UnrealEngineUWP/Engine/Source/Programs/UnrealBuildTool/System/Distcc.cs

// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.

using System;
using System.Collections.Generic;
using System.IO;
using System.Diagnostics;
using System.Xml;
using System.Text.RegularExpressions;
using System.Linq;
using System.Reflection;

namespace UnrealBuildTool
{
	public class Distcc
	{
		public static bool ExecuteActions(List<Action> Actions)
		{
			bool bDistccResult = true;
			if (Actions.Count > 0)
			{
				// Time to sleep after each iteration of the loop in order to not busy wait.
				const float LoopSleepTime = 0.1f;

				int MaxActionsToExecuteInParallel = 0;
				string UserDir = Environment.GetEnvironmentVariable("HOME");
				string HostsInfo = UserDir + "/.dmucs/hosts-info";
				System.IO.StreamReader File = new System.IO.StreamReader(HostsInfo);
				string Line = null;
				while((Line = File.ReadLine()) != null)
				{
					var HostInfo = Line.Split(' ');
					if (HostInfo.Count () == 3) 
					{
						int NumCPUs = 0;
						if (System.Int32.TryParse (HostInfo [1], out NumCPUs)) 
						{
							MaxActionsToExecuteInParallel += NumCPUs;
						}
					}
				}
				File.Close();

				if (BuildConfiguration.bAllowDistccLocalFallback == false) 
				{
					Environment.SetEnvironmentVariable("DISTCC_FALLBACK", "0");
				}

				string DistccExecutable = BuildConfiguration.DistccExecutablesPath + "/distcc";
				string GetHostExecutable = BuildConfiguration.DistccExecutablesPath + "/gethost";

				Log.TraceInformation("Performing {0} actions ({1} in parallel)", Actions.Count, MaxActionsToExecuteInParallel, DistccExecutable, GetHostExecutable);

				Dictionary<Action, ActionThread> ActionThreadDictionary = new Dictionary<Action, ActionThread>();
				int JobNumber = 1;
				using(ProgressWriter ProgressWriter = new ProgressWriter("Compiling source code...", false))
				{
					int ProgressValue = 0;
					while(true)
					{
						// Count the number of pending and still executing actions.
						int NumUnexecutedActions = 0;
						int NumExecutingActions = 0;
						foreach (Action Action in Actions)
						{
							ActionThread ActionThread = null;
							bool bFoundActionProcess = ActionThreadDictionary.TryGetValue(Action, out ActionThread);
							if (bFoundActionProcess == false)
							{
								NumUnexecutedActions++;
							}
							else if (ActionThread != null)
							{
								if (ActionThread.bComplete == false)
								{
									NumUnexecutedActions++;
									NumExecutingActions++;
								}
							}
						}

						// Update the current progress
						int NewProgressValue = Actions.Count + 1 - NumUnexecutedActions;
						if (ProgressValue != NewProgressValue)
						{
							ProgressWriter.Write(ProgressValue, Actions.Count + 1);
							ProgressValue = NewProgressValue;
						}

						// If there aren't any pending actions left, we're done executing.
						if (NumUnexecutedActions == 0)
						{
							break;
						}

						// If there are fewer actions executing than the maximum, look for pending actions that don't have any outdated
						// prerequisites.
						foreach (Action Action in Actions)
						{
							ActionThread ActionProcess = null;
							bool bFoundActionProcess = ActionThreadDictionary.TryGetValue(Action, out ActionProcess);
							if (bFoundActionProcess == false)
							{
								if (NumExecutingActions < Math.Max(1,MaxActionsToExecuteInParallel))
								{
									// Determine whether there are any prerequisites of the action that are outdated.
									bool bHasOutdatedPrerequisites = false;
									bool bHasFailedPrerequisites = false;
									foreach (FileItem PrerequisiteItem in Action.PrerequisiteItems)
									{
										if (PrerequisiteItem.ProducingAction != null && Actions.Contains(PrerequisiteItem.ProducingAction))
										{
											ActionThread PrerequisiteProcess = null;
											bool bFoundPrerequisiteProcess = ActionThreadDictionary.TryGetValue( PrerequisiteItem.ProducingAction, out PrerequisiteProcess );
											if (bFoundPrerequisiteProcess == true)
											{
												if (PrerequisiteProcess == null)
												{
													bHasFailedPrerequisites = true;
												}
												else if (PrerequisiteProcess.bComplete == false)
												{
													bHasOutdatedPrerequisites = true;
												}
												else if (PrerequisiteProcess.ExitCode != 0)
												{
													bHasFailedPrerequisites = true;
												}
											}
											else
											{
												bHasOutdatedPrerequisites = true;
											}
										}
									}

