3 files changed, 39 insertions, 18 deletions

diff --git a/src/trace.c b/src/trace.c
index 335ee43..d21a792 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -2,25 +2,36 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <pthread.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <threads.h>
 
 #include "logerr.h"
 #include "trace.h"
 
 
 
-static thread_local enum TraceLevel
-LEVEL = TraceLevel_INFO;
+static pthread_key_t
+LEVEL_KEY;
 
-static thread_local FILE *
-STREAM = NULL;
+static pthread_key_t
+STREAM_KEY;
 
+static pthread_once_t
+ONCE = PTHREAD_ONCE_INIT;
 
 
+
+static void
+init(void) {
+	assert(pthread_key_create(&LEVEL_KEY,  NULL) == 0);
+	assert(pthread_key_create(&STREAM_KEY, NULL) == 0);
+	assert(pthread_setspecific(LEVEL_KEY, (void *)TraceLevel_INFO) == 0);
+	assert(pthread_setspecific(LEVEL_KEY, stderr) == 0);
+}
+
 void
 vftracef(
 	const char *const file,
@@ -31,7 +42,10 @@ vftracef(
 	const char *restrict format,
 	va_list args
 ) {
-	if (level > LEVEL) {
+	assert(pthread_once(&ONCE, init) == 0);
+
+	const enum TraceLevel current_level = (enum TraceLevel)pthread_getspecific(LEVEL_KEY);
+	if (level > current_level) {
 		return;
 	}
 
@@ -73,23 +87,22 @@ tracef(
 	const char *restrict format,
 	...
 ) {
-	if (STREAM == NULL) {
-		STREAM = stderr;
-	}
+	assert(pthread_once(&ONCE, init) == 0);
+
 	va_list args;
 	va_start(args, format);
-	vftracef(file, function, lineno, STREAM, level, format, args);
+	vftracef(file, function, lineno, pthread_getspecific(STREAM_KEY), level, format, args);
 	va_end(args);
 }
 
-void
+int
 trace_set_stream(FILE *stream) {
-	STREAM = stream;
+	return pthread_setspecific(STREAM_KEY, stream);
 }
 
-void
+int
 trace_set_level(const enum TraceLevel level) {
 	assert(level >= TraceLevel_NONE);
 	assert(level <= TraceLevel_DEBUG);
-	LEVEL = level;
+	return pthread_setspecific(LEVEL_KEY, (void *)level);
 }
diff --git a/src/trace.h b/src/trace.h
index b81e616..be3f6ee 100644
--- a/src/trace.h
+++ b/src/trace.h
@@ -48,8 +48,8 @@ tracef(
 	...
 );
 
-void
+int
 trace_set_stream(FILE *stream);
 
-void
+int
 trace_set_level(const enum TraceLevel level);
diff --git a/tests/trace.c b/tests/trace.c
index aa10c81..5b59a46 100644
--- a/tests/trace.c
+++ b/tests/trace.c
@@ -19,7 +19,7 @@ test_ftracef(void) {
 	FILE *file = NULL;
 	char *str  = NULL;
 
-	const enum TraceLevel orig = LEVEL;
+	const enum TraceLevel orig = (enum TraceLevel)pthread_getspecific(LEVEL_KEY);
 	trace_set_level(TraceLevel_INFO);
 
 	{
@@ -191,7 +191,15 @@ int
 main(void) {
 	int rc = EXIT_FAILURE;
 
-	LEVEL = TraceLevel_DEBUG;
+	if (pthread_once(&ONCE, init)) {
+		perror("pthread_once()");
+		goto out;
+	}
+
+	if (trace_set_level(TraceLevel_DEBUG)) {
+		perror("trace_set_level()");
+		goto out;
+	}
 
 	if (test_ftracef()) {
 		perror("test_ftracef()");