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pthread_cancelstub.c revision 1.13
      1  1.13  christos /*	$NetBSD: pthread_cancelstub.c,v 1.13 2005/09/13 02:45:38 christos Exp $	*/
      2   1.2   thorpej 
      3   1.2   thorpej /*-
      4   1.2   thorpej  * Copyright (c) 2002 The NetBSD Foundation, Inc.
      5   1.2   thorpej  * All rights reserved.
      6   1.2   thorpej  *
      7   1.2   thorpej  * This code is derived from software contributed to The NetBSD Foundation
      8   1.2   thorpej  * by Nathan J. Williams.
      9   1.2   thorpej  *
     10   1.2   thorpej  * Redistribution and use in source and binary forms, with or without
     11   1.2   thorpej  * modification, are permitted provided that the following conditions
     12   1.2   thorpej  * are met:
     13   1.2   thorpej  * 1. Redistributions of source code must retain the above copyright
     14   1.2   thorpej  *    notice, this list of conditions and the following disclaimer.
     15   1.2   thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.2   thorpej  *    notice, this list of conditions and the following disclaimer in the
     17   1.2   thorpej  *    documentation and/or other materials provided with the distribution.
     18   1.2   thorpej  * 3. All advertising materials mentioning features or use of this software
     19   1.2   thorpej  *    must display the following acknowledgement:
     20   1.2   thorpej  *        This product includes software developed by the NetBSD
     21   1.2   thorpej  *        Foundation, Inc. and its contributors.
     22   1.2   thorpej  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23   1.2   thorpej  *    contributors may be used to endorse or promote products derived
     24   1.2   thorpej  *    from this software without specific prior written permission.
     25   1.2   thorpej  *
     26   1.2   thorpej  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27   1.2   thorpej  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28   1.2   thorpej  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29   1.2   thorpej  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30   1.2   thorpej  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31   1.2   thorpej  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32   1.2   thorpej  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33   1.2   thorpej  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34   1.2   thorpej  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35   1.2   thorpej  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36   1.2   thorpej  * POSSIBILITY OF SUCH DAMAGE.
     37   1.2   thorpej  */
     38   1.5     lukem 
     39   1.5     lukem #include <sys/cdefs.h>
     40  1.13  christos __RCSID("$NetBSD: pthread_cancelstub.c,v 1.13 2005/09/13 02:45:38 christos Exp $");
     41   1.6   thorpej 
     42   1.6   thorpej /*
     43  1.11    kleink  * This is necessary because the names are always weak (they are not
     44  1.11    kleink  * POSIX functions).
     45   1.6   thorpej  */
     46   1.6   thorpej #define	fsync_range	_fsync_range
     47  1.11    kleink #define	pollts		_pollts
     48   1.2   thorpej 
     49  1.10    kleink /*
     50  1.10    kleink  * XXX this is necessary to get the prototypes for the __sigsuspend14
     51  1.10    kleink  * XXX and __msync13 internal names, instead of the application-visible
     52  1.10    kleink  * XXX sigsuspend and msync names. It's kind of gross, but we're pretty
     53  1.10    kleink  * XXX intimate with libc already.
