Deduplicate child process message dance

This commit is contained in:
Asher 2020-11-10 15:46:53 -06:00
parent d969a5bd6b
commit 0a01338edd
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GPG Key ID: D63C1EF81242354A
1 changed files with 74 additions and 42 deletions

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@ -13,6 +13,7 @@ export class VscodeProvider {
public readonly serverRootPath: string
public readonly vsRootPath: string
private _vscode?: Promise<cp.ChildProcess>
private timeoutInterval = 10000 // 10s, matches VS Code's timeouts.
public constructor() {
this.vsRootPath = path.resolve(rootPath, "lib/vscode")
@ -52,20 +53,6 @@ export class VscodeProvider {
const vscode = await this.fork()
logger.debug("setting up vs code...")
return new Promise<ipc.WorkbenchOptions>((resolve, reject) => {
const onExit = (code: number | null) => reject(new Error(`VS Code exited unexpectedly with code ${code}`))
vscode.once("message", (message: ipc.VscodeMessage) => {
logger.debug("got message from vs code", field("message", message))
vscode.off("error", reject)
vscode.off("exit", onExit)
return message.type === "options" && message.id === id
? resolve(message.options)
: reject(new Error("Unexpected response during initialization"))
})
vscode.once("error", reject)
vscode.once("exit", onExit)
this.send(
{
@ -78,7 +65,13 @@ export class VscodeProvider {
},
vscode,
)
const message = await this.onMessage<ipc.OptionsMessage>(vscode, (message): message is ipc.OptionsMessage => {
// There can be parallel initializations so wait for the right ID.
return message.type === "options" && message.id === id
})
return message.options
}
private fork(): Promise<cp.ChildProcess> {
@ -88,34 +81,73 @@ export class VscodeProvider {
logger.debug("forking vs code...")
const vscode = cp.fork(path.join(this.serverRootPath, "fork"))
vscode.on("error", (error) => {
logger.error(error.message)
const dispose = () => {
vscode.removeAllListeners()
vscode.kill()
this._vscode = undefined
}
vscode.on("error", (error: Error) => {
logger.error(error.message)
if (error.stack) {
logger.debug(error.stack)
}
dispose()
})
vscode.on("exit", (code) => {
logger.error(`VS Code exited unexpectedly with code ${code}`)
this._vscode = undefined
dispose()
})
this._vscode = new Promise((resolve, reject) => {
const onExit = (code: number | null) => reject(new Error(`VS Code exited unexpectedly with code ${code}`))
vscode.once("message", (message: ipc.VscodeMessage) => {
logger.debug("got message from vs code", field("message", message))
vscode.off("error", reject)
vscode.off("exit", onExit)
this._vscode = this.onMessage<ipc.ReadyMessage>(vscode, (message): message is ipc.ReadyMessage => {
return message.type === "ready"
? resolve(vscode)
: reject(new Error("Unexpected response waiting for ready response"))
})
vscode.once("error", reject)
vscode.once("exit", onExit)
})
}).then(() => vscode)
return this._vscode
}
/**
* Listen to a single message from a process. Reject if the process errors,
* exits, or times out.
*
* `fn` is a function that determines whether the message is the one we're
* waiting for.
*/
private onMessage<T extends ipc.VscodeMessage>(
proc: cp.ChildProcess,
fn: (message: ipc.VscodeMessage) => message is T,
): Promise<T> {
return new Promise((resolve, _reject) => {
const reject = (error: Error) => {
clearTimeout(timeout)
_reject(error)
}
const onExit = (code: number | null) => {
reject(new Error(`VS Code exited unexpectedly with code ${code}`))
}
const timeout = setTimeout(() => {
reject(new Error("timed out"))
}, this.timeoutInterval)
proc.on("message", (message: ipc.VscodeMessage) => {
logger.debug("got message from vscode", field("message", message))
proc.off("error", reject)
proc.off("exit", onExit)
if (fn(message)) {
clearTimeout(timeout)
resolve(message)
}
})
proc.once("error", reject)
proc.once("exit", onExit)
})
}
/**
* VS Code expects a raw socket. It will handle all the web socket frames.
*/