Thanks, Guys, for the insights so far. Well, I have been trying to figure out the best way to work-around my original issue, based on the inputs I received, but today I stumbled onto something really weird.

My perl thread is stuck in read(2) again but this time it is because some other completely unrelated thread has a reference to that pipe. 

[root@onong 5227]# strace -s 1024 -p 5227
Process 5227 attached - interrupt to quit
read(28,

The fd in question is a pipe:

[root@onong tmp]# ls -l /proc/5227/fd
total 0
lr-x------ 1 root root 64 Feb 21 02:02 0 -> /dev/null
l-wx------ 1 root root 64 Feb 21 02:02 1 -> /tmp/abc.log
.
.
lr-x------ 1 root root 64 Feb 21 02:02 28 -> pipe:[28443]


Following are the processes which have a reference to this pipe:

[root@onong tmp]# lsof | grep 28443
perl       5049      root   28r     FIFO                0,6           
+      28443 pipe
ntpd       9936       ntp   28r     FIFO                0,6           
+      28443 pipe
ntpd       9936       ntp   29w     FIFO                0,6           
+      28443 pipe
dhcpd     10228      root   28r     FIFO                0,6           
+      28443 pipe
java      15518      root   28r     FIFO                0,6           
+      28443 pipe

[download]

As you can see, the ntpd process has the write-end of the pipe open!!!!

Any ideas as to how this is even possible????

In reply to Re^2: parent process stuck in read(2) on pipe opened to child process using backtick by onong
in thread parent process stuck in read(2) on pipe opened to child process using backtick by Anonymous Monk

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