Add child restart interval flag (#610)

* Add child restart interval flag

* exempt another CONST from linting

.eslintrc.json

@@ -32,7 +32,7 @@
                 "selector": ["variable", "function", "method", "accessor"],
                 "format": ["camelCase"],
                 "filter": {
-                    "regex": "Reader|DEFAULT_CRASH_RECOVERY_MAX_OLD_SPACE_SIZE",
+                    "regex": "Reader|DEFAULT_CRASH_RECOVERY_MAX_OLD_SPACE_SIZE|DEFAULT_CHILD_RESTART_TASK_INTERVAL",
                     "match": false
                 }
             },

packages/dtslint-runner/expectedFailures.txt

@@ -4,7 +4,6 @@ dialogflow-fulfillment
 electron-clipboard-extended
 electron-notifications
 electron-notify
-fhir
 graphql-resolvers
 keystonejs__adapter-knex
 keystonejs__app-graphql

packages/dtslint-runner/src/index.ts

@@ -72,6 +72,10 @@ if (!module.parent) {
         type: "boolean",
         default: false,
       },
+      childRestartTaskInterval: {
+        type: "number",
+        description: "How often to restart child processes, in number of tasks. Useful to work around memory leaks. Default is not to restart.",
+      }
     })
     .wrap(Math.min(yargs.terminalWidth(), 120)).argv;
 
@@ -92,6 +96,7 @@ if (!module.parent) {
     onlyTestTsNext: !!args.onlyTestTsNext,
     expectOnly: args.expectOnly,
     noInstall: args.noInstall,
+    childRestartTaskInterval: args.childRestartTaskInterval,
   };
 
   logUncaughtErrors(async () => {

packages/dtslint-runner/src/main.ts

@@ -25,6 +25,7 @@ export async function runDTSLint({
   localTypeScriptPath,
   nProcesses,
   shard,
+  childRestartTaskInterval,
 }: RunDTSLintOptions) {
   let definitelyTypedPath;
   console.log("Node version: ", process.version);
@@ -80,6 +81,7 @@ export async function runDTSLint({
     cwd: typesPath,
     crashRecovery: true,
     crashRecoveryMaxOldSpaceSize: 0, // disable retry with more memory
+    childRestartTaskInterval,
     handleStart(input, processIndex) {
       const prefix = processIndex === undefined ? "" : `${processIndex}> `;
       console.log(`${prefix}${input.path} START`);

packages/dtslint-runner/src/types.ts

@@ -28,4 +28,5 @@ export interface RunDTSLintOptions {
   localTypeScriptPath?: string;
   nProcesses: number;
   shard?: { id: number; count: number };
+  childRestartTaskInterval?: number;
 }

packages/utils/src/process.ts

@@ -3,6 +3,7 @@ import { ChildProcess, exec as node_exec, fork, Serializable } from "child_proce
 import { Socket } from "net";
 
 const DEFAULT_CRASH_RECOVERY_MAX_OLD_SPACE_SIZE = 4096;
+const DEFAULT_CHILD_RESTART_TASK_INTERVAL = 1_000_000;
 
 /** Run a command and return the error, stdout, and stderr. (Never throws.) */
 export function exec(cmd: string, cwd?: string): Promise<{ error: Error | undefined; stdout: string; stderr: string }> {
@@ -108,6 +109,7 @@ interface RunWithListeningChildProcessesOptions<In> {
   readonly cwd: string;
   readonly crashRecovery?: boolean;
   readonly crashRecoveryMaxOldSpaceSize?: number;
+  readonly childRestartTaskInterval?: number;
   readonly softTimeoutMs?: number;
   handleOutput(output: unknown, processIndex: number | undefined): void;
   handleStart?(input: In, processIndex: number | undefined): void;
@@ -122,6 +124,7 @@ export function runWithListeningChildProcesses<In extends Serializable>({
   handleOutput,
   crashRecovery,
   crashRecoveryMaxOldSpaceSize = DEFAULT_CRASH_RECOVERY_MAX_OLD_SPACE_SIZE,
+  childRestartTaskInterval = DEFAULT_CHILD_RESTART_TASK_INTERVAL,
   handleStart,
   handleCrash,
   softTimeoutMs = Infinity,
@@ -129,7 +132,6 @@ export function runWithListeningChildProcesses<In extends Serializable>({
   return new Promise(async (resolve, reject) => {
     let inputIndex = 0;
     let processesLeft = nProcesses;
-    const tasksPerChild = 20;
     let tasksSoFar = 0;
     let rejected = false;
     const runningChildren = new Set<ChildProcess>();
@@ -148,6 +150,7 @@ export function runWithListeningChildProcesses<In extends Serializable>({
 
       const onMessage = (outputMessage: unknown) => {
         try {
+          tasksSoFar++;
           const oldCrashRecoveryState = crashRecoveryState;
           crashRecoveryState = CrashRecoveryState.Normal;
           handleOutput(outputMessage as {}, processIndex);
@@ -158,13 +161,12 @@ export function runWithListeningChildProcesses<In extends Serializable>({
               // retry attempt succeeded, restart the child for further tests.
               console.log(`${processIndex}> Restarting...`);
               restartChild(nextTask, process.execArgv);
-            } else if (tasksSoFar > tasksPerChild) {
+            } else if (tasksSoFar >= childRestartTaskInterval) {
               // restart the child to avoid memory leaks.
               stopChild(/*done*/ false);
               startChild(nextTask, process.execArgv);
               tasksSoFar = 0;
             } else {
-              tasksSoFar++;
               nextTask();
             }
           }