1 files changed, 229 insertions, 0 deletions
diff --git a/toolkit/modules/subprocess/subprocess_worker_common.js b/toolkit/modules/subprocess/subprocess_worker_common.js
new file mode 100644
index 000000000..2b681e737
--- /dev/null
+++ b/toolkit/modules/subprocess/subprocess_worker_common.js
@@ -0,0 +1,229 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+/* exported BasePipe, BaseProcess, debug */
+/* globals Process, io */
+
+function debug(message) {
+  self.postMessage({msg: "debug", message});
+}
+
+class BasePipe {
+  constructor() {
+    this.closing = false;
+    this.closed = false;
+
+    this.closedPromise = new Promise(resolve => {
+      this.resolveClosed = resolve;
+    });
+
+    this.pending = [];
+  }
+
+  shiftPending() {
+    let result = this.pending.shift();
+
+    if (this.closing && this.pending.length == 0) {
+      this.close();
+    }
+
+    return result;
+  }
+}
+
+let nextProcessId = 0;
+
+class BaseProcess {
+  constructor(options) {
+    this.id = nextProcessId++;
+
+    this.exitCode = null;
+
+    this.exitPromise = new Promise(resolve => {
+      this.resolveExit = resolve;
+    });
+    this.exitPromise.then(() => {
+      // The input file descriptors will be closed after poll
+      // reports that their input buffers are empty. If we close
+      // them now, we may lose output.
+      this.pipes[0].close(true);
+    });
+
+    this.pid = null;
+    this.pipes = [];
+
+    this.stringArrays = [];
+
+    this.spawn(options);
+  }
+
+  /**
+   * Waits for the process to exit and all of its pending IO operations to
+   * complete.
+   *
+   * @returns {Promise<void>}
+   */
+  awaitFinished() {
+    return Promise.all([
+      this.exitPromise,
+      ...this.pipes.map(pipe => pipe.closedPromise),
+    ]);
+  }
+
+  /**
+   * Creates a null-terminated array of pointers to null-terminated C-strings,
+   * and returns it.
+   *
+   * @param {string[]} strings
+   *        The strings to convert into a C string array.
+   *
+   * @returns {ctypes.char.ptr.array}
+   */
+  stringArray(strings) {
+    let result = ctypes.char.ptr.array(strings.length + 1)();
+
+    let cstrings = strings.map(str => ctypes.char.array()(str));
+    for (let [i, cstring] of cstrings.entries()) {
+      result[i] = cstring;
+    }
+
+    // Char arrays used in char arg and environment vectors must be
+    // explicitly kept alive in a JS object, or they will be reaped
+    // by the GC if it runs before our process is started.
+    this.stringArrays.push(cstrings);
+
+    return result;
+  }
+}
+
+let requests = {
+  init(details) {
+    io.init(details);
+
+    return {data: {}};
+  },
+
+  shutdown() {
+    io.shutdown();
+
+    return {data: {}};
+  },
+
+  close(pipeId, force = false) {
+    let pipe = io.getPipe(pipeId);
+
+    return pipe.close(force).then(() => ({data: {}}));
+  },
+
+  spawn(options) {
+    let process = new Process(options);
+    let processId = process.id;
+
+    io.addProcess(process);
+
+    let fds = process.pipes.map(pipe => pipe.id);
+
+    return {data: {processId, fds, pid: process.pid}};
+  },
+
+  kill(processId, force = false) {
+    let process = io.getProcess(processId);
+
+    process.kill(force ? 9 : 15);
+
+    return {data: {}};
+  },
+
+  wait(processId) {
+    let process = io.getProcess(processId);
+
+    process.wait();
+
+    process.awaitFinished().then(() => {
+      io.cleanupProcess(process);
+    });
+
+    return process.exitPromise.then(exitCode => {
+      return {data: {exitCode}};
+    });
+  },
+
+  read(pipeId, count) {
+    let pipe = io.getPipe(pipeId);
+
+    return pipe.read(count).then(buffer => {
+      return {data: {buffer}};
+    });
+  },
+
+  write(pipeId, buffer) {
+    let pipe = io.getPipe(pipeId);
+
+    return pipe.write(buffer).then(bytesWritten => {
+      return {data: {bytesWritten}};
+    });
+  },
+
+  getOpenFiles() {
+    return {data: new Set(io.pipes.keys())};
+  },
+
+  getProcesses() {
+    let data = new Map(Array.from(io.processes.values())
+                            .filter(proc => proc.exitCode == null)
+                            .map(proc => [proc.id, proc.pid]));
+    return {data};
+  },
+
+  waitForNoProcesses() {
+    return Promise.all(Array.from(io.processes.values(),
+                                  proc => proc.awaitFinished()));
+  },
+};
+
+onmessage = event => {
+  io.messageCount--;
+
+  let {msg, msgId, args} = event.data;
+
+  new Promise(resolve => {
+    resolve(requests[msg](...args));
+  }).then(result => {
+    let response = {
+      msg: "success",
+      msgId,
+      data: result.data,
+    };
+
+    self.postMessage(response, result.transfer || []);
+  }).catch(error => {
+    if (error instanceof Error) {
+      error = {
+        message: error.message,
+        fileName: error.fileName,
+        lineNumber: error.lineNumber,
+        column: error.column,
+        stack: error.stack,
+        errorCode: error.errorCode,
+      };
+    }
+
+    self.postMessage({
+      msg: "failure",
+      msgId,
+      error,
+    });
+  }).catch(error => {
+    console.error(error);
+
+    self.postMessage({
+      msg: "failure",
+      msgId,
+      error: {},
+    });
+  });
+};