tree 17142d8c0e5b3ea0e23d75c91dc55d06dc05cc3e
parent 6fd82bdeeeb399a96ed82ca00ab657e9e2e3d503
author Peter Qiu <zqiu@google.com> 1450307586 -0800
committer Peter Qiu <zqiu@google.com> 1450391125 -0800

Add support for resetting signal masks

By default, child process will inherit signal masks (blocked signals)
from its parent process.  Once the signal is blocked, the child process
will not be able to receive notifications for those signals.

Some parent processes (such as system daemons implemented using
brillo::Daemon) will block signals such as SIGTERM and SIGINT, so that
they can use signalfd to monitor those signals instead.  In this case,
the child process will not be able to receive notification for these
signals.

To fix it, allow the caller to specify a flag to indicate if child
process should reset the signal mask or not.

Bug: None
BUG=chrome-os-partner:47785
TEST=Manual test

Change-Id: I7d32c50e67af0dadbfeca8316f85b9a542e952c0