     54  1.10    kleink  */
     55  1.10    kleink #define __LIBC12_SOURCE__
     56  1.10    kleink 
     57   1.2   thorpej #include <sys/msg.h>
     58   1.2   thorpej #include <sys/types.h>
     59   1.2   thorpej #include <sys/uio.h>
     60   1.2   thorpej #include <sys/wait.h>
     61   1.2   thorpej #include <fcntl.h>
     62   1.2   thorpej #include <poll.h>
     63   1.2   thorpej #include <stdarg.h>
     64   1.2   thorpej #include <unistd.h>
     65   1.2   thorpej 
     66   1.2   thorpej #include <signal.h>
     67   1.2   thorpej #include <sys/mman.h>
     68  1.12    kleink #include <sys/select.h>
     69   1.3   nathanw #include <sys/socket.h>
     70   1.2   thorpej 
     71  1.13  christos #include <compat/sys/mman.h>
     72  1.13  christos 
     73   1.2   thorpej #include "pthread.h"
     74   1.2   thorpej #include "pthread_int.h"
     75   1.2   thorpej 
     76  1.10    kleink int	pthread__cancel_stub_binder;
     77  1.10    kleink 
     78   1.3   nathanw int	_sys_accept(int, struct sockaddr *, socklen_t *);
     79   1.2   thorpej int	_sys_close(int);
     80   1.3   nathanw int	_sys_connect(int, const struct sockaddr *, socklen_t);
     81   1.2   thorpej int	_sys_fcntl(int, int, ...);
     82   1.9    kleink int	_sys_fdatasync(int);
     83   1.2   thorpej int	_sys_fsync(int);
     84   1.6   thorpej int	_sys_fsync_range(int, int, off_t, off_t);
     85   1.2   thorpej ssize_t	_sys_msgrcv(int, void *, size_t, long, int);
     86   1.2   thorpej int	_sys_msgsnd(int, const void *, size_t, int);
     87   1.2   thorpej int	_sys___msync13(void *, size_t, int);
     88   1.2   thorpej int	_sys_open(const char *, int, ...);
     89   1.2   thorpej int	_sys_poll(struct pollfd *, nfds_t, int);
     90  1.11    kleink int	_sys_pollts(struct pollfd *, nfds_t, const struct timespec *,
     91  1.11    kleink 	    const sigset_t *);
     92   1.2   thorpej ssize_t	_sys_pread(int, void *, size_t, off_t);
     93  1.11    kleink int	_sys_pselect(int, fd_set *, fd_set *, fd_set *,
     94  1.11    kleink 	    const struct timespec *, const sigset_t *);
     95   1.2   thorpej ssize_t	_sys_pwrite(int, const void *, size_t, off_t);
     96   1.2   thorpej ssize_t	_sys_read(int, void *, size_t);
     97   1.2   thorpej ssize_t	_sys_readv(int, const struct iovec *, int);
     98   1.2   thorpej int	_sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
     99   1.2   thorpej int	_sys_wait4(pid_t, int *, int, struct rusage *);
    100   1.2   thorpej ssize_t	_sys_write(int, const void *, size_t);
    101   1.2   thorpej ssize_t	_sys_writev(int, const struct iovec *, int);
    102   1.2   thorpej 
    103   1.7   nathanw #define TESTCANCEL(id) 	do {						\
    104   1.7   nathanw 	if (__predict_false((id)->pt_cancel))				\
    105   1.7   nathanw 		pthread_exit(PTHREAD_CANCELED);				\
    106   1.8        cl 	} while (/*CONSTCOND*/0)
    107   1.7   nathanw 
    108   1.2   thorpej 
    109   1.2   thorpej int
    110   1.3   nathanw accept(int s, struct sockaddr *addr, socklen_t *addrlen)
    111   1.3   nathanw {
    112   1.3   nathanw 	int retval;
    113   1.3   nathanw 	pthread_t self;
    114   1.3   nathanw 
    115   1.3   nathanw 	self = pthread__self();
    116   1.7   nathanw 	TESTCANCEL(self);
    117   1.3   nathanw 	retval = _sys_accept(s, addr, addrlen);
    118   1.7   nathanw 	TESTCANCEL(self);
    119   1.3   nathanw 
    120   1.3   nathanw 	return retval;
    121   1.3   nathanw }
    122   1.3   nathanw 
    123   1.3   nathanw int
    124   1.2   thorpej close(int d)
    125   1.2   thorpej {
    126   1.2   thorpej 	int retval;
    127   1.2   thorpej 	pthread_t self;
    128   1.2   thorpej 
    129   1.2   thorpej 	self = pthread__self();
    130   1.7   nathanw 	TESTCANCEL(self);
    131   1.2   thorpej 	retval = _sys_close(d);
    132   1.7   nathanw 	TESTCANCEL(self);
    133   1.3   nathanw 
    134   1.3   nathanw 	return retval;
    135   1.3   nathanw }
    136   1.3   nathanw 
    137   1.3   nathanw int
    138   1.3   nathanw connect(int s, const struct sockaddr *addr, socklen_t namelen)
    139   1.3   nathanw {
    140   1.3   nathanw 	int retval;
    141   1.3   nathanw 	pthread_t self;
    142   1.3   nathanw 
    143   1.3   nathanw 	self = pthread__self();
    144   1.7   nathanw 	TESTCANCEL(self);
    145   1.3   nathanw 	retval = _sys_connect(s, addr, namelen);
    146   1.7   nathanw 	TESTCANCEL(self);
    147   1.2   thorpej 
    148   1.2   thorpej 	return retval;
    149   1.2   thorpej }
    150   1.2   thorpej 
    151   1.2   thorpej int
    152   1.2   thorpej fcntl(int fd, int cmd, ...)
