Class: Capybara::Simulated::QuickJSRuntime::VmPool

Inherits:
Object
  • Object
show all
Defined in:
lib/capybara/simulated/quickjs_runtime.rb

Overview

Pre-warmed pool of bare ‘Quickjs::VM` instances. `Quickjs::VM.new` with `POLYFILL_INTL` is ~140 ms (FormatJS locale tables + IANA TZ bytecode); quickjs.rb #36 released the GVL during construction, so warmer threads build in parallel with the main thread. `build_vm` pops a pre-built VM and only pays for bridge replay + host-fn attach (~30 ms) on the hot path.

Constant Summary collapse

WARMER_COUNT =

4 warmers × ~140 ms ≈ 28 VMs/sec — covers sustained demand for shared-spec-shaped runs. CAPACITY buffers short bursts before warmers backfill.

4
CAPACITY = 
6

Instance Method Summary collapse

Constructor Details

#initialize(vm_options) ⇒ VmPool

Returns a new instance of VmPool.



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# File 'lib/capybara/simulated/quickjs_runtime.rb', line 82

def initialize(vm_options)
  @vm_options = vm_options
  @queue      = SizedQueue.new(CAPACITY)
  @threads    = WARMER_COUNT.times.map {|i|
    Thread.new { warmer_loop }.tap {|t| t.name = "csim-qjs-warmer-#{i}" }
  }
end

Instance Method Details

#checkout ⇒ Object 



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# File 'lib/capybara/simulated/quickjs_runtime.rb', line 90

def checkout = @queue.pop

#shutdown ⇒ Object

SizedQueue#close unblocks pushers + makes future pops return nil — necessary at process exit because a warmer mid-‘VM.new` has the GVL released and would SEGV on interpreter teardown.



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# File 'lib/capybara/simulated/quickjs_runtime.rb', line 95

def shutdown
  @queue.close
  @threads.each {|t| t.join(2) }
end