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/*
Copyright (C) 1995,96,2000,02 Free Software Foundation, Inc.
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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include "pfinet.h"
#include <asm/system.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
struct mutex global_lock = MUTEX_INITIALIZER;
struct mutex net_bh_lock = MUTEX_INITIALIZER;
struct condition net_bh_wakeup = CONDITION_INITIALIZER;
struct task_struct current_contents; /* zeros are right default values */
/* Wake up the owner of the SOCK. If HOW is zero, then just
send SIGIO. If HOW is one, then send SIGIO only if the
SO_WAITDATA flag is off. If HOW is two, then send SIGIO
only if the SO_NOSPACE flag is on, and also clear it. */
int
sock_wake_async (struct socket *sock, int how)
{
/* For now, do nothing. XXX */
return 0;
}
/* This function is the "net_bh worker thread".
The packet receiver thread calls net/core/dev.c::netif_rx with a packet;
netif_rx either drops the packet, or enqueues it and wakes us up
via mark_bh which is really condition_broadcast on net_bh_wakeup.
The packet receiver thread holds net_bh_lock while calling netif_rx.
We wake up and take global_lock, which locks out RPC service threads.
We then also take net_bh_lock running net_bh.
Thus, only this thread running net_bh locks out the packet receiver
thread (which takes only net_bh_lock while calling netif_rx), so packets
are quickly moved from the Mach port's message queue to the `backlog'
queue, or dropped, without synchronizing with RPC service threads.
(The RPC service threads lock out the running of net_bh, but not
the queuing/dropping of packets in netif_rx.) */
any_t
net_bh_worker (any_t arg)
{
char *str1 = "pfinet net_bh_worker before locking net_bh_lock";
char *str2 = "pfinet net_bh_worker after locking net_bh_lock";
char *str3 = "pfinet net_bh_worker after unlocking net_bh_lock";
int stderr_fd = fileno (stderr);
__mutex_lock (&global_lock);
while (1)
{
condition_wait (&net_bh_wakeup, &global_lock);
write (stderr_fd, str1, strlen (str1) + 1);
fflush (stderr);
__mutex_lock (&net_bh_lock);
write (stderr_fd, str2, strlen (str2) + 1);
fflush (stderr);
net_bh ();
__mutex_unlock (&net_bh_lock);
write (stderr_fd, str3, strlen (str3) + 1);
fflush (stderr);
}
/*NOTREACHED*/
return 0;
}
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