1 files changed, 91 insertions, 0 deletions
diff --git a/src/javascript/jsc/bindings/webcore/Microtasks.cpp b/src/javascript/jsc/bindings/webcore/Microtasks.cpp
new file mode 100644
index 000000000..c3f61166c
--- /dev/null
+++ b/src/javascript/jsc/bindings/webcore/Microtasks.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2014 Yoav Weiss (yoav@yoav.ws)
+ * Copyright (C) 2015 Akamai Technologies Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "config.h"
+#include "Microtasks.h"
+
+// #include "CommonVM.h"
+#include "EventLoop.h"
+#include "WorkerGlobalScope.h"
+#include <wtf/MainThread.h>
+#include <wtf/NeverDestroyed.h>
+#include <wtf/SetForScope.h>
+
+namespace WebCore {
+
+MicrotaskQueue::MicrotaskQueue(JSC::VM& vm)
+    : m_vm(vm)
+{
+}
+
+MicrotaskQueue::~MicrotaskQueue() = default;
+
+void MicrotaskQueue::append(std::unique_ptr<EventLoopTask>&& task)
+{
+    m_microtaskQueue.append(WTFMove(task));
+}
+
+void MicrotaskQueue::performMicrotaskCheckpoint()
+{
+    if (m_performingMicrotaskCheckpoint)
+        return;
+
+    SetForScope change(m_performingMicrotaskCheckpoint, true);
+    JSC::JSLockHolder locker(vm());
+
+    Vector<std::unique_ptr<EventLoopTask>> toKeep;
+    while (!m_microtaskQueue.isEmpty()) {
+        Vector<std::unique_ptr<EventLoopTask>> queue = WTFMove(m_microtaskQueue);
+        for (auto& task : queue) {
+            auto* group = task->group();
+            if (!group || group->isStoppedPermanently())
+                continue;
+            if (group->isSuspended())
+                toKeep.append(WTFMove(task));
+            else
+                task->execute();
+        }
+    }
+
+    vm().finalizeSynchronousJSExecution();
+    m_microtaskQueue = WTFMove(toKeep);
+
+    auto checkpointTasks = std::exchange(m_checkpointTasks, {});
+    for (auto& checkpointTask : checkpointTasks) {
+        auto* group = checkpointTask->group();
+        if (!group || group->isStoppedPermanently())
+            continue;
+
+        if (group->isSuspended()) {
+            m_checkpointTasks.append(WTFMove(checkpointTask));
+            continue;
+        }
+
+        checkpointTask->execute();
+    }
+}
+
+void MicrotaskQueue::addCheckpointTask(std::unique_ptr<EventLoopTask>&& task)
+{
+    m_checkpointTasks.append(WTFMove(task));
+}
+
+} // namespace WebCore