Bump net-http-persistent to 3.0.1

* Adds an extra artifice task to vendorize new `connection_pool`
dependency.

* Cherry-pick's needed Windows fix not yet merged into master branch of
`net-http-persistent`.

* Update bundler usages to be compatible with the new version, and fix
unit specs.

14 files changed, 824 insertions, 442 deletions

diff --git a/Rakefile b/Rakefile
index 9c6543a264..77b8c41fea 100644
--- a/Rakefile
+++ b/Rakefile
@@ -251,6 +251,9 @@ rescue Gem::LoadError => e
 
     desc "Vendor a specific version of net-http-persistent"
     task(:"net-http-persistent") { abort msg }
+
+    desc "Vendor a specific version of connection_pool"
+    task(:connection_pool) { abort msg }
   end
 else
   desc "Vendor a specific version of molinillo"
@@ -294,6 +297,14 @@ else
     end
     lib.send(:extend, mixin)
   end
+
+  desc "Vendor a specific version of connection_pool"
+  Automatiek::RakeTask.new("connection_pool") do |lib|
+    lib.download = { :github => "https://github.com/mperham/connection_pool" }
+    lib.namespace = "ConnectionPool"
+    lib.prefix = "Bundler"
+    lib.vendor_lib = "lib/bundler/vendor/connection_pool"
+  end
 end
 
 task :override_version do
diff --git a/lib/bundler/fetcher.rb b/lib/bundler/fetcher.rb
index 8118c2b2e7..7bda26770b 100644
--- a/lib/bundler/fetcher.rb
+++ b/lib/bundler/fetcher.rb
@@ -242,7 +242,7 @@ module Bundler
           Bundler.settings[:ssl_client_cert]
         raise SSLError if needs_ssl && !defined?(OpenSSL::SSL)
 
