Fix metal issue (#6361)

* Fix metal issue

- implement waitForFences for metal backend
- fix a bug that it misses clear the entryPoints when initializing
  RootShaderObject

* format

---------

Co-authored-by: Yong He <yonghe@outlook.com>

Author: kaizhangNV

tools/gfx/metal/metal-device.cpp

@@ -875,7 +875,16 @@ Result DeviceImpl::waitForFences(
     bool waitForAll,
     uint64_t timeout)
 {
-    return SLANG_E_NOT_IMPLEMENTED;
+    // return SLANG_E_NOT_IMPLEMENTED;
+    for (GfxCount i = 0; i < fenceCount; ++i)
+    {
+        FenceImpl* fenceImpl = static_cast<FenceImpl*>(fences[i]);
+        if (!fenceImpl->waitForFence(fenceValues[i], timeout))
+        {
+            return SLANG_FAIL;
+        }
+    }
+    return SLANG_OK;
 }
 
 } // namespace metal

tools/gfx/metal/metal-fence.cpp

@@ -22,6 +22,13 @@ Result FenceImpl::init(DeviceImpl* device, const IFence::Desc& desc)
         return SLANG_FAIL;
     }
     m_event->setSignaledValue(desc.initialValue);
+
+    m_eventListener = NS::TransferPtr(MTL::SharedEventListener::alloc()->init());
+    if (!m_eventListener)
+    {
+        return SLANG_FAIL;
+    }
+
     return SLANG_OK;
 }
 
@@ -49,5 +56,34 @@ Result FenceImpl::getNativeHandle(InteropHandle* outNativeHandle)
     return SLANG_OK;
 }
 
+bool FenceImpl::waitForFence(uint64_t value, uint64_t timeout)
+{
+    // Create a semaphore to synchronize the notification
+    dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
+
+    // Create and store the notification block
+    MTL::SharedEventNotificationBlock block = ^(MTL::SharedEvent* event, uint64_t eventValue) {
+      dispatch_semaphore_signal(semaphore);
+    };
+
+    // Set up notification handler
+    m_event->notifyListener(m_eventListener.get(), value, block);
+
+    // Wait for the notification or timeout
+    if (timeout & (1LLU << 63))
+    {
+        timeout = DISPATCH_TIME_FOREVER;
+    }
+    else
+    {
+        timeout = dispatch_time(DISPATCH_TIME_NOW, timeout);
+    }
+
+    long result = dispatch_semaphore_wait(semaphore, timeout);
+    dispatch_release(semaphore);
+
+    return result == 0;
+}
+
 } // namespace metal
 } // namespace gfx

tools/gfx/metal/metal-fence.h

@@ -16,6 +16,7 @@ class FenceImpl : public FenceBase
 public:
     RefPtr<DeviceImpl> m_device;
     NS::SharedPtr<MTL::SharedEvent> m_event;
+    NS::SharedPtr<MTL::SharedEventListener> m_eventListener;
 
     ~FenceImpl();
 
@@ -29,6 +30,8 @@ class FenceImpl : public FenceBase
 
     virtual SLANG_NO_THROW Result SLANG_MCALL
     getNativeHandle(InteropHandle* outNativeHandle) override;
+
+    bool waitForFence(uint64_t value, uint64_t timeout);
 };
 
 } // namespace metal

tools/gfx/metal/metal-shader-object.cpp

@@ -768,7 +768,7 @@ Result RootShaderObjectImpl::bindAsRoot(BindingContext* context, RootShaderObjec
 Result RootShaderObjectImpl::init(IDevice* device, RootShaderObjectLayoutImpl* layout)
 {
     SLANG_RETURN_ON_FAIL(Super::init(device, layout));
-
+    m_entryPoints.clear();
     for (auto entryPointInfo : layout->getEntryPoints())
     {
         RefPtr<ShaderObjectImpl> entryPoint;