1/* uisthread.c
2 *
3 * Copyright (C) 2010 - 2013 UNISYS CORPORATION
4 * All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT.  See the GNU General Public License for more
15 * details.
16 */
17
18/* @ALL_INSPECTED */
19#include <asm/processor.h>
20#include <linux/signal.h>
21#include <linux/sched.h>
22#include <linux/kthread.h>
23#include "uniklog.h"
24#include "uisutils.h"
25#include "uisthread.h"
26
27#define KILL(a, b, c) kill_pid(find_vpid(a), b, c)
28
29/* this is shorter than using __FILE__ (full path name) in
30 * debug/info/error messages
31 */
32#define CURRENT_FILE_PC UISLIB_PC_uisthread_c
33#define __MYFILE__ "uisthread.c"
34
35/*****************************************************/
36/* Exported functions                                */
37/*****************************************************/
38
39/* returns 0 for failure, 1 for success */
40int
41uisthread_start(struct uisthread_info *thrinfo,
42		int (*threadfn)(void *), void *thrcontext, char *name)
43{
44	thrinfo->should_stop = 0;
45	/* used to stop the thread */
46	init_completion(&thrinfo->has_stopped);
47	thrinfo->task = kthread_create(threadfn, thrcontext, name, NULL);
48	if (IS_ERR(thrinfo->task)) {
49		thrinfo->id = 0;
50		return 0;	/* failure */
51	}
52	thrinfo->id = thrinfo->task->pid;
53	wake_up_process(thrinfo->task);
54	LOGINF("started thread pid:%d\n", thrinfo->id);
55	return 1;
56
57}
58EXPORT_SYMBOL_GPL(uisthread_start);
59
60void
61uisthread_stop(struct uisthread_info *thrinfo)
62{
63	int ret;
64	int stopped = 0;
65
66	if (thrinfo->id == 0)
67		return;		/* thread not running */
68
69	LOGINF("uisthread_stop stopping id:%d\n", thrinfo->id);
70	thrinfo->should_stop = 1;
71	ret = KILL(thrinfo->id, SIGHUP, 1);
72	if (ret) {
73		LOGERR("unable to signal thread %d\n", ret);
74	} else {
75		/* give up if the thread has NOT died in 1 minute */
76		if (wait_for_completion_timeout(&thrinfo->has_stopped, 60 * HZ))
77			stopped = 1;
78		else
79			LOGERR("timed out trying to signal thread\n");
80	}
81	if (stopped) {
82		LOGINF("uisthread_stop stopped id:%d\n", thrinfo->id);
83		thrinfo->id = 0;
84	}
85}
86EXPORT_SYMBOL_GPL(uisthread_stop);
87