-        con = PersistentHTTP.new "bundler", :ENV
+        con = PersistentHTTP.new :name => "bundler", :proxy => :ENV
         if gem_proxy = Bundler.rubygems.configuration[:http_proxy]
           con.proxy = URI.parse(gem_proxy) if gem_proxy != :no_proxy
         end
diff --git a/lib/bundler/vendor/connection_pool/lib/connection_pool.rb b/lib/bundler/vendor/connection_pool/lib/connection_pool.rb
new file mode 100644
index 0000000000..fbcd26c765
--- /dev/null
+++ b/lib/bundler/vendor/connection_pool/lib/connection_pool.rb
@@ -0,0 +1,161 @@
+require_relative 'connection_pool/version'
+require_relative 'connection_pool/timed_stack'
+
+
+# Generic connection pool class for e.g. sharing a limited number of network connections
+# among many threads.  Note: Connections are lazily created.
+#
+# Example usage with block (faster):
+#
+#    @pool = Bundler::ConnectionPool.new { Redis.new }
+#
+#    @pool.with do |redis|
+#      redis.lpop('my-list') if redis.llen('my-list') > 0
+#    end
+#
+# Using optional timeout override (for that single invocation)
+#
+#    @pool.with(timeout: 2.0) do |redis|
+#      redis.lpop('my-list') if redis.llen('my-list') > 0
+#    end
+#
+# Example usage replacing an existing connection (slower):
+#
+#    $redis = Bundler::ConnectionPool.wrap { Redis.new }
+#
+#    def do_work
+#      $redis.lpop('my-list') if $redis.llen('my-list') > 0
+#    end
+#
+# Accepts the following options:
+# - :size - number of connections to pool, defaults to 5
+# - :timeout - amount of time to wait for a connection if none currently available, defaults to 5 seconds
+#
+class Bundler::ConnectionPool
+  DEFAULTS = {size: 5, timeout: 5}
+
+  class Error < RuntimeError
+  end
+
+  def self.wrap(options, &block)
+    Wrapper.new(options, &block)
+  end
+
+  def initialize(options = {}, &block)
+    raise ArgumentError, 'Connection pool requires a block' unless block
+
+    options = DEFAULTS.merge(options)
+
+    @size = options.fetch(:size)
+    @timeout = options.fetch(:timeout)
+
+    @available = TimedStack.new(@size, &block)
+    @key = :"current-#{@available.object_id}"
+    @key_count = :"current-#{@available.object_id}-count"
+  end
+
+if Thread.respond_to?(:handle_interrupt)
+
+  # MRI
+  def with(options = {})
+    Thread.handle_interrupt(Exception => :never) do
+      conn = checkout(options)
+      begin
+        Thread.handle_interrupt(Exception => :immediate) do
+          yield conn
+        end
+      ensure
+        checkin
+      end
+    end
+  end
+
+else
+
+  # jruby 1.7.x
+  def with(options = {})
+    conn = checkout(options)
+    begin
+      yield conn
+    ensure
+      checkin
+    end
+  end
+
+end
+
+  def checkout(options = {})
+    if ::Thread.current[@key]
+      ::Thread.current[@key_count]+= 1
+      ::Thread.current[@key]
+    else
+      ::Thread.current[@key_count]= 1
+      ::Thread.current[@key]= @available.pop(options[:timeout] || @timeout)
+    end
+  end
+
+  def checkin
+    if ::Thread.current[@key]
+      if ::Thread.current[@key_count] == 1
+        @available.push(::Thread.current[@key])
+        ::Thread.current[@key]= nil
+      else
+        ::Thread.current[@key_count]-= 1
+      end
+    else
+      raise Bundler::ConnectionPool::Error, 'no connections are checked out'
+    end
+
+    nil
+  end
+
+  def shutdown(&block)
+    @available.shutdown(&block)
+  end
+
+  # Size of this connection pool
+  def size
+    @size
+  end
+
+  # Number of pool entries available for checkout at this instant.
+  def available
+    @available.length
+  end
+
+  private
+
+  class Wrapper < ::BasicObject
+    METHODS = [:with, :pool_shutdown]
+
+    def initialize(options = {}, &block)
+      @pool = options.fetch(:pool) { ::Bundler::ConnectionPool.new(options, &block) }
+    end
+
+    def with(&block)
+      @pool.with(&block)
+    end
+
+    def pool_shutdown(&block)
+      @pool.shutdown(&block)
+    end
+
+    def pool_size
+      @pool.size
+    end
+
+    def pool_available
+      @pool.available
+    end
+
+    def respond_to?(id, *args)
+      METHODS.include?(id) || with { |c| c.respond_to?(id, *args) }
+    end
+
+    def method_missing(name, *args, &block)
+      with do |connection|
+        connection.send(name, *args, &block)
+      end
+    end
+  end
+end
diff --git a/lib/bundler/vendor/connection_pool/lib/connection_pool/monotonic_time.rb b/lib/bundler/vendor/connection_pool/lib/connection_pool/monotonic_time.rb
new file mode 100644
index 0000000000..5a9c4a27bb
--- /dev/null
+++ b/lib/bundler/vendor/connection_pool/lib/connection_pool/monotonic_time.rb
@@ -0,0 +1,66 @@
+# Global monotonic clock from Concurrent Ruby 1.0.
+# Copyright (c) Jerry D'Antonio -- released under the MIT license.
+# Slightly modified; used with permission.
+# https://github.com/ruby-concurrency/concurrent-ruby
+
+require 'thread'
+
+class Bundler::ConnectionPool
+
+  class_definition = Class.new do
+
+    if defined?(Process::CLOCK_MONOTONIC)
+
+      # @!visibility private
+      def get_time
+        Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      end
+
+    elsif defined?(RUBY_ENGINE) && RUBY_ENGINE == 'jruby'
+
+      # @!visibility private
+      def get_time
+        java.lang.System.nanoTime() / 1_000_000_000.0
+      end
+
+    else
+
+      # @!visibility private
+      def initialize
+        @mutex = Mutex.new
+        @last_time = Time.now.to_f
+      end
+
+      # @!visibility private
+      def get_time
+        @mutex.synchronize do
+          now = Time.now.to_f
+          if @last_time < now
+            @last_time = now
+          else # clock has moved back in time
+            @last_time += 0.000_001
+          end
+        end
+      end
+    end
+  end
+
+  ##
+  # Clock that cannot be set and represents monotonic time since
+  # some unspecified starting point.
+  #
+  # @!visibility private
+  GLOBAL_MONOTONIC_CLOCK = class_definition.new
+  private_constant :GLOBAL_MONOTONIC_CLOCK
+
+  class << self
+    ##
+    # Returns the current time a tracked by the application monotonic clock.
+    #
+    # @return [Float] The current monotonic time when `since` not given else
+    #   the elapsed monotonic time between `since` and the current time
+    def monotonic_time
+      GLOBAL_MONOTONIC_CLOCK.get_time
+    end
+  end
+end
diff --git a/lib/bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb b/lib/bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb
new file mode 100644
index 0000000000..f3fe1e04ad
--- /dev/null
+++ b/lib/bundler/vendor/connection_pool/lib/connection_pool/timed_stack.rb
@@ -0,0 +1,176 @@
+require 'thread'
+require 'timeout'
+require_relative 'monotonic_time'
+
+##
+# Raised when you attempt to retrieve a connection from a pool that has been
+# shut down.
+
+class Bundler::ConnectionPool::PoolShuttingDownError < RuntimeError; end
+
+##
+# The TimedStack manages a pool of homogeneous connections (or any resource
+# you wish to manage).  Connections are created lazily up to a given maximum
+# number.
+
+# Examples:
+#
+#    ts = TimedStack.new(1) { MyConnection.new }
+#
+#    # fetch a connection
+#    conn = ts.pop
+#
+#    # return a connection
+#    ts.push conn
+#
+#    conn = ts.pop
+#    ts.pop timeout: 5
+#    #=> raises Timeout::Error after 5 seconds
+
+class Bundler::ConnectionPool::TimedStack
+  attr_reader :max
+
+  ##
+  # Creates a new pool with +size+ connections that are created from the given
+  # +block+.
+
+  def initialize(size = 0, &block)
+    @create_block = block
+    @created = 0
+    @que = []
+    @max = size
+    @mutex = Mutex.new
+    @resource = ConditionVariable.new
+    @shutdown_block = nil
+  end
+
+  ##
+  # Returns +obj+ to the stack.  +options+ is ignored in TimedStack but may be
+  # used by subclasses that extend TimedStack.
+
+  def push(obj, options = {})
+    @mutex.synchronize do
+      if @shutdown_block
+        @shutdown_block.call(obj)
+      else
+        store_connection obj, options
+      end
+
+      @resource.broadcast
+    end
+  end
+  alias_method :<<, :push
+
+  ##
+  # Retrieves a connection from the stack.  If a connection is available it is
+  # immediately returned.  If no connection is available within the given
+  # timeout a Timeout::Error is raised.
+  #
+  # +:timeout+ is the only checked entry in +options+ and is preferred over
+  # the +timeout+ argument (which will be removed in a future release).  Other
+  # options may be used by subclasses that extend TimedStack.
+
+  def pop(timeout = 0.5, options = {})
+    options, timeout = timeout, 0.5 if Hash === timeout
+    timeout = options.fetch :timeout, timeout
+
+    deadline = Bundler::ConnectionPool.monotonic_time + timeout
+    @mutex.synchronize do
+      loop do
+        raise Bundler::ConnectionPool::PoolShuttingDownError if @shutdown_block
+        return fetch_connection(options) if connection_stored?(options)
+
+        connection = try_create(options)
+        return connection if connection
+
+        to_wait = deadline - Bundler::ConnectionPool.monotonic_time
+        raise Timeout::Error, "Waited #{timeout} sec" if to_wait <= 0
+        @resource.wait(@mutex, to_wait)
+      end
+    end
+  end
+
+  ##
+  # Shuts down the TimedStack which prevents connections from being checked
+  # out.  The +block+ is called once for each connection on the stack.
+
+  def shutdown(&block)
+    raise ArgumentError, "shutdown must receive a block" unless block_given?
+
+    @mutex.synchronize do
+      @shutdown_block = block
+      @resource.broadcast
+
+      shutdown_connections
+    end
+  end
+
+  ##
+  # Returns +true+ if there are no available connections.
+
+  def empty?
+    (@created - @que.length) >= @max
+  end
+
+  ##
+  # The number of connections available on the stack.
+
+  def length
+    @max - @created + @que.length
+  end
+
+  private
+
+  ##
+  # This is an extension point for TimedStack and is called with a mutex.
+  #
+  # This method must returns true if a connection is available on the stack.
+
+  def connection_stored?(options = nil)
+    !@que.empty?
+  end
+
+  ##
+  # This is an extension point for TimedStack and is called with a mutex.
+  #
+  # This method must return a connection from the stack.
+
+  def fetch_connection(options = nil)
+    @que.pop
+  end
+
+  ##
+  # This is an extension point for TimedStack and is called with a mutex.
+  #
+  # This method must shut down all connections on the stack.
+
+  def shutdown_connections(options = nil)
+    while connection_stored?(options)
+      conn = fetch_connection(options)
+      @shutdown_block.call(conn)
+    end
+  end
+
+  ##
+  # This is an extension point for TimedStack and is called with a mutex.
+  #
+  # This method must return +obj+ to the stack.
+
+  def store_connection(obj, options = nil)
+    @que.push obj
+  end
+
+  ##
+  # This is an extension point for TimedStack and is called with a mutex.
+  #
+  # This method must create a connection if and only if the total number of
+  # connections allowed has not been met.
+
+  def try_create(options = nil)
+    unless @created == @max
+      object = @create_block.call
+      @created += 1
+      object
+    end
+  end
+end
diff --git a/lib/bundler/vendor/connection_pool/lib/connection_pool/version.rb b/lib/bundler/vendor/connection_pool/lib/connection_pool/version.rb
new file mode 100644
index 0000000000..b149c0e242
--- /dev/null
+++ b/lib/bundler/vendor/connection_pool/lib/connection_pool/version.rb
@@ -0,0 +1,3 @@
+class Bundler::ConnectionPool
+  VERSION = "2.2.2"
+end
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/faster.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/faster.rb
deleted file mode 100644
index e5e09080c2..0000000000
--- a/lib/bundler/vendor/net-http-persistent/lib/net/http/faster.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-require 'net/protocol'
-
-##
-# Aaron Patterson's monkeypatch (accepted into 1.9.1) to fix Net::HTTP's speed
-# problems.
-#
-# http://gist.github.com/251244
-
-class Net::BufferedIO #:nodoc:
-  alias :old_rbuf_fill :rbuf_fill
-
-  def rbuf_fill
-    if @io.respond_to? :read_nonblock then
-      begin
-        @rbuf << @io.read_nonblock(65536)
-      rescue Errno::EWOULDBLOCK, Errno::EAGAIN => e
-        retry if IO.select [@io], nil, nil, @read_timeout
-        raise Timeout::Error, e.message
-      end
-    else # SSL sockets do not have read_nonblock
-      timeout @read_timeout do
-        @rbuf << @io.sysread(65536)
-      end
-    end
-  end
-end if RUBY_VERSION < '1.9'
-
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent.rb
index 7cbca5bc06..0d4bb350dd 100644
--- a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent.rb
+++ b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent.rb
@@ -1,12 +1,7 @@
 require 'net/http'
-begin
-  require 'net/https'
-rescue LoadError
-  # net/https or openssl
-end if RUBY_VERSION < '1.9' # but only for 1.8
-require 'bundler/vendor/net-http-persistent/lib/net/http/faster'
 require 'uri'
 require 'cgi' # for escaping
+require_relative '../../../../connection_pool/lib/connection_pool'
 
