You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
139 lines
4.2 KiB
139 lines
4.2 KiB
/*
|
|
Example of instantiating of the WebAssembly module and invoking its exported
|
|
function.
|
|
|
|
You can compile and run this example on Linux with:
|
|
|
|
cargo build --release -p wasmtime-c-api
|
|
cc examples/interrupt.c \
|
|
-I crates/c-api/include \
|
|
-I crates/c-api/wasm-c-api/include \
|
|
target/release/libwasmtime.a \
|
|
-lpthread -ldl -lm \
|
|
-o interrupt
|
|
./interrupt
|
|
|
|
Note that on Windows and macOS the command will be similar, but you'll need
|
|
to tweak the `-lpthread` and such annotations as well as the name of the
|
|
`libwasmtime.a` file on Windows.
|
|
|
|
You can also build using cmake:
|
|
|
|
mkdir build && cd build && cmake .. && cmake --build . --target wasmtime-interrupt
|
|
*/
|
|
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <wasm.h>
|
|
#include <wasmtime.h>
|
|
|
|
#ifdef _WIN32
|
|
static void spawn_interrupt(wasm_engine_t *engine) {
|
|
wasmtime_engine_increment_epoch(engine);
|
|
}
|
|
#else
|
|
#include <pthread.h>
|
|
#include <time.h>
|
|
|
|
static void* helper(void *_engine) {
|
|
wasm_engine_t *engine = _engine;
|
|
struct timespec sleep_dur;
|
|
sleep_dur.tv_sec = 1;
|
|
sleep_dur.tv_nsec = 0;
|
|
nanosleep(&sleep_dur, NULL);
|
|
printf("Sending an interrupt\n");
|
|
wasmtime_engine_increment_epoch(engine);
|
|
return 0;
|
|
}
|
|
|
|
static void spawn_interrupt(wasm_engine_t *engine) {
|
|
pthread_t child;
|
|
int rc = pthread_create(&child, NULL, helper, engine);
|
|
assert(rc == 0);
|
|
}
|
|
#endif
|
|
|
|
static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap);
|
|
|
|
int main() {
|
|
// Create a `wasm_store_t` with interrupts enabled
|
|
wasm_config_t *config = wasm_config_new();
|
|
assert(config != NULL);
|
|
wasmtime_config_epoch_interruption_set(config, true);
|
|
wasm_engine_t *engine = wasm_engine_new_with_config(config);
|
|
assert(engine != NULL);
|
|
wasmtime_store_t *store = wasmtime_store_new(engine, NULL, NULL);
|
|
assert(store != NULL);
|
|
wasmtime_context_t *context = wasmtime_store_context(store);
|
|
|
|
// Configure the epoch deadline after which WebAssembly code will trap.
|
|
wasmtime_context_set_epoch_deadline(context, 1);
|
|
|
|
// Read our input file, which in this case is a wasm text file.
|
|
FILE* file = fopen("examples/interrupt.wat", "r");
|
|
assert(file != NULL);
|
|
fseek(file, 0L, SEEK_END);
|
|
size_t file_size = ftell(file);
|
|
fseek(file, 0L, SEEK_SET);
|
|
wasm_byte_vec_t wat;
|
|
wasm_byte_vec_new_uninitialized(&wat, file_size);
|
|
assert(fread(wat.data, file_size, 1, file) == 1);
|
|
fclose(file);
|
|
|
|
// Parse the wat into the binary wasm format
|
|
wasm_byte_vec_t wasm;
|
|
wasmtime_error_t *error = wasmtime_wat2wasm(wat.data, wat.size, &wasm);
|
|
if (error != NULL)
|
|
exit_with_error("failed to parse wat", error, NULL);
|
|
wasm_byte_vec_delete(&wat);
|
|
|
|
// Now that we've got our binary webassembly we can compile our module.
|
|
wasmtime_module_t *module = NULL;
|
|
error = wasmtime_module_new(engine, (uint8_t*) wasm.data, wasm.size, &module);
|
|
wasm_byte_vec_delete(&wasm);
|
|
if (error != NULL)
|
|
exit_with_error("failed to compile module", error, NULL);
|
|
|
|
wasm_trap_t *trap = NULL;
|
|
wasmtime_instance_t instance;
|
|
error = wasmtime_instance_new(context, module, NULL, 0, &instance, &trap);
|
|
if (error != NULL || trap != NULL)
|
|
exit_with_error("failed to instantiate", error, trap);
|
|
wasmtime_module_delete(module);
|
|
|
|
// Lookup our `run` export function
|
|
wasmtime_extern_t run;
|
|
bool ok = wasmtime_instance_export_get(context, &instance, "run", 3, &run);
|
|
assert(ok);
|
|
assert(run.kind == WASMTIME_EXTERN_FUNC);
|
|
|
|
// Spawn a thread to send us an interrupt after a period of time.
|
|
spawn_interrupt(engine);
|
|
|
|
// And call it!
|
|
printf("Entering infinite loop...\n");
|
|
error = wasmtime_func_call(context, &run.of.func, NULL, 0, NULL, 0, &trap);
|
|
assert(error == NULL);
|
|
assert(trap != NULL);
|
|
printf("Got a trap!...\n");
|
|
|
|
wasmtime_store_delete(store);
|
|
wasm_engine_delete(engine);
|
|
return 0;
|
|
}
|
|
|
|
static void exit_with_error(const char *message, wasmtime_error_t *error, wasm_trap_t *trap) {
|
|
fprintf(stderr, "error: %s\n", message);
|
|
wasm_byte_vec_t error_message;
|
|
if (error != NULL) {
|
|
wasmtime_error_message(error, &error_message);
|
|
wasmtime_error_delete(error);
|
|
} else {
|
|
wasm_trap_message(trap, &error_message);
|
|
wasm_trap_delete(trap);
|
|
}
|
|
fprintf(stderr, "%.*s\n", (int) error_message.size, error_message.data);
|
|
wasm_byte_vec_delete(&error_message);
|
|
exit(1);
|
|
}
|
|
|