1 files changed, 80 insertions, 0 deletions
diff --git a/devtools/server/actors/pause-scoped.js b/devtools/server/actors/pause-scoped.js
new file mode 100644
index 0000000000..dc1f2700ee
--- /dev/null
+++ b/devtools/server/actors/pause-scoped.js
@@ -0,0 +1,80 @@
+/* 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";
+
+const { ObjectActor } = require("resource://devtools/server/actors/object.js");
+
+class PauseScopedObjectActor extends ObjectActor {
+  /**
+   * Creates a pause-scoped actor for the specified object.
+   * @see ObjectActor
+   */
+  constructor(obj, hooks, conn) {
+    super(obj, hooks, conn);
+
+    this.hooks.promote = hooks.promote;
+    this.hooks.isThreadLifetimePool = hooks.isThreadLifetimePool;
+
+    const guardWithPaused = [
+      "decompile",
+      "displayString",
+      "ownPropertyNames",
+      "parameterNames",
+      "property",
+      "prototype",
+      "prototypeAndProperties",
+      "scope",
+    ];
+
+    for (const methodName of guardWithPaused) {
+      this[methodName] = this.withPaused(this[methodName]);
+    }
+
+    /**
+     * Handle a protocol request to promote a pause-lifetime grip to a
+     * thread-lifetime grip.
+     */
+    this.threadGrip = this.withPaused(function () {
+      this.hooks.promote();
+      return {};
+    });
+  }
+
+  isPaused() {
+    return this.threadActor ? this.threadActor.state === "paused" : true;
+  }
+
+  withPaused(method) {
+    return function () {
+      if (this.isPaused()) {
+        return method.apply(this, arguments);
+      }
+
+      return {
+        error: "wrongState",
+        message:
+          this.constructor.name +
+          " actors can only be accessed while the thread is paused.",
+      };
+    };
+  }
+
+  /**
+   * Handle a protocol request to release a thread-lifetime grip.
+   */
+  destroy() {
+    if (this.hooks.isThreadLifetimePool()) {
+      return {
+        error: "notReleasable",
+        message: "Only thread-lifetime actors can be released.",
+      };
+    }
+
+    super.destroy();
+    return null;
+  }
+}
+
+exports.PauseScopedObjectActor = PauseScopedObjectActor;