@tye - I'm a newbie in the C++, Perl integration world. I will replicate the issue with Perl PDB file and then see if i can get a proper stack

@BrowserUK - Thanks for your inputs. We will try to add thread level trace in PERLIO_DEBUG and verify the thread which is waiting on Read call

@bulk88 - Thanks for your inputs. We are just running a process and getting the output via pipe in one case and in another case we are writing it to a file. open(MAIL, "| /bin/mailx -s test user\@localhost ") We will use the perl PDB to get the correct stack trace. We will use the combination of Perl debug tracing as listed below and PERLIO_DEBUG option to narrow down the issue

set PERLDB_OPTS= N f A L=listing

I will update with my research and findings