b03d17694a
but probably doesn't work. That's for someone who understand this code better.
294 lines
8.5 KiB
C
294 lines
8.5 KiB
C
/* $NetBSD: mach_semaphore.c,v 1.5 2003/01/21 04:06:08 matt Exp $ */
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/*-
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* Copyright (c) 2002 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Emmanuel Dreyfus
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: mach_semaphore.c,v 1.5 2003/01/21 04:06:08 matt Exp $");
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/signal.h>
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#include <sys/pool.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <compat/mach/mach_types.h>
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#include <compat/mach/mach_message.h>
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#include <compat/mach/mach_semaphore.h>
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#include <compat/mach/mach_clock.h>
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#include <compat/mach/mach_syscallargs.h>
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/* Semaphore list, lock, pools */
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static LIST_HEAD(mach_semaphore_list, mach_semaphore) mach_semaphore_list;
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static struct lock mach_semaphore_list_lock;
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static struct pool mach_semaphore_list_pool;
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static struct pool mach_waiting_proc_pool;
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/* Function to manipulate them */
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static struct mach_semaphore *mach_semaphore_get(int, int);
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static void mach_semaphore_put(struct mach_semaphore *);
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static struct mach_waiting_proc *mach_waiting_proc_get
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(struct proc *, struct mach_semaphore *);
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static void mach_waiting_proc_put
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(struct mach_waiting_proc *, struct mach_semaphore *, int);
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int
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mach_sys_semaphore_wait_trap(l, v, retval)
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struct lwp *l;
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void *v;
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register_t *retval;
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{
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struct mach_sys_semaphore_wait_trap_args /* {
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syscallarg(mach_port_name_t) wait_name;
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} */ *uap = v;
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struct mach_semaphore *ms;
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struct mach_waiting_proc *mwp;
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int blocked = 0;
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ms = (struct mach_semaphore *)SCARG(uap, wait_name);
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lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);
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ms->ms_value--;
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if (ms->ms_value < 0)
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blocked = 1;
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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if (blocked != 0) {
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mwp = mach_waiting_proc_get(l->l_proc, ms);
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while (ms->ms_value < 0)
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tsleep(mwp, PZERO|PCATCH, "sem_wait", 0);
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mach_waiting_proc_put(mwp, ms, 0);
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}
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return 0;
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}
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int
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mach_sys_semaphore_signal_trap(l, v, retval)
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struct lwp *l;
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void *v;
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register_t *retval;
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{
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struct mach_sys_semaphore_signal_trap_args /* {
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syscallarg(mach_port_name_t) signal_name;
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} */ *uap = v;
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struct mach_semaphore *ms;
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struct mach_waiting_proc *mwp;
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int unblocked = 0;
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ms = (struct mach_semaphore *)SCARG(uap, signal_name);
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lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);
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ms->ms_value++;
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if (ms->ms_value >= 0)
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unblocked = 1;
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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if (unblocked != 0) {
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lockmgr(&ms->ms_lock, LK_SHARED, NULL);
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mwp = TAILQ_FIRST(&ms->ms_waiting);
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wakeup(mwp);
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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}
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return 0;
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}
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int
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mach_semaphore_create(args)
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struct mach_trap_args *args;
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{
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mach_semaphore_create_request_t *req = args->smsg;
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mach_semaphore_create_reply_t *rep = args->rmsg;
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size_t *msglen = args->rsize;
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struct mach_semaphore *ms;
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ms = mach_semaphore_get(req->req_value, req->req_policy);
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rep->rep_msgh.msgh_bits =
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MACH_MSGH_REPLY_LOCAL_BITS(MACH_MSG_TYPE_MOVE_SEND_ONCE);
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rep->rep_msgh.msgh_size = sizeof(*rep) - sizeof(rep->rep_trailer);
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rep->rep_msgh.msgh_local_port = req->req_msgh.msgh_local_port;
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rep->rep_msgh.msgh_id = req->req_msgh.msgh_id + 100;
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rep->rep_sem.name = (mach_port_t)ms; /* Waiting for better */
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rep->rep_trailer.msgh_trailer_size = 8;
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*msglen = sizeof(*rep);
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return 0;
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}
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int
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mach_semaphore_destroy(args)
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struct mach_trap_args *args;
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{
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mach_semaphore_destroy_request_t *req = args->smsg;
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mach_semaphore_destroy_reply_t *rep = args->rmsg;
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size_t *msglen = args->rsize;
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struct mach_semaphore *ms;
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ms = (struct mach_semaphore *)req->req_sem.name;
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mach_semaphore_put(ms);