 begin
   require 'net/http/pipeline'
@@ -38,7 +33,7 @@ autoload :OpenSSL, 'openssl'
 #
 #   uri = URI 'http://example.com/awesome/web/service'
 #
-#   http = Bundler::Persistent::Net::HTTP::Persistent.new 'my_app_name'
+#   http = Bundler::Persistent::Net::HTTP::Persistent.new name: 'my_app_name'
 #
 #   # perform a GET
 #   response = http.request uri
@@ -70,13 +65,17 @@ autoload :OpenSSL, 'openssl'
 # Here are the SSL settings, see the individual methods for documentation:
 #
 # #certificate        :: This client's certificate
-# #ca_file            :: The certificate-authority
+# #ca_file            :: The certificate-authorities
+# #ca_path            :: Directory with certificate-authorities
 # #cert_store         :: An SSL certificate store
+# #ciphers            :: List of SSl ciphers allowed
 # #private_key        :: The client's SSL private key
 # #reuse_ssl_sessions :: Reuse a previously opened SSL session for a new
 #                        connection
+# #ssl_timeout        :: SSL session lifetime
 # #ssl_version        :: Which specific SSL version to use
 # #verify_callback    :: For server certificate verification
+# #verify_depth       :: Depth of certificate verification
 # #verify_mode        :: How connections should be verified
 #
 # == Proxies
@@ -154,7 +153,7 @@ autoload :OpenSSL, 'openssl'
 #   uri = URI 'http://example.com/awesome/web/service'
 #   post_uri = uri + 'create'
 #
-#   http = Bundler::Persistent::Net::HTTP::Persistent.new 'my_app_name'
+#   http = Bundler::Persistent::Net::HTTP::Persistent.new name: 'my_app_name'
 #
 #   post = Net::HTTP::Post.new post_uri.path
 #   # ... fill in POST request
@@ -201,9 +200,18 @@ class Bundler::Persistent::Net::HTTP::Persistent
   HAVE_OPENSSL = defined? OpenSSL::SSL # :nodoc:
 
   ##
+  # The default connection pool size is 1/4 the allowed open files.
+
+  if Gem.win_platform? then
+    DEFAULT_POOL_SIZE = 256
+  else
+    DEFAULT_POOL_SIZE = Process.getrlimit(Process::RLIMIT_NOFILE).first / 4
+  end
+
+  ##
   # The version of Bundler::Persistent::Net::HTTP::Persistent you are using
 
-  VERSION = '2.9.4'
+  VERSION = '3.0.1'
 
   ##
   # Exceptions rescued for automatic retry on ruby 2.0.0.  This overlaps with
@@ -248,31 +256,31 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
     http = new 'net-http-persistent detect_idle_timeout'
 
-    connection = http.connection_for uri
+    http.connection_for uri do |connection|
+      sleep_time = 0
 
-    sleep_time = 0
+      http = connection.http
 
-    loop do
-      response = connection.request req
+      loop do
+        response = http.request req
 
-      $stderr.puts "HEAD #{uri} => #{response.code}" if $DEBUG
+        $stderr.puts "HEAD #{uri} => #{response.code}" if $DEBUG
 
-      unless Net::HTTPOK === response then
-        raise Error, "bad response code #{response.code} detecting idle timeout"
-      end
+        unless Net::HTTPOK === response then
+          raise Error, "bad response code #{response.code} detecting idle timeout"
+        end
 
-      break if sleep_time >= max
+        break if sleep_time >= max
 
-      sleep_time += 1
+        sleep_time += 1
 
-      $stderr.puts "sleeping #{sleep_time}" if $DEBUG
-      sleep sleep_time
+        $stderr.puts "sleeping #{sleep_time}" if $DEBUG
+        sleep sleep_time
+      end
     end
   rescue
     # ignore StandardErrors, we've probably found the idle timeout.
   ensure
-    http.shutdown
-
     return sleep_time unless $!
   end
 
@@ -281,7 +289,9 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
   attr_reader :certificate
 
+  ##
   # For Net::HTTP parity
+
   alias cert certificate
 
   ##
@@ -291,12 +301,23 @@ class Bundler::Persistent::Net::HTTP::Persistent
   attr_reader :ca_file
 
   ##
+  # A directory of SSL certificates to be used as certificate authorities.
+  # Setting this will set verify_mode to VERIFY_PEER.
+
+  attr_reader :ca_path
+
+  ##
   # An SSL certificate store.  Setting this will override the default
   # certificate store.  See verify_mode for more information.
 
   attr_reader :cert_store
 
   ##
+  # The ciphers allowed for SSL connections
+
+  attr_reader :ciphers
+
+  ##
   # Sends debug_output to this IO via Net::HTTP#set_debug_output.
   #
   # Never use this method in production code, it causes a serious security
@@ -310,11 +331,6 @@ class Bundler::Persistent::Net::HTTP::Persistent
   attr_reader :generation # :nodoc:
 
