Module: Wurk::PidCache

Includes:
CoreExt
Defined in:
lib/wurk/pid_cache.rb

Overview

Process.pid is a real syscall on Linux — glibc dropped its getpid cache in 2.25 — and the fetch+execute path reads it twice per job (Component.tid and the fetcher's per-queue key cache, both of which read it only to notice a fork). Measured at ~640ns a call against ~110ns for this memo, which is about 1% of a job's CPU spent asking the kernel a question whose answer changes at most once in a process's life.

Refreshed in the child half of every fork, so a swarm child never answers with the pid it inherited — the whole reason those two call sites read it.

Same shape as redis-client's PIDCache, deliberately not borrowed from it: that is a private constant of a dependency, and this one is on our hot path.

Defined Under Namespace

Modules: CoreExt

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Methods included from CoreExt

#_fork

Class Attribute Details

.pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/wurk/pid_cache.rb', line 19

def pid
  @pid
end

Instance Attribute Details

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/wurk/pid_cache.rb', line 40

def pid
  @pid
end

Class Method Details

.update! ⇒ Object 



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# File 'lib/wurk/pid_cache.rb', line 21

def update!
  @pid = ::Process.pid
end