Add sigdump func to fluent-ctl

lib/fluent/command/ctl.rb

@@ -36,6 +36,7 @@ class Ctl
         restart: "HUP",
         flush: "USR1",
         reload: "USR2",
+        dump: "CONT",
       }
       WINSVC_CONTROL_CODE_MAP = {
         shutdown: SERVICE_CONTROL_STOP,
@@ -44,13 +45,15 @@ class Ctl
         restart: 128,
         flush: 129,
         reload: SERVICE_CONTROL_PARAMCHANGE,
+        dump: 130,
       }
     else
       COMMAND_MAP = {
         shutdown: :TERM,
         restart: :HUP,
         flush: :USR1,
         reload: :USR2,
+        dump: :CONT,
       }
     end
 

lib/fluent/supervisor.rb

@@ -16,6 +16,7 @@
 
 require 'fileutils'
 require 'open3'
+require 'pathname'
 
 require 'fluent/config'
 require 'fluent/counter'
@@ -106,6 +107,16 @@ def run_rpc_server
         end
         nil
       }
+      @rpc_server.mount_proc('/api/processes.dump') { |req, res|
+        $log.debug "fluentd RPC got /api/processes.dump request"
+        if Fluent.windows?
+          supervisor_dump_handler_for_windows
+        else
+          Process.kill :CONT, $$
+          send_signal_to_workers(:CONT)
+        end
+        nil
+      }
       @rpc_server.mount_proc('/api/plugins.flushBuffers') { |req, res|
         $log.debug "fluentd RPC got /api/plugins.flushBuffers request"
         if Fluent.windows?
@@ -215,44 +226,50 @@ def install_windows_event_handler
       Thread.new do
         ipc = Win32::Ipc.new(nil)
         events = [
-          Win32::Event.new("#{@pid_signame}_STOP_EVENT_THREAD"),
-          Win32::Event.new("#{@pid_signame}"),
-          Win32::Event.new("#{@pid_signame}_HUP"),
-          Win32::Event.new("#{@pid_signame}_USR1"),
-          Win32::Event.new("#{@pid_signame}_USR2"),
+          {win32_event: Win32::Event.new("#{@pid_signame}_STOP_EVENT_THREAD"), action: :stop_event_thread},
+          {win32_event: Win32::Event.new("#{@pid_signame}"), action: :stop},
+          {win32_event: Win32::Event.new("#{@pid_signame}_HUP"), action: :hup},
+          {win32_event: Win32::Event.new("#{@pid_signame}_USR1"), action: :usr1},
+          {win32_event: Win32::Event.new("#{@pid_signame}_USR2"), action: :usr2},
+          {win32_event: Win32::Event.new("#{@pid_signame}_CONT"), action: :cont},
         ]
         if @signame
           signame_events = [
-            Win32::Event.new("#{@signame}"),
-            Win32::Event.new("#{@signame}_HUP"),
-            Win32::Event.new("#{@signame}_USR1"),
-            Win32::Event.new("#{@signame}_USR2"),
+            {win32_event: Win32::Event.new("#{@signame}"), action: :stop},
+            {win32_event: Win32::Event.new("#{@signame}_HUP"), action: :hup},
+            {win32_event: Win32::Event.new("#{@signame}_USR1"), action: :usr1},
+            {win32_event: Win32::Event.new("#{@signame}_USR2"), action: :usr2},
+            {win32_event: Win32::Event.new("#{@signame}_CONT"), action: :cont},
           ]
           events.concat(signame_events)
         end
         begin
           loop do
-            idx = ipc.wait_any(events, Windows::Synchronize::INFINITE)
-            if idx > 0 && idx <= events.length
-              $log.debug("Got Win32 event \"#{events[idx - 1].name}\"")
+            ipc_idx = ipc.wait_any(events.map {|e| e[:win32_event]}, Windows::Synchronize::INFINITE)
+            event_idx = ipc_idx - 1
+
+            if event_idx >= 0 && event_idx < events.length
+              $log.debug("Got Win32 event \"#{events[event_idx][:win32_event].name}\"")
             else
-              $log.warn("Unexpected reutrn value of Win32::Ipc#wait_any: #{idx}")
+              $log.warn("Unexpected return value of Win32::Ipc#wait_any: #{ipc_idx}")
             end
-            case idx
-            when 2, 6
+            case events[event_idx][:action]
+            when :stop
               stop(true)
-            when 3, 7
+            when :hup
               supervisor_sighup_handler
-            when 4, 8
+            when :usr1
               supervisor_sigusr1_handler
-            when 5, 9
+            when :usr2
               supervisor_sigusr2_handler
-            when 1
+            when :cont
+              supervisor_dump_handler_for_windows
+            when :stop_event_thread
               break
             end
           end
         ensure
-          events.each { |event| event.close }
+          events.each { |event| event[:win32_event].close }
         end
       end
     end
@@ -302,6 +319,26 @@ def supervisor_sigusr2_handler
       $log.error "Failed to reload config file: #{e}"
     end
 
