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 "_glthread_: failed to allocate key for thread specific data"
  61 #define GET_TSD_ERROR "_glthread_: failed to get thread specific data"
  62 #define SET_TSD_ERROR "_glthread_: 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 typedef mtx_t u_mutex;
  83
  84 #define u_mutex_declare_static(name) \
  85    static u_mutex name = _MTX_INITIALIZER_NP
  86
  87 #define u_mutex_init(name)    mtx_init(&(name), mtx_plain)
  88 #define u_mutex_destroy(name) mtx_destroy(&(name))
  89 #define u_mutex_lock(name)    (void) mtx_lock(&(name))
  90 #define u_mutex_unlock(name)  (void) mtx_unlock(&(name))
  91
  92
  93 static INLINE unsigned long
  94 u_thread_self(void)
  95 {
  96    /*
  97     * XXX: Callers of u_thread_self assume it is a lightweight function,
  98     * returning a numeric value.  But unfortunately C11's thrd_current() gives
  99     * no such guarantees.  In fact, it's pretty hard to have a compliant
 100     * implementation of thrd_current() on Windows with such characteristics.
 101     * So for now, we side-step this mess and use Windows thread primitives
 102     * directly here.
 103     *
 104     * FIXME: On the other hand, u_thread_self() is a bad
 105     * abstraction.  Even with pthreads, there is no guarantee that
 106     * pthread_self() will return numeric IDs -- we should be using
 107     * pthread_equal() instead of assuming we can compare thread ids...
 108     */
 109 #ifdef _WIN32
 110    return GetCurrentThreadId();
 111 #else
 112    return (unsigned long) (uintptr_t) thrd_current();
 113 #endif
 114 }
 115
 116
 117 static INLINE void
 118 u_tsd_init(struct u_tsd *tsd)
 119 {
 120    if (tss_create(&tsd->key, NULL/*free*/) != 0) {
 121       perror(INIT_TSD_ERROR);
 122       exit(-1);
 123    }
 124    tsd->initMagic = INIT_MAGIC;
 125 }
 126
 127
 128 static INLINE void *
 129 u_tsd_get(struct u_tsd *tsd)
 130 {
 131    if (tsd->initMagic != INIT_MAGIC) {
 132       u_tsd_init(tsd);
 133    }
 134    return tss_get(tsd->key);
 135 }
 136
 137
 138 static INLINE void
 139 u_tsd_set(struct u_tsd *tsd, void *ptr)
 140 {
 141    if (tsd->initMagic != INIT_MAGIC) {
 142       u_tsd_init(tsd);
 143    }
 144    if (tss_set(tsd->key, ptr) != 0) {
 145       perror(SET_TSD_ERROR);
 146       exit(-1);
 147    }
 148 }
 149
 150
 151 static INLINE void
 152 u_tsd_destroy(struct u_tsd *tsd)
 153 {
 154    if (tsd->initMagic != INIT_MAGIC) {
 155       return;
 156    }
 157    tss_delete(tsd->key);
 158    tsd->initMagic = 0x0;
 159 }
 160
 161
 162 #ifdef __cplusplus
 163 }
 164 #endif
 165
 166 #endif /* _U_THREAD_H_ */