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-rw-r--r--sysdeps/mach/hurd/select.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/select.c b/sysdeps/mach/hurd/select.c
new file mode 100644
index 0000000000..d1c5913cb8
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+++ b/sysdeps/mach/hurd/select.c
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+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#include <ansidecl.h>
+#include <sys/types.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
+ readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
+ (if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
+ after waiting the interval specified therein. Returns the number of ready
+ descriptors, or -1 for errors. */
+int
+DEFUN(__select, (nfds, readfds, writefds, exceptfds, timeout),
+ int nfds AND fd_set *readfds AND fd_set *writefds AND
+ fd_set *exceptfds AND struct timeval *timeout)
+{
+ int i;
+ mach_port_t port;
+ int got;
+ int *types;
+ struct hurd_userlink *ulink;
+ mach_port_t *ports;
+ struct hurd_fd **cells;
+ error_t err;
+ fd_set rfds, wfds, xfds;
+ int firstfd, lastfd;
+ mach_msg_timeout_t to = (timeout != NULL ?
+ (timeout->tv_sec * 1000 +
+ timeout->tv_usec / 1000) :
+ 0);
+
+ /* Use local copies so we can't crash from user bogosity. */
+ if (readfds == NULL)
+ FD_ZERO (&rfds);
+ else
+ rfds = *readfds;
+ if (writefds == NULL)
+ FD_ZERO (&wfds);
+ else
+ wfds = *writefds;
+ if (exceptfds == NULL)
+ FD_ZERO (&xfds);
+ else
+ xfds = *exceptfds;
+
+ HURD_CRITICAL_BEGIN;
+ __mutex_lock (&_hurd_dtable_lock);
+
+ if (nfds > _hurd_dtablesize)
+ nfds = _hurd_dtablesize;
+
+ /* Collect the ports for interesting FDs. */
+ cells = __alloca (nfds * sizeof (*cells));
+ ports = __alloca (nfds * sizeof (*ports));
+ types = __alloca (nfds * sizeof (*types));
+ ulink = __alloca (nfds * sizeof (*ulink));
+ firstfd = lastfd = -1;
+ for (i = 0; i < nfds; ++i)
+ {
+ int type = 0;
+ if (readfds != NULL && FD_ISSET (i, &rfds))
+ type |= SELECT_READ;
+ if (writefds != NULL && FD_ISSET (i, &wfds))
+ type |= SELECT_WRITE;
+ if (exceptfds != NULL && FD_ISSET (i, &xfds))
+ type |= SELECT_URG;
+ types[i] = type;
+ if (type)
+ {
+ cells[i] = _hurd_dtable[i];
+ ports[i] = _hurd_port_get (&cells[i]->port, &ulink[i]);
+ if (ports[i] == MACH_PORT_NULL)
+ {
+ /* If one descriptor is bogus, we fail completely. */
+ while (i-- > 0)
+ _hurd_port_free (&cells[i]->port, &ulink[i], ports[i]);
+ errno = EBADF;
+ break;
+ }
+ lastfd = i;
+ if (firstfd == -1)
+ firstfd = i;
+ }
+ }
+
+ __mutex_unlock (&_hurd_dtable_lock);
+ HURD_CRITICAL_END;
+
+ if (i < nfds)
+ return -1;
+
+ /* Get a port to receive the io_select_reply messages on. */
+ port = __mach_reply_port ();
+
+ /* Send them all io_select request messages. */
+ got = 0;
+ err = 0;
+ for (i = firstfd; i <= lastfd; ++i)
+ if (types[i])
+ {
+ if (!err)
+ {
+ int tag = i;
+ err = __io_select (ports[i], port,
+ /* Poll for each but the last. */
+ (i == lastfd && got == 0) ? to : 0,
+ &types[i], &tag);
+ if (!err)
+ {
+ if (tag != i)
+ err = EGRATUITOUS;
+ else if (types[i] & (SELECT_READ|SELECT_URG|SELECT_WRITE))
+ ++got;
+ }
+ }
+ _hurd_port_free (&cells[i]->port, &ulink[i], ports[i]);
+ }
+
+ /* Now wait for reply messages. */
+ if (!err && got == 0 && port != MACH_PORT_NULL)
+ {
+ /* Now wait for io_select_reply messages on PORT,
+ timing out as appropriate. */
+
+ union
+ {
+ mach_msg_header_t head;
+ struct
+ {
+ mach_msg_header_t head;
+ mach_msg_type_t err_type;
+ error_t err;
+ } error;
+ struct
+ {
+ mach_msg_header_t head;
+ mach_msg_type_t err_type;
+ error_t err;
+ mach_msg_type_t result_type;
+ int result;
+ mach_msg_type_t tag_type;
+ int tag;
+ } success;
+ } msg;
+ mach_msg_option_t options = (timeout == NULL ? 0 : MACH_RCV_TIMEOUT);
+ error_t msgerr;
+ while ((msgerr = __mach_msg (&msg.head,
+ MACH_RCV_MSG | options,
+ sizeof msg, 0, port, to,
+ MACH_PORT_NULL)) == MACH_MSG_SUCCESS)
+ {
+ /* We got a message. Decode it. */
+#define IO_SELECT_REPLY_MSGID (21012 + 100) /* XXX */
+ const mach_msg_type_t inttype =
+ { MACH_MSG_TYPE_INTEGER_32, 32, 1, 1, 0, 0 };
+ if (msg.head.msgh_id == IO_SELECT_REPLY_MSGID &&
+ msg.head.msgh_size >= sizeof msg.error &&
+ !(msg.head.msgh_bits & MACH_MSGH_BITS_COMPLEX) &&
+ *(int *) &msg.error.err_type == *(int *) &inttype)
+ {
+ /* This is a properly formatted message so far.