   ##
-  # Where this instance's connections live in the thread local variables
-
-  attr_reader :generation_key # :nodoc:
-
-  ##
   # Headers that are added to every request using Net::HTTP#add_field
 
   attr_reader :headers
@@ -369,7 +385,9 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
   attr_reader :private_key
 
+  ##
   # For Net::HTTP parity
+
   alias key private_key
 
   ##
@@ -383,14 +401,14 @@ class Bundler::Persistent::Net::HTTP::Persistent
   attr_reader :no_proxy
 
   ##
-  # Seconds to wait until reading one block.  See Net::HTTP#read_timeout
+  # Test-only accessor for the connection pool
 
-  attr_accessor :read_timeout
+  attr_reader :pool # :nodoc:
 
   ##
-  # Where this instance's request counts live in the thread local variables
+  # Seconds to wait until reading one block.  See Net::HTTP#read_timeout
 
-  attr_reader :request_key # :nodoc:
+  attr_accessor :read_timeout
 
   ##
   # By default SSL sessions are reused to avoid extra SSL handshakes.  Set
@@ -418,17 +436,33 @@ class Bundler::Persistent::Net::HTTP::Persistent
   attr_reader :ssl_generation # :nodoc:
 
   ##
-  # Where this instance's SSL connections live in the thread local variables
+  # SSL session lifetime
 
-  attr_reader :ssl_generation_key # :nodoc:
+  attr_reader :ssl_timeout
 
   ##
   # SSL version to use.
   #
   # By default, the version will be negotiated automatically between client
-  # and server.  Ruby 1.9 and newer only.
+  # and server.  Ruby 1.9 and newer only. Deprecated since Ruby 2.5.
+
+  attr_reader :ssl_version
+
+  ##
+  # Minimum SSL version to use, e.g. :TLS1_1
+  #
+  # By default, the version will be negotiated automatically between client
+  # and server.  Ruby 2.5 and newer only.
+
+  attr_reader :min_version
+
+  ##
+  # Maximum SSL version to use, e.g. :TLS1_2
+  #
+  # By default, the version will be negotiated automatically between client
+  # and server.  Ruby 2.5 and newer only.
 
-  attr_reader :ssl_version if RUBY_VERSION > '1.9'
+  attr_reader :max_version
 
   ##
   # Where this instance's last-use times live in the thread local variables
@@ -436,16 +470,21 @@ class Bundler::Persistent::Net::HTTP::Persistent
   attr_reader :timeout_key # :nodoc:
 
   ##
-  # SSL verification callback.  Used when ca_file is set.
+  # SSL verification callback.  Used when ca_file or ca_path is set.
 
   attr_reader :verify_callback
 
   ##
+  # Sets the depth of SSL certificate verification
+
+  attr_reader :verify_depth
+
+  ##
   # HTTPS verify mode.  Defaults to OpenSSL::SSL::VERIFY_PEER which verifies
   # the server certificate.
   #
-  # If no ca_file or cert_store is set the default system certificate store is
-  # used.
+  # If no ca_file, ca_path or cert_store is set the default system certificate
+  # store is used.
   #
   # You can use +verify_mode+ to override any default values.
 
@@ -478,8 +517,12 @@ class Bundler::Persistent::Net::HTTP::Persistent
   #   proxy = URI 'http://proxy.example'
   #   proxy.user     = 'AzureDiamond'
   #   proxy.password = 'hunter2'
+  #
+  # Set +pool_size+ to limit the maximum number of connections allowed.
+  # Defaults to 1/4 the number of allowed file handles.  You can have no more
+  # than this many threads with active HTTP transactions.
 
-  def initialize name = nil, proxy = nil
+  def initialize name: nil, proxy: nil, pool_size: DEFAULT_POOL_SIZE
     @name = name
 
     @debug_output     = nil
@@ -494,26 +537,30 @@ class Bundler::Persistent::Net::HTTP::Persistent
     @idle_timeout     = 5
     @max_requests     = nil
     @socket_options   = []
+    @ssl_generation   = 0 # incremented when SSL session variables change
 
     @socket_options << [Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1] if
       Socket.const_defined? :TCP_NODELAY
 
-    key = ['net_http_persistent', name].compact
-    @generation_key     = [key, 'generations'    ].join('_').intern
-    @ssl_generation_key = [key, 'ssl_generations'].join('_').intern
-    @request_key        = [key, 'requests'       ].join('_').intern
-    @timeout_key        = [key, 'timeouts'       ].join('_').intern
+    @pool = Bundler::Persistent::Net::HTTP::Persistent::Pool.new size: pool_size do |http_args|
+      Bundler::Persistent::Net::HTTP::Persistent::Connection.new Net::HTTP, http_args, @ssl_generation
+    end
 
     @certificate        = nil
     @ca_file            = nil
+    @ca_path            = nil
+    @ciphers            = nil
     @private_key        = nil
+    @ssl_timeout        = nil
     @ssl_version        = nil
+    @min_version        = nil
+    @max_version        = nil
     @verify_callback    = nil
+    @verify_depth       = nil
     @verify_mode        = nil
     @cert_store         = nil
 
     @generation         = 0 # incremented when proxy URI changes
-    @ssl_generation     = 0 # incremented when SSL session variables change
 
     if HAVE_OPENSSL then
       @verify_mode        = OpenSSL::SSL::VERIFY_PEER
@@ -522,9 +569,6 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
     @retry_change_requests = false
 
-    @ruby_1 = RUBY_VERSION < '2'
-    @retried_on_ruby_2 = !@ruby_1
-
     self.proxy = proxy if proxy
   end
 
@@ -550,6 +594,15 @@ class Bundler::Persistent::Net::HTTP::Persistent
   end
 
   ##
+  # Sets the SSL certificate authority path.
+
+  def ca_path= path
+    @ca_path = path
+
+    reconnect_ssl
+  end
+
+  ##
   # Overrides the default SSL certificate store used for verifying
   # connections.
 
