file kaio_mq_setattr.c was initially added on branch fedora-branch.
[glibc/history.git] / hurd / intr-msg.c
blob0ca6af35804009762d945fec77693c2d86fcd7a0
1 /* Replacement for mach_msg used in interruptible Hurd RPCs.
2 Copyright (C) 1995,96,97,98,99,2000,2001,2002,2005
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 #include <mach.h>
22 #include <mach/mig_errors.h>
23 #include <mach/mig_support.h>
24 #include <hurd/signal.h>
25 #include <assert.h>
27 #include "intr-msg.h"
29 #ifdef NDR_CHAR_ASCII /* OSF Mach flavors have different names. */
30 # define mig_reply_header_t mig_reply_error_t
31 #endif
33 error_t
34 _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg,
35 mach_msg_option_t option,
36 mach_msg_size_t send_size,
37 mach_msg_size_t rcv_size,
38 mach_port_t rcv_name,
39 mach_msg_timeout_t timeout,
40 mach_port_t notify)
42 error_t err;
43 struct hurd_sigstate *ss;
44 const mach_msg_option_t user_option = option;
45 const mach_msg_timeout_t user_timeout = timeout;
47 struct clobber
49 #ifdef NDR_CHAR_ASCII
50 NDR_record_t ndr;
51 #else
52 mach_msg_type_t type;
53 #endif
54 error_t err;
56 union msg
58 mach_msg_header_t header;
59 mig_reply_header_t reply;
60 struct
62 mach_msg_header_t header;
63 #ifdef NDR_CHAR_ASCII
64 NDR_record_t ndr;
65 #else
66 int type;
67 #endif
68 int code;
69 } check;
70 struct
72 mach_msg_header_t header;
73 struct clobber data;
74 } request;
76 union msg *const m = (void *) msg;
77 mach_msg_bits_t msgh_bits;
78 mach_port_t remote_port;
79 mach_msg_id_t msgid;
80 struct clobber save_data;
82 if ((option & (MACH_SEND_MSG|MACH_RCV_MSG)) != (MACH_SEND_MSG|MACH_RCV_MSG)
83 || _hurd_msgport_thread == MACH_PORT_NULL)
85 /* Either this is not an RPC (i.e., only a send or only a receive),
86 so it can't be interruptible; or, the signal thread is not set up
87 yet, so we cannot do the normal signal magic. Do a normal,
88 uninterruptible mach_msg call instead. */
89 return __mach_msg (&m->header, option, send_size, rcv_size, rcv_name,
90 timeout, notify);
93 ss = _hurd_self_sigstate ();
95 /* Save state that gets clobbered by an EINTR reply message.
96 We will need to restore it if we want to retry the RPC. */
97 msgh_bits = m->header.msgh_bits;
98 remote_port = m->header.msgh_remote_port;
99 msgid = m->header.msgh_id;
100 assert (rcv_size >= sizeof m->request);
101 save_data = m->request.data;
103 /* Tell the signal thread that we are doing an interruptible RPC on
104 this port. If we get a signal and should return EINTR, the signal
105 thread will set this variable to MACH_PORT_NULL. The RPC might
106 return EINTR when some other thread gets a signal, in which case we
107 want to restart our call. */
108 ss->intr_port = m->header.msgh_remote_port;
110 /* A signal may arrive here, after intr_port is set, but before the
111 mach_msg system call. The signal handler might do an interruptible
112 RPC, and clobber intr_port; then it would not be set properly when we
113 actually did send the RPC, and a later signal wouldn't interrupt that
114 RPC. So, _hurd_setup_sighandler saves intr_port in the sigcontext,
115 and sigreturn restores it. */
117 message:
119 /* XXX
120 At all points here (once SS->intr_port is set), the signal thread
121 thinks we are "about to enter the syscall", and might mutate our
122 return-value register. This is bogus.
125 if (ss->cancel)
127 /* We have been cancelled. Don't do an RPC at all. */
128 ss->intr_port = MACH_PORT_NULL;
129 ss->cancel = 0;
130 return EINTR;
133 /* Note that the signal trampoline code might modify our OPTION! */
134 err = INTR_MSG_TRAP (msg, option, send_size,
135 rcv_size, rcv_name, timeout, notify);
137 switch (err)
139 case MACH_RCV_TIMED_OUT:
140 if (user_option & MACH_RCV_TIMEOUT)
141 /* The real user RPC timed out. */
142 break;
143 else
144 /* The operation was supposedly interrupted, but still has
145 not returned. Declare it interrupted. */
146 goto interrupted;
148 case MACH_SEND_INTERRUPTED: /* RPC didn't get out. */
149 if (!(option & MACH_SEND_MSG))
151 /* Oh yes, it did! Since we were not doing a message send,
152 this return code cannot have come from the kernel!
153 Instead, it was the signal thread mutating our state to tell
154 us not to enter this RPC. However, we are already in the receive!
155 Since the signal thread thought we weren't in the RPC yet,
156 it didn't do an interrupt_operation.
