examples(allocation): free memory after unmarshalling a result from t…

…he guest (cgo)

Signed-off-by: Luca Burgazzoli <[email protected]>

examples/allocation/tinygo/greet.go

@@ -90,9 +90,21 @@ func main() {
 	if err != nil {
 		log.Panicln(err)
 	}
-	// Note: This pointer is still owned by TinyGo, so don't try to free it!
+
 	greetingPtr := uint32(ptrSize[0] >> 32)
 	greetingSize := uint32(ptrSize[0])
+
+	// This pointer is managed by TinyGo, but TinyGo is unaware of external usage.
+	// So, we have to free it when finished
+	if greetingPtr != 0 {
+		defer func() {
+			_, err := free.Call(ctx, uint64(greetingPtr))
+			if err != nil {
+				log.Panicln(err)
+			}
+		}()
+	}
+
 	// The pointer is a linear memory offset, which is where we write the name.
 	if bytes, ok := mod.Memory().Read(greetingPtr, greetingSize); !ok {
 		log.Panicf("Memory.Read(%d, %d) out of range of memory size %d",

examples/allocation/tinygo/testdata/greet.go

@@ -1,5 +1,8 @@
 package main
 
+// #include <stdlib.h>
+import "C"
+
 import (
 	"fmt"
 	"reflect"
@@ -53,7 +56,7 @@ func _greet(ptr, size uint32) {
 func _greeting(ptr, size uint32) (ptrSize uint64) {
 	name := ptrToString(ptr, size)
 	g := greeting(name)
-	ptr, size = stringToPtr(g)
+	ptr, size = stringToNativePtr(g)
 	return (uint64(ptr) << uint64(32)) | uint64(size)
 }
 
@@ -77,3 +80,19 @@ func stringToPtr(s string) (uint32, uint32) {
 	unsafePtr := uintptr(unsafe.Pointer(ptr))
 	return uint32(unsafePtr), uint32(len(buf))
 }
+
+// stringToNativePtr returns a pointer and size pair for the given string in a way
+// compatible with WebAssembly numeric types. The pointer is not automatically
+// managed by TinyGo hence it must be freed by the host.
+func stringToNativePtr(s string) (uint32, uint32) {
+	if len(s) == 0 {
+		return 0, 0
+	}
+
+	size := C.ulong(len(s))
+	ptr := unsafe.Pointer(C.malloc(size))
+
+	copy(unsafe.Slice((*byte)(ptr), size), []byte(s))
+
+	return uint32(uintptr(ptr)), uint32(len(s))
+}

internal/integration_test/vs/bench_allocation.go

@@ -37,7 +37,7 @@ func init() {
 
 func allocationCall(m Module, _ int) error {
 	nameSize := uint32(len(allocationParam))
-	// Instead of an arbitrary memory offset, use Rust's allocator. Notice
+	// Instead of an arbitrary memory offset, use TinyGo's allocator. Notice
 	// there is nothing string-specific in this allocation function. The same
 	// function could be used to pass binary serialized data to Wasm.
 	namePtr, err := m.CallI32_I32(testCtx, "malloc", nameSize)
@@ -50,14 +50,19 @@ func allocationCall(m Module, _ int) error {
 		return err
 	}
 
-	// Now, we can call "greet", which reads the string we wrote to memory!
-	if err = m.CallI32I32_V(testCtx, "greet", namePtr, nameSize); err != nil {
-		return err
+	// Now, we can call "greeting", which reads the string we wrote to memory!
+	fnErr := m.CallI32I32_V(testCtx, "greet", namePtr, nameSize)
+	if fnErr != nil {
+		return fnErr
 	}
 
