From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Thu, 16 May 2019 19:08:52 +0000 (-0400)
Subject: sessiond: use epoll()/poll() instead of select()
X-Git-Tag: v2.12.0-rc1~452
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=2d54bfb67f451a491c8cdfb6f6caea3981dc21a8;hp=2d54bfb67f451a491c8cdfb6f6caea3981dc21a8

sessiond: use epoll()/poll() instead of select()

The select(2) system call is an ancient ABI limited to processes
containing at most FD_SETSIZE file descriptors overall (typically
1024).

This select call will fail if the target file descriptor is above
FD_SETSIZE in a session daemon containing many file descriptors.
This is unlikely to happen in normal use given than
sessiond_init_thread_quit_pipe() is called early by main(). Odd
scenarios could trigger this, for instance if the parent process leaves
a large number of file descriptors open, or if a library which
allocates file descriptors is LD_PRELOADed with the sessiond.

Never use select, use the lttng epoll/poll wrapper instead.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
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