									// If there are any failed prerequisites of this action, don't execute it.
									if (bHasFailedPrerequisites)
									{
										// Add a null entry in the dictionary for this action.
										ActionThreadDictionary.Add( Action, null );
									}
									// If there aren't any outdated prerequisites of this action, execute it.
									else if (!bHasOutdatedPrerequisites)
									{
										if ((Action.ActionType == ActionType.Compile || Action.ActionType == ActionType.Link) && DistccExecutable != null && GetHostExecutable != null) 
										{
											string NewCommandArguments = "--wait -1 \"" + DistccExecutable + "\" " + Action.CommandPath + " " + Action.CommandArguments;
											Action.CommandPath = GetHostExecutable;
											Action.CommandArguments = NewCommandArguments;
										}

										ActionThread ActionThread = new ActionThread(Action, JobNumber, Actions.Count);
										JobNumber++;
										ActionThread.Run();

										ActionThreadDictionary.Add(Action, ActionThread);

										NumExecutingActions++;
									}
								}
							}
						}

						System.Threading.Thread.Sleep(TimeSpan.FromSeconds(LoopSleepTime));
					}
				}

				Log.WriteLineIf(BuildConfiguration.bLogDetailedActionStats, TraceEventType.Information, "-------- Begin Detailed Action Stats ----------------------------------------------------------");
				Log.WriteLineIf(BuildConfiguration.bLogDetailedActionStats, TraceEventType.Information, "^Action Type^Duration (seconds)^Tool^Task^Using PCH");

				double TotalThreadSeconds = 0;

				// Check whether any of the tasks failed and log action stats if wanted.
				foreach (KeyValuePair<Action, ActionThread> ActionProcess in ActionThreadDictionary)
				{
					Action Action = ActionProcess.Key;
					ActionThread ActionThread = ActionProcess.Value;

					// Check for pending actions, preemptive failure
					if (ActionThread == null)
					{
						bDistccResult = false;
						continue;
					}
					// Check for executed action but general failure
					if (ActionThread.ExitCode != 0)
					{
						bDistccResult = false;
					}
					// Log CPU time, tool and task.
					double ThreadSeconds = Action.Duration.TotalSeconds;

					Log.WriteLineIf(BuildConfiguration.bLogDetailedActionStats,
						TraceEventType.Information,
						"^{0}^{1:0.00}^{2}^{3}^{4}", 
						Action.ActionType.ToString(),
						ThreadSeconds,
						Path.GetFileName(Action.CommandPath), 
						Action.StatusDescription,
						Action.bIsUsingPCH);

					// Update statistics
					switch (Action.ActionType)
					{
					case ActionType.BuildProject:
						UnrealBuildTool.TotalBuildProjectTime += ThreadSeconds;
						break;

					case ActionType.Compile:
						UnrealBuildTool.TotalCompileTime += ThreadSeconds;
						break;

					case ActionType.CreateAppBundle:
						UnrealBuildTool.TotalCreateAppBundleTime += ThreadSeconds;
						break;

					case ActionType.GenerateDebugInfo:
						UnrealBuildTool.TotalGenerateDebugInfoTime += ThreadSeconds;
						break;

					case ActionType.Link:
						UnrealBuildTool.TotalLinkTime += ThreadSeconds;
						break;

					default:
						UnrealBuildTool.TotalOtherActionsTime += ThreadSeconds;
						break;
					}

					// Keep track of total thread seconds spent on tasks.
					TotalThreadSeconds += ThreadSeconds;
				}

				Log.WriteLineIf(BuildConfiguration.bLogDetailedActionStats || BuildConfiguration.bPrintDebugInfo,
					TraceEventType.Information, 
					"-------- End Detailed Actions Stats -----------------------------------------------------------");

				// Log total CPU seconds and numbers of processors involved in tasks.
				Log.WriteLineIf(BuildConfiguration.bLogDetailedActionStats || BuildConfiguration.bPrintDebugInfo, 
					TraceEventType.Information, "Cumulative thread seconds ({0} processors): {1:0.00}", System.Environment.ProcessorCount, TotalThreadSeconds);
			}
			return bDistccResult;
		}
	}
}