    153   1.2   thorpej {
    154   1.2   thorpej 	int retval;
    155   1.2   thorpej 	pthread_t self;
    156   1.2   thorpej 	va_list ap;
    157   1.2   thorpej 
    158   1.2   thorpej 	self = pthread__self();
    159   1.7   nathanw 	TESTCANCEL(self);
    160   1.2   thorpej 	va_start(ap, cmd);
    161   1.2   thorpej 	retval = _sys_fcntl(fd, cmd, va_arg(ap, void *));
    162   1.2   thorpej 	va_end(ap);
    163   1.7   nathanw 	TESTCANCEL(self);
    164   1.2   thorpej 
    165   1.2   thorpej 	return retval;
    166   1.2   thorpej }
    167   1.2   thorpej 
    168   1.2   thorpej int
    169   1.9    kleink fdatasync(int d)
    170   1.9    kleink {
    171   1.9    kleink 	int retval;
    172   1.9    kleink 	pthread_t self;
    173   1.9    kleink 
    174   1.9    kleink 	self = pthread__self();
    175   1.9    kleink 	TESTCANCEL(self);
    176   1.9    kleink 	retval = _sys_fdatasync(d);
    177   1.9    kleink 	TESTCANCEL(self);
    178   1.9    kleink 
    179   1.9    kleink 	return retval;
    180   1.9    kleink }
    181   1.9    kleink 
    182   1.9    kleink int
    183   1.2   thorpej fsync(int d)
    184   1.2   thorpej {
    185   1.2   thorpej 	int retval;
    186   1.2   thorpej 	pthread_t self;
    187   1.2   thorpej 
    188   1.2   thorpej 	self = pthread__self();
    189   1.7   nathanw 	TESTCANCEL(self);
    190   1.2   thorpej 	retval = _sys_fsync(d);
    191   1.7   nathanw 	TESTCANCEL(self);
    192   1.2   thorpej 
    193   1.2   thorpej 	return retval;
    194   1.2   thorpej }
    195   1.2   thorpej 
    196   1.6   thorpej int
    197   1.6   thorpej fsync_range(int d, int f, off_t s, off_t e)
    198   1.6   thorpej {
    199   1.6   thorpej 	int retval;
    200   1.6   thorpej 	pthread_t self;
    201   1.6   thorpej 
    202   1.6   thorpej 	self = pthread__self();
    203   1.7   nathanw 	TESTCANCEL(self);
    204   1.6   thorpej 	retval = _sys_fsync_range(d, f, s, e);
    205   1.7   nathanw 	TESTCANCEL(self);
    206   1.6   thorpej 
    207   1.6   thorpej 	return retval;
    208   1.6   thorpej }
    209   1.6   thorpej 
    210   1.2   thorpej ssize_t
    211   1.2   thorpej msgrcv(int msgid, void *msgp, size_t msgsz, long msgtyp, int msgflg)
    212   1.2   thorpej {
    213   1.2   thorpej 	ssize_t retval;
    214   1.2   thorpej 	pthread_t self;
    215   1.2   thorpej 
    216   1.2   thorpej 	self = pthread__self();
    217   1.7   nathanw 	TESTCANCEL(self);
    218   1.2   thorpej 	retval = _sys_msgrcv(msgid, msgp, msgsz, msgtyp, msgflg);
    219   1.7   nathanw 	TESTCANCEL(self);
    220   1.2   thorpej 
    221   1.2   thorpej 	return retval;
    222   1.2   thorpej }
    223   1.2   thorpej 
    224   1.2   thorpej int
    225   1.2   thorpej msgsnd(int msgid, const void *msgp, size_t msgsz, int msgflg)
    226   1.2   thorpej {
    227   1.2   thorpej 	int retval;
    228   1.2   thorpej 	pthread_t self;
    229   1.2   thorpej 
    230   1.2   thorpej 	self = pthread__self();
