From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 14 Jul 2012 19:21:22 +0000 (+0300)
Subject: Be more efficient when running commands synchronously
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=666bf60f80a3f220a112c2a97ed00b72871924d3;p=builder.git

Be more efficient when running commands synchronously
---

diff --git a/source/externaltask.cpp b/source/externaltask.cpp
index fea331a..5f5d394 100644
--- a/source/externaltask.cpp
+++ b/source/externaltask.cpp
@@ -91,12 +91,21 @@ void ExternalTask::start()
 }
 
 Task::Status ExternalTask::check()
+{
+	return do_wait(false);
+}
+
+Task::Status ExternalTask::wait()
+{
+	return do_wait(true);
+}
+
+Task::Status ExternalTask::do_wait(bool block)
 {
 	if(pid>0)
 	{
-		// XXX This is sub-optimal, should have support for a blocking wait
 		int status;
-		if(waitpid(pid, &status, WNOHANG)==pid)
+		if(waitpid(pid, &status, (block ? 0 : WNOHANG))==pid)
 		{
 			if(WIFEXITED(status))
 				exit_code = WEXITSTATUS(status);
@@ -145,9 +154,7 @@ string ExternalTask::run_and_capture_output(const Arguments &argv, const FS::Pat
 	task.set_stdout(CAPTURE);
 	task.set_stderr(IGNORE);
 	task.start();
-	Task::Status status;
-	while((status=task.check())==RUNNING) ;
-	if(status!=SUCCESS)
+	if(task.wait()!=SUCCESS)
 		throw runtime_error(format("%s failed", argv.front()));
 	return task.get_output();
 }
diff --git a/source/externaltask.h b/source/externaltask.h
index d997f9a..a5f10ec 100644
--- a/source/externaltask.h
+++ b/source/externaltask.h
@@ -45,7 +45,11 @@ public:
 	virtual std::string get_command() const;
 	virtual void start();
 	virtual Status check();
+	Status wait();
+private:
+	Status do_wait(bool);
 
+public:
 	void set_stdout(Destination);
 	void set_stderr(Destination);
 	const std::string &get_output() const { return output; }