xref: /wasmtime-44.0.1/examples/threads.c (revision 331b0dee)
1 #ifndef _WIN32
2 
3 #include <inttypes.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <pthread.h>
8 #include <unistd.h>
9 #include <wasm.h>
10 #include <wasmtime.h>
11 
12 #define own
13 
14 static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap);
15 
16 const int N_THREADS = 10;
17 const int N_REPS = 3;
18 
19 // A function to be called from Wasm code.
20 own wasm_trap_t* callback(const wasm_val_vec_t* args, wasm_val_vec_t* results) {
21   assert(args->data[0].kind == WASM_I32);
22   printf("> Thread %d running\n", args->data[0].of.i32);
23   return NULL;
24 }
25 
26 
27 typedef struct {
28   wasm_engine_t* engine;
29   wasm_shared_module_t* module;
30   int id;
31 } thread_args;
32 
33 void* run(void* args_abs) {
34   thread_args* args = (thread_args*)args_abs;
35 
36   // Rereate store and module.
37   own wasm_store_t* store = wasm_store_new(args->engine);
38   own wasm_module_t* module = wasm_module_obtain(store, args->module);
39 
40   // Run the example N times.
41   for (int i = 0; i < N_REPS; ++i) {
42     usleep(100000);
43 
44     // Create imports.
45     own wasm_functype_t* func_type = wasm_functype_new_1_0(wasm_valtype_new_i32());
46     own wasm_func_t* func = wasm_func_new(store, func_type, callback);
47     wasm_functype_delete(func_type);
48 
49     wasm_val_t val = {.kind = WASM_I32, .of = {.i32 = (int32_t)args->id}};
50     own wasm_globaltype_t* global_type =
51       wasm_globaltype_new(wasm_valtype_new_i32(), WASM_CONST);
52     own wasm_global_t* global = wasm_global_new(store, global_type, &val);
53     wasm_globaltype_delete(global_type);
54 
55     // Instantiate.
56     wasm_extern_t* imports[] = {
57       wasm_func_as_extern(func), wasm_global_as_extern(global),
58     };
59     wasm_extern_vec_t imports_vec = WASM_ARRAY_VEC(imports);
60     own wasm_instance_t* instance =
61       wasm_instance_new(store, module, &imports_vec, NULL);
62     if (!instance) {
63       printf("> Error instantiating module!\n");
64       return NULL;
65     }
66 
67     wasm_func_delete(func);
68     wasm_global_delete(global);
69 
70     // Extract export.
71     own wasm_extern_vec_t exports;
72     wasm_instance_exports(instance, &exports);
73     if (exports.size == 0) {
74       printf("> Error accessing exports!\n");
75       return NULL;
76     }
77     const wasm_func_t *run_func = wasm_extern_as_func(exports.data[0]);
78     if (run_func == NULL) {
79       printf("> Error accessing export!\n");
80       return NULL;
81     }
82 
83     wasm_instance_delete(instance);
84 
85     // Call.
86     wasm_val_vec_t args_vec = WASM_EMPTY_VEC;
87     wasm_val_vec_t results_vec = WASM_EMPTY_VEC;
88     if (wasm_func_call(run_func, &args_vec, &results_vec)) {
89       printf("> Error calling function!\n");
90       return NULL;
91     }
92 
93     wasm_extern_vec_delete(&exports);
94   }
95 
96   wasm_module_delete(module);
97   wasm_store_delete(store);
98 
99   free(args_abs);
100 
101   return NULL;
102 }
103 
104 int main(int argc, const char *argv[]) {
105   // Initialize.
106   wasm_engine_t* engine = wasm_engine_new();
107 
108   // Load our input file to parse it next
109   FILE* file = fopen("examples/threads.wat", "r");
110   if (!file) {
111     printf("> Error loading file!\n");
112     return 1;
113   }
114   fseek(file, 0L, SEEK_END);
115   size_t file_size = ftell(file);
116   fseek(file, 0L, SEEK_SET);
117   wasm_byte_vec_t wat;
118   wasm_byte_vec_new_uninitialized(&wat, file_size);
119   if (fread(wat.data, file_size, 1, file) != 1) {
120     printf("> Error loading module!\n");
121     return 1;
122   }
123   fclose(file);
124 
125   // Parse the wat into the binary wasm format
126   wasm_byte_vec_t binary;
127   wasmtime_error_t *error = wasmtime_wat2wasm(wat.data, wat.size, &binary);
128   if (error != NULL)
129     exit_with_error("failed to parse wat", error, NULL);
130   wasm_byte_vec_delete(&wat);
131 
132   // Compile and share.
133   own wasm_store_t* store = wasm_store_new(engine);
134   own wasm_module_t* module = wasm_module_new(store, &binary);
135   if (!module) {
136     printf("> Error compiling module!\n");
137     return 1;
138   }
139 
140   wasm_byte_vec_delete(&binary);
141 
142   own wasm_shared_module_t* shared = wasm_module_share(module);
143 
144   wasm_module_delete(module);
145   wasm_store_delete(store);
146 
147   // Spawn threads.
148   pthread_t threads[N_THREADS];
149   for (int i = 0; i < N_THREADS; i++) {
150     thread_args* args = malloc(sizeof(thread_args));
151     args->id = i;
152     args->engine = engine;
153     args->module = shared;
154     printf("Initializing thread %d...\n", i);
155     pthread_create(&threads[i], NULL, &run, args);
156   }
157 
158   for (int i = 0; i < N_THREADS; i++) {
159     printf("Waiting for thread: %d\n", i);
160     pthread_join(threads[i], NULL);
161   }
162 
163   wasm_shared_module_delete(shared);
164   wasm_engine_delete(engine);
165 
166   return 0;
167 }
168 
169 static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap) {
170   fprintf(stderr, "error: %s\n", message);
171   wasm_byte_vec_t error_message;
172   if (error != NULL) {
173     wasmtime_error_message(error, &error_message);
174   } else {
175     wasm_trap_message(trap, &error_message);
176   }
177   fprintf(stderr, "%.*s\n", (int) error_message.size, error_message.data);
178   wasm_byte_vec_delete(&error_message);
179   exit(1);
180 }
181 
182 #else
183 // TODO implement example for Windows
184 int main(int argc, const char *argv[]) {
185   return 0;
186 }
187 #endif // _WIN32
188