    231   1.7   nathanw 	TESTCANCEL(self);
    232   1.2   thorpej 	retval = _sys_msgsnd(msgid, msgp, msgsz, msgflg);
    233   1.7   nathanw 	TESTCANCEL(self);
    234   1.2   thorpej 
    235   1.2   thorpej 	return retval;
    236   1.2   thorpej }
    237   1.2   thorpej 
    238   1.2   thorpej int
    239   1.2   thorpej __msync13(void *addr, size_t len, int flags)
    240   1.2   thorpej {
    241   1.2   thorpej 	int retval;
    242   1.2   thorpej 	pthread_t self;
    243   1.2   thorpej 
    244   1.2   thorpej 	self = pthread__self();
    245   1.7   nathanw 	TESTCANCEL(self);
    246   1.2   thorpej 	retval = _sys___msync13(addr, len, flags);
    247   1.7   nathanw 	TESTCANCEL(self);
    248   1.2   thorpej 
    249   1.2   thorpej 	return retval;
    250   1.2   thorpej }
    251   1.2   thorpej 
    252   1.2   thorpej int
    253   1.2   thorpej open(const char *path, int flags, ...)
    254   1.2   thorpej {
    255   1.2   thorpej 	int retval;
    256   1.2   thorpej 	pthread_t self;
    257   1.2   thorpej 	va_list ap;
    258   1.2   thorpej 
    259   1.2   thorpej 	self = pthread__self();
    260   1.7   nathanw 	TESTCANCEL(self);
    261   1.2   thorpej 	va_start(ap, flags);
    262   1.2   thorpej 	retval = _sys_open(path, flags, va_arg(ap, mode_t));
    263   1.2   thorpej 	va_end(ap);
    264   1.7   nathanw 	TESTCANCEL(self);
    265   1.2   thorpej 
    266   1.2   thorpej 	return retval;
    267   1.2   thorpej }
    268   1.2   thorpej 
    269   1.2   thorpej int
    270   1.2   thorpej poll(struct pollfd *fds, nfds_t nfds, int timeout)
    271   1.2   thorpej {
    272   1.2   thorpej 	int retval;
    273   1.2   thorpej 	pthread_t self;
    274   1.2   thorpej 
    275   1.2   thorpej 	self = pthread__self();
    276   1.7   nathanw 	TESTCANCEL(self);
    277   1.2   thorpej 	retval = _sys_poll(fds, nfds, timeout);
    278   1.7   nathanw 	TESTCANCEL(self);
    279   1.2   thorpej 
    280   1.2   thorpej 	return retval;
    281   1.2   thorpej }
    282   1.2   thorpej 
    283  1.11    kleink int
    284  1.11    kleink pollts(struct pollfd *fds, nfds_t nfds, const struct timespec *ts,
    285  1.11    kleink     const sigset_t *sigmask)
    286  1.11    kleink {
    287  1.11    kleink 	int retval;
    288  1.11    kleink 	pthread_t self;
    289  1.11    kleink 
    290  1.11    kleink 	self = pthread__self();
    291  1.11    kleink 	TESTCANCEL(self);
    292  1.11    kleink 	retval = _sys_pollts(fds, nfds, ts, sigmask);
    293  1.11    kleink 	TESTCANCEL(self);
    294  1.11    kleink 
    295  1.11    kleink 	return retval;
    296  1.11    kleink }
    297  1.11    kleink 
    298   1.2   thorpej ssize_t
    299   1.2   thorpej pread(int d, void *buf, size_t nbytes, off_t offset)
    300   1.2   thorpej {
    301   1.2   thorpej 	ssize_t retval;
    302   1.2   thorpej 	pthread_t self;
    303   1.2   thorpej 
    304   1.2   thorpej 	self = pthread__self();
    305   1.7   nathanw 	TESTCANCEL(self);
    306   1.2   thorpej 	retval = _sys_pread(d, buf, nbytes, offset);
