Fix foreground process group on restart #904
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* This utility required to reset foregroup pgrp as needed in src/terminal.cpp.
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* This utility required to reset foregroup pgrp as needed in src/terminal.cpp.
* Sometimes 'dmtcp_launch' is called from inside a shell script
(e.g., for a batch job). In this case, on restart, the foreground
process group leader is the restarted process, and yet the
process group leader is the parent (presumably the login shell).
So, the foreground process group leader is not the leader of a
process group. To fix this, we set the process group leader to
also be the leader of the foreground process group.
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karya0
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Nov 4, 2023
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| MACRO(getpgrp) \ | ||
| MACRO(_libc_getpgrp) /* src/plugin/pid/pid_syscallsreal.c */ \ |
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Suggested change
| MACRO(getpgrp) \ | |
| MACRO(_libc_getpgrp) /* src/plugin/pid/pid_syscallsreal.c */ \ |
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[ There's still a bug during restart in this PR. I'll fix that later. It's not yet ready for final review. the script test is failing to restart. ]
'
The key to reviewing this is to read the changes in
src/terminal.cpp(i.e., the most recent commit: "Fix foreground process group on restart").Without this PR, we have the bug described in Issue #903. The problem occurs when
dmtcp_launchis called from a shell script instead of from the command line. On restart, the restarted process acts as if it's in background, and ^C (and other input?) does not reach the restarted process.Sometimes 'dmtcp_launch' is called from inside a shell script (e.g., for a batch job). In this case, on restart, the foreground process group leader is the restarted process, and yet the process group leader is the parent (presumably the login shell). So, the foreground process group leader is not the leader of a process group. To fix this, we set the process group leader to also be the leader of the foreground process group.