157 XXX */
158 goto retry_receive;
160 /* FALLTHROUGH */
162 /* These are the other codes that mean a pseudo-receive modified
163 the message buffer and we might need to clean up the port rights. */
164 case MACH_SEND_TIMED_OUT:
165 case MACH_SEND_INVALID_NOTIFY:
166 #ifdef MACH_SEND_NO_NOTIFY
167 case MACH_SEND_NO_NOTIFY:
168 #endif
169 #ifdef MACH_SEND_NOTIFY_IN_PROGRESS
170 case MACH_SEND_NOTIFY_IN_PROGRESS:
171 #endif
172 if (MACH_MSGH_BITS_REMOTE (msg->msgh_bits) == MACH_MSG_TYPE_MOVE_SEND)
174 __mach_port_deallocate (__mach_task_self (), msg->msgh_remote_port);
175 msg->msgh_bits
176 = (MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND,
177 MACH_MSGH_BITS_LOCAL (msg->msgh_bits))
178 | MACH_MSGH_BITS_OTHER (msg->msgh_bits));
180 if (msg->msgh_bits & MACH_MSGH_BITS_COMPLEX)
182 #ifndef MACH_MSG_PORT_DESCRIPTOR
183 /* Check for MOVE_SEND rights in the message. These hold refs
184 that we need to release in case the message is in fact never
185 re-sent later. Since it might in fact be re-sent, we turn
186 these into COPY_SEND's after deallocating the extra user ref;
187 the caller is responsible for still holding a ref to go with
188 the original COPY_SEND right, so the resend copies it again. */
190 mach_msg_type_long_t *ty = (void *) (msg + 1);
191 while ((void *) ty < (void *) msg + msg->msgh_size)
193 mach_msg_type_name_t name;
194 mach_msg_type_size_t size;
195 mach_msg_type_number_t number;
197 inline void clean_ports (mach_port_t *ports, int dealloc)
199 mach_msg_type_number_t i;
200 switch (name)
202 case MACH_MSG_TYPE_MOVE_SEND:
203 for (i = 0; i < number; i++)
204 __mach_port_deallocate (__mach_task_self (), *ports++);
205 if (ty->msgtl_header.msgt_longform)
206 ty->msgtl_name = MACH_MSG_TYPE_COPY_SEND;
207 else
208 ty->msgtl_header.msgt_name = MACH_MSG_TYPE_COPY_SEND;
209 break;
210 case MACH_MSG_TYPE_COPY_SEND:
211 case MACH_MSG_TYPE_MOVE_RECEIVE:
212 break;
213 default:
214 if (MACH_MSG_TYPE_PORT_ANY (name))
215 assert (! "unexpected port type in interruptible RPC");
217 if (dealloc)
218 __vm_deallocate (__mach_task_self (),
219 (vm_address_t) ports,
220 number * sizeof (mach_port_t));
223 if (ty->msgtl_header.msgt_longform)
225 name = ty->msgtl_name;
226 size = ty->msgtl_size;
227 number = ty->msgtl_number;
228 ty = (void *) ty + sizeof (mach_msg_type_long_t);
230 else
232 name = ty->msgtl_header.msgt_name;
233 size = ty->msgtl_header.msgt_size;
234 number = ty->msgtl_header.msgt_number;
235 ty = (void *) ty + sizeof (mach_msg_type_t);
238 if (ty->msgtl_header.msgt_inline)
240 clean_ports ((void *) ty, 0);
241 /* calculate length of data in bytes, rounding up */
242 ty = (void *) ty + (((((number * size) + 7) >> 3)
243 + sizeof (mach_msg_type_t) - 1)
244 &~ (sizeof (mach_msg_type_t) - 1));
246 else
248 clean_ports (*(void **) ty,
249 ty->msgtl_header.msgt_deallocate);
250 ty = (void *) ty + sizeof (void *);
253 #else /* Untyped Mach IPC flavor. */
254 mach_msg_body_t *body = (void *) (msg + 1);
255 mach_msg_descriptor_t *desc = (void *) (body + 1);
256 mach_msg_descriptor_t *desc_end = desc + body->msgh_descriptor_count;
257 for (; desc < desc_end; ++desc)
258 switch (desc->type.type)
260 case MACH_MSG_PORT_DESCRIPTOR:
261 switch (desc->port.disposition)
263 case MACH_MSG_TYPE_MOVE_SEND:
264 __mach_port_deallocate (mach_task_self (),
265 desc->port.name);
266 desc->port.disposition = MACH_MSG_TYPE_COPY_SEND;
267 break;
268 case MACH_MSG_TYPE_COPY_SEND:
269 case MACH_MSG_TYPE_MOVE_RECEIVE:
270 break;
271 default:
272 assert (! "unexpected port type in interruptible RPC");
274 break;
275 case MACH_MSG_OOL_DESCRIPTOR:
276 if (desc->out_of_line.deallocate)
277 __vm_deallocate (__mach_task_self (),
278 (vm_address_t) desc->out_of_line.address,
279 desc->out_of_line.size);
280 break;
281 case MACH_MSG_OOL_PORTS_DESCRIPTOR:
282 switch (desc->ool_ports.disposition)
284 case MACH_MSG_TYPE_MOVE_SEND:
286 mach_msg_size_t i;
287 const mach_port_t *ports = desc->ool_ports.address;
288 for (i = 0; i < desc->ool_ports.count; ++i)
289 __mach_port_deallocate (__mach_task_self (), ports[i]);
290 desc->ool_ports.disposition = MACH_MSG_TYPE_COPY_SEND;
291 break;
293 case MACH_MSG_TYPE_COPY_SEND:
294 case MACH_MSG_TYPE_MOVE_RECEIVE:
295 break;
296 default:
297 assert (! "unexpected port type in interruptible RPC");
299 if (desc->ool_ports.deallocate)
300 __vm_deallocate (__mach_task_self (),
301 (vm_address_t) desc->ool_ports.address,
302 desc->ool_ports.count
303 * sizeof (mach_port_t));
304 break;
305 default:
306 assert (! "unexpected descriptor type in interruptible RPC");
308 #endif
310 break;
312 case EINTR:
313 /* Either the process was stopped and continued,
314 or the server doesn't support interrupt_operation. */
315 if (ss->intr_port != MACH_PORT_NULL)
316 /* If this signal was for us and it should interrupt calls, the
317 signal thread will have cleared SS->intr_port.
