From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 21 Jun 2019 17:59:15 +0000 (+0300)
Subject: Read output from external task while waiting
X-Git-Url: http://git.tdb.fi/?p=builder.git;a=commitdiff_plain;h=a5a1ecb806ec2dec26701b931b8d2d6cbe7f4928

Read output from external task while waiting

Waiting for the process to finish first may lead to a deadlock if it
produces more output than can fit in the pipe's buffers.
---

diff --git a/source/externaltask.cpp b/source/externaltask.cpp
index d9832c2..f7ab199 100644
--- a/source/externaltask.cpp
+++ b/source/externaltask.cpp
@@ -128,9 +128,9 @@ Task::Status ExternalTask::wait()
 
 Task::Status ExternalTask::do_wait(bool block)
 {
-	if(process)
+	while(process)
 	{
-		if(process->wait(block))
+		if(process->wait(!capture_pipe))
 		{
 			exit_code = process->get_exit_code();
 			delete process;
@@ -138,7 +138,7 @@ Task::Status ExternalTask::do_wait(bool block)
 		}
 
 		// Do this after waiting to avoid a race condition
-		while(capture_pipe && IO::poll(*capture_pipe, IO::P_INPUT, Time::zero))
+		while(capture_pipe && IO::poll(*capture_pipe, IO::P_INPUT, 10*Time::msec))
 		{
 			char buf[1024];
 			unsigned len = capture_pipe->read(buf, sizeof(buf));
@@ -149,7 +149,10 @@ Task::Status ExternalTask::do_wait(bool block)
 		}
 
 		if(process)
-			return RUNNING;
+		{
+			if(!block)
+				return RUNNING;
+		}
 		else
 			signal_finished.emit(!exit_code);
 	}