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rep->rep_msgh.msgh_bits =
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MACH_MSGH_REPLY_LOCAL_BITS(MACH_MSG_TYPE_MOVE_SEND_ONCE);
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rep->rep_msgh.msgh_size = sizeof(*rep) - sizeof(rep->rep_trailer);
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rep->rep_msgh.msgh_local_port = req->req_msgh.msgh_local_port;
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rep->rep_msgh.msgh_id = req->req_msgh.msgh_id + 100;
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rep->rep_trailer.msgh_trailer_size = 8;
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*msglen = sizeof(*rep);
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return 0;
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}
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void
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mach_semaphore_init(void)
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{
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LIST_INIT(&mach_semaphore_list);
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lockinit(&mach_semaphore_list_lock, PZERO|PCATCH, "mach_sem", 0, 0);
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pool_init(&mach_semaphore_list_pool, sizeof (struct mach_semaphore),
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0, 0, 128, "mach_sem_pool", NULL);
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pool_init(&mach_waiting_proc_pool, sizeof (struct mach_waiting_proc),
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0, 0, 128, "mach_waitp_pool", NULL);
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return;
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}
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static struct mach_semaphore *
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mach_semaphore_get(value, policy)
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int value;
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int policy;
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{
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struct mach_semaphore *ms;
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ms = (struct mach_semaphore *)pool_get(&mach_semaphore_list_pool,
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M_WAITOK);
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ms->ms_value = value;
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ms->ms_policy = policy;
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TAILQ_INIT(&ms->ms_waiting);
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lockinit(&ms->ms_lock, PZERO|PCATCH, "mach_waitp", 0, 0);
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lockmgr(&mach_semaphore_list_lock, LK_EXCLUSIVE, NULL);
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LIST_INSERT_HEAD(&mach_semaphore_list, ms, ms_list);
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lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
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return ms;
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}
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static void
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mach_semaphore_put(ms)
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struct mach_semaphore *ms;
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{
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struct mach_waiting_proc *mwp;
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lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);
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while ((mwp = TAILQ_FIRST(&ms->ms_waiting)) != NULL)
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mach_waiting_proc_put(mwp, ms, 0);
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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lockmgr(&ms->ms_lock, LK_DRAIN, NULL);
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lockmgr(&mach_semaphore_list_lock, LK_EXCLUSIVE, NULL);
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LIST_REMOVE(ms, ms_list);
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lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
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pool_put(&mach_semaphore_list_pool, ms);
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return;
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}
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static struct mach_waiting_proc *
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mach_waiting_proc_get(p, ms)
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struct proc *p;
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struct mach_semaphore *ms;
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{
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struct mach_waiting_proc *mwp;
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mwp = (struct mach_waiting_proc *)pool_get(&mach_waiting_proc_pool,
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M_WAITOK);
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mwp->mwp_p = p;
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lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);
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TAILQ_INSERT_TAIL(&ms->ms_waiting, mwp, mwp_list);
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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return mwp;
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}
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static void
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mach_waiting_proc_put(mwp, ms, locked)
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struct mach_waiting_proc *mwp;
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struct mach_semaphore *ms;
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int locked;
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{
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if (!locked)
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lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);
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TAILQ_REMOVE(&ms->ms_waiting, mwp, mwp_list);
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if (!locked)
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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pool_put(&mach_waiting_proc_pool, mwp);
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return;
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}
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/*
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* Cleanup after process exit. Need improvements, there
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* can be some memory leaks here.
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*/
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void
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mach_semaphore_cleanup(p)
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struct proc *p;
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{
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struct mach_semaphore *ms;
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struct mach_waiting_proc *mwp;
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lockmgr(&mach_semaphore_list_lock, LK_SHARED, NULL);
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LIST_FOREACH(ms, &mach_semaphore_list, ms_list) {
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lockmgr(&ms->ms_lock, LK_SHARED, NULL);
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TAILQ_FOREACH(mwp, &ms->ms_waiting, mwp_list)
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if (mwp->mwp_p == p) {
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lockmgr(&ms->ms_lock, LK_UPGRADE, NULL);
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mach_waiting_proc_put(mwp, ms, 0);
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ms->ms_value++;
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if (ms->ms_value >= 0)
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wakeup(TAILQ_FIRST(&ms->ms_waiting));
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}
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lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
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}
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lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
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return;
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}
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