轮询系统调用超时 [英] poll system call timeout

问题描述

附加strace会显示很多这样的消息:

Attaching strace shows a lot of these messages:

poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}], 6, 0) = 0 (Timeout)

poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}], 6, 0) = 0 (Timeout)

poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}], 6, 0) = 0 (Timeout)

poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}], 6, 0) = 0 (Timeout)

如何找到程序试图访问的文件，从而导致poll系统调用超时?

How can I find what file the program is trying to access that causes poll system call to timeout?

strace生成大量消息，使调试变得困难

strace generates a lot of messages which make it hard to debug

推荐答案

如何找到程序试图访问的文件，导致轮询系统调用超时?

How can I find what file the program is trying to access that causes poll system call to timeout?

调用:

lsof -p <pid>

看看有问题的文件描述符指的是什么.

And see what the file descriptors in question refer to.

您还可以查看Linux上的proc文件系统:

You can also take a look into proc filesystem on Linux:

ls -l /proc/<pid>/fd

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