samples/terminate: Add a sample to demonstrate wasm_runtime_terminate (#3043)

This is basically a modified copy of the "shared-module" example.

samples/terminate/src/main.c

@@ -0,0 +1,183 @@
+
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#include "wasm_export.h"
+#include "bh_read_file.h"
+#include "bh_getopt.h"
+
+void
+print_usage(void)
+{
+    fprintf(stdout, "Options:\r\n");
+    fprintf(stdout, "  -f [path of wasm file] \n");
+}
+
+static void *
+runner(void *vp)
+{
+    wasm_module_inst_t inst = vp;
+    bool ok = wasm_runtime_init_thread_env();
+    assert(ok);
+    wasm_application_execute_main(inst, 0, NULL);
+    wasm_runtime_destroy_thread_env();
+    return inst;
+}
+
+int
+main(int argc, char *argv_main[])
+{
+    int exit_code = 1;
+    static char global_heap_buf[512 * 1024];
+    char *buffer;
+    char error_buf[128];
+    int opt;
+    char *wasm_path = NULL;
+    int ret;
+    int pipe_fds[2];
+
+    const unsigned int N = 4;
+    wasm_module_t module = NULL;
+    wasm_module_inst_t module_inst[N];
+    pthread_t th[N];
+    unsigned int i;
+    uint32 buf_size, stack_size = 8092, heap_size = 8092;
+
+    for (i = 0; i < N; i++) {
+        module_inst[i] = NULL;
+    }
+
+    RuntimeInitArgs init_args;
+    memset(&init_args, 0, sizeof(RuntimeInitArgs));
+
+    while ((opt = getopt(argc, argv_main, "hf:")) != -1) {
+        switch (opt) {
+            case 'f':
+                wasm_path = optarg;
+                break;
+            case 'h':
+                print_usage();
+                return 0;
+            case '?':
+                print_usage();
+                return 0;
+        }
+    }
+    if (optind == 1) {
+        print_usage();
+        return 0;
+    }
+
+    memset(&init_args, 0, sizeof(init_args));
+    init_args.mem_alloc_type = Alloc_With_Pool;
+    init_args.mem_alloc_option.pool.heap_buf = global_heap_buf;
+    init_args.mem_alloc_option.pool.heap_size = sizeof(global_heap_buf);
+
+    if (!wasm_runtime_full_init(&init_args)) {
+        printf("Init runtime environment failed.\n");
+        return -1;
+    }
+
+    buffer = bh_read_file_to_buffer(wasm_path, &buf_size);
+
+    if (!buffer) {
+        printf("Open wasm app file [%s] failed.\n", wasm_path);
+        goto fail;
+    }
+
+    module = wasm_runtime_load((uint8 *)buffer, buf_size, error_buf,
+                               sizeof(error_buf));
+    if (!module) {
+        printf("Load wasm module failed. error: %s\n", error_buf);
+        goto fail;
+    }
+
+    /* Ensure that fd_read on FD 0 blocks. */
+    ret = pipe(pipe_fds);
+    if (ret != 0) {
+        goto fail;
+    }
+    wasm_runtime_set_wasi_args_ex(module, NULL, 0, NULL, 0, NULL, 0, NULL, 0,
+                                  pipe_fds[0], -1, -1);
+
+    for (i = 0; i < N; i++) {
+        module_inst[i] = wasm_runtime_instantiate(module, stack_size, heap_size,
+                                                  error_buf, sizeof(error_buf));
+
+        if (!module_inst[i]) {
+            printf("Instantiate wasm module failed. error: %s\n", error_buf);
+            goto fail;
+        }
+
+        /* Note: ensure that module inst has an exec env so that
+         * it can receive the termination request.
+         */
+        wasm_runtime_get_exec_env_singleton(module_inst[i]);
+
+        if ((i % 2) == 0) {
+            printf("terminating thread %u before starting\n", i);
+            wasm_runtime_terminate(module_inst[i]);
+        }
+
+        printf("starting thread %u\n", i);
+        ret = pthread_create(&th[i], NULL, runner, module_inst[i]);
+        if (ret != 0) {
+            goto fail;
+        }
+    }
+
+    printf("sleeping a bit to ensure that the threads actually started\n");
+    sleep(1);
+
+    for (i = 0; i < N; i++) {
+        if ((i % 2) != 0) {
+            printf("terminating thread %u\n", i);
+            wasm_runtime_terminate(module_inst[i]);
+        }
+    }
+
+    for (i = 0; i < N; i++) {
+        printf("joining thread %u\n", i);
+        void *status;
+        ret = pthread_join(th[i], &status);
+        if (ret != 0) {
+            goto fail;
+        }
+    }
+
+    for (i = 0; i < N; i++) {
+        const char *exception = wasm_runtime_get_exception(module_inst[i]);
+        if (exception != NULL) {
+            if (!strstr(exception, "terminated by user")) {
+                printf("thread %u got an exception: %s (unexpected)\n", i,
+                       exception);
+                goto fail;
+            }
+            printf("thread %u got an exception: %s (expected)\n", i, exception);
+        }
+        else {
+            printf("thread %u got no exception (unexpected)\n", i);
+            goto fail;
+        }
+    }
+
+    exit_code = 0;
+fail:
+    for (i = 0; i < N; i++) {
+        if (module_inst[i])
+            wasm_runtime_deinstantiate(module_inst[i]);
+    }
+    if (module)
+        wasm_runtime_unload(module);
+    if (buffer)
+        BH_FREE(buffer);
+    wasm_runtime_destroy();
+    return exit_code;
+}