diff options
Diffstat (limited to 'lib/rainbows/app_pool.rb')
| -rw-r--r-- | lib/rainbows/app_pool.rb | 182 |
1 files changed, 89 insertions, 93 deletions
diff --git a/lib/rainbows/app_pool.rb b/lib/rainbows/app_pool.rb index 7996e2b..b406b32 100644 --- a/lib/rainbows/app_pool.rb +++ b/lib/rainbows/app_pool.rb @@ -2,105 +2,101 @@ require 'thread' -module Rainbows +# Rack middleware to limit application-level concurrency independently +# of network conncurrency in \Rainbows! Since the +worker_connections+ +# option in \Rainbows! is only intended to limit the number of +# simultaneous clients, this middleware may be used to limit the +# number of concurrent application dispatches independently of +# concurrent clients. +# +# Instead of using M:N concurrency in \Rainbows!, this middleware +# allows M:N:P concurrency where +P+ is the AppPool +:size+ while +# +M+ remains the number of +worker_processes+ and +N+ remains the +# number of +worker_connections+. +# +# rainbows master +# \_ rainbows worker[0] +# | \_ client[0,0]------\ ___app[0] +# | \_ client[0,1]-------\ /___app[1] +# | \_ client[0,2]-------->--< ... +# | ... __/ `---app[P] +# | \_ client[0,N]----/ +# \_ rainbows worker[1] +# | \_ client[1,0]------\ ___app[0] +# | \_ client[1,1]-------\ /___app[1] +# | \_ client[1,2]-------->--< ... +# | ... __/ `---app[P] +# | \_ client[1,N]----/ +# \_ rainbows worker[M] +# \_ client[M,0]------\ ___app[0] +# \_ client[M,1]-------\ /___app[1] +# \_ client[M,2]-------->--< ... +# ... __/ `---app[P] +# \_ client[M,N]----/ +# +# AppPool should be used if you want to enforce a lower value of +P+ +# than +N+. +# +# AppPool has no effect on the Rev or EventMachine concurrency models +# as those are single-threaded/single-instance as far as application +# concurrency goes. In other words, +P+ is always +one+ when using +# Rev or EventMachine. As of \Rainbows! 0.7.0, it is safe to use with +# Revactor and the new FiberSpawn and FiberPool concurrency models. +# +# Since this is Rack middleware, you may load this in your Rack +# config.ru file and even use it in threaded servers other than +# \Rainbows! +# +# use Rainbows::AppPool, :size => 30 +# map "/lobster" do +# run Rack::Lobster.new +# end +# +# You may to load this earlier or later in your middleware chain +# depending on the concurrency/copy-friendliness of your middleware(s). +class Rainbows::AppPool < Struct.new(:pool, :re) - # Rack middleware to limit application-level concurrency independently - # of network conncurrency in \Rainbows! Since the +worker_connections+ - # option in \Rainbows! is only intended to limit the number of - # simultaneous clients, this middleware may be used to limit the - # number of concurrent application dispatches independently of - # concurrent clients. - # - # Instead of using M:N concurrency in \Rainbows!, this middleware - # allows M:N:P concurrency where +P+ is the AppPool +:size+ while - # +M+ remains the number of +worker_processes+ and +N+ remains the - # number of +worker_connections+. - # - # rainbows master - # \_ rainbows worker[0] - # | \_ client[0,0]------\ ___app[0] - # | \_ client[0,1]-------\ /___app[1] - # | \_ client[0,2]-------->--< ... - # | ... __/ `---app[P] - # | \_ client[0,N]----/ - # \_ rainbows worker[1] - # | \_ client[1,0]------\ ___app[0] - # | \_ client[1,1]-------\ /___app[1] - # | \_ client[1,2]-------->--< ... - # | ... __/ `---app[P] - # | \_ client[1,N]----/ - # \_ rainbows worker[M] - # \_ client[M,0]------\ ___app[0] - # \_ client[M,1]-------\ /___app[1] - # \_ client[M,2]-------->--< ... - # ... __/ `---app[P] - # \_ client[M,N]----/ - # - # AppPool should be used if you want to enforce a lower value of +P+ - # than +N+. - # - # AppPool has no effect on the Rev or EventMachine concurrency models - # as those are single-threaded/single-instance as far as application - # concurrency goes. In other words, +P+ is always +one+ when using - # Rev or EventMachine. As of \Rainbows! 