src/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 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 *
  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
  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
 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 *
 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
 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
 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
 188 mapi_table_make_current(const struct mapi_table *tbl)
 189 {
 190    u_current_set(tbl);
 191 }