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 
32 #include "u_current.h"
33 #include "u_thread.h"
34 #include "mapi.h"
35 #include "stub.h"
36 #include "table.h"
37 
38 /* dynamic stubs will run out before this array */
39 static const struct mapi_stub *mapi_stub_map[MAPI_TABLE_NUM_SLOTS];
40 static int mapi_num_stubs;
41 
42 static const struct mapi_stub *
get_stub(const char * name,const struct mapi_stub * alias)43 get_stub(const char *name, const struct mapi_stub *alias)
44 {
45    const struct mapi_stub *stub;
46 
47    stub = stub_find_public(name);
48    if (!stub) {
49       struct mapi_stub *dyn = stub_find_dynamic(name, 1);
50       if (dyn) {
51          stub_fix_dynamic(dyn, alias);
52          stub = dyn;
53       }
54    }
55 
56    return stub;
57 }
58 
59 /**
60  * Initialize mapi.  spec consists of NULL-separated strings.  The first string
61  * denotes the version.  It is followed by variable numbers of entries.  Each
62  * entry can have multiple names.  An empty name terminates an entry.  An empty
63  * entry terminates the spec.  A spec of two entries, Foo and Bar, is as
64  * follows
65  *
66  *   "1\0"
67  *   "Foo\0"
68  *   "FooEXT\0"
69  *   "\0"
70  *   "Bar\0"
71  *   "\0"
72  */
73 void
mapi_init(const char * spec)74 mapi_init(const char *spec)
75 {
76    u_mutex_declare_static(mutex);
77    const char *p;
78    int ver, count;
79 
80    u_mutex_lock(mutex);
81 
82    /* already initialized */
83    if (mapi_num_stubs) {
84       u_mutex_unlock(mutex);
85       return;
86    }
87 
88    count = 0;
89    p = spec;
90 
91    /* parse version string */
92    ver = atoi(p);
93    if (ver != 1) {
94       u_mutex_unlock(mutex);
95       return;
96    }
97    p += strlen(p) + 1;
98 
99    while (*p) {
100       const struct mapi_stub *stub;
101 
102       stub = get_stub(p, NULL);
103       /* out of dynamic entries */
104       if (!stub)
105          break;
106       p += strlen(p) + 1;
107 
108       while (*p) {
109          get_stub(p, stub);
110          p += strlen(p) + 1;
111       }
112 
113       mapi_stub_map[count++] = stub;
114       p++;
115    }
116 
117    mapi_num_stubs = count;
118 
119    u_mutex_unlock(mutex);
120 }
121 
122 /**
123  * Return the address of an entry.  Optionally generate the entry if it does
124  * not exist.
125  */
126 mapi_proc
mapi_get_proc_address(const char * name)127 mapi_get_proc_address(const char *name)
128 {
129    const struct mapi_stub *stub;
130 
131    stub = stub_find_public(name);
132    if (!stub)
133       stub = stub_find_dynamic(name, 0);
134 
135    return (stub) ? (mapi_proc) stub_get_addr(stub) : NULL;
136 }
137 
138 /**
139  * Create a dispatch table.
140  */
141 struct mapi_table *
mapi_table_create(void)142 mapi_table_create(void)
143 {
144    const struct mapi_table *noop = table_get_noop();
145    struct mapi_table *tbl;
146 
147    tbl = malloc(MAPI_TABLE_SIZE);
148    if (tbl)
149       memcpy(tbl, noop, MAPI_TABLE_SIZE);
150 
151    return tbl;
152 }
153 
154 /**
155  * Destroy a dispatch table.
156  */
157 void
mapi_table_destroy(struct mapi_table * tbl)158 mapi_table_destroy(struct mapi_table *tbl)
159 {
160    free(tbl);
161 }
162 
163 /**
164  * Fill a dispatch table.  The order of the procs is determined when mapi_init
165  * is called.
166  */
167 void
mapi_table_fill(struct mapi_table * tbl,const mapi_proc * procs)168 mapi_table_fill(struct mapi_table *tbl, const mapi_proc *procs)
169 {
170    const struct mapi_table *noop = table_get_noop();
171    int i;
172 
173    for (i = 0; i < mapi_num_stubs; i++) {
174       const struct mapi_stub *stub = mapi_stub_map[i];
175       int slot = stub_get_slot(stub);
176       mapi_func func = (mapi_func) procs[i];
177 
178       if (!func)
179          func = table_get_func(noop, slot);
180       table_set_func(tbl, slot, func);
181    }
182 }
183 
184 /**
185  * Make a dispatch table current.
186  */
187 void
mapi_table_make_current(const struct mapi_table * tbl)188 mapi_table_make_current(const struct mapi_table *tbl)
189 {
190    u_current_set(tbl);
191 }
192