+    def supervisor_dump_handler_for_windows
+      # As for UNIX-like, SIGCONT signal to each process makes the process output its dump-file,
+      # and it is implemented before the implementation of the function for Windows.
+      # It is possible to trap SIGCONT and handle it here also on UNIX-like,
+      # but for backward compatibility, this handler is currently for a Windows-only.
+      raise "[BUG] This function is for Windows ONLY." unless Fluent.windows?
+
+      Thread.new do
+        begin
+          FluentSigdump.dump_windows
+        rescue => e
+          $log.error "failed to dump: #{e}"
+        end
+      end
+
+      send_signal_to_workers(:CONT)
+    rescue => e
+      $log.error "failed to dump: #{e}"
+    end
+
     def kill_worker
       if config[:worker_pid]
         pids = config[:worker_pid].clone
@@ -358,6 +395,14 @@ def send_command_to_workers(signal)
         restart(true)
       when :USR2
         reload
+      when :CONT
+        dump_all_windows_workers
+      end
+    end
+
+    def dump_all_windows_workers
+      @monitors.each do |m|
+        m.send_command("DUMP\n")
       end
     end
   end
@@ -896,6 +941,9 @@ def install_main_process_command_handlers
           when "RELOAD"
             $log.debug "fluentd main process get #{cmd} command"
             reload_config
+          when "DUMP"
+            $log.debug "fluentd main process get #{cmd} command"
+            dump
           else
             $log.warn "fluentd main process get unknown command [#{cmd}]"
           end
@@ -945,6 +993,16 @@ def reload_config
       end
     end
 
+    def dump
+      Thread.new do
+        begin
+          FluentSigdump.dump_windows
+        rescue => e
+          $log.error("failed to dump: #{e}")
+        end
+      end
+    end
+
     def logging_with_console_output
       yield $log
       unless @log.stdout?
@@ -1054,4 +1112,27 @@ def build_spawn_command
       fluentd_spawn_cmd
     end
   end
+
+  module FluentSigdump
+    def self.dump_windows
+      raise "[BUG] WindowsSigdump::dump is for Windows ONLY." unless Fluent.windows?
+
+      # Sigdump outputs under `/tmp` dir without `SIGDUMP_PATH` specified,
+      # but `/tmp` dir may not exist on Windows by default.
+      # So use the systemroot-temp-dir instead.
+      dump_filepath = ENV['SIGDUMP_PATH'].nil? || ENV['SIGDUMP_PATH'].empty? \
+        ? "#{ENV['windir']}/Temp/fluentd-sigdump-#{Process.pid}.log"
+        : get_path_with_pid(ENV['SIGDUMP_PATH'])
+
+      require 'sigdump'
+      Sigdump.dump(dump_filepath)
+
+      $log.info "dump to #{dump_filepath}."
+    end
+
+    def self.get_path_with_pid(raw_path)
+      path = Pathname.new(raw_path)
+      path.sub_ext("-#{Process.pid}#{path.extname}").to_s
+    end
+  end
 end

lib/fluent/winsvc.rb

@@ -84,6 +84,8 @@ def service_user_defined_control(code)
         set_event("#{@service_name}_HUP")
       when 129
         set_event("#{@service_name}_USR1")
+      when 130
+        set_event("#{@service_name}_CONT")
       end
     end
 

test/plugin/test_in_object_space.rb

@@ -17,13 +17,19 @@ def waiting(seconds, instance)
   end
 
   class FailObject
-    def self.class
-      raise "error"
-    end
   end
 
   def setup
     Fluent::Test.setup
+    # Overriding this behavior in the global scope will have an unexpected influence on other tests.
+    # So this should be overridden here and be removed in `teardown`.
+    def FailObject.class
+      raise "FailObject error for tests in ObjectSpaceInputTest."
+    end
+  end
+
+  def teardown
+    FailObject.singleton_class.remove_method(:class)
   end
 
   TESTCONFIG = %[

test/test_supervisor.rb

@@ -213,6 +213,49 @@ def server.config
     $log.out.reset if $log && $log.out && $log.out.respond_to?(:reset)
   end
 
+  data("Normal", {raw_path: "C:\\Windows\\Temp\\sigdump.log", expected: "C:\\Windows\\Temp\\sigdump-#{$$}.log"})
+  data("UNIX style", {raw_path: "/Windows/Temp/sigdump.log", expected: "/Windows/Temp/sigdump-#{$$}.log"})
+  data("No extension", {raw_path: "C:\\Windows\\Temp\\sigdump", expected: "C:\\Windows\\Temp\\sigdump-#{$$}"})
+  data("Multi-extension", {raw_path: "C:\\Windows\\Temp\\sig.dump.bk", expected: "C:\\Windows\\Temp\\sig.dump-#{$$}.bk"})
+  def test_fluentsigdump_get_path_with_pid(data)
+    p data
+    path = Fluent::FluentSigdump.get_path_with_pid(data[:raw_path])
+    assert_equal(data[:expected], path)
+  end
+
+  def test_supervisor_event_dump_windows
+    omit "Only for Windows, alternative to UNIX signals" unless Fluent.windows?
+
+    server = DummyServer.new
+    def server.config
+      {:signame => "TestFluentdEvent"}
+    end
+    server.install_windows_event_handler
+
+    assert_rr do
+      # Have to use mock because `Sigdump.dump` seems to be somehow incompatible with RR.
+      # The `mock(server).restart(true) { nil }` line in `test_rpc_server_windows` cause the next error.
+      # Failure: test_supervisor_event_dump_windows(SupervisorTest):
+      #   class()
+      #   Called 0 times.
+      #   Expected 1 times.
+      # .../Ruby26-x64/lib/ruby/gems/2.6.0/gems/sigdump-0.2.4/lib/sigdump.rb:74:in `block in dump_object_count'
+      #     73: ObjectSpace.each_object {|o|
+      #     74:   c = o.class <-- HERE!
+      mock(Sigdump).dump(anything)
+
+      begin
+        sleep 0.1 # Wait for starting windows event thread
+        event = Win32::Event.open("TestFluentdEvent_CONT")
+        event.set
+        event.close
+        sleep 1.0 # Wait for dumping
+      ensure
+        server.stop_windows_event_thread
+      end
+    end
+  end
+
   data(:ipv4 => ["0.0.0.0", "127.0.0.1", false],
        :ipv6 => ["[::]", "[::1]", true],
        :localhost_ipv4 => ["localhost", "127.0.0.1", false])