hurd: Reimplement libc locks using mach's gsync

	* hurd/Makefile (routines): Add hurdlock.
	* hurd/Versions (GLIBC_PRIVATE): Added new entry to export the above
	interface.
	(HURD_CTHREADS_0.3): Remove __libc_getspecific.
	* hurd/hurdpid.c: Include <lowlevellock.h>
	(_S_msg_proc_newids): Use lll_wait to synchronize.
	* hurd/hurdsig.c: (reauth_proc): Use __mutex_lock and __mutex_unlock.
	* hurd/setauth.c: Include <hurdlock.h>, use integer for synchronization.
	* mach/Makefile (lock-headers): Remove machine-lock.h.
	* mach/lock-intern.h: Include <lowlevellock.h> instead of
	<machine-lock.h>.
	(__spin_lock_t): New type.
	(__SPIN_LOCK_INITIALIZER): New macro.
	(__spin_lock, __spin_unlock, __spin_try_lock, __spin_lock_locked,
	__mutex_init, __mutex_lock_solid, __mutex_unlock_solid, __mutex_lock,
	__mutex_unlock, __mutex_trylock): Use lll to implement locks.
	* mach/mutex-init.c: Include <lowlevellock.h> instead of <cthreads.h>.
	(__mutex_init): Initialize with lll.
	* manual/errno.texi (EOWNERDEAD, ENOTRECOVERABLE): New errno values.
	* sysdeps/mach/Makefile: Add libmachuser as dependencies for libs
	needing lll.
	* sysdeps/mach/hurd/bits/errno.h: Regenerate.
	* sysdeps/mach/hurd/cthreads.c (__libc_getspecific): Remove function.
	* sysdeps/mach/hurd/bits/libc-lock.h: Remove file.
	* sysdeps/mach/hurd/setpgid.c: Include <lowlevellock.h>.
	(__setpgid): Use lll for synchronization.
	* sysdeps/mach/hurd/setsid.c: Likewise with __setsid.
	* sysdeps/mach/bits/libc-lock.h: Include <tls.h> and <lowlevellock.h>
	instead of <cthreads.h>.
	(_IO_lock_inexpensive): New macro
	(__libc_lock_recursive_t, __rtld_lock_recursive_t): New structures.
	(__libc_lock_self0): New declaration.
	(__libc_lock_owner_self): New macro.
	(__libc_key_t): Remove type.
	(_LIBC_LOCK_INITIALIZER): New macro.
	(__libc_lock_define_initialized, __libc_lock_init, __libc_lock_fini,
	__libc_lock_fini_recursive, __rtld_lock_fini_recursive,
	__libc_lock_lock, __libc_lock_trylock, __libc_lock_unlock,
	__libc_lock_define_initialized_recursive,
	__rtld_lock_define_initialized_recursive,
	__libc_lock_init_recursive, __libc_lock_trylock_recursive,
	__libc_lock_lock_recursive, __libc_lock_unlock_recursive,
	__rtld_lock_initialize, __rtld_lock_trylock_recursive,
	__rtld_lock_lock_recursive, __rtld_lock_unlock_recursive
	__libc_once_define, __libc_mutex_unlock): Reimplement with lll.
	(__libc_lock_define_recursive, __rtld_lock_define_recursive,
	_LIBC_LOCK_RECURSIVE_INITIALIZER, _RTLD_LOCK_RECURSIVE_INITIALIZER):
	New macros.
	Include <libc-lockP.h> to reimplement libc_key* with pthread_key*.
	* hurd/hurdlock.c: New file.
	* hurd/hurdlock.h: New file.
	* mach/lowlevellock.h: New file

1 files changed, 81 insertions, 0 deletions

diff --git a/mach/lowlevellock.h b/mach/lowlevellock.h
new file mode 100644
index 0000000000..20c66ca979
--- /dev/null
+++ b/mach/lowlevellock.h
@@ -0,0 +1,81 @@
+/* Low-level lock implementation.  Mach gsync-based version.
+   Copyright (C) 1994-2017 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _MACH_LOWLEVELLOCK_H
+#define _MACH_LOWLEVELLOCK_H   1
+
+#include <mach/gnumach.h>
+#include <atomic.h>
+
+/* Gsync flags.  */
+#ifndef GSYNC_SHARED
+  #define GSYNC_SHARED      0x01
+  #define GSYNC_QUAD        0x02
+  #define GSYNC_TIMED       0x04
+  #define GSYNC_BROADCAST   0x08
+  #define GSYNC_MUTATE      0x10
+#endif
+
+/* Static initializer for low-level locks.  */
+#define LLL_INITIALIZER   0
+
+/* Wait on address PTR, without blocking if its contents
+ * are different from VAL.  */
+#define lll_wait(ptr, val, flags)   \
+  __gsync_wait (__mach_task_self (),   \
+    (vm_offset_t)(ptr), (val), 0, 0, (flags))
+
+/* Wake one or more threads waiting on address PTR.  */
+#define lll_wake(ptr, flags)   \
+  __gsync_wake (__mach_task_self (), (vm_offset_t)(ptr), 0, (flags))
+
+/* Acquire the lock at PTR.  */
+#define lll_lock(ptr, flags)   \
+  ({   \
+     int *__iptr = (int *)(ptr);   \
+     int __flags = (flags);   \
+     if (*__iptr != 0 ||   \
+         atomic_compare_and_exchange_bool_acq (__iptr, 1, 0) != 0)   \
+       while (1)   \
+         {   \
+           if (atomic_exchange_acq (__iptr, 2) == 0)   \
+             break;   \
+           lll_wait (__iptr, 2, __flags);   \
+         }   \
+     (void)0;   \
+   })
+
+/* Try to acquire the lock at PTR, without blocking.
+   Evaluates to zero on success.  */
+#define lll_trylock(ptr)   \
+  ({   \
+     int *__iptr = (int *)(ptr);   \
+     *__iptr == 0 &&   \
+       atomic_compare_and_exchange_bool_acq (__iptr, 1, 0) == 0 ? 0 : -1;   \
+   })
+
+/* Release the lock at PTR.  */
+#define lll_unlock(ptr, flags)   \
+  ({   \
+     int *__iptr = (int *)(ptr);   \
+     if (atomic_exchange_rel (__iptr, 0) == 2)   \
+       lll_wake (__iptr, (flags));   \
+     (void)0;   \
+   })
+
+#endif