why so many connection to same Emulator port with ESTABLISHED and TIME_WAIT

问题

I am struggling to find some way to deal with two permanent errors in my project when using Android Studio

Emulator: emulator: ERROR: AdbHostServer.cpp:102: Unable to connect to adb daemon on port: 5037

Emulator: socketTcpLoopbackClientFor: error: fd 56668 above FD_SETSIZE (32768)

No matter which Android/API version I use these two erros don't disapear. I find a bit weird the number of Emulator Connections to such port. Maybe it is desinged to work that way or maybe I messed upp some thing and I can't find what (I have unistall and reinstall Android Studio from scratch and same issue persist)

Here are the Event Log

01/06/2020
00:08   Gradle sync started
00:08   * daemon not running; starting now at tcp:5037
00:08   * daemon started successfully
00:08   Gradle sync finished in 2 s 418 ms (from cached state)
00:08   Executing tasks: [:app:assembleDebug] in project C:\WSs\FireStoreDemos\AppFirestore
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56296 above FD_SETSIZE (32768)
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56296 above FD_SETSIZE (32768)
00:08   Emulator: emulator: ERROR: AdbHostServer.cpp:102: Unable to connect to adb daemon on port: 5037
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56668 above FD_SETSIZE (32768)
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56668 above FD_SETSIZE (32768)
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56928 above FD_SETSIZE (32768)
00:08   Emulator: socketTcpLoopbackClientFor: error: fd 56928 above FD_SETSIZE (32768)
00:08   Gradle build finished in 19 s 659 ms
00:08   Install successfully finished in 584 ms.: App restart successful without requiring a re-install.

And the error "Emulator: socketTcpLoopbackClientFor: error: fd 60252 above FD_SETSIZE (32768)" keeps poping up a lot every minute while I am running the application.

And here what I consider strange

C:\Users>netstat -ano | findstr "5037"
  TCP    127.0.0.1:5037         0.0.0.0:0              LISTENING       11880
  TCP    127.0.0.1:5037         127.0.0.1:54602        ESTABLISHED     11880
  TCP    127.0.0.1:5037         127.0.0.1:54631        ESTABLISHED     11880
  TCP    127.0.0.1:5037         127.0.0.1:54643        ESTABLISHED     11880
  TCP    127.0.0.1:5037         127.0.0.1:54647        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54648        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54649        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54650        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54662        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54663        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54665        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54666        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54667        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54668        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54669        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54670        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54671        ESTABLISHED     11880
  TCP    127.0.0.1:5037         127.0.0.1:54672        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:54673        ESTABLISHED     11880
  TCP    127.0.0.1:5037         127.0.0.1:54674        TIME_WAIT       0
  TCP    127.0.0.1:54602        127.0.0.1:5037         ESTABLISHED     348
  TCP    127.0.0.1:54631        127.0.0.1:5037         ESTABLISHED     5224
  TCP    127.0.0.1:54634        127.0.0.1:5037         TIME_WAIT       0
  TCP    127.0.0.1:54636        127.0.0.1:5037         TIME_WAIT       0
  TCP    127.0.0.1:54639        127.0.0.1:5037         TIME_WAIT       0
  TCP    127.0.0.1:54641        127.0.0.1:5037         TIME_WAIT       0
  TCP    127.0.0.1:54643        127.0.0.1:5037         ESTABLISHED     348
  TCP    127.0.0.1:54671        127.0.0.1:5037         ESTABLISHED     348
  TCP    127.0.0.1:54673        127.0.0.1:5037         ESTABLISHED     348

C:\Users>

So my straight question is: why so many ESTABLISHED and TIME_WAIT connections to 5037?

Some usefull comments that might help me to move forward: does Android Studio really needs to use such port during startup and before I run/debug the application? Any trick to only start the Daemon when debugging (as a poor analogy we don't keep TomCat up running all time when coding in Spring Boot). I can't understand why I get this message "daemon not running; starting now at tcp:5037" immediatly after started Android Studio since I didn't start to effectivelly use of the Emulator neither by run nor by debug yet.

回答1:

As the only reasonable answer I found untill now, I am answering my own question partially based on other proposal

It seems it is somehow an issue with Multi-core CPU from emulators. So just uncheck Multi-core CPU following Avd Manager -> Select emulator -> edit -> Advanced Settings -> Multi-core CPU -> UNCHECK this option

Maybe in future someone can add a better explanation over here

来源：https://stackoverflow.com/questions/62125502/why-so-many-connection-to-same-emulator-port-with-established-and-time-wait

标签

android

android-studio

android-emulator

adb

android-sdk-tools