1 files changed, 111 insertions, 0 deletions
diff --git a/sysdeps/htl/pt-mutex-trylock.c b/sysdeps/htl/pt-mutex-trylock.c
new file mode 100644
index 0000000000..b19611b229
--- /dev/null
+++ b/sysdeps/htl/pt-mutex-trylock.c
@@ -0,0 +1,111 @@
+/* Try to Lock a mutex.  Generic version.
+   Copyright (C) 2002-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+#include <pt-internal.h>
+
+#define LOSE do { * (int *) 0 = 0; } while (1)
+
+/* Lock MUTEX, return EBUSY if we can't get it.  */
+int
+__pthread_mutex_trylock (struct __pthread_mutex *mutex)
+{
+  int err;
+  struct __pthread *self;
+  const struct __pthread_mutexattr *attr = mutex->__attr;
+
+  if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR)
+    attr = &__pthread_errorcheck_mutexattr;
+  if (attr == __PTHREAD_RECURSIVE_MUTEXATTR)
+    attr = &__pthread_recursive_mutexattr;
+
+  __pthread_spin_lock (&mutex->__lock);
+  if (__pthread_spin_trylock (&mutex->__held) == 0)
+    /* Acquired the lock.  */
+    {
+#if defined(ALWAYS_TRACK_MUTEX_OWNER)
+# ifndef NDEBUG
+      self = _pthread_self ();
+      if (self != NULL)
+	/* The main thread may take a lock before the library is fully
+	   initialized, in particular, before the main thread has a
+	   TCB.  */
+	{
+	  assert (mutex->__owner == NULL);
+	  mutex->__owner = _pthread_self ();
+	}
+# endif
+#endif
+
+      if (attr != NULL)
+	switch (attr->__mutex_type)
+	  {
+	  case PTHREAD_MUTEX_NORMAL:
+	    break;
+
+	  case PTHREAD_MUTEX_RECURSIVE:
+	    mutex->__locks = 1;
+	  case PTHREAD_MUTEX_ERRORCHECK:
+	    mutex->__owner = _pthread_self ();
+	    break;
+
+	  default:
+	    LOSE;
+	  }
+
+      __pthread_spin_unlock (&mutex->__lock);
+      return 0;
+    }
+
+  err = EBUSY;
+
+  if (attr != NULL)
+    {
+      self = _pthread_self ();
+      switch (attr->__mutex_type)
+	{
+	case PTHREAD_MUTEX_NORMAL:
+	  break;
+
+	case PTHREAD_MUTEX_ERRORCHECK:
+	  /* We could check if MUTEX->OWNER is SELF, however, POSIX
+	     does not permit pthread_mutex_trylock to return EDEADLK
+	     instead of EBUSY, only pthread_mutex_lock.  */
+	  break;
+
+	case PTHREAD_MUTEX_RECURSIVE:
+	  if (mutex->__owner == self)
+	    {
+	      mutex->__locks++;
+	      err = 0;
+	    }
+	  break;
+
+	default:
+	  LOSE;
+	}
+    }
+
+  __pthread_spin_unlock (&mutex->__lock);
+
+  return err;
+}
+
+strong_alias (__pthread_mutex_trylock, _pthread_mutex_trylock);
+strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock);