Rust编写Windows服务

编写Windows服务可选语言很多, 其中C#最简单。本着练手Rust语言，尝试用Rust编写一个服务。

一：Windows服务程序大致原理

参考官网C/C++创建服务流程
https://learn.microsoft.com/zh-cn/windows/win32/services/service-program-tasks

• 编写服务程序的main函数
  1. main函数中，填充数据结构 DispatchTable: [[服务名，ServiceMain函数], [NULL, NULL]]
  2. 调用StartServiceCtrlDispatcher( DispatchTable )

int __cdecl _tmain(int argc, TCHAR *argv[])
{ SERVICE_TABLE_ENTRY DispatchTable[] = { { SVCNAME, (LPSERVICE_MAIN_FUNCTION) SvcMain }, { NULL, NULL } }; if (!StartServiceCtrlDispatcher( DispatchTable )) { SvcReportEvent(TEXT("StartServiceCtrlDispatcher")); } 
} 

• 编写 ServiceMain 函数
  1. 注册控制处理函数 RegisterServiceCtrlHandler(SvcCtrlHandler )
  2. 设置服务状态，SERVICE_START_PENDING
  3. 做一些预备工作，比如初始化日志/注册事件等
  4. 设置服务状态，SERVICE_START_RUNNING
  5. 开始loop处理我们自己的代码（loop循环中可以接受3中注册的事件，当通知停止时退出循环）
• 编写控件处理程序函数
  1. 接受事件管理器发送的消息并处理，比如收到SERVICE_CONTROL_STOP时，使用3中注册的事件句柄发送停止事件

二：Rust中编写windows服务

借用第三方库 windows-service = "0.7.0"
https://crates.io/crates/windows-service
参考windows-service中ping-service示例提取了一个模板，只有替换编写两处/* */代码

use std::{ffi::OsString,sync::mpsc,time::Duration,
};
use windows_service::{define_windows_service,service::{ServiceControl, ServiceControlAccept, ServiceExitCode, ServiceState, ServiceStatus,ServiceType,},service_control_handler::{self, ServiceControlHandlerResult},service_dispatcher,
};static SERVICE_NAME: &str = "Rust Demo Service";fn main() -> Result<(), windows_service::Error> {service_dispatcher::start(SERVICE_NAME, ffi_service_main)?;Ok(())
}define_windows_service!(ffi_service_main, my_service_main);fn my_service_main(arguments: Vec<OsString>) {let _ = arguments;/*这里服务还没开始， 可以填写初始化日志文件等操作*/let (shutdown_tx, shutdown_rx) = mpsc::channel();// 对应SvcCtrlHandlerlet _event_handler = move |control_event| -> ServiceControlHandlerResult {match control_event {ServiceControl::Interrogate => ServiceControlHandlerResult::NoError,// 处理停止事件ServiceControl::Stop => {shutdown_tx.send(()).unwrap();ServiceControlHandlerResult::NoError}// 其他用户事件都当作停止事件处理ServiceControl::UserEvent(code) => {if code.to_raw() == 130 {shutdown_tx.send(()).unwrap();}ServiceControlHandlerResult::NoError}_ => ServiceControlHandlerResult::NotImplemented,}};let status_handle = service_control_handler::register(SERVICE_NAME, _event_handler);let status_handle = status_handle.unwrap();let _ = status_handle.set_service_status(ServiceStatus {service_type: ServiceType::OWN_PROCESS,current_state: ServiceState::Running,controls_accepted: ServiceControlAccept::STOP,exit_code: ServiceExitCode::Win32(0),checkpoint: 0,wait_hint: Duration::default(),process_id: None,});loop {/*这里写自己的代码逻辑，下面时处理一次循环后睡眠5秒，若是接受到停止等消息退出循环*/match shutdown_rx.recv_timeout(Duration::from_secs(5)) {Ok(_) | Err(mpsc::RecvTimeoutError::Disconnected) => break,Err(mpsc::RecvTimeoutError::Timeout) => (),}}let _ = status_handle.set_service_status(ServiceStatus {service_type: ServiceType::OWN_PROCESS,current_state: ServiceState::Stopped,controls_accepted: ServiceControlAccept::empty(),exit_code: ServiceExitCode::Win32(0),checkpoint: 0,wait_hint: Duration::default(),process_id: None,});
}

