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/*
* Copyright (C) 2006 Giridhar Pemmasani
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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.
*
*/
#include "ntoskernel.h"
/* workqueue implementation for 2.4 kernels */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8)
#define SIG_LOCK(t) (&(t)->sigmask_lock)
#else
#define SIG_LOCK(t) (&(t)->sighand->siglock)
#endif
static int workq_thread(void *data)
{
workqueue_struct_t *workq = data;
work_struct_t *work;
unsigned long flags;
lock_kernel();
strncpy(current->comm, workq->name, sizeof(current->comm));
current->comm[sizeof(current->comm) - 1] = 0;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,7)
daemonize();
#else
daemonize(workq->name);
#endif
unlock_kernel();
#ifdef PF_NOFREEZE
current->flags |= PF_NOFREEZE;
set_user_nice(current, -5);
#endif
while (1) {
if (wait_event_interruptible(workq->waitq_head,
workq->pending)) {
/* TODO: deal with signal */
spin_lock_irq(SIG_LOCK(current));
flush_signals(current);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,7)
recalc_sigpending(current);
#else
recalc_sigpending();
#endif
spin_unlock_irq(SIG_LOCK(current));
continue;
}
spin_lock_irqsave(&workq->lock, flags);
if (workq->pending-- < 0)
break;
if (list_empty(&workq->work_list))
work = NULL;
else {
struct list_head *entry = workq->work_list.next;
work = list_entry(entry, work_struct_t, list);
list_del(entry);
if (work->workq) {
assert(work->workq == workq);
work->workq = NULL;
} else
work = NULL;
}
spin_unlock_irqrestore(&workq->lock, flags);
if (work)
work->func(work->data);
}
/* set workq for each work to NULL so if cancel_delayed_work
* is called later, it won't access workq */
list_for_each_entry(work, &workq->work_list, list) {
work->workq = NULL;
}
spin_unlock_irqrestore(&workq->lock, flags);
WORKTRACE("%s exiting", workq->name);
workq->pid = 0;
return 0;
}
wfastcall void wrap_queue_work(workqueue_struct_t *workq, work_struct_t *work)
{
unsigned long flags;
spin_lock_irqsave(&workq->lock, flags);
if (!work->workq) {
work->workq = workq;
list_add_tail(&work->list, &workq->work_list);
workq->pending++;
wake_up_interruptible(&workq->waitq_head);
}
spin_unlock_irqrestore(&workq->lock, flags);
}
void wrap_cancel_delayed_work(work_struct_t *work)
{
workqueue_struct_t *workq;
unsigned long flags;
if ((workq = xchg(&work->workq, NULL))) {
spin_lock_irqsave(&workq->lock, flags);
list_del(&work->list);
/* don't decrement workq->pending here; otherwise, it
* may prematurely terminate the thread, as this work
* may already have been done (pending may have been
* decremented for it) */
spin_unlock_irqrestore(&workq->lock, flags);
}
}
workqueue_struct_t *wrap_create_wq(const char *name)
{
workqueue_struct_t *workq = kmalloc(sizeof(*workq), GFP_KERNEL);
if (!workq) {
WARNING("couldn't allocate memory");
return NULL;
}
memset(workq, 0, sizeof(*workq));
init_waitqueue_head(&workq->waitq_head);
spin_lock_init(&workq->lock);
workq->name = name;
INIT_LIST_HEAD(&workq->work_list);
/* we don't need to wait for thread to start, so completion
* not used */
workq->pid = kernel_thread(workq_thread, workq, 0);
if (workq->pid <= 0) {
kfree(workq);
WARNING("couldn't start thread %s", name);
return NULL;
}
return workq;
}
void wrap_destroy_wq(workqueue_struct_t *workq)
{
while (workq->pid) {
workq->pending = -1;
wake_up_interruptible(&workq->waitq_head);
schedule();
}
kfree(workq);
}
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