wasm2c: add multithreaded example

wasm2c/.gitignore

@@ -1,4 +1,5 @@
 wasm-rt-impl.o
+wasm-rt-exceptions-impl.o
 examples/**/*.o
 examples/fac/fac
 examples/rot13/rot13
@@ -9,3 +10,7 @@ examples/callback/callback
 examples/callback/callback.c
 examples/callback/callback.h
 examples/callback/callback.wasm
+examples/threads/threads
+examples/threads/sample.c
+examples/threads/sample.h
+examples/threads/sample.wasm

wasm2c/examples/threads/Makefile

@@ -0,0 +1,20 @@
+#SANITIZERS=-fsanitize=address -fsanitize=undefined -fno-sanitize-recover=all
+CFLAGS=-I../.. -g -O2 -Wall -Wextra -Wno-unused -Wno-unused-parameter -Wno-array-bounds -Wno-ignored-optimization-argument -Wno-tautological-constant-out-of-range-compare -Wno-infinite-recursion -fno-optimize-sibling-calls -frounding-math -fsignaling-nans ${SANITIZERS} -pthread
+LDFLAGS=${SANITIZERS} -pthread
+
+all: threads
+
+threads: threads.o sample.o ../../wasm-rt-impl.o ../../wasm-rt-exceptions-impl.o -lm
+
+clean:
+	rm -rf threads sample.wasm sample.c sample.h *.o ../../*.o
+
+sample.wasm: sample.wat ../../../bin/wat2wasm
+	../../../bin/wat2wasm --debug-names $< -o $@
+
+sample.c: sample.wasm ../../../bin/wasm2c
+	../../../bin/wasm2c $< -o $@
+
+threads.o: sample.c
+
+.PHONY: all clean

wasm2c/examples/threads/sample.wat

@@ -0,0 +1,6 @@
+;; Module for demonstrating multi-threaded runtime
+
+(func (export "multiplyby3") (param i32) (result i32) (i32.mul (local.get 0) (i32.const 3)))
+
+(func $stackoverflow (export "stackoverflow")
+      (call $stackoverflow))

wasm2c/examples/threads/threads.c

@@ -0,0 +1,75 @@
+#include <pthread.h>
+#include <stdio.h>
+
+#include "sample.h"
+#include "wasm-rt-exceptions.h"
+#include "wasm-rt-impl.h"
+
+#define NUM_THREADS 1024
+
+void* do_thread(void* arg) {
+  int param;
+  memcpy(&param, arg, sizeof(int));
+
+  void* context = wasm_rt_init_thread();
+
+  w2c_sample inst;
+  wasm2c_sample_instantiate(&inst);
+
+  wasm_rt_trap_t code = wasm_rt_impl_try();
+  if (code != 0) {
+    if (code == WASM_RT_TRAP_OOB || code == WASM_RT_TRAP_EXHAUSTION) {
+      int returnval = w2c_sample_multiplyby3(&inst, param);
+      memcpy(arg, &returnval, sizeof(int));
+
+      wasm2c_sample_free(&inst);
+      wasm_rt_free_thread(context);
+
+      return arg;
+    } else {
+      fprintf(stderr, "Expected OOB or exhaustion trap but got %s\n",
+              wasm_rt_strerror(code));
+      return NULL;
+    }
+  }
+
+  w2c_sample_stackoverflow(&inst);
+
+  fprintf(stderr, "Expected trap but did not get one\n");
+  return NULL;
+}
+
+int main(int argc, char** argv) {
+  pthread_t threads[NUM_THREADS];
+  int arguments[NUM_THREADS];
+
+  /* Initialize the Wasm runtime. */
+  wasm_rt_init();
+
+  for (int i = 0; i < NUM_THREADS; ++i) {
+    arguments[i] = i;
+    if (pthread_create(&threads[i], NULL, do_thread, &arguments[i])) {
+      perror("pthread_create");
+      exit(EXIT_FAILURE);
+    }
+  }
+
+  for (int i = 0; i < NUM_THREADS; ++i) {
+    void* retval;
+    if (pthread_join(threads[i], &retval)) {
+      perror("pthread_join");
+      exit(EXIT_FAILURE);
+    }
+
+    if ((retval != &arguments[i]) || (arguments[i] != 3 * i)) {
+      fprintf(stderr, "Unexpected return value from thread.\n");
+      exit(EXIT_FAILURE);
+    }
+  }
+
+  wasm_rt_free();
+
+  printf("%d/%d threads trapped successfully.\n", NUM_THREADS, NUM_THREADS);
+
+  return EXIT_SUCCESS;
+}