tests: update barrier test to check for race condition in active threads

Author: max-krasnyansky

tests/test-barrier.cpp

@@ -11,19 +11,7 @@
 
 #define MAX_NARGS 2
 
-int main(int argc, char *argv[]) {
-
-    int n_threads = std::max(1, std::min(4, (int) std::thread::hardware_concurrency()));
-    int n_rounds  = 100;
-
-    if (argc > 1) {
-        n_threads = std::atoi(argv[1]);
-    }
-
-    if (argc > 2) {
-        n_rounds  = std::atoi(argv[2]);
-    }
-
+static void test_barrier(int n_threads, int n_rounds) {
     struct ggml_init_params params = {
         /* .mem_size   = */ 1024*1024*1024,
         /* .mem_buffer = */ NULL,
@@ -56,7 +44,7 @@ int main(int argc, char *argv[]) {
         exit(1);
     }
 
-    // Create compute plan
+    // The test runs with constant number of threads
     struct ggml_cplan cplan = ggml_graph_plan(gf, n_threads, threadpool);
 
     std::vector<uint8_t> work_data(cplan.work_size);
@@ -89,6 +77,80 @@ int main(int argc, char *argv[]) {
 
     ggml_threadpool_free(threadpool);
     ggml_free(ctx);
+}
+
+static void test_active(int n_threads, int n_rounds) {
+    struct ggml_init_params params = {
+        /* .mem_size   = */ 1024*1024*1024,
+        /* .mem_buffer = */ NULL,
+        /* .no_alloc   = */ false,
+    };
+
+    struct ggml_context * ctx = ggml_init(params);
+
+    // Create graph
+    struct ggml_cgraph * gf = ggml_new_graph(ctx);
+
+    // Small graph with, parallel ops with barriers
+    struct ggml_tensor * out = ggml_new_tensor_1d(ctx, GGML_TYPE_F32,  64);
+    for (int i = 0; i < 2; i++) {
+        struct ggml_tensor * a = ggml_new_tensor_2d(ctx, GGML_TYPE_Q4_0, 64, 128);
+        out = ggml_mul_mat(ctx, a, out);
+
+        struct ggml_tensor * d = ggml_new_tensor_2d(ctx, GGML_TYPE_Q4_0, 128, 64);
+        out = ggml_mul_mat(ctx, d, out);
+    }
+
+    ggml_build_forward_expand(gf, out);
+    int n_nodes = ggml_graph_n_nodes(gf);
+
+    // Create threadpool
+    struct ggml_threadpool_params tpp  = ggml_threadpool_params_default(n_threads);
+    struct ggml_threadpool* threadpool = ggml_threadpool_new(&tpp);
+    if (!threadpool) {
+        fprintf(stderr, "threadpool create failed : n_threads %d\n", n_threads);
+        exit(1);
+    }
+
+    std::cerr << "graph-compute with"
+              << "\n n_threads: " << n_threads
+              << "\n   n_nodes: " << n_nodes
+              << "\n  n_rounds: " << n_rounds
+              << "\n";
+    // ggml_graph_print(gf);
+
+    // In this test we keep changing number of threads every 4th iteration
+    // to test for race conditions in that path
+
+    for (int i=0; i < n_rounds; i++) {
+        struct ggml_cplan cplan = ggml_graph_plan(gf, (i % 4) == 0 ? 1 : n_threads, threadpool);
+
+        std::vector<uint8_t> work_data(cplan.work_size);
+        cplan.work_data = work_data.data();
+
+        ggml_graph_compute(gf, &cplan);
+    }
+
+    ggml_threadpool_free(threadpool);
+    ggml_free(ctx);
+}
+
+int main(int argc, char *argv[]) {
+
+    int n_threads = std::max(1, std::min(4, (int) std::thread::hardware_concurrency()));
+    int n_rounds  = 100;
+
+    if (argc > 1) {
+        n_threads = std::atoi(argv[1]);
+    }
+
+    if (argc > 2) {
+        n_rounds  = std::atoi(argv[2]);
+    }
+
+    test_barrier(n_threads, n_rounds);
+
+    test_active(n_threads,  n_rounds * 100);
 
     return 0;
 }