三：具体实例

笔记本策略经常恢复到合上盖子睡眠功能，写个小服务定时设置合上盖子不做任何操作
逻辑比较简单，定时调用WinAPI函数CallNtPowerInformation获取配置信息，不符合当前设置执行修改
完整如下

use std::{ffi::{c_void, OsString},sync::mpsc,time::Duration,
};
use windows::Win32::{Foundation::STATUS_SUCCESS, System::Power::{CallNtPowerInformation, POWER_INFORMATION_LEVEL, SYSTEM_POWER_POLICY}};
use windows_service::{define_windows_service,service::{ServiceControl, ServiceControlAccept, ServiceExitCode, ServiceState, ServiceStatus,ServiceType,},service_control_handler::{self, ServiceControlHandlerResult},service_dispatcher,
};static SERVICE_NAME: &str = "Power Lid Service";fn main() -> Result<(), windows_service::Error> {service_dispatcher::start(SERVICE_NAME, ffi_service_main)?;Ok(())
}define_windows_service!(ffi_service_main, my_service_main);fn my_service_main(arguments: Vec<OsString>) {let _ = arguments;let (shutdown_tx, shutdown_rx) = mpsc::channel();let _event_handler = move |control_event| -> ServiceControlHandlerResult {match control_event {ServiceControl::Interrogate => ServiceControlHandlerResult::NoError,ServiceControl::Stop => {shutdown_tx.send(()).unwrap();ServiceControlHandlerResult::NoError}ServiceControl::UserEvent(code) => {if code.to_raw() == 130 {shutdown_tx.send(()).unwrap();}ServiceControlHandlerResult::NoError}_ => ServiceControlHandlerResult::NotImplemented,}};let status_handle = service_control_handler::register(SERVICE_NAME, _event_handler);let status_handle = status_handle.unwrap();let _ = status_handle.set_service_status(ServiceStatus {service_type: ServiceType::OWN_PROCESS,current_state: ServiceState::Running,controls_accepted: ServiceControlAccept::STOP,exit_code: ServiceExitCode::Win32(0),checkpoint: 0,wait_hint: Duration::default(),process_id: None,});loop {unsafe {let mut a: SYSTEM_POWER_POLICY = std::mem::zeroed();let status = CallNtPowerInformation(POWER_INFORMATION_LEVEL { 0: 8 },None,0,Some(&mut a as *mut SYSTEM_POWER_POLICY as *mut c_void),size_of::<SYSTEM_POWER_POLICY>() as u32,);if status != STATUS_SUCCESS {println!("获取电源状态失败: {:x} !", status.0);return;}if a.LidClose.Action.0 == 0 {println!("状态已为0, 忽略");return;} else {println!("状态为{:x}", a.LidClose.Action.0);a.LidClose.Action.0 = 0;let status = CallNtPowerInformation(POWER_INFORMATION_LEVEL { 0: 0 },Some(&mut a as *mut SYSTEM_POWER_POLICY as *mut c_void),size_of::<SYSTEM_POWER_POLICY>() as u32,None,0,);if status != STATUS_SUCCESS {println!("设置ac电源状态失败: {:x} !", status.0);return;} else {println!("设置AC电源状态成功");}let status = CallNtPowerInformation(POWER_INFORMATION_LEVEL { 0: 1 },Some(&mut a as *mut SYSTEM_POWER_POLICY as *mut c_void),size_of::<SYSTEM_POWER_POLICY>() as u32,None,0,);if status != STATUS_SUCCESS {println!("设置dc电源状态失败: {:x} !", status.0);return;} else {println!("设置DC电源状态成功");}}}match shutdown_rx.recv_timeout(Duration::from_secs(5)) {Ok(_) | Err(mpsc::RecvTimeoutError::Disconnected) => break,Err(mpsc::RecvTimeoutError::Timeout) => (),}}let _ = status_handle.set_service_status(ServiceStatus {service_type: ServiceType::OWN_PROCESS,current_state: ServiceState::Stopped,controls_accepted: ServiceControlAccept::empty(),exit_code: ServiceExitCode::Win32(0),checkpoint: 0,wait_hint: Duration::default(),process_id: None,});
}