Bug 1620025 - Improve source front management. r=ochameau

Differential Revision: https://phabricator.services.mozilla.com/D65803

--HG--
extra : moz-landing-system : lando

devtools/shared/client/devtools-client.js

@@ -806,6 +806,14 @@ DevToolsClient.prototype = {
   get transport() {
     return this._transport;
   },
+
+  dumpPools() {
+    for (const pool of this._pools) {
+      console.log(`%c${pool.actorID}`, "font-weight: bold;", [
+        ...pool.__poolMap.keys(),
+      ]);
+    }
+  },
 };
 
 EventEmitter.decorate(DevToolsClient.prototype);

devtools/shared/fronts/thread.js

@@ -48,6 +48,7 @@ class ThreadFront extends FrontClassWithSpec(threadSpec) {
     this.before("paused", this._beforePaused);
     this.before("resumed", this._beforeResumed);
     this.before("detached", this._beforeDetached);
+    this.targetFront.on("will-navigate", this._onWillNavigate.bind(this));
     // Attribute name from which to retrieve the actorID out of the target actor's form
     this.formAttributeName = "threadActor";
   }
@@ -262,14 +263,6 @@ class ThreadFront extends FrontClassWithSpec(threadSpec) {
     this[gripCacheName] = {};
   }
 
-  _clearFrameFronts() {
-    for (const front of this.poolChildren()) {
-      if (front instanceof FrameFront) {
-        this.unmanage(front);
-      }
-    }
-  }
-
   /**
    * Invalidate pause-lifetime grip clients and clear the list of current grip
    * clients.
@@ -294,14 +287,18 @@ class ThreadFront extends FrontClassWithSpec(threadSpec) {
   _beforeResumed() {
     this._state = "attached";
     this._onThreadState(null);
-    this._clearFrameFronts();
+    this.unmanageChildren(FrameFront);
   }
 
   _beforeDetached(packet) {
     this._state = "detached";
     this._onThreadState(packet);
     this._clearThreadGrips();
-    this._clearFrameFronts();
+    this.unmanageChildren(FrameFront);
+  }
+
+  _onWillNavigate() {
+    this.unmanageChildren(SourceFront);
   }
 
   /**

devtools/shared/protocol/Pool.js

@@ -84,6 +84,14 @@ class Pool extends EventEmitter {
     this._poolMap.set(actor.actorID, actor);
   }
 
+  unmanageChildren(FrontType) {
+    for (const front of this.poolChildren()) {
+      if (!FrontType || front instanceof FrontType) {
+        this.unmanage(front);
+      }
+    }
+  }
+
   /**
    * Remove an actor as a child of this pool.
    */

devtools/shared/protocol/tests/xpcshell/test_protocol_children.js

@@ -378,6 +378,11 @@ function expectRootChildren(size) {
   }
 }
 
+function childrenOfType(pool, type) {
+  const children = [...rootFront.poolChildren()];
+  return children.filter(child => child instanceof type);
+}
+
 add_task(async function() {
   DevToolsServer.createRootActor = conn => {
     return RootActor(conn);
@@ -404,6 +409,7 @@ add_task(async function() {
   await testManyChildren(trace);
   await testGenerator(trace);
   await testPolymorphism(trace);
+  await testUnmanageChildren(trace);
 
   await client.close();
 });
@@ -712,3 +718,17 @@ async function testPolymorphism(trace) {
     rootFront.requestPolymorphism(0, rootFront);
   }, /Was expecting one of these actors 'childActor,otherChildActor' but instead got an actor of type: 'root'/);
 }
+
+async function testUnmanageChildren(trace) {
+  // There is already one front of type OtherChildFront
+  Assert.equal(childrenOfType(rootFront, OtherChildFront).length, 1);
+
+  // Create another front of type OtherChildFront
+  const front = await rootFront.getPolymorphism(1);
+  Assert.ok(front instanceof OtherChildFront);
+  Assert.equal(childrenOfType(rootFront, OtherChildFront).length, 2);
+
+  // Remove all fronts of type OtherChildFront
+  rootFront.unmanageChildren(OtherChildFront);
+  Assert.equal(childrenOfType(rootFront, OtherChildFront).length, 0);
+}