multithreading - 进程死锁，Unix命令？

Question

我想知道如何知道一个进程的线程是否在 Unix/Linux 机器上死锁了？另外，是否有用于了解进程处于哪个阶段(或状态)的命令？如果你知道任何工具，请推荐。谢谢。

Answer 1

感谢/proc/<pid>/syscall ，这就是我最终实现 quick and dirty processes futex(op=FUTEX_WAIT) scanner 的方式.

#!/bin/bash
#
# Find all processes that are executing a futex(2) call with op=FUTEX_WAIT
# In some cases this can be helpful in finding deadlock-ed processes.
#

test ! $UID -eq 0 && echo -e "WARNING: Not running as root, only processes for this user are being scanned\n" >&2;
pids=$(ps -u $UID -opid --no-headers)

for pid in $pids; do
        cat /proc/$pid/syscall |

        awk "{if (\$1 == 202 && \$3 == \"0x0\") {
                print $pid
        }}";

        # $1 is the syscall, we compare to 202 which is the futex call
        # See: /usr/include/asm/unistd.h

        # $2 is the 1st param, $3 is the 2nd param, etc
        # We compare the second param to 0x0 which is FUTEX_WAIT
        # See: /usr/include/linux/futex.h
done