@@ -560,92 +613,55 @@ class Bundler::Persistent::Net::HTTP::Persistent
   end
 
   ##
-  # Finishes all connections on the given +thread+ that were created before
-  # the given +generation+ in the threads +generation_key+ list.
-  #
-  # See #shutdown for a bunch of scary warning about misusing this method.
-
-  def cleanup(generation, thread = Thread.current,
-              generation_key = @generation_key) # :nodoc:
-    timeouts = thread[@timeout_key]
+  # The ciphers allowed for SSL connections
 
-    (0...generation).each do |old_generation|
-      next unless thread[generation_key]
+  def ciphers= ciphers
+    @ciphers = ciphers
 
-      conns = thread[generation_key].delete old_generation
-
-      conns.each_value do |conn|
-        finish conn, thread
-
-        timeouts.delete conn.object_id if timeouts
-      end if conns
-    end
+    reconnect_ssl
   end
 
   ##
   # Creates a new connection for +uri+
 
   def connection_for uri
-    Thread.current[@generation_key]     ||= Hash.new { |h,k| h[k] = {} }
-    Thread.current[@ssl_generation_key] ||= Hash.new { |h,k| h[k] = {} }
-    Thread.current[@request_key]        ||= Hash.new 0
-    Thread.current[@timeout_key]        ||= Hash.new EPOCH
-
     use_ssl = uri.scheme.downcase == 'https'
 
-    if use_ssl then
-      raise Bundler::Persistent::Net::HTTP::Persistent::Error, 'OpenSSL is not available' unless
-        HAVE_OPENSSL
-
-      ssl_generation = @ssl_generation
-
-      ssl_cleanup ssl_generation
-
-      connections = Thread.current[@ssl_generation_key][ssl_generation]
-    else
-      generation = @generation
-
-      cleanup generation
+    net_http_args = [uri.host, uri.port]
 
-      connections = Thread.current[@generation_key][generation]
-    end
+    net_http_args.concat @proxy_args if
+      @proxy_uri and not proxy_bypass? uri.host, uri.port
 
-    net_http_args = [uri.host, uri.port]
-    connection_id = net_http_args.join ':'
+    connection = @pool.checkout net_http_args
 
-    if @proxy_uri and not proxy_bypass? uri.host, uri.port then
-      connection_id << @proxy_connection_id
-      net_http_args.concat @proxy_args
-    else
-      net_http_args.concat [nil, nil, nil, nil]
-    end
+    http = connection.http
 
-    connection = connections[connection_id]
+    connection.ressl @ssl_generation if
+      connection.ssl_generation != @ssl_generation
 
-    unless connection = connections[connection_id] then
-      connections[connection_id] = http_class.new(*net_http_args)
-      connection = connections[connection_id]
-      ssl connection if use_ssl
-    else
-      reset connection if expired? connection
+    if not http.started? then
+      ssl   http if use_ssl
+      start http
+    elsif expired? connection then
+      reset connection
     end
 
-    start connection unless connection.started?
-
-    connection.read_timeout = @read_timeout if @read_timeout
-    connection.keep_alive_timeout = @idle_timeout if @idle_timeout && connection.respond_to?(:keep_alive_timeout=)
+    http.read_timeout = @read_timeout if @read_timeout
+    http.keep_alive_timeout = @idle_timeout if @idle_timeout
 
-    connection
+    return yield connection
   rescue Errno::ECONNREFUSED
-    address = connection.proxy_address || connection.address
-    port    = connection.proxy_port    || connection.port
+    address = http.proxy_address || http.address
+    port    = http.proxy_port    || http.port
 
     raise Error, "connection refused: #{address}:#{port}"
   rescue Errno::EHOSTDOWN
-    address = connection.proxy_address || connection.address
-    port    = connection.proxy_port    || connection.port
+    address = http.proxy_address || http.address
+    port    = http.proxy_port    || http.port
 
     raise Error, "host down: #{address}:#{port}"
+  ensure
+    @pool.checkin net_http_args
   end
 
   ##
@@ -653,12 +669,11 @@ class Bundler::Persistent::Net::HTTP::Persistent
   # this connection
 
   def error_message connection
-    requests = Thread.current[@request_key][connection.object_id] - 1 # fixup
-    last_use = Thread.current[@timeout_key][connection.object_id]
+    connection.requests -= 1 # fixup
 
-    age = Time.now - last_use
+    age = Time.now - connection.last_use
 
-    "after #{requests} requests on #{connection.object_id}, " \
+    "after #{connection.requests} requests on #{connection.http.object_id}, " \
       "last used #{age} seconds ago"
   end
 
@@ -682,26 +697,23 @@ class Bundler::Persistent::Net::HTTP::Persistent
   # maximum request count, false otherwise.
 
   def expired? connection
-    requests = Thread.current[@request_key][connection.object_id]
-    return true  if     @max_requests && requests >= @max_requests
+    return true  if     @max_requests && connection.requests >= @max_requests
     return false unless @idle_timeout
     return true  if     @idle_timeout.zero?
 
-    last_used = Thread.current[@timeout_key][connection.object_id]
-
-    Time.now - last_used > @idle_timeout
+    Time.now - connection.last_use > @idle_timeout
   end
 
   ##
   # Starts the Net::HTTP +connection+
 
-  def start connection
-    connection.set_debug_output @debug_output if @debug_output
-    connection.open_timeout = @open_timeout if @open_timeout
+  def start http
+    http.set_debug_output @debug_output if @debug_output
+    http.open_timeout = @open_timeout if @open_timeout
 
-    connection.start
+    http.start
 
-    socket = connection.instance_variable_get :@socket
+    socket = http.instance_variable_get :@socket
 
     if socket then # for fakeweb
       @socket_options.each do |option|
@@ -713,25 +725,11 @@ class Bundler::Persistent::Net::HTTP::Persistent
   ##
   # Finishes the Net::HTTP +connection+
 
-  def finish connection, thread = Thread.current
-    if requests = thread[@request_key] then
-      requests.delete connection.object_id
-    end
-
+  def finish connection
     connection.finish
-  rescue IOError
-  end
 
-  def http_class # :nodoc:
-    if RUBY_VERSION > '2.0' then
-      Net::HTTP
-    elsif [:Artifice, :FakeWeb, :WebMock].any? { |klass|
-             Object.const_defined?(klass)
-          } or not @reuse_ssl_sessions then
-        Net::HTTP
-    else
-      Bundler::Persistent::Net::HTTP::Persistent::SSLReuse
-    end
+    connection.http.instance_variable_set :@ssl_session, nil unless
+      @reuse_ssl_sessions
   end
 
   ##
@@ -754,55 +752,9 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
   ##
   # Is the request +req+ idempotent or is retry_change_requests allowed.
-  #
-  # If +retried_on_ruby_2+ is true, true will be returned if we are on ruby,
-  # retry_change_requests is allowed and the request is not idempotent.
-
-  def can_retry? req, retried_on_ruby_2 = false
-    return @retry_change_requests && !idempotent?(req) if retried_on_ruby_2
-
-    @retry_change_requests || idempotent?(req)
-  end
-
-  if RUBY_VERSION > '1.9' then
-    ##
-    # Workaround for missing Net::HTTPHeader#connection_close? on Ruby 1.8
-
-    def connection_close? header
-      header.connection_close?
-    end
-
-    ##
-    # Workaround for missing Net::HTTPHeader#connection_keep_alive? on Ruby 1.8
-
-    def connection_keep_alive? header
-      header.connection_keep_alive?
-    end
-  else
-    ##
-    # Workaround for missing Net::HTTPRequest#connection_close? on Ruby 1.8
-
-    def connection_close? header
-      header['connection'] =~ /close/ or header['proxy-connection'] =~ /close/
-    end
 
