From d0227f8d0245d6ec0c11d7e955f7681d8552ef63 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Thu, 13 Mar 2025 13:58:35 +0100
Subject: [PATCH] JSONLogger: Acquire a lock to prevent log messages from
clobbering each other
---
src/libutil/logging.cc | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index 406452738..1b0b2d0d9 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -6,6 +6,7 @@
#include "config-global.hh"
#include "source-path.hh"
#include "position.hh"
+#include "sync.hh"
#include <atomic>
#include <sstream>
@@ -201,9 +202,22 @@ struct JSONLogger : Logger {
unreachable();
}
+ struct State
+ {
+ };
+
+ Sync<State> _state;
+
void write(const nlohmann::json & json)
{
- writeLine(fd, "@nix " + json.dump(-1, ' ', false, nlohmann::json::error_handler_t::replace));
+ auto line =
+ "@nix " +
+ json.dump(-1, ' ', false, nlohmann::json::error_handler_t::replace);
+
+ /* Acquire a lock to prevent log messages from clobbering each
+ other. */
+ auto state(_state.lock());
+ writeLine(fd, line);
}
void log(Verbosity lvl, std::string_view s) override