1 files changed, 60 insertions, 0 deletions
diff --git a/devtools/shared/security/DevToolsSocketStatus.sys.mjs b/devtools/shared/security/DevToolsSocketStatus.sys.mjs
new file mode 100644
index 0000000000..8acfbdd8c4
--- /dev/null
+++ b/devtools/shared/security/DevToolsSocketStatus.sys.mjs
@@ -0,0 +1,60 @@
+/* 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/. */
+
+/**
+ * Singleton that should be updated whenever a socket is opened or closed for
+ * incoming connections.
+ *
+ * Notifies observers via "devtools-socket" when the status might have have
+ * changed.
+ *
+ * Currently observed by browser/base/content/browser.js in order to display
+ * the "remote control" visual cue also used for Marionette and Remote Agent.
+ */
+export const DevToolsSocketStatus = {
+  _browserToolboxSockets: 0,
+  _otherSockets: 0,
+
+  /**
+   * Check if there are opened DevTools sockets.
+   *
+   * @param {Object=} options
+   * @param {boolean=} options.excludeBrowserToolboxSockets
+   *     Exclude sockets opened by local Browser Toolbox sessions. Defaults to
+   *     false.
+   *
+   * @return {boolean}
+   *     Returns true if there are DevTools sockets opened and matching the
+   *     provided options if any.
+   */
+  hasSocketOpened(options = {}) {
+    const { excludeBrowserToolboxSockets = false } = options;
+    if (excludeBrowserToolboxSockets) {
+      return this._otherSockets > 0;
+    }
+    return this._browserToolboxSockets + this._otherSockets > 0;
+  },
+
+  notifySocketOpened(options) {
+    const { fromBrowserToolbox } = options;
+    if (fromBrowserToolbox) {
+      this._browserToolboxSockets++;
+    } else {
+      this._otherSockets++;
+    }
+
+    Services.obs.notifyObservers(this, "devtools-socket");
+  },
+
+  notifySocketClosed(options) {
+    const { fromBrowserToolbox } = options;
+    if (fromBrowserToolbox) {
+      this._browserToolboxSockets--;
+    } else {
+      this._otherSockets--;
+    }
+
+    Services.obs.notifyObservers(this, "devtools-socket");
+  },
+};