-	// This pointer was allocated by Rust, but owned by Go, So, we have to
+	// This pointer was allocated by TinyGo, but owned by Go, So, we have to
 	// deallocate it when finished
-	return m.CallI32_V(testCtx, "free", namePtr)
+	if err := m.CallI32_V(testCtx, "free", namePtr); err != nil {
+		return err
+	}
+
+	return nil
 }
 
 func RunTestAllocation(t *testing.T, runtime func() Runtime) {

internal/integration_test/vs/bench_allocation_cgo.go

@@ -0,0 +1,89 @@
+package vs
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"testing"
+
+	"github.com/tetratelabs/wazero/internal/testing/require"
+)
+
+var (
+	// allocationWasm is compiled from ../../../examples/allocation/tinygo/testdata/src/greet.go
+	// We can't use go:embed as it is outside this directory. Copying it isn't ideal due to size and drift.
+	allocationCGOWasmPath = "../../../examples/allocation/tinygo/testdata/greet.wasm"
+	allocationCGOWasm     []byte
+	allocationCGOParam    = "wazero"
+	allocationCGOResult   = []byte("wasm >> Hello, wazero!")
+	allocationCGOConfig   *RuntimeConfig
+)
+
+func init() {
+	allocationCGOWasm = readRelativeFile(allocationCGOWasmPath)
+	allocationCGOConfig = &RuntimeConfig{
+		ModuleName: "greeting",
+		ModuleWasm: allocationCGOWasm,
+		FuncNames:  []string{"malloc", "free", "greeting"},
+		NeedsWASI:  true, // Needed for TinyGo
+		LogFn: func(buf []byte) error {
+			if !bytes.Equal(allocationCGOResult, buf) {
+				return fmt.Errorf("expected %q, but was %q", allocationCGOResult, buf)
+			}
+			return nil
+		},
+	}
+}
+
+func AllocationCGOCall(m Module, _ int) error {
+	nameSize := uint32(len(allocationCGOParam))
+	// Instead of an arbitrary memory offset, use TinyGo's allocator. Notice
+	// there is nothing string-specific in this allocation function. The same
+	// function could be used to pass binary serialized data to Wasm.
+	namePtr, err := m.CallI32_I32(testCtx, "malloc", nameSize)
+	if err != nil {
+		return err
+	}
+
+	// The pointer is a linear memory offset, which is where we write the name.
+	if err = m.WriteMemory(namePtr, []byte(allocationCGOParam)); err != nil {
+		return err
+	}
+
+	// Now, we can call "greeting", which reads the string we wrote to memory!
+	ptrSize, fnErr := m.CallI32I32_I64(testCtx, "greeting", namePtr, nameSize)
+	if fnErr != nil {
+		return fnErr
+	}
+
+	// This pointer was allocated by TinyGo, but owned by Go, So, we have to
+	// deallocate it when finished
+	if err := m.CallI32_V(testCtx, "free", namePtr); err != nil {
+		return err
+	}
+
+	// This pointer was allocated by TinyGo, but owned by Go, So, we have to
+	// deallocate it when finished
+	if err := m.CallI32_V(testCtx, "free", uint32(ptrSize>>32)); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func RunTestAllocationCGO(t *testing.T, runtime func() Runtime) {
+	testCall(t, runtime, allocationCGOConfig, testAllocationCGOCall)
+}
+
+func testAllocationCGOCall(t *testing.T, m Module, instantiation, iteration int) {
+	err := AllocationCGOCall(m, iteration)
+	require.NoError(t, err, "instantiation[%d] iteration[%d] failed: %v", instantiation, iteration, err)
+}
+
+func RunTestBenchmarkAllocationCGO_Call_CompilerFastest(t *testing.T, vsRuntime Runtime) {
+	runTestBenchmark_Call_CompilerFastest(t, allocationCGOConfig, "Allocation", AllocationCGOCall, vsRuntime)
+}
+
+func RunBenchmarkAllocationCGO(b *testing.B, runtime func() Runtime) {
+	benchmark(b, runtime, allocationCGOConfig, AllocationCGOCall)
+}

internal/integration_test/vs/compiler/compiler_test.go

@@ -16,6 +16,14 @@ func BenchmarkAllocation(b *testing.B) {
 	vs.RunBenchmarkAllocation(b, runtime)
 }
 
+func TestAllocationCGO(t *testing.T) {
+	vs.RunTestAllocationCGO(t, runtime)
+}
+
+func BenchmarkAllocationCGO(b *testing.B) {
+	vs.RunBenchmarkAllocationCGO(b, runtime)
+}
+
 func TestFactorial(t *testing.T) {
 	vs.RunTestFactorial(t, runtime)
 }

internal/integration_test/vs/interpreter/interpreter_test.go

@@ -20,6 +20,18 @@ func TestBenchmarkAllocation_Call_CompilerFastest(t *testing.T) {
 	vs.RunTestBenchmarkAllocation_Call_CompilerFastest(t, runtime())
 }
 
