diff --git a/Source/JavaScriptCore/runtime/DeferredWorkTimer.cpp b/Source/JavaScriptCore/runtime/DeferredWorkTimer.cpp
index 4d3699ca36390..592e0f7afe700 100644
--- a/Source/JavaScriptCore/runtime/DeferredWorkTimer.cpp
+++ b/Source/JavaScriptCore/runtime/DeferredWorkTimer.cpp
@@ -152,7 +152,7 @@ void DeferredWorkTimer::runRunLoop()
         RunLoop::run();
 }
 
-DeferredWorkTimer::Ticket DeferredWorkTimer::addPendingWork(VM& vm, JSObject* target, Vector<Strong<JSCell>>&& dependencies)
+DeferredWorkTimer::Ticket DeferredWorkTimer::addPendingWork(VM& vm, JSObject* target, Vector<Strong<JSCell>>&& dependencies, WorkKind workKind)
 {
     ASSERT(vm.currentThreadIsHoldingAPILock() || (Thread::mayBeGCThread() && vm.heap.worldIsStopped()));
     for (unsigned i = 0; i < dependencies.size(); ++i)
@@ -166,8 +166,13 @@ DeferredWorkTimer::Ticket DeferredWorkTimer::addPendingWork(VM& vm, JSObject* ta
     Ticket ticket = ticketData.get();
 
     dataLogLnIf(DeferredWorkTimerInternal::verbose, "Adding new pending ticket: ", RawPointer(ticket));
-    auto result = m_pendingTickets.add(WTFMove(ticketData));
-    RELEASE_ASSERT(result.isNewEntry);
+    if (onAddPendingWork) {
+        onAddPendingWork(WTFMove(ticketData), workKind);
+    } else {
+        auto result = m_pendingTickets.add(WTFMove(ticketData));
+        RELEASE_ASSERT(result.isNewEntry);
+    }
+    
 
     return ticket;
 }
@@ -192,6 +197,11 @@ bool DeferredWorkTimer::hasDependancyInPendingWork(Ticket ticket, JSCell* depend
 
 void DeferredWorkTimer::scheduleWorkSoon(Ticket ticket, Task&& task)
 {
+    if (onScheduleWorkSoon) {
+        onScheduleWorkSoon(ticket, WTFMove(task));
+        return;
+    }
+
     Locker locker { m_taskLock };
     m_tasks.append(std::make_tuple(ticket, WTFMove(task)));
     if (!isScheduled() && !m_currentlyRunningTask)
@@ -210,6 +220,10 @@ bool DeferredWorkTimer::cancelPendingWork(Ticket ticket)
         result = true;
     }
 
+     if (onCancelPendingWork) {
+        onCancelPendingWork(ticket);
+    }
+
     return result;
 }
 
diff --git a/Source/JavaScriptCore/runtime/DeferredWorkTimer.h b/Source/JavaScriptCore/runtime/DeferredWorkTimer.h
index 1d68a922d27cb..6b3c55c1d53c6 100644
--- a/Source/JavaScriptCore/runtime/DeferredWorkTimer.h
+++ b/Source/JavaScriptCore/runtime/DeferredWorkTimer.h
@@ -45,6 +45,12 @@ class JS_EXPORT_PRIVATE DeferredWorkTimer final : public JSRunLoopTimer {
 public:
     using Base = JSRunLoopTimer;
 
+    enum class WorkKind : uint8_t {
+        Other,
+        Atomics,
+        WebAssembly,
+    };
+
     struct TicketData {
     private:
         WTF_MAKE_FAST_ALLOCATED;
@@ -65,7 +71,7 @@ class JS_EXPORT_PRIVATE DeferredWorkTimer final : public JSRunLoopTimer {
 
     void doWork(VM&) final;
 
-    Ticket addPendingWork(VM&, JSObject* target, Vector<Strong<JSCell>>&& dependencies);
+    Ticket addPendingWork(VM&, JSObject* target, Vector<Strong<JSCell>>&& dependencies, WorkKind kind = WorkKind::Other);
     bool hasPendingWork(Ticket);
     bool hasDependancyInPendingWork(Ticket, JSCell* dependency);
     bool cancelPendingWork(Ticket);
@@ -83,6 +89,10 @@ class JS_EXPORT_PRIVATE DeferredWorkTimer final : public JSRunLoopTimer {
     void runRunLoop();
 
     static Ref<DeferredWorkTimer> create(VM& vm) { return adoptRef(*new DeferredWorkTimer(vm)); }
+
+    WTF::Function<void(std::unique_ptr<TicketData>, WorkKind)> onAddPendingWork;
+    WTF::Function<void(Ticket, Task&&)> onScheduleWorkSoon;
+    WTF::Function<void(Ticket)> onCancelPendingWork;
 private:
     DeferredWorkTimer(VM&);
 
diff --git a/Source/JavaScriptCore/runtime/WaiterListManager.h b/Source/JavaScriptCore/runtime/WaiterListManager.h
index 0097bbb10a561..20a870c800c8e 100644
--- a/Source/JavaScriptCore/runtime/WaiterListManager.h
+++ b/Source/JavaScriptCore/runtime/WaiterListManager.h
@@ -48,7 +48,7 @@ class Waiter final : public WTF::BasicRawSentinelNode<Waiter>, public ThreadSafe
 
