Upgrade to WasmEdge 0.13.0

Due to the WasmEdge C API breaking changes, this document shows the guideline for programming with WasmEdge C API to upgrade from the 0.12.1 to the 0.13.0 version.

In this version, there are only new features. Developers can build their original source with this WasmEdge version directly.

Concepts

1. Introduced new API for setting data and its finalizer into module instances when creation.

   Developers can use the WasmEdge_ModuleInstanceCreateWithData() API to set the host data and its finalizer into the module instance.

2. Asynchronously invoking WASM function by executor.

   Developers can use the WasmEdge_ExecutorAsyncInvoke() API to execute a WASM function asynchronously.

3. Unified WasmEdge CLI.

   Developers can use the WasmEdge_Driver_UniTool() API to trigger the unified WasmEdge CLI.

Set data and its finalizer into a module instance when creation

Besides setting host data into a host function, developers can set and move ownership of host data into a Module instance context with its finalizer. This may be useful when implementing the plug-ins.

/* Struct definition. */
typedef struct Point {
  int X;
  int Y;
} Point;

/* Host function body definition. */
WasmEdge_Result Print(void *Data,
                      const WasmEdge_CallingFrameContext *CallFrameCxt,
                      const WasmEdge_Value *In, WasmEdge_Value *Out) {
  Point *P = (Point *)In;
  printf("Point: (%d, %d)\n", P->X, P->Y);
  return WasmEdge_Result_Success;
}

/* Finalizer definition. */
void PointFinalizer(void *Data) {
  if (Data) {
    free((Point *)Data);
  }
}

/* Create a module instance with host data and its finalizer. */
WasmEdge_String ExportName = WasmEdge_StringCreateByCString("module");
Point *Data = (Point *)malloc(sizeof(Point));
Data->X = 5;
Data->Y = -5;
WasmEdge_ModuleInstanceContext *HostModCxt =
    WasmEdge_ModuleInstanceCreateWithData(ExportName, Data, PointFinalizer);
/*
 * When the `HostModCxt` being destroyed, the finalizer will be invoked and the
 * `Data` will be its argument.
 */
WasmEdge_StringDelete(ExportName);

Unified WasmEdge CLI

The WasmEdge_Driver_UniTool() API presents the same function as running the wasmedge tool.

#include <wasmedge/wasmedge.h>
#include <stdio.h>
int main(int argc, const char *argv[]) {
  /* Run the WasmEdge unified tool. */
  /* (Within both runtime and AOT compiler) */
  return WasmEdge_Driver_UniTool(argc, argv);
}