+func TestAllocationGCO(t *testing.T) {
+	vs.RunTestAllocationCGO(t, runtime)
+}
+
+func BenchmarkAllocationCGO(b *testing.B) {
+	vs.RunBenchmarkAllocationCGO(b, runtime)
+}
+
+func TestBenchmarkAllocationCGO_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationCGO_Call_CompilerFastest(t, runtime())
+}
+
 func TestFactorial(t *testing.T) {
 	vs.RunTestFactorial(t, runtime)
 }

internal/integration_test/vs/runtime.go

@@ -37,6 +37,7 @@ type Runtime interface {
 type Module interface {
 	CallI32_I32(ctx context.Context, funcName string, param uint32) (uint32, error)
 	CallI32I32_V(ctx context.Context, funcName string, x, y uint32) error
+	CallI32I32_I64(ctx context.Context, funcName string, x, y uint32) (uint64, error)
 	CallI32_V(ctx context.Context, funcName string, param uint32) error
 	CallV_V(ctx context.Context, funcName string) error
 	CallI64_I64(ctx context.Context, funcName string, param uint64) (uint64, error)
@@ -183,6 +184,14 @@ func (m *wazeroModule) CallI32I32_V(ctx context.Context, funcName string, x, y u
 	return
 }
 
+func (m *wazeroModule) CallI32I32_I64(ctx context.Context, funcName string, x, y uint32) (uint64, error) {
+	if results, err := m.funcs[funcName].Call(ctx, uint64(x), uint64(y)); err != nil {
+		return 0, err
+	} else {
+		return results[0], nil
+	}
+}
+
 func (m *wazeroModule) CallI32_V(ctx context.Context, funcName string, param uint32) (err error) {
 	_, err = m.funcs[funcName].Call(ctx, uint64(param))
 	return
@@ -191,10 +200,9 @@ func (m *wazeroModule) CallI32_V(ctx context.Context, funcName string, param uin
 func (m *wazeroModule) CallI64_I64(ctx context.Context, funcName string, param uint64) (uint64, error) {
 	if results, err := m.funcs[funcName].Call(ctx, param); err != nil {
 		return 0, err
-	} else if len(results) > 0 {
+	} else {
 		return results[0], nil
 	}
-	return 0, nil
 }
 
 func (m *wazeroModule) WriteMemory(offset uint32, bytes []byte) error {

internal/integration_test/vs/wasmedge/wasmedge.go

@@ -155,6 +155,14 @@ func (m *wasmedgeModule) CallI32I32_V(_ context.Context, funcName string, x, y u
 	return
 }
 
+func (m *wasmedgeModule) CallI32I32_I64(_ context.Context, funcName string, x, y uint32) (uint64, error) {
+	if result, err := m.vm.Execute(funcName, int32(x), int32(y)); err != nil {
+		return 0, err
+	} else {
+		return uint64(result[0].(int64)), nil
+	}
+}
+
 func (m *wasmedgeModule) CallV_V(_ context.Context, funcName string) (err error) {
 	_, err = m.vm.Execute(funcName)
 	return

internal/integration_test/vs/wasmedge/wasmedge_test.go

@@ -24,6 +24,30 @@ func TestBenchmarkAllocation_Call_CompilerFastest(t *testing.T) {
 	vs.RunTestBenchmarkAllocation_Call_CompilerFastest(t, runtime())
 }
 
+func TestAllocationCGO(t *testing.T) {
+	vs.RunTestAllocationCGO(t, runtime)
+}
+
+func BenchmarkAllocationCGO(b *testing.B) {
+	vs.RunBenchmarkAllocationCGO(b, runtime)
+}
+
+func TestBenchmarkAllocationCGO_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationCGO_Call_CompilerFastest(t, runtime())
+}
+
+func TestAllocationTinyMem(t *testing.T) {
+	vs.RunTestAllocationTinyMem(t, runtime)
+}
+
+func BenchmarkAllocationTinyMem(b *testing.B) {
+	vs.RunBenchmarkAllocationTinyMem(b, runtime)
+}
+
+func TestBenchmarkAllocationTinyMem_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationTinyMem_Call_CompilerFastest(t, runtime())
+}
+
 func TestFactorial(t *testing.T) {
 	vs.RunTestFactorial(t, runtime)
 }

internal/integration_test/vs/wasmer/wasmer.go

@@ -170,6 +170,15 @@ func (m *wasmerModule) CallI32I32_V(_ context.Context, funcName string, x, y uin
 	return
 }
 
