fix cpu multinomial

mindspore/ccsrc/backend/kernel_compiler/cpu/multinomial_cpu_kernel.cc

@@ -16,7 +16,6 @@
 
 #include "backend/kernel_compiler/cpu/multinomial_cpu_kernel.h"
 #include <algorithm>
-#include <random>
 #include "runtime/device/cpu/cpu_device_address.h"
 
 namespace mindspore {
@@ -35,6 +34,16 @@ void MultinomialCpuKernel::InitKernel(const CNodePtr &kernel_node) {
 
   seed_ = static_cast<int>(GetValue<int64_t>(AnfAlgo::GetCNodePrimitive(kernel_node)->GetAttr("seed")));
   seed2_ = static_cast<int>(GetValue<int64_t>(AnfAlgo::GetCNodePrimitive(kernel_node)->GetAttr("seed2")));
+  int64_t RNG_seed = 0;
+  if (seed2_ > 0) {
+    RNG_seed = seed2_;
+  } else if (seed_ > 0) {
+    RNG_seed = seed_;
+  } else {
+    std::random_device rd;
+    RNG_seed = static_cast<int64_t>(rd());
+  }
+  rng_.seed(RNG_seed);
 }
 
 bool MultinomialCpuKernel::Launch(const std::vector<kernel::AddressPtr> &inputs,
@@ -91,20 +100,10 @@ bool MultinomialCpuKernel::Launch(const std::vector<kernel::AddressPtr> &inputs,
 
     // Initialize random generator.
     std::uniform_real_distribution<float> dist(0.0, 1.0);
-    int64_t RNG_seed = 0;
-    if (seed2_ > 0) {
-      RNG_seed = seed2_;
-    } else if (seed_ > 0) {
-      RNG_seed = seed_;
-    } else {
-      std::random_device rd;
-      RNG_seed = static_cast<int64_t>(rd());
-    }
-    std::default_random_engine rng{RNG_seed};
 
     // Sample data from cumulative array.
     for (int n = 0; n < num_sample; ++n) {
-      auto rand_prob = dist(rng);
+      auto rand_prob = dist(rng_);
       int begin = 0;
       int end = num_col - 1;
 

mindspore/ccsrc/backend/kernel_compiler/cpu/multinomial_cpu_kernel.h

@@ -19,6 +19,7 @@
 #include <memory>
 #include <unordered_map>
 #include <vector>
+#include <random>
 #include "backend/kernel_compiler/cpu/cpu_kernel.h"
 #include "backend/kernel_compiler/cpu/cpu_kernel_factory.h"
 #include "nnacl/base/tile_base.h"
@@ -39,6 +40,7 @@ class MultinomialCpuKernel : public CPUKernel {
   std::vector<size_t> input_shape_;
   int seed_{0};
   int seed2_{0};
+  std::default_random_engine rng_;
 };
 
 MS_REG_CPU_KERNEL(