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