Win32-services: Windows service applications

This package provides a partial binding to the Win32 System Services API. It's now possible to write Windows service applications using Haskell.

The binding is partial. Here are a few ways in which it differs from the official API:

• Only services running within their own process are supported. These are processes of the WIN32_OWN_PROCESS type.

• In cases where multiple versions of the same function exist (for compatibility), this binding only offers one of them.

• None of the extended control codes are supported. Handlers you write will automatically report this to the operating system when such controls are received.

• Only facilities for writing services are supported; not controlling them.

Effort has been made to simplify using the API without hiding what is happening behind the scenes. Users are encouraged to read Microsoft's documentation under 'Dev Center - Desktop > Docs > Desktop app development documentation > System Services > Services'. The official example has been ported to Haskell. This can be found in the examples directory of the source tree.

Simple Example and Usage

module Main where

import Control.Concurrent.MVar
import System.Win32.SystemServices.Services

main = do
    mStop <- newEmptyMVar
    startServiceCtrlDispatcher "Test" 3000 (handler mStop) $ \_ _ h -> do
        setServiceStatus h running
        takeMVar mStop

handler mStop hStatus STOP = do
    setServiceStatus hStatus stopPending
    putMVar mStop ()
    return True
handler _ _ INTERROGATE = return True
handler _ _ _           = return False

running = SERVICE_STATUS WIN32_OWN_PROCESS RUNNING [ACCEPT_STOP] nO_ERROR 0 0 0
stopPending = running { currentState = STOP_PENDING
                      , controlsAccepted = []
                      , waitHint = 3000 }

C:programmingtest>ghc --make -threaded Main.hs
[1 of 1] Compiling Main             ( Main.hs, Main.o )
Linking Main.exe ...
<linker warnings omitted>
C:\programming\test>copy Main.exe c:\svc\Test.exe
1 file(s) copied.

Execute the following from an elevated command prompt to register the service:

C:\svc>sc create Test binPath= c:\svc\Test.exe
[SC] CreateService SUCCESS

The service can now be started and stopped from the services console.

Installation Notes:

Depending on which version of Windows and the Windows SDK you are using the .cabal file will need to be modified before installing. A simple `cabal install Win32-services` may not work. For example, If you are building on Windows 8 64-bit with the Windows 8 SDK the 'extra-lib-dirs' field will need to be changed to read as follows:

Extra-Lib-Dirs: "C:\\Program Files (x86)\\Windows Kits\\8.0\\Lib\\win8\\um\\x86"

Release Notes:

Changes in 0.2

• Writing services of the WIN32_OWN_PROCESS type is now easier. Handler registration is performed automatically. By the time the service main function is entered, the service will already be in the START_PENDING state. It is the user's responsibility to enter the RUNNING state as soon as possible.

• Once the service main function exits two things will occur. The service will enter the STOPPED state, and the handler function will be freed.

• The registerServiceCtrlHandlerEx function is no longer exported. Handlers are registered automatically by the startServiceCtrlDispatcher function.

• The queryServiceStatus function has been added.

Changes in 0.1

• First release

Modules

[Last Documentation]

Downloads

• Win32-services-0.2.tar.gz [browse] (Cabal source package)
• Package description (as included in the package)

Maintainer's Corner

Package maintainers

• MichaelSteele, gussen

For package maintainers and hackage trustees

• edit package information

Candidates

• 0.4, 0.4.0.1