Call pthread's recursive mutex on Linux (Issue #245)

Add CMake test for PTHREAD_MUTEX_RECURSIVE

Add autoconf/configure compile test for PTHREAD_MUTEX_RECURSIVE

Replace "#ifdef PTHREAD_MUTEX_RECURSIVE"
   with "#ifdef HAVE_PTHREAD_MUTEX_RECURSIVE"
and define HAVE_PTHREAD_MUTEX_RECURSIVE in config.h

1 files changed, 7 insertions, 0 deletions

diff --git a/CMake/pthread_mutex_recursive.c b/CMake/pthread_mutex_recursive.c
new file mode 100644
index 000000000..2a058822f
--- /dev/null
+++ b/CMake/pthread_mutex_recursive.c
@@ -0,0 +1,7 @@
+/*
+  FLTK feature test: do we have PTHREAD_MUTEX_RECURSIVE ?
+*/
+#include <pthread.h>
+int main() {
+  return PTHREAD_MUTEX_RECURSIVE;
+}