onexit()

onexit()由用户实现，在策略退出时处理扫尾工作，可以不定义。最长执行 5 分钟，超时会被强制结束。各语言在哪些情况下调用onexit()，见 策略结构。

示例

• 测试onexit()函数：

  • javascript
  • python
  • rust

  
      javascript
      
      
  function main(){
      Log("Starting, will stop after 5 seconds and execute cleanup function!")
      Sleep(1000 * 5)
  }
  
  // 扫尾函数实现
  function onexit(){
      var beginTime = new Date().getTime()
      while(true){
          var nowTime = new Date().getTime()
          Log("Program stop countdown..cleanup started, elapsed time:", (nowTime - beginTime) / 1000, "seconds!")
          Sleep(1000)
      }
  }
  

  
      python
      
      
  import time
  def main():
      Log("Starting, will stop after 5 seconds and execute cleanup function!")
      Sleep(1000 * 5)
  
  def onexit():
      beginTime = time.time() * 1000
      while True:
          ts = time.time() * 1000
          Log("Program stop countdown..cleanup started, elapsed time:", (ts - beginTime) / 1000, "seconds!")
          Sleep(1000)
  

  
      rust
      
      
  fn main() {
      Log!("Starting, will stop after 5 seconds and execute cleanup function!");
      Sleep(1000 * 5);
  }
  
  // 扫尾函数实现
  fn onexit() {
      let beginTime = Unix() * 1000;
      loop {
          let nowTime = Unix() * 1000;
          Log!("Program stop countdown..cleanup started, elapsed time:", (nowTime - beginTime) / 1000, "seconds!");
          Sleep(1000);
      }
  }
  

• 回测系统中，策略通常写成不停轮询的死循环，回测数据结束时main()并没有正常返回，JavaScript、Python策略因此不会执行onexit()。可以在回测中（IsVirtual()为真）捕获回测结束时抛出的异常（EOF），让main()返回，从而执行onexit()。Rust策略在回测结束时 API 调用返回Err，退出循环即可。

  • javascript
  • python
  • rust

  
      javascript
      
      
  function main() {
      if (exchange.GetName().startsWith("Futures_")) {
          Log("Exchange is futures")
          exchange.SetContractType("swap")
      } else {
          Log("Exchange is spot")
      }
  
      if (IsVirtual()) {
          try {
              onTick()
          } catch (e) {
              Log("error:", e)
          }
      } else {
          onTick()
      }
  }
  
  function onTick() {
      while (true) {
          var ticker = exchange.GetTicker()
          LogStatus(_D(), ticker ? ticker.Last : "--")
          Sleep(500)
      }
  }
  
  function onexit() {
      Log("Executing cleanup function")
  }
  

  
      python
      
      
  def main():
      if exchange.GetName().startswith("Futures_"):
          Log("Exchange is futures")
      else:
          Log("Exchange is spot")
  
      if IsVirtual():
          try:
              onTick()
          except Exception as e:
              Log(e)
      else:
          onTick()
  
  def onTick():
      while True:
          ticker = exchange.GetTicker()
          LogStatus(_D(), ticker["Last"] if ticker else "--")
          Sleep(500)
  
  def onexit():
      Log("Executing cleanup function")
  

  
      rust
      
      
  fn onTick() {
      loop {
          match exchange.GetTicker(None) {
              Ok(ticker) => LogStatus!(_D(None), ticker.Last),
              Err(e) => {
                  // 回测结束时API调用返回Err，退出循环使main返回，从而触发onexit()扫尾函数
                  Log!("error:", e);
                  break;
              }
          }
          Sleep(500);
      }
  }
  
  fn main() {
      if exchange.GetName().starts_with("Futures_") {
          Log!("Exchange is futures");
          let _ = exchange.SetContractType("swap");
      } else {
          Log!("Exchange is spot");
      }
  
      onTick();
  }
  
  fn onexit() {
      Log!("Executing cleanup function");
  }