summaryrefslogtreecommitdiff
path: root/src/mapi/stub.c
blob: 45ccc6a3acfa8b3a295b94777c3f35ec1873d709 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 2010 LunarG Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Chia-I Wu <olv@lunarg.com>
 */

#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "u_current.h"
#include "u_thread.h"
#include "entry.h"
#include "stub.h"
#include "table.h"

#define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))

struct mapi_stub {
   const void *name;
   int slot;
   mapi_func addr;
};

/* define public_string_pool and public_stubs */
#define MAPI_TMP_PUBLIC_STUBS
#include "mapi_tmp.h"

static struct mapi_stub dynamic_stubs[MAPI_TABLE_NUM_DYNAMIC];
static int num_dynamic_stubs;
static int next_dynamic_slot = MAPI_TABLE_NUM_STATIC;

void
stub_init_once(void)
{
#ifdef HAVE_PTHREAD
   static pthread_once_t once = PTHREAD_ONCE_INIT;
   pthread_once(&once, entry_patch_public);
#else
   static int first = 1;
   if (first) {
      first = 0;
      entry_patch_public();
   }
#endif
}

static int
stub_compare(const void *key, const void *elem)
{
   const char *name = (const char *) key;
   const struct mapi_stub *stub = (const struct mapi_stub *) elem;
   const char *stub_name;

   stub_name = &public_string_pool[(unsigned long) stub->name];

   return strcmp(name, stub_name);
}

/**
 * Return the public stub with the given name.
 */
const struct mapi_stub *
stub_find_public(const char *name)
{
   return (const struct mapi_stub *) bsearch(name, public_stubs,
         ARRAY_SIZE(public_stubs), sizeof(public_stubs[0]), stub_compare);
}

/**
 * Add a dynamic stub.
 */
static struct mapi_stub *
stub_add_dynamic(const char *name)
{
   struct mapi_stub *stub;
   int idx;

   idx = num_dynamic_stubs;
   /* minus 1 to make sure we can never reach the last slot */
   if (idx >= MAPI_TABLE_NUM_DYNAMIC - 1)
      return NULL;

   stub = &dynamic_stubs[idx];

   /* dispatch to the last slot, which is reserved for no-op */
   stub->addr = entry_generate(
         MAPI_TABLE_NUM_STATIC + MAPI_TABLE_NUM_DYNAMIC - 1);
   if (!stub->addr)
      return NULL;

   stub->name = (const void *) strdup(name);
   /* to be fixed later */
   stub->slot = -1;

   num_dynamic_stubs = idx + 1;

   return stub;
}

/**
 * Return the dynamic stub with the given name.  If no such stub exists and
 * generate is true, a new stub is generated.
 */
struct mapi_stub *
stub_find_dynamic(const char *name, int generate)
{
   static mtx_t dynamic_mutex = _MTX_INITIALIZER_NP;
   struct mapi_stub *stub = NULL;
   int count, i;
   
   mtx_lock(&dynamic_mutex);

   if (generate)
      assert(!stub_find_public(name));

   count = num_dynamic_stubs;
   for (i = 0; i < count; i++) {
      if (strcmp(name, (const char *) dynamic_stubs[i].name) == 0) {
         stub = &dynamic_stubs[i];
         break;
      }
   }

   /* generate a dynamic stub */
   if (generate && !stub)
         stub = stub_add_dynamic(name);

   mtx_unlock(&dynamic_mutex);

   return stub;
}

static const struct mapi_stub *
search_table_by_slot(const struct mapi_stub *table, size_t num_entries,
                     int slot)
{
   size_t i;
   for (i = 0; i < num_entries; ++i) {
      if (table[i].slot == slot)
         return &table[i];
   }
   return NULL;
}

const struct mapi_stub *
stub_find_by_slot(int slot)
{
   const struct mapi_stub *stub =
      search_table_by_slot(public_stubs, ARRAY_SIZE(public_stubs), slot);
   if (stub)
      return stub;
   return search_table_by_slot(dynamic_stubs, num_dynamic_stubs, slot);
}

void
stub_fix_dynamic(struct mapi_stub *stub, const struct mapi_stub *alias)
{
   int slot;

   if (stub->slot >= 0)
      return;

   if (alias)
      slot = alias->slot;
   else
      slot = next_dynamic_slot++;

   entry_patch(stub->addr, slot);
   stub->slot = slot;
}

/**
 * Return the name of a stub.
 */
const char *
stub_get_name(const struct mapi_stub *stub)
{
   const char *name;

   if (stub >= public_stubs &&
       stub < public_stubs + ARRAY_SIZE(public_stubs))
      name = &public_string_pool[(unsigned long) stub->name];
   else
      name = (const char *) stub->name;

   return name;
}

/**
 * Return the slot of a stub.
 */
int
stub_get_slot(const struct mapi_stub *stub)
{
   return stub->slot;
}

/**
 * Return the address of a stub.
 */
mapi_func
stub_get_addr(const struct mapi_stub *stub)
{
   assert(stub->addr || (unsigned int) stub->slot < MAPI_TABLE_NUM_STATIC);
   return (stub->addr) ? stub->addr : entry_get_public(stub->slot);
}