[llvm] [Offload] Implement hasPendingWork on CUDA (PR #152728)

[Callum Fare via llvm-commits]

https://github.com/callumfare created https://github.com/llvm/llvm-project/pull/152728

Following on from #152304, implement the new query in the CUDA plugin

>From a51ac5cee23fcacf093e2475e5f3855de057a466 Mon Sep 17 00:00:00 2001
From: Callum Fare <callum at codeplay.com>
Date: Fri, 8 Aug 2025 15:08:43 +0100
Subject: [PATCH] [Offload] Implement hasPendingWork on CUDA

---
 offload/plugins-nextgen/cuda/src/rtl.cpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/offload/plugins-nextgen/cuda/src/rtl.cpp b/offload/plugins-nextgen/cuda/src/rtl.cpp
index f3f3783b3ce7c..6ae17c4265894 100644
--- a/offload/plugins-nextgen/cuda/src/rtl.cpp
+++ b/offload/plugins-nextgen/cuda/src/rtl.cpp
@@ -914,9 +914,19 @@ struct CUDADeviceTy : public GenericDeviceTy {
     return Plugin::check(Res, "error in cuStreamWaitEvent: %s");
   }
 
-  // TODO: This should be implementable on CUDA
   Expected<bool> hasPendingWorkImpl(AsyncInfoWrapperTy &AsyncInfo) override {
-    return true;
+    CUstream Stream;
+    if (auto Err = getStream(AsyncInfo, Stream))
+      return Err;
+
+    CUresult Ret = cuStreamQuery(Stream);
+    if (Ret == CUDA_SUCCESS)
+      return false;
+
+    if (Ret == CUDA_ERROR_NOT_READY)
+      return true;
+
+    return Plugin::check(Ret, "error in cuStreamQuery: %s");
   }
 
   /// Synchronize the current thread with the event.