-    ##
-    # Workaround for missing Net::HTTPRequest#connection_keep_alive? on Ruby
-    # 1.8
-
-    def connection_keep_alive? header
-      header['connection'] =~ /keep-alive/ or
-        header['proxy-connection'] =~ /keep-alive/
-    end
-  end
-
-  ##
-  # Deprecated in favor of #expired?
-
-  def max_age # :nodoc:
-    return Time.now + 1 unless @idle_timeout
-
-    Time.now - @idle_timeout
+  def can_retry? req
+    @retry_change_requests && !idempotent?(req)
   end
 
   ##
@@ -824,9 +776,9 @@ class Bundler::Persistent::Net::HTTP::Persistent
   # <tt>net-http-persistent</tt> #pipeline will be present.
 
   def pipeline uri, requests, &block # :yields: responses
-    connection = connection_for uri
-
-    connection.pipeline requests, &block
+    connection_for uri do |connection|
+      connection.http.pipeline requests, &block
+    end
   end
 
   ##
@@ -959,18 +911,17 @@ class Bundler::Persistent::Net::HTTP::Persistent
   # Finishes then restarts the Net::HTTP +connection+
 
   def reset connection
-    Thread.current[@request_key].delete connection.object_id
-    Thread.current[@timeout_key].delete connection.object_id
+    http = connection.http
 
     finish connection
 
-    start connection
+    start http
   rescue Errno::ECONNREFUSED
-    e = Error.new "connection refused: #{connection.address}:#{connection.port}"
+    e = Error.new "connection refused: #{http.address}:#{http.port}"
     e.set_backtrace $@
     raise e
   rescue Errno::EHOSTDOWN
-    e = Error.new "host down: #{connection.address}:#{connection.port}"
+    e = Error.new "host down: #{http.address}:#{http.port}"
     e.set_backtrace $@
     raise e
   end
@@ -991,52 +942,56 @@ class Bundler::Persistent::Net::HTTP::Persistent
     retried      = false
     bad_response = false
 
-    req = request_setup req || uri
+    uri      = URI uri
+    req      = request_setup req || uri
+    response = nil
 
-    connection = connection_for uri
-    connection_id = connection.object_id
+    connection_for uri do |connection|
+      http = connection.http
 
-    begin
-      Thread.current[@request_key][connection_id] += 1
-      response = connection.request req, &block
+      begin
+        connection.requests += 1
 
-      if connection_close?(req) or
-         (response.http_version <= '1.0' and
-          not connection_keep_alive?(response)) or
-         connection_close?(response) then
-        connection.finish
-      end
-    rescue Net::HTTPBadResponse => e
-      message = error_message connection
+        response = http.request req, &block
+
+        if req.connection_close? or
+           (response.http_version <= '1.0' and
+            not response.connection_keep_alive?) or
+           response.connection_close? then
+          finish connection
+        end
+      rescue Net::HTTPBadResponse => e
+        message = error_message connection
 
-      finish connection
+        finish connection
 
-      raise Error, "too many bad responses #{message}" if
+        raise Error, "too many bad responses #{message}" if
         bad_response or not can_retry? req
 
-      bad_response = true
-      retry
-    rescue *RETRIED_EXCEPTIONS => e # retried on ruby 2
-      request_failed e, req, connection if
-        retried or not can_retry? req, @retried_on_ruby_2
+        bad_response = true
+        retry
+      rescue *RETRIED_EXCEPTIONS => e
+        request_failed e, req, connection if
+          retried or not can_retry? req
 
-      reset connection
+        reset connection
 
-      retried = true
-      retry
-    rescue Errno::EINVAL, Errno::ETIMEDOUT => e # not retried on ruby 2
-      request_failed e, req, connection if retried or not can_retry? req
+        retried = true
+        retry
+      rescue Errno::EINVAL, Errno::ETIMEDOUT => e # not retried on ruby 2
+        request_failed e, req, connection if retried or not can_retry? req
 
-      reset connection
+        reset connection
 
-      retried = true
-      retry
-    rescue Exception => e
-      finish connection
+        retried = true
+        retry
+      rescue Exception => e
+        finish connection
 
-      raise
-    ensure
-      Thread.current[@timeout_key][connection_id] = Time.now
+        raise
+      ensure
+        connection.last_use = Time.now
+      end
     end
 
     @http_versions["#{uri.host}:#{uri.port}"] ||= response.http_version
@@ -1056,7 +1011,6 @@ class Bundler::Persistent::Net::HTTP::Persistent
 
     finish connection
 
-
     raise Error, message, exception.backtrace
   end
 
@@ -1090,45 +1044,15 @@ class Bundler::Persistent::Net::HTTP::Persistent
   end
 
   ##
-  # Shuts down all connections for +thread+.
-  #
-  # Uses the current thread by default.
-  #
-  # If you've used Bundler::Persistent::Net::HTTP::Persistent across multiple threads you should
-  # call this in each thread when you're done making HTTP requests.
+  # Shuts down all connections
   #
-  # *NOTE*: Calling shutdown for another thread can be dangerous!
+  # *NOTE*: Calling shutdown for can be dangerous!
   #
-  # If the thread is still using the connection it may cause an error!  It is
-  # best to call #shutdown in the thread at the appropriate time instead!
+  # If any thread is still using a connection it may cause an error!  Call
+  # #shutdown when you are completely done making requests!
 
-  def shutdown thread = Thread.current
-    generation = reconnect
-    cleanup generation, thread, @generation_key
-
-    ssl_generation = reconnect_ssl
-    cleanup ssl_generation, thread, @ssl_generation_key
-
-    thread[@request_key] = nil
-    thread[@timeout_key] = nil
-  end
-
-  ##
-  # Shuts down all connections in all threads
-  #
-  # *NOTE*: THIS METHOD IS VERY DANGEROUS!
-  #
-  # Do not call this method if other threads are still using their
-  # connections!  Call #shutdown at the appropriate time instead!
-  #
-  # Use this method only as a last resort!
-
-  def shutdown_in_all_threads
-    Thread.list.each do |thread|
-      shutdown thread
-    end
-
-    nil
+  def shutdown
+    @pool.shutdown { |http| http.finish }
   end
 
   ##
@@ -1137,9 +1061,14 @@ class Bundler::Persistent::Net::HTTP::Persistent
   def ssl connection
     connection.use_ssl = true
 
+    connection.ciphers     = @ciphers     if @ciphers
+    connection.ssl_timeout = @ssl_timeout if @ssl_timeout
     connection.ssl_version = @ssl_version if @ssl_version
+    connection.min_version = @min_version if @min_version
+    connection.max_version = @max_version if @max_version
 
-    connection.verify_mode = @verify_mode
+    connection.verify_depth = @verify_depth
+    connection.verify_mode  = @verify_mode
 
     if OpenSSL::SSL::VERIFY_PEER == OpenSSL::SSL::VERIFY_NONE and
        not Object.const_defined?(:I_KNOW_THAT_OPENSSL_VERIFY_PEER_EQUALS_VERIFY_NONE_IS_WRONG) then
@@ -1168,8 +1097,10 @@ application:
       WARNING
     end
 