318 Since it's not cleared, the signal was for another thread,
319 or SA_RESTART is set. Restart the interrupted call. */
321 /* Make sure we have a valid reply port. The one we were using
322 may have been destroyed by interruption. */
323 m->header.msgh_local_port = rcv_name = __mig_get_reply_port ();
324 m->header.msgh_bits = msgh_bits;
325 option = user_option;
326 timeout = user_timeout;
327 goto message;
329 /* FALLTHROUGH */
331 case MACH_RCV_PORT_DIED:
332 /* Server didn't respond to interrupt_operation,
333 so the signal thread destroyed the reply port. */
334 /* FALLTHROUGH */
336 interrupted:
337 err = EINTR;
339 /* The EINTR return indicates cancellation, so clear the flag. */
340 ss->cancel = 0;
341 break;
343 case MACH_RCV_INTERRUPTED: /* RPC sent; no reply. */
344 option &= ~MACH_SEND_MSG; /* Don't send again. */
345 retry_receive:
346 if (ss->intr_port == MACH_PORT_NULL)
348 /* This signal or cancellation was for us. We need to wait for
349 the reply, but not hang forever. */
350 option |= MACH_RCV_TIMEOUT;
351 /* Never decrease the user's timeout. */
352 if (!(user_option & MACH_RCV_TIMEOUT)
353 || timeout > _hurd_interrupted_rpc_timeout)
354 timeout = _hurd_interrupted_rpc_timeout;
356 else
358 option = user_option;
359 timeout = user_timeout;
361 goto message; /* Retry the receive. */
363 case MACH_MSG_SUCCESS:
365 /* We got a reply. Was it EINTR? */
366 #ifdef MACH_MSG_TYPE_BIT
367 const union
369 mach_msg_type_t t;
370 int i;
371 } check =
372 { t: { MACH_MSG_TYPE_INTEGER_T, sizeof (integer_t) * 8,
373 1, TRUE, FALSE, FALSE, 0 } };
374 #endif
376 if (m->reply.RetCode == EINTR &&
377 m->header.msgh_size == sizeof m->reply &&
378 #ifdef MACH_MSG_TYPE_BIT
379 m->check.type == check.i &&
380 #endif
381 !(m->header.msgh_bits & MACH_MSGH_BITS_COMPLEX))
383 /* It is indeed EINTR. Is the interrupt for us? */
384 if (ss->intr_port != MACH_PORT_NULL)
386 /* Nope; repeat the RPC.
387 XXX Resources moved? */
389 assert (m->header.msgh_id == msgid + 100);
391 /* We know we have a valid reply port, because we just
392 received the EINTR reply on it. Restore it and the
393 other fields in the message header needed for send,
394 since the header now reflects receipt of the reply. */
395 m->header.msgh_local_port = rcv_name;
396 m->header.msgh_remote_port = remote_port;
397 m->header.msgh_id = msgid;
398 m->header.msgh_bits = msgh_bits;
399 /* Restore the two words clobbered by the reply data. */
400 m->request.data = save_data;
402 /* Restore the original mach_msg options.
403 OPTION may have had MACH_RCV_TIMEOUT added,
404 and/or MACH_SEND_MSG removed. */
405 option = user_option;
406 timeout = user_timeout;
408 /* Now we are ready to repeat the original message send. */
409 goto message;
411 else
412 /* The EINTR return indicates cancellation,
413 so clear the flag. */
414 ss->cancel = 0;
417 break;
419 default: /* Quiet -Wswitch-enum. */
420 break;
423 ss->intr_port = MACH_PORT_NULL;
425 return err;