    307   1.7   nathanw 	TESTCANCEL(self);
    308   1.2   thorpej 
    309   1.2   thorpej 	return retval;
    310   1.2   thorpej }
    311   1.2   thorpej 
    312  1.11    kleink int
    313  1.11    kleink pselect(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
    314  1.11    kleink     const struct timespec *timeout, const sigset_t *sigmask)
    315  1.11    kleink {
    316  1.11    kleink 	int retval;
    317  1.11    kleink 	pthread_t self;
    318  1.11    kleink 
    319  1.11    kleink 	self = pthread__self();
    320  1.11    kleink 	TESTCANCEL(self);
    321  1.11    kleink 	retval = _sys_pselect(nfds, readfds, writefds, exceptfds, timeout,
    322  1.11    kleink 	    sigmask);
    323  1.11    kleink 	TESTCANCEL(self);
    324  1.11    kleink 
    325  1.11    kleink 	return retval;
    326  1.11    kleink }
    327  1.11    kleink 
    328   1.2   thorpej ssize_t
    329   1.2   thorpej pwrite(int d, const void *buf, size_t nbytes, off_t offset)
    330   1.2   thorpej {
    331   1.2   thorpej 	ssize_t retval;
    332   1.2   thorpej 	pthread_t self;
    333   1.2   thorpej 
    334   1.2   thorpej 	self = pthread__self();
    335   1.7   nathanw 	TESTCANCEL(self);
    336   1.2   thorpej 	retval = _sys_pwrite(d, buf, nbytes, offset);
    337   1.7   nathanw 	TESTCANCEL(self);
    338   1.2   thorpej 
    339   1.2   thorpej 	return retval;
    340   1.2   thorpej }
    341   1.2   thorpej 
    342   1.2   thorpej ssize_t
    343   1.2   thorpej read(int d, void *buf, size_t nbytes)
    344   1.2   thorpej {
    345   1.2   thorpej 	ssize_t retval;
    346   1.2   thorpej 	pthread_t self;
    347   1.2   thorpej 
    348   1.2   thorpej 	self = pthread__self();
    349   1.7   nathanw 	TESTCANCEL(self);
    350   1.2   thorpej 	retval = _sys_read(d, buf, nbytes);
    351   1.7   nathanw 	TESTCANCEL(self);
    352   1.2   thorpej 
    353   1.2   thorpej 	return retval;
    354   1.2   thorpej }
    355   1.2   thorpej 
    356   1.2   thorpej ssize_t
    357   1.2   thorpej readv(int d, const struct iovec *iov, int iovcnt)
    358   1.2   thorpej {
    359   1.2   thorpej 	ssize_t retval;
    360   1.2   thorpej 	pthread_t self;
    361   1.2   thorpej 
    362   1.2   thorpej 	self = pthread__self();
    363   1.7   nathanw 	TESTCANCEL(self);
    364   1.2   thorpej 	retval = _sys_readv(d, iov, iovcnt);
    365   1.7   nathanw 	TESTCANCEL(self);
    366   1.2   thorpej 
    367   1.2   thorpej 	return retval;
    368   1.2   thorpej }
    369   1.2   thorpej 
    370   1.2   thorpej int
    371   1.2   thorpej select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
    372   1.2   thorpej     struct timeval *timeout)
    373   1.2   thorpej {
    374   1.2   thorpej 	int retval;
    375   1.2   thorpej 	pthread_t self;
    376   1.2   thorpej 
    377   1.2   thorpej 	self = pthread__self();
    378   1.7   nathanw 	TESTCANCEL(self);
    379   1.2   thorpej 	retval = _sys_select(nfds, readfds, writefds, exceptfds, timeout);