0.7.0, it is safe to use with - # Revactor and the new FiberSpawn and FiberPool concurrency models. - # - # Since this is Rack middleware, you may load this in your Rack - # config.ru file and even use it in threaded servers other than - # \Rainbows! - # - # use Rainbows::AppPool, :size => 30 - # map "/lobster" do - # run Rack::Lobster.new - # end - # - # You may to load this earlier or later in your middleware chain - # depending on the concurrency/copy-friendliness of your middleware(s). - - class AppPool < Struct.new(:pool, :re) - - # +opt+ is a hash, +:size+ is the size of the pool (default: 6) - # meaning you can have up to 6 concurrent instances of +app+ - # within one \Rainbows! worker process. We support various - # methods of the +:copy+ option: +dup+, +clone+, +deep+ and +none+. - # Depending on your +app+, one of these options should be set. - # The default +:copy+ is +:dup+ as is commonly seen in existing - # Rack middleware. - def initialize(app, opt = {}) - self.pool = Queue.new - (1...(opt[:size] || 6)).each do - pool << case (opt[:copy] || :dup) - when :none then app - when :dup then app.dup - when :clone then app.clone - when :deep then Marshal.load(Marshal.dump(app)) # unlikely... - else - raise ArgumentError, "unsupported copy method: #{opt[:copy].inspect}" - end + # +opt+ is a hash, +:size+ is the size of the pool (default: 6) + # meaning you can have up to 6 concurrent instances of +app+ + # within one \Rainbows! worker process. We support various + # methods of the +:copy+ option: +dup+, +clone+, +deep+ and +none+. + # Depending on your +app+, one of these options should be set. + # The default +:copy+ is +:dup+ as is commonly seen in existing + # Rack middleware. + def initialize(app, opt = {}) + self.pool = Queue.new + (1...(opt[:size] || 6)).each do + pool << case (opt[:copy] || :dup) + when :none then app + when :dup then app.dup + when :clone then app.clone + when :deep then Marshal.load(Marshal.dump(app)) # unlikely... + else + raise ArgumentError, "unsupported copy method: #{opt[:copy].inspect}" end - pool << app # the original end + pool << app # the original + end - # Rack application endpoint, +env+ is the Rack environment - def call(env) # :nodoc: + # Rack application endpoint, +env+ is the Rack environment + def call(env) # :nodoc: - # we have to do this check at call time (and not initialize) - # because of preload_app=true and models being changeable with SIGHUP - # fortunately this is safe for all the reentrant (but not multithreaded) - # classes that depend on it and a safe no-op for multithreaded - # concurrency models - self.re ||= begin - case env["rainbows.model"] - when :FiberSpawn, :FiberPool, :Revactor, :NeverBlock, :RevFiberSpawn - self.pool = Rainbows::Fiber::Queue.new(pool) - end - true + # we have to do this check at call time (and not initialize) + # because of preload_app=true and models being changeable with SIGHUP + # fortunately this is safe for all the reentrant (but not multithreaded) + # classes that depend on it and a safe no-op for multithreaded + # concurrency models + self.re ||= begin + case env["rainbows.model"] + when :FiberSpawn, :FiberPool, :Revactor, :NeverBlock, :RevFiberSpawn + self.pool = Rainbows::Fiber::Queue.new(pool) end - - app = pool.shift - app.call(env) - ensure - pool << app + true end + + app = pool.shift + app.call(env) + ensure + pool << app end end |