Add libstdthreads.

This library implements the C11 threads interface on top of the pthreads
library.  As discussed on the lists, the preferred way to implement
this, is as a separate library.

It is unlikely that these functions will be used a lot in the future. It
would have been easier if the C11 working group standardized (a subset
of) pthreads and clock_nanosleep(). Having it as a separate library
allows the embedded people to omit it from their system.

Discussed on:	arch@, threads@

1 files changed, 106 insertions, 0 deletions

diff --git a/lib/libstdthreads/threads.h b/lib/libstdthreads/threads.h
new file mode 100644
index 000000000000..aba9ca13df3c
--- /dev/null
+++ b/lib/libstdthreads/threads.h
@@ -0,0 +1,106 @@
+/*-
+ * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _THREADS_H_
+#define	_THREADS_H_
+
+#include <time.h>
+
+/*
+ * The C11 threads interface.
+ *
+ * This interface is implemented as a light-weight wrapper around
+ * <pthread.h>.  To prevent namespace pollution, the once_flag object,
+ * its corresponding ONCE_FLAG_INIT and TSS_DTOR_ITERATIONS have been
+ * copied from this header file.  They must be kept in sync.
+ */
+
+typedef struct pthread_cond	*cnd_t;
+typedef struct pthread_mutex	*mtx_t;
+typedef struct pthread		*thrd_t;
+typedef int			 tss_t;
+
+typedef struct {
+	int	__state;
+	mtx_t	__mutex;
+} once_flag;
+
+typedef void (*tss_dtor_t)(void *);
+typedef int (*thrd_start_t)(void *);
+
+enum {
+	mtx_plain = 0x1,
+	mtx_recursive = 0x2,
+	mtx_timed = 0x4
+};
+
+enum {
+	thrd_busy = 1,
+	thrd_error = 2,
+	thrd_nomem = 3,
+	thrd_success = 4,
+	thrd_timedout = 5
+};
+
+#if !defined(__cplusplus) || __cplusplus < 201103L
+#define	thread_local		_Thread_local
+#endif
+#define	ONCE_FLAG_INIT		{ 0, NULL }
+#define	TSS_DTOR_ITERATIONS	4
+
+__BEGIN_DECLS
+void	call_once(once_flag *, void (*)(void));
+int	cnd_broadcast(cnd_t *);
+void	cnd_destroy(cnd_t *);
+int	cnd_init(cnd_t *);
+int	cnd_signal(cnd_t *);
+int	cnd_timedwait(cnd_t *__restrict, mtx_t *__restrict,
+    const struct timespec *__restrict);
+int	cnd_wait(cnd_t *, mtx_t *);
+void	mtx_destroy(mtx_t *);
+int	mtx_init(mtx_t *, int);
+int	mtx_lock(mtx_t *);
+int	mtx_timedlock(mtx_t *__restrict, const struct timespec *__restrict);
+int	mtx_trylock(mtx_t *);
+int	mtx_unlock(mtx_t *);
+int	thrd_create(thrd_t *, thrd_start_t, void *);
+thrd_t	thrd_current(void);
+int	thrd_detach(thrd_t);
+int	thrd_equal(thrd_t, thrd_t);
+_Noreturn void
+	thrd_exit(int);
+int	thrd_join(thrd_t, int *);
+int	thrd_sleep(const struct timespec *, struct timespec *);
+void	thrd_yield(void);
+int	tss_create(tss_t *, tss_dtor_t);
+void	tss_delete(tss_t);
+void *	tss_get(tss_t);
+int	tss_set(tss_t, void *);
+__END_DECLS
+
+#endif /* !_THREADS_H_ */