[llvm] [flang][cuda][rt] Track asynchronous allocation stream for deallocation (PR #137073)

[Zhen Wang via llvm-commits]

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@@ -21,6 +22,106 @@
 #include "cuda_runtime.h"
 
 namespace Fortran::runtime::cuda {
+
+struct DeviceAllocation {
+  void *ptr;
+  std::size_t size;
+  cudaStream_t stream;
+};
+
+// Compare address values. nullptr will be sorted at the end of the array.
+int compareDeviceAlloc(const void *a, const void *b) {
+  const DeviceAllocation *deva = (const DeviceAllocation *)a;
+  const DeviceAllocation *devb = (const DeviceAllocation *)b;
+  if (deva->ptr == nullptr && devb->ptr == nullptr)
+    return 0;
+  if (deva->ptr == nullptr)
+    return 1;
+  if (devb->ptr == nullptr)
+    return -1;
+  return deva->ptr < devb->ptr ? -1 : (deva->ptr > devb->ptr ? 1 : 0);
+}
+
+// Dynamic array for tracking asynchronous allocations.
+static DeviceAllocation *deviceAllocations = nullptr;
+Lock lock;
+static int maxDeviceAllocations{512}; // Initial size
+static int numDeviceAllocations{0};
+static constexpr int allocNotFound{-1};
+
+static void initAllocations() {
+  if (!deviceAllocations) {
+    deviceAllocations = static_cast<DeviceAllocation *>(
+        malloc(maxDeviceAllocations * sizeof(DeviceAllocation)));
+    if (!deviceAllocations) {
+      Terminator terminator{__FILE__, __LINE__};
+      terminator.Crash("Failed to allocate tracking array");
+    }
+  }
+}
+
+// Double the size of the allocation array when size if
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wangzpgi wrote:

uncomplete sentence?

https://github.com/llvm/llvm-project/pull/137073