std.experimental.logger threading design

[Robert burner Schadek via Digitalmars-d]

On Wednesday, 17 August 2016 at 07:48:02 UTC, kookman wrote:
> I was interested low(er) cost logging and stumbled across a 
> proposal by Max Klimov from about 16 months ago to add an 
> AsyncLogger to std.experimental.logger (ref 
> http://forum.dlang.org/thread/lcsjtxorbbagmbvbllns@forum.dlang.org). The resulting PR 3194 has been dormant for some time. I was going to resuscitate it, but I wanted to change the approach - rather than make AsyncLogger a generic wrapper for another logger type, I wanted to make a specialist logger that was designed to always be the stdThreadLocalLogger. It would be a stub that merely sends a LogEntry (as a message) to the stdSharedLogger (which would be any logger type).
>
> When taking a closer look at std.experimental.logger I realized 
> that with the current design, becauseThreadLocalLog is just 
> another Logger, it is paying all the cost of  sychronization, 
> even though it is thread local.
>
> Am I interpreting the purpose of stdThreadLocalLogger 
> differently to how it was intended?

stdThreadLocalLog's log functions are synchronized because they 
read global and instance global data structures. And I didn't 
want make in possible to introduce the possibilities for race 
conditions. Thats why the logXXX member functions of Logger are 
synchronized.

You can still build up a LogEntry and send it, it just has to be 
in synchronized block.