1/*
2 * Mesa 3-D graphics library
3 * Version:  7.9
4 *
5 * Copyright (C) 2010 LunarG Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
24 *
25 * Authors:
26 *    Chia-I Wu <olv@lunarg.com>
27 */
28
29#include <stdlib.h>
30#include <string.h>
31#include <assert.h>
32
33#include "u_current.h"
34#include "u_thread.h"
35#include "entry.h"
36#include "stub.h"
37#include "table.h"
38
39#define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
40
41struct mapi_stub {
42   const void *name;
43   int slot;
44   mapi_func addr;
45};
46
47/* define public_string_pool and public_stubs */
48#define MAPI_TMP_PUBLIC_STUBS
49#include "mapi_tmp.h"
50
51static struct mapi_stub dynamic_stubs[MAPI_TABLE_NUM_DYNAMIC];
52static int num_dynamic_stubs;
53static int next_dynamic_slot = MAPI_TABLE_NUM_STATIC;
54
55void
56stub_init_once(void)
57{
58#ifdef HAVE_PTHREAD
59   static pthread_once_t once = PTHREAD_ONCE_INIT;
60   pthread_once(&once, entry_patch_public);
61#else
62   static int first = 1;
63   if (first) {
64      first = 0;
65      entry_patch_public();
66   }
67#endif
68}
69
70static int
71stub_compare(const void *key, const void *elem)
72{
73   const char *name = (const char *) key;
74   const struct mapi_stub *stub = (const struct mapi_stub *) elem;
75   const char *stub_name;
76
77   stub_name = &public_string_pool[(unsigned long) stub->name];
78
79   return strcmp(name, stub_name);
80}
81
82/**
83 * Return the public stub with the given name.
84 */
85const struct mapi_stub *
86stub_find_public(const char *name)
87{
88   return (const struct mapi_stub *) bsearch(name, public_stubs,
89         ARRAY_SIZE(public_stubs), sizeof(public_stubs[0]), stub_compare);
90}
91
92/**
93 * Add a dynamic stub.
94 */
95static struct mapi_stub *
96stub_add_dynamic(const char *name)
97{
98   struct mapi_stub *stub;
99   int idx;
100
101   idx = num_dynamic_stubs;
102   /* minus 1 to make sure we can never reach the last slot */
103   if (idx >= MAPI_TABLE_NUM_DYNAMIC - 1)
104      return NULL;
105
106   stub = &dynamic_stubs[idx];
107
108   /* dispatch to the last slot, which is reserved for no-op */
109   stub->addr = entry_generate(
110         MAPI_TABLE_NUM_STATIC + MAPI_TABLE_NUM_DYNAMIC - 1);
111   if (!stub->addr)
112      return NULL;
113
114   stub->name = (const void *) name;
115   /* to be fixed later */
116   stub->slot = -1;
117
118   num_dynamic_stubs = idx + 1;
119
120   return stub;
121}
122
123/**
124 * Return the dynamic stub with the given name.  If no such stub exists and
125 * generate is true, a new stub is generated.
126 */
127struct mapi_stub *
128stub_find_dynamic(const char *name, int generate)
129{
130   u_mutex_declare_static(dynamic_mutex);
131   struct mapi_stub *stub = NULL;
132   int count, i;
133
134   u_mutex_lock(dynamic_mutex);
135
136   if (generate)
137      assert(!stub_find_public(name));
138
139   count = num_dynamic_stubs;
140   for (i = 0; i < count; i++) {
141      if (strcmp(name, (const char *) dynamic_stubs[i].name) == 0) {
142         stub = &dynamic_stubs[i];
143         break;
144      }
145   }
146
147   /* generate a dynamic stub */
148   if (generate && !stub)
149         stub = stub_add_dynamic(name);
150
151   u_mutex_unlock(dynamic_mutex);
152
153   return stub;
154}
155
156void
157stub_fix_dynamic(struct mapi_stub *stub, const struct mapi_stub *alias)
158{
159   int slot;
160
161   if (stub->slot >= 0)
162      return;
163
164   if (alias)
165      slot = alias->slot;
166   else
167      slot = next_dynamic_slot++;
168
169   entry_patch(stub->addr, slot);
170   stub->slot = slot;
171}
172
173/**
174 * Return the name of a stub.
175 */
176const char *
177stub_get_name(const struct mapi_stub *stub)
178{
179   const char *name;
180
181   if (stub >= public_stubs &&
182       stub < public_stubs + ARRAY_SIZE(public_stubs))
183      name = &public_string_pool[(unsigned long) stub->name];
184   else
185      name = (const char *) stub->name;
186
187   return name;
188}
189
190/**
191 * Return the slot of a stub.
192 */
193int
194stub_get_slot(const struct mapi_stub *stub)
195{
196   return stub->slot;
197}
198
199/**
200 * Return the address of a stub.
201 */
202mapi_func
203stub_get_addr(const struct mapi_stub *stub)
204{
205   assert(stub->addr || (unsigned int) stub->slot < MAPI_TABLE_NUM_STATIC);
206   return (stub->addr) ? stub->addr : entry_get_public(stub->slot);
207}
208