-    if @ca_file then
-      connection.ca_file = @ca_file
+    connection.ca_file = @ca_file if @ca_file
+    connection.ca_path = @ca_path if @ca_path
+
+    if @ca_file or @ca_path then
       connection.verify_mode = OpenSSL::SSL::VERIFY_PEER
       connection.verify_callback = @verify_callback if @verify_callback
     end
@@ -1189,11 +1120,12 @@ application:
   end
 
   ##
-  # Finishes all connections that existed before the given SSL parameter
-  # +generation+.
+  # SSL session lifetime
+
+  def ssl_timeout= ssl_timeout
+    @ssl_timeout = ssl_timeout
 
-  def ssl_cleanup generation # :nodoc:
-    cleanup generation, Thread.current, @ssl_generation_key
+    reconnect_ssl
   end
 
   ##
@@ -1203,7 +1135,34 @@ application:
     @ssl_version = ssl_version
 
     reconnect_ssl
-  end if RUBY_VERSION > '1.9'
+  end
+
+  ##
+  # Minimum SSL version to use
+
+  def min_version= min_version
+    @min_version = min_version
+
+    reconnect_ssl
+  end
+
+  ##
+  # maximum SSL version to use
+
+  def max_version= max_version
+    @max_version = max_version
+
+    reconnect_ssl
+  end
+
+  ##
+  # Sets the depth of SSL certificate verification
+
+  def verify_depth= verify_depth
+    @verify_depth = verify_depth
+
+    reconnect_ssl
+  end
 
   ##
   # Sets the HTTPS verify mode.  Defaults to OpenSSL::SSL::VERIFY_PEER.
@@ -1229,5 +1188,6 @@ application:
 
 end
 
-require 'bundler/vendor/net-http-persistent/lib/net/http/persistent/ssl_reuse'
+require 'bundler/vendor/net-http-persistent/lib/net/http/persistent/connection'
+require 'bundler/vendor/net-http-persistent/lib/net/http/persistent/pool'
 
