async-wasi

Run an Wasm App in an asynchronous way

This example demonstrates how to call a wasm function in asynchronous way. Also, it presents how to set environment variables, arguments and preopen-dirs via async-wasi interface.

This example consists of two projects:

• wasm-app is a wasm application, which is a common application but compiled into a wasm binary instead of a general binary execution.

• run-wasm-app is a host application that is responsible for creating a WasmEdge Vm instance, loading the wasm binary generated from wasm-app and finally running it over WasmEdge Runtime.

Now let's build and run this example.

• Install rustup and Rust

  Go to the official Rust webpage and follow the instructions to install rustup and Rust.

  It is recommended to use Rust 1.71 or above in the stable channel.

  Then, add wasm32-wasi target to the Rustup toolchain:

  rustup target add wasm32-wasi

• Install WasmEdge Runtime

  Refer to the Quick Install section of WasmEdge Runtime Book to install WasmEdge Runtime. Or, use the following command directly

  # NOTICE that the installation script needs `sudo` access
  
  # install wasmedge to the directory /usr/local/
  curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash -s -- -v 0.14.0
  source $HOME/.wasmedge/env

  For users in China mainland (中国大陆地区), try the following command to install WasmEdge Runtime if failed to run the command above

  # NOTICE that the installation script needs `sudo` access
  
  bash install_zh.sh -v 0.14.0

• Download example

  git clone [email protected]:second-state/wasmedge-rustsdk-examples.git
  cd wasmedge-rustsdk-examples/async-wasi

• Build wasm-app

  cargo build -p wasm-app --target wasm32-wasi --release

  If the command runs successfully, wasm-app.wasm can be found in the directory of ./target/wasm32-wasi/release/.

• Build and run run-wasm-app

  cargo run -p run-wasm-app -- ../target/wasm32-wasi/release/wasm-app.wasm

  If the command runs successfully, then the following message is printed out on the screen:

  [tick] i=0
  [wasm-app] enter >>>>>
  [wasm-app] ENV=VAL
  [wasm-app] entry in the current guest preopened dir:
    "/README.md"
    "/run-wasm-app"
    "/wasm-app"
  [wasm-app] say hello: 0
  [tick] i=1
  [tick] i=2
  [wasm-app] say hello: 1
  [tick] i=3
  [tick] i=4
  [wasm-app] say hello: 2
  [tick] i=5
  [tick] i=6
  [wasm-app] say hello: 3
  [tick] i=7
  [tick] i=8
  [wasm-app] say hello: 4
  [tick] i=9
  [tick] i=10
  [wasm-app] say hello: 5
  [tick] i=11
  [tick] i=12
  [wasm-app] say hello: 6
  [tick] i=13
  [tick] i=14
  [wasm-app] say hello: 7
  [tick] i=15
  [wasm-app] say hello: 8
  [tick] i=16
  [tick] i=17
  [wasm-app] say hello: 9
  [tick] i=18
  [tick] i=19
  [wasm-app] exit <<<<<
  exit_code: 0