Merge remote branch 'brice/feature/process-instrumentation' into next

2 files changed, 141 insertions, 0 deletions

diff --git a/lib/puppet/util/instrumentation.rb b/lib/puppet/util/instrumentation.rb
new file mode 100644
index 000000000..5981bea59
--- /dev/null
+++ b/lib/puppet/util/instrumentation.rb
@@ -0,0 +1,12 @@
+require 'puppet/util/instrumentation/process_name'
+
+module Puppet::Util::Instrumentation
+
+  def instrument(title)
+    Puppet::Util::Instrumentation::ProcessName.instrument(title) do
+      yield
+    end
+  end
+  module_function :instrument
+
+end
\ No newline at end of file
diff --git a/lib/puppet/util/instrumentation/process_name.rb b/lib/puppet/util/instrumentation/process_name.rb
new file mode 100644
index 000000000..370d29e2e
--- /dev/null
+++ b/lib/puppet/util/instrumentation/process_name.rb
@@ -0,0 +1,129 @@
+require 'puppet'
+require 'puppet/util/instrumentation'
+
+module Puppet::Util::Instrumentation
+  class ProcessName
+
+    # start scrolling when process name is longer than
+    SCROLL_LENGTH = 50
+
+    @active = false
+    class << self
+      attr_accessor :active, :reason
+    end
+
+    trap(:QUIT) do
+      active? ? disable : enable
+    end
+
+    def self.active?
+      !! @active
+    end
+
+    def self.enable
+      mutex.synchronize do
+        Puppet.info("Process Name instrumentation is enabled")
+        @active = true
+        @x = 0
+        setproctitle
+      end
+    end
+
+    def self.disable
+      mutex.synchronize do
+        Puppet.info("Process Name instrumentation is disabled")
+        @active = false
+        $0 = @oldname
+      end
+    end
+
+    def self.instrument(activity)
+      # inconditionnally start the scroller thread here
+      # because it doesn't seem possible to start a new thrad
+      # from the USR2 signal handler
+      @scroller ||= Thread.new do
+        loop do
+          scroll if active?
+          sleep 1
+        end
+      end
+
+      push_activity(Thread.current, activity)
+      yield
+    ensure
+      pop_activity(Thread.current)
+    end
+
+    def self.setproctitle
+      @oldname ||= $0
+      $0 = "#{base}: " + rotate(process_name,@x) if active?
+    end
+
+    def self.push_activity(thread, activity)
+      mutex.synchronize do
+        @reason ||= {}
+        @reason[thread] ||= []
+        @reason[thread].push(activity)
+        setproctitle
+      end
+    end
+
+    def self.pop_activity(thread)
+      mutex.synchronize do
+        @reason[thread].pop
+        if @reason[thread].empty?
+          @reason.delete(thread)
+        end
+        setproctitle
+      end
+    end
+
+    def self.process_name
+      out = (@reason || {}).inject([]) do |out, reason|
+        out << "#{thread_id(reason[0])} #{reason[1].join(',')}"
+      end
+      out.join(' | ')
+    end
+
+    # certainly non-portable
+    def self.thread_id(thread)
+      thread.inspect.gsub(/^#<.*:0x([a-f0-9]+) .*>$/, '\1')
+    end
+
+    def self.rotate(string, steps)
+      steps ||= 0
+      if string.length > 0 && steps > 0
+        steps = steps % string.length
+        return string[steps..string.length].concat " -- #{string[0..(steps-1)]}"
+      end
+      string
+    end
+
+    def self.base
+      basename = case Puppet.run_mode.name
+      when :master
+        "master"
+      when :agent
+        "agent"
+      else
+        "puppet"
+      end
+    end
+
+    def self.mutex
+      #Thread.exclusive {
+        @mutex ||= Sync.new
+      #}
+      @mutex
+    end
+
+    def self.scroll
+      return if process_name.length < SCROLL_LENGTH
+      mutex.synchronize do
+        setproctitle
+        @x += 1
+      end
+    end
+
+  end
+end
\ No newline at end of file