Computer Laboratory

tesla_class_perthread.c
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1 /*-
2  * Copyright (c) 2011, 2013 Robert N. M. Watson
3  * Copyright (c) 2012-2013 Jonathan Anderson
4  * All rights reserved.
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
8  * ("CTSRD"), as part of the DARPA CRASH research programme.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  * notice, this list of conditions and the following disclaimer in the
17  * documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $Id$
32  */
33 
34 #include "tesla_internal.h"
35 
36 /*
37  * Routines for managing TESLA per-thread state, used in per-thread automata.
38  * Kernel and userspace implementations differ quite a lot, due to very
39  * different guarantees for kernel per-thread storage and pthread
40  * thread-specific state. For example, the kernel implementation guarantees
41  * that space will be available if the initial tesla_class allocation
42  * succeedes, and instruments thread create and destroy to ensure this is the
43  * case. However, it has to do a lot more book-keeping, and allocates space
44  * that might never be used. In userspace, per-thread state is allocated the
45  * first time TESLA sees the thread, but malloc may fail, meaning that TESLA
46  * has to handle the possibility of not finding the state it needs.
47  */
48 
49 #ifdef _KERNEL
50 
51 /*
52  * Registration state for per-thread storage.
53  */
54 static eventhandler_tag tesla_perthread_ctor_tag;
55 static eventhandler_tag tesla_perthread_dtor_tag;
56 
57 static void
58 tesla_perthread_ctor(__unused void *arg, struct thread *td)
59 {
60  struct tesla_store *store;
61  uint32_t error;
62 
63  store = tesla_malloc(sizeof(*store));
64  error = tesla_store_init(store, TESLA_CONTEXT_THREAD,
65  TESLA_MAX_CLASSES, TESLA_MAX_INSTANCES);
66  tesla_assert(error == TESLA_SUCCESS, ("tesla_store_init failed"));
67  td->td_tesla = store;
68 }
69 
70 static void
71 tesla_perthread_dtor(__unused void *arg, struct thread *td)
72 {
73  struct tesla_store *store;
74 
75  store = td->td_tesla;
76  td->td_tesla = NULL;
77  tesla_store_free(store);
78 }
79 
80 static void
81 tesla_perthread_sysinit(__unused void *arg)
82 {
83 
84  tesla_perthread_ctor_tag = EVENTHANDLER_REGISTER(thread_ctor,
85  tesla_perthread_ctor, NULL, EVENTHANDLER_PRI_ANY);
86  tesla_perthread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor,
87  tesla_perthread_dtor, NULL, EVENTHANDLER_PRI_ANY);
88 }
89 SYSINIT(tesla_perthread, SI_SUB_TESLA, SI_ORDER_FIRST,
90  tesla_perthread_sysinit, NULL);
91 
92 #endif /* !_KERNEL */
93 
94 int
95 tesla_class_perthread_postinit(__unused struct tesla_class *c)
96 {
97  return 0;
98 }
99 
100 void
101 tesla_class_perthread_acquire(__unused struct tesla_class *c)
102 {
103 }
104 
105 void
106 tesla_class_perthread_release(__unused struct tesla_class *c)
107 {
108 }
109 
110 void
111 tesla_class_perthread_destroy(__unused struct tesla_class *c)
112 {
113 }