1 files changed, 73 insertions, 0 deletions
diff --git a/gl/lib/glthread/threadlib.c b/gl/lib/glthread/threadlib.c
new file mode 100644
index 0000000..28bf3c6
--- /dev/null
+++ b/gl/lib/glthread/threadlib.c
@@ -0,0 +1,73 @@
+/* Multithreading primitives.
+   Copyright (C) 2005-2020 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005.  */
+
+#include <config.h>
+
+/* ========================================================================= */
+
+#if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS
+
+/* Use the POSIX threads library.  */
+
+# include <pthread.h>
+# include <stdlib.h>
+
+# if PTHREAD_IN_USE_DETECTION_HARD
+
+/* The function to be executed by a dummy thread.  */
+static void *
+dummy_thread_func (void *arg)
+{
+  return arg;
+}
+
+int
+glthread_in_use (void)
+{
+  static int tested;
+  static int result; /* 1: linked with -lpthread, 0: only with libc */
+
+  if (!tested)
+    {
+      pthread_t thread;
+
+      if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0)
+        /* Thread creation failed.  */
+        result = 0;
+      else
+        {
+          /* Thread creation works.  */
+          void *retval;
+          if (pthread_join (thread, &retval) != 0)
+            abort ();
+          result = 1;
+        }
+      tested = 1;
+    }
+  return result;
+}
+
+# endif
+
+#endif
+
+/* ========================================================================= */
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;