src/mapi/mapi/mapi.c

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