Manuel Stoeckl authored Dec 21, 2019 and Simon Ser committed Jan 21, 2020

libwayland now uses only one file descriptor to keep track of all
the timer event sources associated with an event loop. An array-based
binary heap is used to determine which event source has the earliest
deadline.

(Previously, each timer event source had its own timerfd, making it easy
for the a process using many timer event sources to run out of file
descriptors.)

Signed-off-by: Manuel Stoeckl <code@mstoeckl.com>