+func (m *wasmerModule) CallI32I32_I64(_ context.Context, funcName string, x, y uint32) (uint64, error) {
+	fn := m.funcs[funcName]
+	if result, err := fn.Call(int32(x), int32(y)); err != nil {
+		return 0, err
+	} else {
+		return uint64(result.(int64)), nil
+	}
+}
+
 func (m *wasmerModule) CallI32_V(_ context.Context, funcName string, param uint32) (err error) {
 	fn := m.funcs[funcName]
 	_, err = fn.Call(int32(param))

internal/integration_test/vs/wasmer/wasmer_test.go

@@ -22,6 +22,30 @@ func TestBenchmarkAllocation_Call_CompilerFastest(t *testing.T) {
 	vs.RunTestBenchmarkAllocation_Call_CompilerFastest(t, runtime())
 }
 
+func TestAllocationCGO(t *testing.T) {
+	vs.RunTestAllocationCGO(t, runtime)
+}
+
+func BenchmarkAllocationCGO(b *testing.B) {
+	vs.RunBenchmarkAllocationCGO(b, runtime)
+}
+
+func TestBenchmarkAllocationCGO_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationCGO_Call_CompilerFastest(t, runtime())
+}
+
+func TestAllocationTinyMem(t *testing.T) {
+	vs.RunTestAllocationTinyMem(t, runtime)
+}
+
+func BenchmarkAllocationTinyMem(b *testing.B) {
+	vs.RunBenchmarkAllocationTinyMem(b, runtime)
+}
+
+func TestBenchmarkAllocationTinyMem_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationTinyMem_Call_CompilerFastest(t, runtime())
+}
+
 func TestFactorial(t *testing.T) {
 	vs.RunTestFactorial(t, runtime)
 }

internal/integration_test/vs/wasmtime/wasmtime.go

@@ -170,6 +170,15 @@ func (m *wasmtimeModule) CallI32I32_V(_ context.Context, funcName string, x, y u
 	return
 }
 
+func (m *wasmtimeModule) CallI32I32_I64(_ context.Context, funcName string, x, y uint32) (uint64, error) {
+	fn := m.funcs[funcName]
+	if result, err := fn.Call(m.store, int32(x), int32(y)); err != nil {
+		return 0, err
+	} else {
+		return uint64(result.(int64)), nil
+	}
+}
+
 func (m *wasmtimeModule) CallV_V(_ context.Context, funcName string) (err error) {
 	fn := m.funcs[funcName]
 	_, err = fn.Call(m.store)

internal/integration_test/vs/wasmtime/wasmtime_test.go

@@ -22,6 +22,30 @@ func TestBenchmarkAllocation_Call_CompilerFastest(t *testing.T) {
 	vs.RunTestBenchmarkAllocation_Call_CompilerFastest(t, runtime())
 }
 
+func TestAllocationCGO(t *testing.T) {
+	vs.RunTestAllocationCGO(t, runtime)
+}
+
+func BenchmarkAllocationCGO(b *testing.B) {
+	vs.RunBenchmarkAllocationCGO(b, runtime)
+}
+
+func TestBenchmarkAllocationCGO_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationCGO_Call_CompilerFastest(t, runtime())
+}
+
+func TestAllocationTinyMem(t *testing.T) {
+	vs.RunTestAllocationTinyMem(t, runtime)
+}
+
+func BenchmarkAllocationTinyMem(b *testing.B) {
+	vs.RunBenchmarkAllocationTinyMem(b, runtime)
+}
+
+func TestBenchmarkAllocationTinyMem_Call_CompilerFastest(t *testing.T) {
+	vs.RunTestBenchmarkAllocationTinyMem_Call_CompilerFastest(t, runtime())
+}
+
 func TestFactorial(t *testing.T) {
 	vs.RunTestFactorial(t, runtime)
 }