Bug 1372670 - part 5 - add nsIThreadManager::spinEventLoopUntilEmpty; r=erahm,florian

A number of places in JS need to drain the current thread's event queue,
which cannot be done with nsIThreadManager::spinEventLoopUntil, since we
need to not wait for an incoming event when attempting to process one.

addon-sdk/source/test/addons/content-permissions/httpd.js

@@ -5177,11 +5177,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

addon-sdk/source/test/addons/content-script-messages-latency/httpd.js

@@ -5177,11 +5177,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

addon-sdk/source/test/addons/e10s-content/lib/httpd.js

@@ -5178,11 +5178,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

addon-sdk/source/test/addons/places/lib/httpd.js

@@ -5177,11 +5177,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

addon-sdk/source/test/lib/httpd.js

@@ -5178,11 +5178,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

dom/indexedDB/test/unit/test_success_events_after_abort.js

@@ -46,12 +46,9 @@ function* testSteps()
   if (this.window) {
     // Make sure the success event isn't queued somehow.
     let comp = SpecialPowers.wrap(Components);
-    let thread = comp.classes["@mozilla.org/thread-manager;1"]
-                     .getService(comp.interfaces.nsIThreadManager)
-                     .currentThread;
-    while (thread.hasPendingEvents()) {
-      thread.processNextEvent(false);
-    }
+    let tm = comp.classes["@mozilla.org/thread-manager;1"]
+                 .getService(comp.interfaces.nsIThreadManager);
+    tm.spinEventLoopUntilEmpty();
   }
 
   finishTest();

services/sync/tps/extensions/mozmill/resource/stdlib/httpd.js

@@ -5343,11 +5343,7 @@ function server(port, basePath)
 
   gThreadManager.spinEventLoopUntil(() => srv.isStopped());
 
-  var thread = gThreadManager.currentThread;
-
-  // get rid of any pending requests
-  while (thread.hasPendingEvents())
-    thread.processNextEvent(true);
+  gThreadManager.spinEventLoopUntilEmpty();
 
   DEBUG = false;
 }

testing/xpcshell/head.js

@@ -216,12 +216,10 @@ function _do_main() {
   _testLogger.info("running event loop");
 
   var tm = Components.classes["@mozilla.org/thread-manager;1"].getService();
-  var thr = tm.currentThread;
 
   tm.spinEventLoopUntil(() => _quit);
 
-  while (thr.hasPendingEvents())
-    thr.processNextEvent(true);
+  tm.spinEventLoopUntilEmpty();
 }
 
 function _do_quit() {

xpcom/tests/unit/test_nsIProcess_stress.js

@@ -2,8 +2,8 @@ function run_test() {
   set_process_running_environment();
 
   var file = get_test_program("TestQuickReturn");
-  var thread = Components.classes["@mozilla.org/thread-manager;1"]
-                         .getService().currentThread;
+  var tm = Components.classes["@mozilla.org/thread-manager;1"]
+                     .getService();
 
   for (var i = 0; i < 1000; i++) {
     var process = Components.classes["@mozilla.org/process/util;1"]
@@ -20,8 +20,7 @@ function run_test() {
     // We need to ensure that we process any events on the main thread -
     // this allow threads to clean up properly and avoid out of memory
     // errors during the test.
-    while (thread.hasPendingEvents())
-      thread.processNextEvent(false);
+    tm.spinEventLoopUntilEmpty();
   }
 
-}
+}

xpcom/threads/nsIThreadManager.idl

@@ -105,6 +105,14 @@ interface nsIThreadManager : nsISupports
    */
   void spinEventLoopUntil(in nsINestedEventLoopCondition condition);
 
+  /**
+   * Spin the current thread's event loop until there are no more pending
+   * events.  This could be done with spinEventLoopUntil, but that would
+   * require access to the current thread from JavaScript, which we are
+   * moving away from.
+   */
+  void spinEventLoopUntilEmpty();
+
   /**
    * This queues a runnable to the main thread's idle queue.
    *

xpcom/threads/nsThreadManager.cpp

@@ -364,6 +364,18 @@ nsThreadManager::SpinEventLoopUntil(nsINestedEventLoopCondition* aCondition)
   return rv;
 }
 
+NS_IMETHODIMP
+nsThreadManager::SpinEventLoopUntilEmpty()
+{
+  nsIThread* thread = NS_GetCurrentThread();
+
+  while (NS_HasPendingEvents(thread)) {
+    (void)NS_ProcessNextEvent(thread, false);
+  }
+
+  return NS_OK;
+}
+
 uint32_t
 nsThreadManager::GetHighestNumberOfThreads()
 {