Support for parallel test execution.

1 files changed, 4 insertions, 1 deletions

diff --git a/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/controller/LocalController.java b/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/controller/LocalController.java
index 9e01e67d..b16c8c4f 100644
--- a/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/controller/LocalController.java
+++ b/org.jacoco.agent.rt/src/org/jacoco/agent/rt/internal/controller/LocalController.java
@@ -64,7 +64,10 @@ public class LocalController implements IAgentController {
 	}
 
 	private OutputStream openFile() throws IOException {
-		return new FileOutputStream(destFile, append);
+		final FileOutputStream file = new FileOutputStream(destFile, append);
+		// Avoid concurrent writes from different agents running in parallel:
+		file.getChannel().lock();
+		return file;
 	}
 
 }