1 /* Replacement for mach_msg used in interruptible Hurd RPCs.
2 Copyright (C) 1995, 1996 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If
17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
18 Cambridge, MA 02139, USA. */
21 #include <mach/mig_errors.h>
22 #include <mach/mig_support.h>
23 #include <hurd/signal.h>
29 _hurd_intr_rpc_mach_msg (mach_msg_header_t
*msg
,
30 mach_msg_option_t option
,
31 mach_msg_size_t send_size
,
32 mach_msg_size_t rcv_size
,
34 mach_msg_timeout_t timeout
,
37 struct hurd_sigstate
*ss
= _hurd_self_sigstate ();
39 /* Notice now if the user requested a timeout. OPTION may have the bit
40 added by interruption semantics, and we must distinguish. */
41 int user_timeout
= option
& MACH_RCV_TIMEOUT
;
43 /* Tell the signal thread that we are doing an interruptible RPC on
44 this port. If we get a signal and should return EINTR, the signal
45 thread will set this variable to MACH_PORT_NULL. The RPC might
46 return EINTR when some other thread gets a signal, in which case we
47 want to restart our call. */
48 ss
->intr_port
= msg
->msgh_remote_port
;
50 /* A signal may arrive here, after intr_port is set, but before
51 the mach_msg system call. The signal handler might do an
52 interruptible RPC, and clobber intr_port; then it would not be
53 set properly when we actually did send the RPC, and a later
54 signal wouldn't interrupt that RPC. So,
55 _hurd_setup_sighandler saves intr_port in the sigcontext, and
56 sigreturn restores it. */
66 err
= INTR_MSG_TRAP (msg
, option
, send_size
,
67 rcv_size
, rcv_name
, timeout
, notify
);
71 case MACH_RCV_TIMED_OUT
:
73 /* The real user RPC timed out. */
76 /* The operation was supposedly interrupted, but still has
77 not returned. Declare it interrupted. */
80 case MACH_SEND_INTERRUPTED
: /* RPC didn't get out. */
81 case EINTR
: /* Server not cooperating with interrupt. */
82 if (ss
->intr_port
!= MACH_PORT_NULL
)
83 /* If this signal was for us and it should interrupt calls, the
84 signal thread will have cleared SS->intr_port.
85 Since it's not cleared, the signal was for another thread,
86 or SA_RESTART is set. Restart the interrupted call. */
89 if (rcv_name
!= MACH_PORT_NULL
)
90 /* Make sure we have a valid reply port. The one we were using
91 may have been destroyed by interruption. */
92 msg
->msgh_local_port
= rcv_name
= __mig_get_reply_port ();
97 case MACH_RCV_PORT_DIED
:
98 /* Server didn't respond to interrupt_operation,
99 so the signal thread destroyed the reply port. */
105 /* The EINTR return indicates cancellation, so clear the flag. */
109 case MACH_RCV_INTERRUPTED
: /* RPC sent; no reply. */
110 option
&= ~MACH_SEND_MSG
; /* Don't send again. */
111 if (ss
->intr_port
== MACH_PORT_NULL
)
113 /* This signal or cancellation was for us. We need to wait for
114 the reply, but not hang forever. */
115 option
|= MACH_RCV_TIMEOUT
;
116 /* Never decrease the user's timeout. */
117 if (!user_timeout
|| timeout
> _hurd_interrupted_rpc_timeout
)
118 timeout
= _hurd_interrupted_rpc_timeout
;
120 goto message
; /* Retry the receive. */
122 case MACH_MSG_SUCCESS
:
123 if (option
& MACH_RCV_MSG
)
125 /* We got a reply. Was it EINTR? */
126 mig_reply_header_t
*const reply
= (void *) msg
;
133 MACH_MSG_TYPE_INTEGER_32
,
141 if (msg
->msgh_size
== sizeof *reply
&&
142 !(msg
->msgh_bits
& MACH_MSGH_BITS_COMPLEX
) &&
143 *(int *) &reply
->RetCodeType
== check
.i
&&
144 reply
->RetCode
== EINTR
)
146 /* It is indeed EINTR. Is the interrupt for us? */
147 if (ss
->intr_port
!= MACH_PORT_NULL
)
148 /* Nope; repeat the RPC.
149 XXX Resources moved? */
152 /* The EINTR return indicates cancellation, so clear the
159 default: /* Quiet -Wswitch-enum. */
162 ss
->intr_port
= MACH_PORT_NULL
;