+ See if it is a success or a failure. */
+ if (msg.error.err)
+ {
+ err = msg.error.err;
+ if (msg.head.msgh_size != sizeof msg.error)
+ __mach_msg_destroy (&msg);
+ }
+ else if (msg.head.msgh_size != sizeof msg.success ||
+ *(int *) &msg.success.tag_type != *(int *) &inttype ||
+ *(int *) &msg.success.result_type != *(int *) &inttype)
+ __mach_msg_destroy (&msg);
+ else if ((msg.success.result &
+ (SELECT_READ|SELECT_WRITE|SELECT_URG)) == 0 ||
+ msg.success.tag < firstfd || msg.success.tag > lastfd)
+ err = EGRATUITOUS;
+ else
+ {
+ /* This is a winning io_select_reply message!
+ Record the readiness it indicates and send a reply. */
+ if (types[msg.success.tag] == 0)
+ /* This descriptor is ready and it was not before,
+ so we increment our count of ready descriptors. */
+ ++got;
+ types[msg.success.tag] |= msg.success.result;
+ }
+ }
+
+ if (msg.head.msgh_remote_port != MACH_PORT_NULL)
+ __mach_port_deallocate (__mach_task_self (),
+ msg.head.msgh_remote_port);
+
+ if (got || err == EINTR)
+ {
+ /* Poll for another message. */
+ to = 0;
+ options |= MACH_RCV_TIMEOUT;
+ }
+ }
+
+ if (err == MACH_RCV_TIMED_OUT)
+ /* This is the normal value for ERR. We might have timed out and
+ read no messages. Otherwise, after receiving the first message,
+ we poll for more messages. We receive with a timeout of 0 to
+ effect a poll, so ERR is MACH_RCV_TIMED_OUT when the poll finds no
+ message waiting. */
+ err = 0;
+
+ if (got && err == EINTR)
+ /* Some calls were interrupted, but at least one descriptor
+ is known to be ready now, so we will return success. */
+ err = 0;
+ }
+
+ if (port != MACH_PORT_NULL)
+ /* We must destroy the port if we made some select requests
+ that might send notification on that port after we no longer care.
+ If the port were reused, that notification could confuse the next
+ select call to use the port. The notification might be valid,
+ but the descriptor may have changed to a different server. */
+ __mach_port_destroy (__mach_task_self (), port);
+
+ if (timeout && got == 0 && err == MACH_RCV_TIMED_OUT)
+ /* No io_select call returned success immediately, and the last call
+ blocked for our full timeout period and then timed out. So the
+ multiplex times out too. */
+ return 0;
+
+ if (err)
+ return __hurd_fail (err);
+
+ /* Set the user bitarrays. */
+ for (i = 0; i < nfds; ++i)
+ {
+ if (readfds != NULL)
+ if (types[i] & SELECT_READ)
+ FD_SET (i, readfds);
+ else
+ FD_CLR (i, readfds);
+ if (writefds != NULL)
+ if (types[i] & SELECT_WRITE)
+ FD_SET (i, writefds);
+ else
+ FD_CLR (i, writefds);
+ if (exceptfds != NULL)
+ if (types[i] & SELECT_URG)
+ FD_SET (i, exceptfds);
+ else
+ FD_CLR (i, exceptfds);
+ }
+
+ return got;
+}
+
+weak_alias (__select, select)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 15:02:49 +0000