     Waiter(JSPromise* promise)
         : m_vm(&promise->vm())
-        , m_ticket(m_vm->deferredWorkTimer->addPendingWork(*m_vm, promise, { }))
+        , m_ticket(m_vm->deferredWorkTimer->addPendingWork(*m_vm, promise, { }, DeferredWorkTimer::WorkKind::Atomics))
         , m_isAsync(true)
     {
     }
diff --git a/Source/JavaScriptCore/wasm/WasmStreamingCompiler.cpp b/Source/JavaScriptCore/wasm/WasmStreamingCompiler.cpp
index dcaa8c78e490e..6740ec80d4100 100644
--- a/Source/JavaScriptCore/wasm/WasmStreamingCompiler.cpp
+++ b/Source/JavaScriptCore/wasm/WasmStreamingCompiler.cpp
@@ -51,7 +51,7 @@ StreamingCompiler::StreamingCompiler(VM& vm, CompilerMode compilerMode, JSGlobal
     dependencies.append(Strong<JSCell>(vm, globalObject));
     if (importObject)
         dependencies.append(Strong<JSCell>(vm, importObject));
-    m_ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies));
+    m_ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies), DeferredWorkTimer::WorkKind::WebAssembly);
     ASSERT(vm.deferredWorkTimer->hasPendingWork(m_ticket));
     ASSERT(vm.deferredWorkTimer->hasDependancyInPendingWork(m_ticket, globalObject));
     ASSERT(!importObject || vm.deferredWorkTimer->hasDependancyInPendingWork(m_ticket, importObject));
diff --git a/Source/JavaScriptCore/wasm/js/JSWebAssembly.cpp b/Source/JavaScriptCore/wasm/js/JSWebAssembly.cpp
index ab95507ce8d4f..42b81de2f87dd 100644
--- a/Source/JavaScriptCore/wasm/js/JSWebAssembly.cpp
+++ b/Source/JavaScriptCore/wasm/js/JSWebAssembly.cpp
@@ -147,7 +147,7 @@ void JSWebAssembly::webAssemblyModuleValidateAsync(JSGlobalObject* globalObject,
     Vector<Strong<JSCell>> dependencies;
     dependencies.append(Strong<JSCell>(vm, globalObject));
 
-    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies));
+    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies), DeferredWorkTimer::WorkKind::WebAssembly);
     Wasm::Module::validateAsync(vm, WTFMove(source), createSharedTask<Wasm::Module::CallbackType>([ticket, promise, globalObject, &vm] (Wasm::Module::ValidationResult&& result) mutable {
         vm.deferredWorkTimer->scheduleWorkSoon(ticket, [promise, globalObject, result = WTFMove(result), &vm](DeferredWorkTimer::Ticket) mutable {
             auto scope = DECLARE_THROW_SCOPE(vm);
@@ -186,7 +186,7 @@ static void instantiate(VM& vm, JSGlobalObject* globalObject, JSPromise* promise
     dependencies.append(Strong<JSCell>(vm, promise));
 
     scope.release();
-    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, instance, WTFMove(dependencies));
+    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, instance, WTFMove(dependencies), DeferredWorkTimer::WorkKind::WebAssembly);
     // Note: This completion task may or may not get called immediately.
     module->module().compileAsync(vm, instance->memoryMode(), createSharedTask<Wasm::CalleeGroup::CallbackType>([ticket, promise, instance, module, resolveKind, creationMode, &vm] (Ref<Wasm::CalleeGroup>&& refCalleeGroup) mutable {
         RefPtr<Wasm::CalleeGroup> calleeGroup = WTFMove(refCalleeGroup);
@@ -238,7 +238,7 @@ static void compileAndInstantiate(VM& vm, JSGlobalObject* globalObject, JSPromis
     Vector<Strong<JSCell>> dependencies;
     dependencies.append(Strong<JSCell>(vm, importObject));
     dependencies.append(Strong<JSCell>(vm, moduleKeyCell));
-    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies));
+    auto ticket = vm.deferredWorkTimer->addPendingWork(vm, promise, WTFMove(dependencies), DeferredWorkTimer::WorkKind::WebAssembly);
     Wasm::Module::validateAsync(vm, WTFMove(source), createSharedTask<Wasm::Module::CallbackType>([ticket, promise, importObject, moduleKeyCell, globalObject, resolveKind, creationMode, &vm] (Wasm::Module::ValidationResult&& result) mutable {
         vm.deferredWorkTimer->scheduleWorkSoon(ticket, [promise, importObject, moduleKeyCell, globalObject, result = WTFMove(result), resolveKind, creationMode, &vm](DeferredWorkTimer::Ticket) mutable {
             auto scope = DECLARE_THROW_SCOPE(vm);