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/connection.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/connection.rb
new file mode 100644
index 0000000000..a57a5d1352
--- /dev/null
+++ b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/connection.rb
@@ -0,0 +1,40 @@
+##
+# A Net::HTTP connection wrapper that holds extra information for managing the
+# connection's lifetime.
+
+class Bundler::Persistent::Net::HTTP::Persistent::Connection # :nodoc:
+
+  attr_accessor :http
+
+  attr_accessor :last_use
+
+  attr_accessor :requests
+
+  attr_accessor :ssl_generation
+
+  def initialize http_class, http_args, ssl_generation
+    @http           = http_class.new(*http_args)
+    @ssl_generation = ssl_generation
+
+    reset
+  end
+
+  def finish
+    @http.finish
+  rescue IOError
+  ensure
+    reset
+  end
+
+  def reset
+    @last_use = Bundler::Persistent::Net::HTTP::Persistent::EPOCH
+    @requests = 0
+  end
+
+  def ressl ssl_generation
+    @ssl_generation = ssl_generation
+
+    finish
+  end
+
+end
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/pool.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/pool.rb
new file mode 100644
index 0000000000..9af0b328b2
--- /dev/null
+++ b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/pool.rb
@@ -0,0 +1,50 @@
+class Bundler::Persistent::Net::HTTP::Persistent::Pool < Bundler::ConnectionPool # :nodoc:
+
+  attr_reader :available # :nodoc:
+  attr_reader :key # :nodoc:
+
+  def initialize(options = {}, &block)
+    super
+
+    @available = Bundler::Persistent::Net::HTTP::Persistent::TimedStackMulti.new(@size, &block)
+    @key = "current-#{@available.object_id}"
+  end
+
+  def checkin net_http_args
+    stack = Thread.current[@key][net_http_args] ||= []
+
+    raise Bundler::ConnectionPool::Error, 'no connections are checked out' if
+      stack.empty?
+
+    conn = stack.pop
+
+    if stack.empty?
+      @available.push conn, connection_args: net_http_args
+    end
+
+    nil
+  end
+
+  def checkout net_http_args
+    stacks = Thread.current[@key] ||= {}
+    stack  = stacks[net_http_args] ||= []
+
+    if stack.empty? then
+      conn = @available.pop connection_args: net_http_args
+    else
+      conn = stack.last
+    end
+
+    stack.push conn
+
+    conn
+  end
+
+  def shutdown
+    Thread.current[@key] = nil
+    super
+  end
+end
+
+require 'bundler/vendor/net-http-persistent/lib/net/http/persistent/timed_stack_multi'
+
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/ssl_reuse.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/ssl_reuse.rb
deleted file mode 100644
index 1b6b789f6d..0000000000
--- a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/ssl_reuse.rb
+++ /dev/null
@@ -1,129 +0,0 @@
-##
-# This Net::HTTP subclass adds SSL session reuse and Server Name Indication
-# (SNI) RFC 3546.
-#
-# DO NOT DEPEND UPON THIS CLASS
-#
-# This class is an implementation detail and is subject to change or removal
-# at any time.
-
-class Bundler::Persistent::Net::HTTP::Persistent::SSLReuse < Net::HTTP
-
-  @is_proxy_class = false
-  @proxy_addr = nil
-  @proxy_port = nil
-  @proxy_user = nil
-  @proxy_pass = nil
-
-  def initialize address, port = nil # :nodoc:
-    super
-
-    @ssl_session = nil
-  end
-
-  ##
-  # From ruby trunk r33086 including http://redmine.ruby-lang.org/issues/5341
-
-  def connect # :nodoc:
-    D "opening connection to #{conn_address()}..."
-    s = timeout(@open_timeout) { TCPSocket.open(conn_address(), conn_port()) }
-    D "opened"
-    if use_ssl?
-      ssl_parameters = Hash.new
-      iv_list = instance_variables
-      SSL_ATTRIBUTES.each do |name|
-        ivname = "@#{name}".intern
-        if iv_list.include?(ivname) and
-           value = instance_variable_get(ivname)
-          ssl_parameters[name] = value
-        end
-      end
-      unless @ssl_context then
-        @ssl_context = OpenSSL::SSL::SSLContext.new
-        @ssl_context.set_params(ssl_parameters)
-      end
-      s = OpenSSL::SSL::SSLSocket.new(s, @ssl_context)
-      s.sync_close = true
-    end
-    @socket = Net::BufferedIO.new(s)
-    @socket.read_timeout = @read_timeout
-    @socket.continue_timeout = @continue_timeout if
-      @socket.respond_to? :continue_timeout
-    @socket.debug_output = @debug_output
-    if use_ssl?
-      begin
-        if proxy?
-          @socket.writeline sprintf('CONNECT %s:%s HTTP/%s',
-                                    @address, @port, HTTPVersion)
-          @socket.writeline "Host: #{@address}:#{@port}"
-          if proxy_user
-            credential = ["#{proxy_user}:#{proxy_pass}"].pack('m')
-            credential.delete!("\r\n")
-            @socket.writeline "Proxy-Authorization: Basic #{credential}"
-          end
-          @socket.writeline ''
-          Net::HTTPResponse.read_new(@socket).value
-        end
-        s.session = @ssl_session if @ssl_session
-        # Server Name Indication (SNI) RFC 3546
-        s.hostname = @address if s.respond_to? :hostname=
-        timeout(@open_timeout) { s.connect }
-        if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
-          s.post_connection_check(@address)
-        end
-        @ssl_session = s.session
-      rescue => exception
-        D "Conn close because of connect error #{exception}"
-        @socket.close if @socket and not @socket.closed?
-        raise exception
-      end
-    end
-    on_connect
-  end if RUBY_VERSION > '1.9'
-
-  ##
-  # From ruby_1_8_7 branch r29865 including a modified
-  # http://redmine.ruby-lang.org/issues/5341
-
-  def connect # :nodoc:
-    D "opening connection to #{conn_address()}..."
-    s = timeout(@open_timeout) { TCPSocket.open(conn_address(), conn_port()) }
-    D "opened"
-    if use_ssl?
-      unless @ssl_context.verify_mode
-        warn "warning: peer certificate won't be verified in this SSL session"
-        @ssl_context.verify_mode = OpenSSL::SSL::VERIFY_NONE
-      end
-      s = OpenSSL::SSL::SSLSocket.new(s, @ssl_context)
-      s.sync_close = true
-    end
-    @socket = Net::BufferedIO.new(s)
-    @socket.read_timeout = @read_timeout
-    @socket.debug_output = @debug_output
-    if use_ssl?
-      if proxy?
-        @socket.writeline sprintf('CONNECT %s:%s HTTP/%s',
-                                  @address, @port, HTTPVersion)
-        @socket.writeline "Host: #{@address}:#{@port}"
-        if proxy_user
-          credential = ["#{proxy_user}:#{proxy_pass}"].pack('m')
-          credential.delete!("\r\n")
-          @socket.writeline "Proxy-Authorization: Basic #{credential}"
-        end
-        @socket.writeline ''
-        Net::HTTPResponse.read_new(@socket).value
-      end
-      s.session = @ssl_session if @ssl_session
-      s.connect
-      if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
-        s.post_connection_check(@address)
-      end
-      @ssl_session = s.session
-    end
-    on_connect
-  end if RUBY_VERSION < '1.9'
-
-  private :connect
-
-end
-
diff --git a/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/timed_stack_multi.rb b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/timed_stack_multi.rb
new file mode 100644
index 0000000000..280997e32a
--- /dev/null
+++ b/lib/bundler/vendor/net-http-persistent/lib/net/http/persistent/timed_stack_multi.rb
@@ -0,0 +1,69 @@
+class Bundler::Persistent::Net::HTTP::Persistent::TimedStackMulti < Bundler::ConnectionPool::TimedStack # :nodoc:
+
+  def initialize(size = 0, &block)
+    super
+
+    @enqueued = 0
+    @ques = Hash.new { |h, k| h[k] = [] }
+    @lru = {}
+    @key = :"connection_args-#{object_id}"
+  end
+
+  def empty?
+    (@created - @enqueued) >= @max
+  end
+
+  def length
+    @max - @created + @enqueued
+  end
+
+  private
+
+  def connection_stored? options = {} # :nodoc:
+    !@ques[options[:connection_args]].empty?
+  end
+
+  def fetch_connection options = {} # :nodoc:
+    connection_args = options[:connection_args]
+
+    @enqueued -= 1
+    lru_update connection_args
+    @ques[connection_args].pop
+  end
+
+  def lru_update connection_args # :nodoc:
+    @lru.delete connection_args
+    @lru[connection_args] = true
+  end
+
+  def shutdown_connections # :nodoc:
+    @ques.each_key do |key|
+      super connection_args: key
+    end
+  end
+
+  def store_connection obj, options = {} # :nodoc:
+    @ques[options[:connection_args]].push obj
+    @enqueued += 1
+  end
+
+  def try_create options = {} # :nodoc:
+    connection_args = options[:connection_args]
+
+    if @created >= @max && @enqueued >= 1
+      oldest, = @lru.first
+      @lru.delete oldest
+      @ques[oldest].pop
+
+      @created -= 1
+    end
+
+    if @created < @max
+      @created += 1
+      lru_update connection_args
+      return @create_block.call(connection_args)
+    end
+  end
+
+end
+
diff --git a/lib/bundler/vendored_persistent.rb b/lib/bundler/vendored_persistent.rb
index 7670b83992..045a761dac 100644
--- a/lib/bundler/vendored_persistent.rb
+++ b/lib/bundler/vendored_persistent.rb
@@ -20,13 +20,15 @@ require_relative "vendor/net-http-persistent/lib/net/http/persistent"
 module Bundler
   class PersistentHTTP < Persistent::Net::HTTP::Persistent
     def connection_for(uri)
-      connection = super
-      warn_old_tls_version_rubygems_connection(uri, connection)
-      connection
+      super(uri) do |connection|
+        result = yield connection
+        warn_old_tls_version_rubygems_connection(uri, connection)
+        result
+      end
     end
 
     def warn_old_tls_version_rubygems_connection(uri, connection)
-      return unless connection.use_ssl?
+      return unless connection.http.use_ssl?
       return unless (uri.host || "").end_with?("rubygems.org")
 
       socket = connection.instance_variable_get(:@socket)
diff --git a/spec/bundler/vendored_persistent_spec.rb b/spec/bundler/vendored_persistent_spec.rb
index c760c067e0..b4d68c2ea0 100644
--- a/spec/bundler/vendored_persistent_spec.rb
+++ b/spec/bundler/vendored_persistent_spec.rb
@@ -5,13 +5,13 @@ require "bundler/vendored_persistent"
 RSpec.describe Bundler::PersistentHTTP do
   describe "#warn_old_tls_version_rubygems_connection" do
     let(:uri) { "https://index.rubygems.org" }
-    let(:connection) { instance_double(subject.http_class) }
+    let(:connection) { instance_double(Bundler::Persistent::Net::HTTP::Persistent::Connection) }
     let(:tls_version) { "TLSv1.2" }
     let(:socket) { double("Socket") }
     let(:socket_io) { double("SocketIO") }
 
     before do
-      allow(connection).to receive(:use_ssl?).and_return(!tls_version.nil?)
+      allow(connection).to receive_message_chain(:http, :use_ssl?).and_return(!tls_version.nil?)
       allow(socket).to receive(:io).and_return(socket_io) if socket
       connection.instance_variable_set(:@socket, socket)