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React Native Native Module 在 iOS 上循环调用导致崩溃

来源：stackoverflow 2024-02-18 15:18:24 0浏览收藏

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问题内容

我正在尝试在 ios 上的 react native 中构建 grpc 客户端。

对于上下文：react native 不直接支持 grpc，必须从 swift 调用自定义本机模块，该模块进行 grpc 调用并返回值。

grpc 服务器是本地编译的 golang 模块，它使用 http2server 模块。我没有编写 grpc 服务器，因此我无法更改它的代码。

react native 方法似乎正在循环执行本机 grpc 客户端调用，导致 golang 的 http2server 模块崩溃。

此 grpc 客户端调用是从按钮 onpress() 事件调用的，而不是从循环调用的。我尝试将 grpc 调用包装在超时测试中，以防止调用太快。

我的本机模块有一个导出函数，如下所示：

@objc(swiftnativegrpcclient) class swiftnativegrpcclient: nsobject {
  // ...
  @objc func swiftgetgrpctest(
    _ resolve: rctpromiseresolveblock,
    rejecter reject: rctpromiserejectblock
  ) {
    print("swiftnativegrpcclient.swiftgetgrpctest()")
    // connect to grpc channel if necessary
    if (self.securegrpcchannel == nil) {
      self.createsecurechannel()
    }
    // out of paranoia, don't let this call be used less than
    // once per second
    if (getmillisecondssincelastcall() < 1000) {
      print("method called to soon.")
      reject("0", "method called too soon", nil)
      return
    }
    let grpcserviceclient = service_servicename(channel: self.securegrpcchannel!)
    let testrequest: service_testrequest = service_testrequest()
    // service_testresponse should contain a string:
    // "grpc response success"
    let testresponse: service_testresponse
    let testcall = grpcserviceclient.gettest(testrequest)
    do {
        try testresponse = testcall.response.wait()
        print(testresponse)
    } catch {        
      print("rpc method 'getinfo' failed \(error)")
      return
    }
    // update the last call time to ensure this isn't being called
    // more than once per second
    self.lastcalltime = dispatchtime.now()
    resolve(getinforesponse)
  }
  // ...
}

我的 react native 调用本机模块是这样的：

const { swiftnativegrpcclient } = nativemodules;

export default function app() {
  const nativegrpcclient = useref(swiftnativegrpcclient)
  const [lastcalltime, setlastcalltime] = usestate(new date())

  const rngetgrpctest = async () => {
    try {
      const currenttime = new date()
      console.log(`lastcalltime: ${lastcalltime}`)
      console.log(`currenttime: ${currenttime}`)
      const timediff = currenttime - lastcalltime
      console.log(`timediff: ${timediff} ms`)
      // just checking... don't let this method
      // be executed more than once per second
      if (timediff > 1000) {
        await nativegrpcclient.current.swiftgetgrpctest()
      }
    } catch (error) {
      console.error(error.message)
    }
    setlastcalltime(currenttime)
  }
  // ...
}

xcode 输出如下所示

看起来 grpc 客户端正在对 grpc 服务器进行多次调用。在崩溃之前，您会看到 react native 模块发射器发出大约 20 次相同的响应

2021-12-01 15:23:56.400068+0200 testapp[13091:123303] [javascript] { output: 'swiftnativegrpcclient.swiftgetgrpctest()\n' }

2021-12-01 15:23:58.698908+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.699576+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.700075+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.700606+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.701067+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.701596+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.702036+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.702726+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.704172+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.704766+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.705121+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.705497+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.705833+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.715472+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
panic: 2021-12-01 15:23:58.715856+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.716342+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.716751+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.717020+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.717247+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.717510+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
2021-12-01 15:23:58.718216+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
close of closed channel

goroutine 24507 [2021-12-01 15:23:58.718544+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }
running]:
2021-12-01 15:23:58.718827+0200 testapp[13091:123303] [javascript] got output from naive module emitter:
2021-12-01 15:23:58.719167+0200 testapp[13091:123303] [javascript] { output: '1638365038 [inf] test.go:3294 grpc response success\n' }