    380   1.7   nathanw 	TESTCANCEL(self);
    381   1.2   thorpej 
    382   1.2   thorpej 	return retval;
    383   1.2   thorpej }
    384   1.2   thorpej 
    385   1.2   thorpej pid_t
    386   1.2   thorpej wait4(pid_t wpid, int *status, int options, struct rusage *rusage)
    387   1.2   thorpej {
    388   1.2   thorpej 	pid_t retval;
    389   1.2   thorpej 	pthread_t self;
    390   1.2   thorpej 
    391   1.2   thorpej 	self = pthread__self();
    392   1.7   nathanw 	TESTCANCEL(self);
    393   1.2   thorpej 	retval = _sys_wait4(wpid, status, options, rusage);
    394   1.7   nathanw 	TESTCANCEL(self);
    395   1.2   thorpej 
    396   1.2   thorpej 	return retval;
    397   1.2   thorpej }
    398   1.2   thorpej 
    399   1.2   thorpej ssize_t
    400   1.2   thorpej write(int d, const void *buf, size_t nbytes)
    401   1.2   thorpej {
    402   1.2   thorpej 	ssize_t retval;
    403   1.2   thorpej 	pthread_t self;
    404   1.2   thorpej 
    405   1.2   thorpej 	self = pthread__self();
    406   1.7   nathanw 	TESTCANCEL(self);
    407   1.2   thorpej 	retval = _sys_write(d, buf, nbytes);
    408   1.7   nathanw 	TESTCANCEL(self);
    409   1.2   thorpej 
    410   1.2   thorpej 	return retval;
    411   1.2   thorpej }
    412   1.2   thorpej 
    413   1.2   thorpej ssize_t
    414   1.2   thorpej writev(int d, const struct iovec *iov, int iovcnt)
    415   1.2   thorpej {
    416   1.2   thorpej 	ssize_t retval;
    417   1.2   thorpej 	pthread_t self;
    418   1.2   thorpej 
    419   1.2   thorpej 	self = pthread__self();
    420   1.7   nathanw 	TESTCANCEL(self);
    421   1.2   thorpej 	retval = _sys_writev(d, iov, iovcnt);
    422   1.7   nathanw 	TESTCANCEL(self);
    423   1.2   thorpej 
    424   1.2   thorpej 	return retval;
    425   1.2   thorpej }
    426   1.2   thorpej 
    427   1.2   thorpej 
    428   1.2   thorpej __strong_alias(_close, close)
    429   1.2   thorpej __strong_alias(_fcntl, fcntl)
    430   1.9    kleink __strong_alias(_fdatasync, fdatasync)
    431   1.2   thorpej __strong_alias(_fsync, fsync)
    432   1.6   thorpej __weak_alias(fsync_range, _fsync_range)
    433   1.2   thorpej __strong_alias(_msgrcv, msgrcv)
    434   1.2   thorpej __strong_alias(_msgsnd, msgsnd)
    435   1.2   thorpej __strong_alias(___msync13, __msync13)
    436   1.2   thorpej __strong_alias(_open, open)
    437   1.2   thorpej __strong_alias(_poll, poll)
    438  1.11    kleink __weak_alias(pollts, _pollts)
    439   1.2   thorpej __strong_alias(_pread, pread)
    440  1.11    kleink __strong_alias(_pselect, pselect)
    441   1.2   thorpej __strong_alias(_pwrite, pwrite)
    442   1.2   thorpej __strong_alias(_read, read)
    443   1.2   thorpej __strong_alias(_readv, readv)
    444   1.2   thorpej __strong_alias(_select, select)
    445   1.2   thorpej __strong_alias(_wait4, wait4)
    446   1.2   thorpej __strong_alias(_write, write)
    447   1.2   thorpej __strong_alias(_writev, writev)
    448