From fad5928f1cc150b947eee4c477e1676892b5f479 Mon Sep 17 00:00:00 2001
From: Sebastian Ramacher <sramacher@debian.org>
Date: Fri, 5 Jul 2013 15:26:12 +0200
Subject: [PATCH] Use pthread_once to call bindtextdomain only once

Calling bindtextdomain everytime in discid_new incurs a little overhead. If
pthread is available, we can ensure with pthread_once that bindtextdomain is
called exactly once.

The autoconf function AX_PTHREADS is available from autoconf-archive. In cmake
FIND_LIBRARY(Threads) is used to find pthread.

Signed-off-by: Sebastian Ramacher <sramacher@debian.org>
---
 CMakeLists.txt    | 19 +++++++++++++++++++
 config-cmake.h.in |  3 +++
 configure.ac      |  8 ++++++++
 src/disc.c        | 17 ++++++++++++++++-
 4 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e44a268..152dffa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -152,6 +152,25 @@ ENDIF()
 STRING(REPLACE ";" " " libdiscid_OSDEP_STR "${libdiscid_OSDEP_SRCS}")
 MESSAGE(STATUS "Using discid implementation ${libdiscid_OSDEP_STR}")
 
+# check if pthread is available
+IF(ENABLE_NLS)
+	SET(CMAKE_THREAD_PREFER_PTHREAD TRUE)
+	IF(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER MATCHES "clang")
+		# FIND_PACKAGE(Threads) prefers -lpthread over -pthread, -pthread is
+		# recommend though
+		SET(THREADS_HAVE_PTHREAD_ARG "-pthread")
+	ENDIF()
+	FIND_PACKAGE(Threads)
+	IF(CMAKE_USE_PTHREADS_INIT)
+		SET(HAVE_PTHREAD TRUE)
+		SET(libdiscid_LIBS ${LIBDISCID_LIBS} ${CMAKE_THREAD_LIBS_INIT})
+		IF(${CMAKE_THREAD_LIBS_INIT} MATCHES "-pthread")
+			# if we have -pthread, also pass -pthread to CC
+			SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
+		ENDIF()
+	ENDIF()
+ENDIF()
+
 ADD_LIBRARY(libdiscid SHARED ${libdiscid_OSDEP_SRCS} ${libdiscid_RCS} src/base64.c src/disc.c src/sha1.c)
 TARGET_LINK_LIBRARIES(libdiscid ${libdiscid_OSDEP_LIBS} ${libdiscid_LIBS})
 SET_TARGET_PROPERTIES(libdiscid PROPERTIES
diff --git a/config-cmake.h.in b/config-cmake.h.in
index 6d00d21..96fc0d9 100644
--- a/config-cmake.h.in
+++ b/config-cmake.h.in
@@ -12,6 +12,9 @@
 /* enable string translation (gettext) */
 #cmakedefine ENABLE_NLS
 
+/* pthread is available */
+#cmakedefine HAVE_PTHREAD
+
 /**
  * Values needed by our sha1.h
  */
diff --git a/configure.ac b/configure.ac
index 7e4877a..9948625 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,6 +87,14 @@ AC_CHECK_SIZEOF(long)
 
 AM_GNU_GETTEXT([external])
 AM_GNU_GETTEXT_VERSION(0.18.1)
+if test "$USE_NLS" = "yes"; then
+	AX_PTHREAD([
+		AC_DEFINE(HAVE_PTHREAD, [], "pthread is available")
+		LIBS="$PTHREAD_LIBS $LIBS"
+		CFLAGS="$CLAFGS $PTHREAD_CFLAGS"
+		CC="$PTHREAD_CC"
+	])
+fi
 
 if test "$cross_compiling" = "yes" && test "$os" = "win32"; then
   AC_MSG_WARN([detected cross compilation: disabling tests!!!])
diff --git a/src/disc.c b/src/disc.c
index 9dce8af..eb08a6b 100644
--- a/src/disc.c
+++ b/src/disc.c
@@ -43,6 +43,17 @@
 #define TRACK_NUM_IS_VALID(disc, i) \
 	( i >= disc->first_track_num && i <= disc->last_track_num )
 
+#ifdef ENABLE_NLS
+static void init_nls(void) {
+	bindtextdomain(PACKAGE, LOCALEDIR);
+}
+
+#ifdef HAVE_PTHREAD
+#include <pthread.h>
+static pthread_once_t nls_initialized = PTHREAD_ONCE_INIT;
+#endif
+#endif
+
 
 static void create_disc_id(mb_disc_private *d, char buf[]);
 static void create_freedb_disc_id(mb_disc_private *d, char buf[]);
@@ -61,7 +72,11 @@ DiscId *discid_new() {
 	 * just in case the prefix was set weird
 	 */
 #ifdef ENABLE_NLS
-	bindtextdomain(PACKAGE, LOCALEDIR);
+#ifdef HAVE_PTHREAD
+	pthread_once(&nls_initialized, init_nls);
+#else
+	init_nls();
+#endif
 #endif
 	printf(_("one two three\n"));
 	/* initializes everything to zero */