通过本机 swift 模块向 react native 返回响应后，golang 的 http2server 在 handleping() 方法期间崩溃。看起来 grpc 连接已关闭，然后再次尝试关闭，http2server 没有妥善处理该连接

这是 xcode 控制台日志：

2021-12-01 15:23:58.717247+0200 testApp[13091:123303] [javascript] Got output from Naive Module Emitter:
2021-12-01 15:23:58.717510+0200 testApp[13091:123303] [javascript] { output: '1638365038 [INF] test.go:3294 gRPC response success\n' }
2021-12-01 15:23:58.718216+0200 testApp[13091:123303] [javascript] Got output from Naive Module Emitter:
close of closed channel
goroutine 24507 [2021-12-01 15:23:58.718544+0200 testApp[13091:123303] [javascript] { output: '1638365038 [INF] test.go:3294 gRPC response success\n' }
running]:
goroutine 24507 [2021-12-01 15:23:58.718544+0200 testApp[13091:123303] [javascript] { output: '1638365038 [INF] test.go:3294 gRPC response success\n' }
running]:
2021-12-01 15:23:58.718827+0200 testApp[13091:123303] [javascript] Got output from Naive Module Emitter:
2021-12-01 15:23:58.719167+0200 testApp[13091:123303] [javascript] { output: '1638365038 [INF] test.go:3294 gRPC response success\n' }
google.golang.org/grpc/internal/transport.(*http2Server).handlePing(0xc00007a1c0, 0xc003c08090)
    google.golang.org/[email protected]/internal/transport/http2_server.go:680 +0x6d
google.golang.org/grpc/internal/transport.(*http2Server).HandleStreams(0xc00015d800, 0xc0029d0f68, 0x10a742005)
    google.golang.org/[email protected]/internal/transport/http2_server.go:494 +0x31f
google.golang.org/grpc.(*Server).serveStreams(0xc000499860, {0x10b916390, 0xc00015d800})
    google.golang.org/[email protected]/server.go:742 +0x114
google.golang.org/grpc.(*Server).handleRawConn.func1()
    google.golang.org/[email protected]/server.go:703 +0x34
created by google.golang.org/grpc.(*Server).handleRawConn
    google.golang.org/[email protected]/server.go:702 +0x405
CoreSimulator 757.5 - Device: iPhone SE (2nd generation) (ECBD797A-E2B4-49F2-9DD5-BC8FB95EFACC) - Runtime: iOS 14.5 (18E182) - DeviceType: iPhone SE (2nd generation)

当我使用完全相同的 swift 代码创建一个测试项目，但没有 react native 前端时，我没有遇到此崩溃。 react native 以某种方式参与了崩溃行为，可能是由于 native 模块的功能如何发挥作用？

有人知道如何防止这种循环发生吗？

正确答案

如果其他人也遇到类似问题，

我的问题与循环的出现无关。

我需要在 swift 函数结束时关闭 grpc 通道。这可以使用 defer 语句来完成：

@objc(SwiftNativeGrpcClient) class SwiftNativeGrpcClient: NSObject {
  // ...
  @objc func swiftGetGrpcTest(
    _ resolve: RCTPromiseResolveBlock,
    rejecter reject: RCTPromiseRejectBlock
  ) {
    if (self.secureGrpcChannel == nil) {
      self.createSecureChannel()
    }
    let grpcServiceClient = Service_ServiceName(channel: self.secureGrpcChannel!)
    defer {
        // close the channel when the method exits
        try? grpcServiceClient.channel.close().wait()
    }
    let testRequest: Service_TestRequest = Service_TestRequest()
    // Service_TestResponse should contain a String:
    // "gRPC response success"
    let testResponse: Service_TestResponse
    let testCall = grpcServiceClient.getTest(testRequest)
    do {
        try testResponse = testCall.response.wait()
        print(testResponse)
        resolve(getInfoResponse)
    } catch {        
      print("RPC method failed \(error)")
      reject("0","RPC method failed: \(error)", nil)
      return
    }
    // update the last call time to ensure this isn't being called
    // more than once per second
  }
  // ...
}

循环控制台输出是由两件事的相互作用引起的：