timegm() is like mktime() in that it converts a struct tm to
a timestamp, but it treats the struct tm as UTC instead of as
local time.
timegm() is nonstandard, but availabe in both Linux and BSD,
and it's a useful function to have.
We stopped using gettimeofday() in Core::EventLoop a while back,
in favor of clock_gettime() for monotonic time.
Maintaining an optimization for a syscall we're not using doesn't make
a lot of sense, so let's go back to the old-style sys$gettimeofday().
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
This patch adds a single "kernel info page" that is mappable read-only
by any process and contains the current time of day.
This is then used to implement a version of gettimeofday() that doesn't
have to make a syscall.
To protect against race condition issues, the info page also has a
serial number which is incremented whenever the kernel updates the
contents of the page. Make sure to verify that the serial number is the
same before and after reading the information you want from the page.
