feat(mgb/comp_node): generate uid for cuda comp node

GitOrigin-RevId: 34fa5a2fb613de80ae14034ff4337ffd2ec3f3e3

src/core/impl/comp_node/cuda/comp_node.cpp

@@ -245,6 +245,12 @@ class CudaCompNode::CompNodeImpl final: public CompNode::Impl {
                 throw;
             });
         }
+
+        uint64_t get_uid() override {
+            return m_uid;
+        }
+    private:
+        uint64_t m_uid;
 };
 MGB_DYN_TYPE_OBJ_FINAL_IMPL(CudaCompNode::CompNodeImpl);
 
@@ -310,6 +316,17 @@ void CudaCompNodeImpl::init(
     m_locator_logical = locator_logical;
     m_initialized = true;
 
+#if defined(__linux__) || defined(TARGET_OS_MAC)
+    FILE *fp;
+    fp = fopen("/dev/urandom", "r");
+    mgb_assert(fread(&m_uid, sizeof(m_uid), 1, fp) == 1);
+    fclose(fp);
+#else
+    m_uid = std::chrono::duration_cast<std::chrono::nanoseconds>(
+        std::chrono::system_clock::now().time_since_epoch()
+    ).count();
+#endif
+
     auto on_succ = [this](cudaStream_t stream) {
         auto locator = m_locator;
         log_comp_node_created(locator, m_locator_logical);

src/core/include/megbrain/comp_node.h

@@ -359,6 +359,10 @@ class CompNode {
             return m_impl ? m_impl->locator_logical().to_string() : "invalid";
         }
 
+        uint64_t get_uid() {
+            return m_impl->get_uid();
+        }
+
         //! get the physical locator that created this comp node
         Locator locator() const {
             return m_impl->locator();
@@ -522,6 +526,10 @@ class CompNode {
 
                 virtual void add_callback(megdnn::thin_function<void()>&&);
 
+                virtual uint64_t get_uid() {
+                    mgb_throw(MegBrainError, "get_uid is not impl yet");
+                };
+
             protected:
                 ImplBase(free_func_t fd, free_func_t fh)
                         : free_device{fd}, free_host{fh} {}

src/core/test/comp_node.cpp

@@ -264,6 +264,19 @@ TEST(TestCompNodeCuda, MemNode) {
     ASSERT_NE(cn00.mem_node(), cn1.mem_node());
 }
 
+TEST(TestCompNodeCuda, Uid) {
+    REQUIRE_GPU(2);
+
+    auto cn00 = CompNode::load("gpu0"),
+         cn1 = CompNode::load("gpu1"),
+         cn01 = CompNode::load("gpu0:0"),
+         cn02 = CompNode::load("gpu0:2");
+    ASSERT_EQ(cn00, CompNode::load("gpu0"));
+    ASSERT_EQ(cn00.get_uid(), cn01.get_uid());
+    ASSERT_NE(cn00.get_uid(), cn02.get_uid());
+    ASSERT_NE(cn00.get_uid(), cn1.get_uid());
+}
+
 
 TEST(TestCompNodeCPU, PhysicalDispatch) {
     constexpr int ID = 0x2a6453e0;