From 4691a35b7b0cd158b2f4a15fa1f005df4957e615 Mon Sep 17 00:00:00 2001
From: Andri Yngvason <andri@yngvason.is>
Date: Tue, 26 Dec 2023 11:58:35 +0000
Subject: [PATCH] logging: Add method to set thread local log function

This allows the user to override the log function in the current thread
without receiving log messages from concurrent tasks.
---
 include/neatvnc.h |  1 +
 src/logging.c     | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/include/neatvnc.h b/include/neatvnc.h
index 06034ee..535baea 100644
--- a/include/neatvnc.h
+++ b/include/neatvnc.h
@@ -238,5 +238,6 @@ void nvnc_set_cursor(struct nvnc*, struct nvnc_fb*, uint16_t width,
 void nvnc_default_logger(const struct nvnc_log_data* meta, const char* message);
 
 void nvnc_set_log_fn(nvnc_log_fn);
+void nvnc_set_log_fn_thread_local(nvnc_log_fn fn);
 void nvnc_set_log_level(enum nvnc_log_level);
 void nvnc__log(const struct nvnc_log_data*, const char* fmt, ...);
diff --git a/src/logging.c b/src/logging.c
index 1dd651f..d43cb95 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -25,6 +25,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <ctype.h>
+#include <threads.h>
 
 #ifdef HAVE_LIBAVUTIL
 #include <libavutil/avutil.h>
@@ -33,6 +34,7 @@
 #define EXPORT __attribute__((visibility("default")))
 
 static nvnc_log_fn log_fn = nvnc_default_logger;
+static thread_local nvnc_log_fn thread_local_log_fn = NULL;
 
 #ifndef NDEBUG
 static enum nvnc_log_level log_level = NVNC_LOG_DEBUG;
@@ -42,6 +44,11 @@ static enum nvnc_log_level log_level = NVNC_LOG_WARNING;
 
 static bool is_initialised = false;
 
+static nvnc_log_fn get_log_fn(void)
+{
+	return thread_local_log_fn ? thread_local_log_fn : log_fn;
+}
+
 static char* trim_left(char* str)
 {
 	while (isspace(*str))
@@ -97,7 +104,7 @@ static void nvnc__vlog(const struct nvnc_log_data* meta, const char* fmt,
 
 	if (meta->level <= log_level) {
 		vsnprintf(message, sizeof(message), fmt, args);
-		log_fn(meta, trim(message));
+		get_log_fn()(meta, trim(message));
 	}
 
 	if (meta->level == NVNC_LOG_PANIC)
@@ -179,6 +186,12 @@ void nvnc_set_log_fn(nvnc_log_fn fn)
 	log_fn = fn;
 }
 
+EXPORT
+void nvnc_set_log_fn_thread_local(nvnc_log_fn fn)
+{
+	thread_local_log_fn = fn;
+}
+
 EXPORT
 void nvnc__log(const struct nvnc_log_data* meta,
 		const char* fmt, ...)