src/mapi/u_thread.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   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
  17  * OR 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
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * Thread support for gl dispatch.
  28  *
  29  * Initial version by John Stone (j.stone@acm.org) (johns@cs.umr.edu)
  30  *                and Christoph Poliwoda (poliwoda@volumegraphics.com)
  31  * Revised by Keith Whitwell
  32  * Adapted for new gl dispatcher by Brian Paul
  33  * Modified for use in mapi by Chia-I Wu
  34  */
  35
  36 /*
  37  * If this file is accidentally included by a non-threaded build,
  38  * it should not cause the build to fail, or otherwise cause problems.
  39  * In general, it should only be included when needed however.
  40  */
  41
  42 #ifndef _U_THREAD_H_
  43 #define _U_THREAD_H_
  44
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include "u_compiler.h"
  48
  49 #include "c11/threads.h"
  50
  51 #if defined(HAVE_PTHREAD) || defined(_WIN32)
  52 #ifndef THREADS
  53 #define THREADS
  54 #endif
  55 #endif
  56
  57 /*
  58  * Error messages
  59  */
  60 #define INIT_TSD_ERROR "Mesa: failed to allocate key for thread specific data"
  61 #define GET_TSD_ERROR "Mesa: failed to get thread specific data"
  62 #define SET_TSD_ERROR "Mesa: thread failed to set thread specific data"
  63
  64
  65 /*
  66  * Magic number to determine if a TSD object has been initialized.
  67  * Kind of a hack but there doesn't appear to be a better cross-platform
  68  * solution.
  69  */
  70 #define INIT_MAGIC 0xff8adc98
  71
  72 #ifdef __cplusplus
  73 extern "C" {
  74 #endif
  75
  76
  77 struct u_tsd {
  78    tss_t key;
  79    unsigned initMagic;
  80 };
  81
  82
  83 static INLINE unsigned long
  84 u_thread_self(void)
  85 {
  86    /*
  87     * XXX: Callers of u_thread_self assume it is a lightweight function,
  88     * returning a numeric value.  But unfortunately C11's thrd_current() gives
  89     * no such guarantees.  In fact, it's pretty hard to have a compliant
  90     * implementation of thrd_current() on Windows with such characteristics.
  91     * So for now, we side-step this mess and use Windows thread primitives
  92     * directly here.
  93     *
  94     * FIXME: On the other hand, u_thread_self() is a bad
  95     * abstraction.  Even with pthreads, there is no guarantee that
  96     * pthread_self() will return numeric IDs -- we should be using
  97     * pthread_equal() instead of assuming we can compare thread ids...
  98     */
  99 #ifdef _WIN32
 100    return GetCurrentThreadId();
 101 #else
 102    return (unsigned long) (uintptr_t) thrd_current();
 103 #endif
 104 }
 105
 106
 107 static INLINE void
 108 u_tsd_init(struct u_tsd *tsd)
 109 {
 110    if (tss_create(&tsd->key, NULL/*free*/) != 0) {
 111       perror(INIT_TSD_ERROR);
 112       exit(-1);
 113    }
 114    tsd->initMagic = INIT_MAGIC;
 115 }
 116
 117
 118 static INLINE void *
 119 u_tsd_get(struct u_tsd *tsd)
 120 {
 121    if (tsd->initMagic != INIT_MAGIC) {
 122       u_tsd_init(tsd);
 123    }
 124    return tss_get(tsd->key);
 125 }
 126
 127
 128 static INLINE void
 129 u_tsd_set(struct u_tsd *tsd, void *ptr)
 130 {
 131    if (tsd->initMagic != INIT_MAGIC) {
 132       u_tsd_init(tsd);
 133    }
 134    if (tss_set(tsd->key, ptr) != 0) {
 135       perror(SET_TSD_ERROR);
 136       exit(-1);
 137    }
 138 }
 139
 140
 141 static INLINE void
 142 u_tsd_destroy(struct u_tsd *tsd)
 143 {
 144    if (tsd->initMagic != INIT_MAGIC) {
 145       return;
 146    }
 147    tss_delete(tsd->key);
 148    tsd->initMagic = 0x0;
 149 }
 150
 151
 152 #ifdef __cplusplus
 153 }
 154 #endif
 155
 156 #endif /* _U_THREAD_H_ */