diff options
Diffstat (limited to 'libports/begin-rpc.c')
| -rw-r--r-- | libports/begin-rpc.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/libports/begin-rpc.c b/libports/begin-rpc.c new file mode 100644 index 00000000..ebe3473c --- /dev/null +++ b/libports/begin-rpc.c @@ -0,0 +1,111 @@ +/* + Copyright (C) 1995, 1996 Free Software Foundation, Inc. + Written by Michael I. Bushnell. + + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "ports.h" +#include <cthreads.h> + +#define INHIBITED (PORTS_INHIBITED | PORTS_INHIBIT_WAIT) + +error_t +ports_begin_rpc (void *portstruct, mach_msg_id_t msg_id, struct rpc_info *info) +{ + int *block_flags = 0; + + struct port_info *pi = portstruct; + + mutex_lock (&_ports_lock); + + do + { + /* If our receive right is gone, then abandon the RPC. */ + if (pi->port_right == MACH_PORT_NULL) + { + mutex_unlock (&_ports_lock); + return EOPNOTSUPP; + } + + if (_ports_flags & INHIBITED) + /* All RPC's are inhibited. */ + block_flags = &_ports_flags; + else if (pi->bucket->flags & INHIBITED) + /* RPC's are inhibited for this port's bucket. */ + block_flags = &pi->bucket->flags; + else if (pi->class->flags & INHIBITED) + /* RPC's are inhibited for this port's class. */ + block_flags = &pi->class->flags; + else if (pi->flags & INHIBITED) + /* RPC's are inhibited for this port itself. */ + block_flags = &pi->flags; + else + block_flags = 0; + + if (block_flags) + /* We maybe want to block. */ + { + if (msg_id) + /* See if this particular RPC shouldn'be be inhibitable. */ + { + struct ports_msg_id_range *range = pi->class->uninhibitable_rpcs; + while (range) + if (msg_id >= range->start && msg_id < range->end) + { + block_flags = 0; + break; + } + else + range = range->next; + } + + if (block_flags) + { + *block_flags |= PORTS_BLOCKED; + if (hurd_condition_wait (&_ports_block, &_ports_lock)) + /* We've been cancelled, just return EINTR. If we were the + only one blocking, PORTS_BLOCKED will still be turned on, + but that's ok, it will just cause a (harmless) extra + condition_broadcast(). */ + { + mutex_unlock (&_ports_lock); + return EINTR; + } + } + } + } + while (block_flags); + + /* Record that that an RPC is in progress */ + info->thread = hurd_thread_self (); + info->next = pi->current_rpcs; + info->notifies = 0; + if (pi->current_rpcs) + pi->current_rpcs->prevp = &info->next; + info->prevp = &pi->current_rpcs; + pi->current_rpcs = info; + + pi->class->rpcs++; + pi->bucket->rpcs++; + _ports_total_rpcs++; + + mutex_unlock (&_ports_lock); + + return 0; +} + + |