[PATCH alsa-lib 2/2] conf: Check the availability of PTHREAD_MUTEX_RECURSIVE

[Takashi Iwai <tiwai@suse.de>]

Check the availability of PTHREAD_MUTEX_RECURSIVE in configure script
and use it only when possible.  A fairly old version of glibc still
seems working, but just to be sure.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 configure.ac  | 9 +++++++++
 src/conf.c    | 2 ++
 src/pcm/pcm.c | 2 ++
 3 files changed, 13 insertions(+)

diff --git a/configure.ac b/configure.ac
index ec254762bed6..a17f2c4aef5c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -266,6 +266,15 @@ else
   AC_MSG_RESULT(no)
 fi
 
+dnl Check for pthread
+if test "$HAVE_LIBPTHREAD" = "yes"; then
+  AC_CHECK_DECL(PTHREAD_MUTEX_RECURSIVE,
+    AC_DEFINE(HAVE_PTHREAD_MUTEX_RECURSIVE, [],
+      [Define if your pthreads implementation have PTHREAD_MUTEX_RECURSIVE]),
+    ,
+    [#include <pthread.h>])
+fi
+
 dnl Check for __thread
 AC_MSG_CHECKING([for __thread])
 AC_LINK_IFELSE([AC_LANG_PROGRAM([#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) && ((__GNUC__ < 4) || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) || (__GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ < 2))
diff --git a/src/conf.c b/src/conf.c
index 2b52b44e9144..9a887433a4fe 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -490,7 +490,9 @@ static void snd_config_init_mutex(void)
 	pthread_mutexattr_t attr;
 
 	pthread_mutexattr_init(&attr);
+#ifdef HAVE_PTHREAD_MUTEX_RECURSIVE
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+#endif
 	pthread_mutex_init(&snd_config_update_mutex, &attr);
 	pthread_mutexattr_destroy(&attr);
 }
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index 8a7a5950de3c..200b10c2c09c 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -2600,7 +2600,9 @@ int snd_pcm_new(snd_pcm_t **pcmp, snd_pcm_type_t type, const char *name,
 	INIT_LIST_HEAD(&pcm->async_handlers);
 #ifdef THREAD_SAFE_API
 	pthread_mutexattr_init(&attr);
+#ifdef HAVE_PTHREAD_MUTEX_RECURSIVE
 	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+#endif
 	pthread_mutex_init(&pcm->lock, &attr);
 	/* use locking as default;
 	 * each plugin may suppress this in its open call
-- 
2.13.0