src/mapi/mapi.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2010 LunarG Inc.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Chia-I Wu <olv@lunarg.com>
  26  */
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include "u_current.h"
  32 #include "u_thread.h"
  33 #include "mapi.h"
  34 #include "stub.h"
  35 #include "table.h"
  36
  37 /* dynamic stubs will run out before this array */
  38 static const struct mapi_stub *mapi_stub_map[MAPI_TABLE_NUM_SLOTS];
  39 static int mapi_num_stubs;
  40
  41 static const struct mapi_stub *
  42 get_stub(const char *name, const struct mapi_stub *alias)
  43 {
  44    const struct mapi_stub *stub;
  45
  46    stub = stub_find_public(name);
  47    if (!stub) {
  48       struct mapi_stub *dyn = stub_find_dynamic(name, 1);
  49       if (dyn) {
  50          stub_fix_dynamic(dyn, alias);
  51          stub = dyn;
  52       }
  53    }
  54
  55    return stub;
  56 }
  57
  58 /**
  59  * Initialize mapi.  spec consists of NULL-separated strings.  The first string
  60  * denotes the version.  It is followed by variable numbers of entries.  Each
  61  * entry can have multiple names.  An empty name terminates an entry.  An empty
  62  * entry terminates the spec.  A spec of two entries, Foo and Bar, is as
  63  * follows
  64  *
  65  *   "1\0"
  66  *   "Foo\0"
  67  *   "FooEXT\0"
  68  *   "\0"
  69  *   "Bar\0"
  70  *   "\0"
  71  */
  72 void
  73 mapi_init(const char *spec)
  74 {
  75    u_mutex_declare_static(mutex);
  76    const char *p;
  77    int ver, count;
  78
  79    u_mutex_lock(mutex);
  80
  81    /* already initialized */
  82    if (mapi_num_stubs) {
  83       u_mutex_unlock(mutex);
  84       return;
  85    }
  86
  87    count = 0;
  88    p = spec;
  89
  90    /* parse version string */
  91    ver = atoi(p);
  92    if (ver != 1) {
  93       u_mutex_unlock(mutex);
  94       return;
  95    }
  96    p += strlen(p) + 1;
  97
  98    while (*p) {
  99       const struct mapi_stub *stub;
 100
 101       stub = get_stub(p, NULL);
 102       /* out of dynamic entries */
 103       if (!stub)
 104          break;
 105       p += strlen(p) + 1;
 106
 107       while (*p) {
 108          get_stub(p, stub);
 109          p += strlen(p) + 1;
 110       }
 111
 112       mapi_stub_map[count++] = stub;
 113       p++;
 114    }
 115
 116    mapi_num_stubs = count;
 117
 118    u_mutex_unlock(mutex);
 119 }
 120
 121 /**
 122  * Return the address of an entry.  Optionally generate the entry if it does
 123  * not exist.
 124  */
 125 mapi_proc
 126 mapi_get_proc_address(const char *name)
 127 {
 128    const struct mapi_stub *stub;
 129
 130    stub = stub_find_public(name);
 131    if (!stub)
 132       stub = stub_find_dynamic(name, 0);
 133
 134    return (stub) ? (mapi_proc) stub_get_addr(stub) : NULL;
 135 }
 136
 137 /**
 138  * Create a dispatch table.
 139  */
 140 struct mapi_table *
 141 mapi_table_create(void)
 142 {
 143    const struct mapi_table *noop = table_get_noop();
 144    struct mapi_table *tbl;
 145
 146    tbl = malloc(MAPI_TABLE_SIZE);
 147    if (tbl)
 148       memcpy(tbl, noop, MAPI_TABLE_SIZE);
 149
 150    return tbl;
 151 }
 152
 153 /**
 154  * Destroy a dispatch table.
 155  */
 156 void
 157 mapi_table_destroy(struct mapi_table *tbl)
 158 {
 159    free(tbl);
 160 }
 161
 162 /**
 163  * Fill a dispatch table.  The order of the procs is determined when mapi_init
 164  * is called.
 165  */
 166 void
 167 mapi_table_fill(struct mapi_table *tbl, const mapi_proc *procs)
 168 {
 169    const struct mapi_table *noop = table_get_noop();
 170    int i;
 171
 172    for (i = 0; i < mapi_num_stubs; i++) {
 173       const struct mapi_stub *stub = mapi_stub_map[i];
 174       int slot = stub_get_slot(stub);
 175       mapi_func func = (mapi_func) procs[i];
 176
 177       if (!func)
 178          func = table_get_func(noop, slot);
 179       table_set_func(tbl, slot, func);
 180    }
 181 }
 182
 183 /**
 184  * Make a dispatch table current.
 185  */
 186 void
 187 mapi_table_make_current(const struct mapi_table *tbl)
 188 {
 189    u_current_set(tbl);
 190 }