From f515e91176cb4fcb1df379cdf664c90b3a565c95 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 19 Jul 2012 13:41:40 +0300
Subject: [PATCH] Improve task management to use blocking wait if possible

---
 source/builder.cpp | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/source/builder.cpp b/source/builder.cpp
index df7edab..7b0f018 100644
--- a/source/builder.cpp
+++ b/source/builder.cpp
@@ -457,10 +457,11 @@ int Builder::do_build()
 
 	bool fail = false;
 	bool finish = false;
+	bool starved = false;
 
 	while(!finish)
 	{
-		if(tasks.size()<jobs && !fail)
+		if(tasks.size()<jobs && !fail && !starved)
 		{
 			Target *tgt = cmdline->get_buildable_target();
 			if(tgt)
@@ -488,13 +489,20 @@ int Builder::do_build()
 			}
 			else if(tasks.empty())
 				finish = true;
+			else
+				starved = true;
 		}
 		else
 			Time::sleep(10*Time::msec);
 
 		for(unsigned i=0; i<tasks.size();)
 		{
-			Task::Status status = tasks[i]->check();
+			Task::Status status;
+			if(jobs==1 || (tasks.size()==1 && starved))
+				status = tasks[i]->wait();
+			else
+				status = tasks[i]->check();
+
 			if(status!=Task::RUNNING)
 			{
 				++count;
@@ -505,6 +513,7 @@ int Builder::do_build()
 					fail = true;
 				if(tasks.empty() && fail)
 					finish = true;
+				starved = false;
 			}
 			else
 				++i;
-- 
2.43.0