       512
                       0
                       NothinROR

pIPE_UNLIMITED_INSTANCES :: DWORD Source

Parameter types

type LPSECURITY_ATTRIBUTES = Ptr SECURITY_ATTRIBUTES Source

type OpenMode = UINT Source

The named pipe open mode.

This must specify one of:

• pIPE_ACCESS_DUPLEX
• pIPE_ACCESS_INBOUND
• pIPE_ACCESS_OUTBOUND

It may also specify:

• fILE_FLAG_WRITE_THROUGH
• fILE_FLAG_OVERLAPPED

It may also specify any combination of:

• wRITE_DAC
• wRITE_OWNER
• aCCESS_SYSTEM_SECURITY

pIPE_ACCESS_DUPLEX :: OpenMode Source

pIPE_ACCESS_INBOUND :: OpenMode Source

pIPE_ACCESS_OUTBOUND :: OpenMode Source

fILE_FLAG_OVERLAPPED :: FileAttributeOrFlag Source

type PipeMode = UINT Source

The pipe mode.

One of the following type modes can be specified. The same type mode must be specified for each instance of the pipe.

• pIPE_TYPE_BYTE
• pIPE_TYPE_MESSAGE

One of the following read modes can be specified. Different instances of the same pipe can specify different read modes.

• pIPE_READMODE_BYTE
• pIPE_READMODE_MESSAGE

One of the following wait modes can be specified. Different instances of the same pipe can specify different wait modes.

• pIPE_WAIT
• pIPE_NOWAIT

One of the following remote-client modes can be specified. Different instances of the same pipe can specify different remote-client modes.

• pIPE_ACCEPT_REMOTE_CLIENT
• pIPE_REJECT_REMOTE_CLIENT

pIPE_TYPE_BYTE :: PipeMode Source

pIPE_TYPE_MESSAGE :: PipeMode Source

pIPE_READMODE_BYTE :: PipeMode Source

pIPE_READMODE_MESSAGE :: PipeMode Source

pIPE_WAIT :: PipeMode Source

pIPE_NOWAIT :: PipeMode Source

pIPE_ACCEPT_REMOTE_CLIENTS :: PipeMode Source

If the createNamedPipe nMaxInstances parameter is pIPE_UNLIMITED_INSTANCES, the number of pipe instances that can be created is limited only by the availability of system resources.

pIPE_REJECT_REMOTE_CLIENTS :: PipeMode Source

Named pipe client APIs

connect to a named pipe

connect Source

A reliable connect call, as designed in https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipe-client

The arguments are passed directly to createFile.

Note we pick the more familiar posix naming convention, do not confuse this function with connectNamedPipe (which corresponds to posix accept)

waiting for named pipe instances

waitNamedPipe Source

Wait until a named pipe instance is available. If there is no instance at hand before the timeout, it will error with ERROR_SEM_TIMEOUT, i.e. invalid argument (The semaphore timeout period has expired)

It returns True if there is an available instance, subsequent createFile might still fail, if another thread will take turn and connect before, or if the other end shuts down the name pipe.

It returns False if timeout fired.

type TimeOut = DWORD Source

Timeout in milliseconds.

• nMPWAIT_USE_DEFAULT_WAIT indicates that the timeout value passed to createNamedPipe should be used.
• nMPWAIT_WAIT_FOREVER - waitNamedPipe will block forever, until a named pipe instance is available.

nMPWAIT_USE_DEFAULT_WAIT :: TimeOut Source

nMPWAIT_WAIT_FOREVER :: TimeOut Source