Preperation for new release of mesa

1 files changed, 335 insertions, 0 deletions

diff --git a/mesalib/src/mapi/glapi/glapi.c b/mesalib/src/mapi/glapi/glapi.c
new file mode 100644
index 000000000..13de594aa
--- /dev/null
+++ b/mesalib/src/mapi/glapi/glapi.c
@@ -0,0 +1,335 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.1
+ *
+ * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*
+ * This file manages the OpenGL API dispatch layer.
+ * The dispatch table (struct _glapi_table) is basically just a list
+ * of function pointers.
+ * There are functions to set/get the current dispatch table for the
+ * current thread and to manage registration/dispatch of dynamically
+ * added extension functions.
+ *
+ * It's intended that this file and the other glapi*.[ch] files are
+ * flexible enough to be reused in several places:  XFree86, DRI-
+ * based libGL.so, and perhaps the SGI SI.
+ *
+ * NOTE: There are no dependencies on Mesa in this code.
+ *
+ * Versions (API changes):
+ *   2000/02/23  - original version for Mesa 3.3 and XFree86 4.0
+ *   2001/01/16  - added dispatch override feature for Mesa 3.5
+ *   2002/06/28  - added _glapi_set_warning_func(), Mesa 4.1.
+ *   2002/10/01  - _glapi_get_proc_address() will now generate new entrypoints
+ *                 itself (using offset ~0).  _glapi_add_entrypoint() can be
+ *                 called afterward and it'll fill in the correct dispatch
+ *                 offset.  This allows DRI libGL to avoid probing for DRI
+ *                 drivers!  No changes to the public glapi interface.
+ */
+
+
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#include "glapi/mesa.h"
+#else
+#include "main/glheader.h"
+#include "main/compiler.h"
+#endif
+
+#include "glapi/glapi.h"
+#include "glapi/glapitable.h"
+
+extern _glapi_proc __glapi_noop_table[];
+
+
+/**
+ * \name Current dispatch and current context control variables
+ *
+ * Depending on whether or not multithreading is support, and the type of
+ * support available, several variables are used to store the current context
+ * pointer and the current dispatch table pointer.  In the non-threaded case,
+ * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this
+ * purpose.
+ *
+ * In the "normal" threaded case, the variables \c _glapi_Dispatch and
+ * \c _glapi_Context will be \c NULL if an application is detected as being
+ * multithreaded.  Single-threaded applications will use \c _glapi_Dispatch
+ * and \c _glapi_Context just like the case without any threading support.
+ * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state
+ * data \c _gl_DispatchTSD and \c ContextTSD are used.  Drivers and the
+ * static dispatch functions access these variables via \c _glapi_get_dispatch
+ * and \c _glapi_get_context.
+ *
+ * There is a race condition in setting \c _glapi_Dispatch to \c NULL.  It is
+ * possible for the original thread to be setting it at the same instant a new
+ * thread, perhaps running on a different processor, is clearing it.  Because
+ * of that, \c ThreadSafe, which can only ever be changed to \c GL_TRUE, is
+ * used to determine whether or not the application is multithreaded.
+ * 
+ * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are
+ * hardcoded to \c NULL.  Instead the TLS variables \c _glapi_tls_Dispatch and
+ * \c _glapi_tls_Context are used.  Having \c _glapi_Dispatch and
+ * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability
+ * between TLS enabled loaders and non-TLS DRI drivers.
+ */
+/*@{*/
+#if defined(GLX_USE_TLS)
+
+PUBLIC __thread struct _glapi_table * _glapi_tls_Dispatch
+    __attribute__((tls_model("initial-exec")))
+    = (struct _glapi_table *) __glapi_noop_table;
+
+PUBLIC __thread void * _glapi_tls_Context
+    __attribute__((tls_model("initial-exec")));
+
+PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
+
+PUBLIC const void *_glapi_Context = NULL;
+
+#else
+
+#if defined(THREADS)
+
+static GLboolean ThreadSafe = GL_FALSE;  /**< In thread-safe mode? */
+
+_glthread_TSD _gl_DispatchTSD;           /**< Per-thread dispatch pointer */
+
+static _glthread_TSD ContextTSD;         /**< Per-thread context pointer */
+
+#endif /* defined(THREADS) */
+
+PUBLIC struct _glapi_table *_glapi_Dispatch = (struct _glapi_table *) __glapi_noop_table;
+
+PUBLIC void *_glapi_Context = NULL;
+
+#endif /* defined(GLX_USE_TLS) */
+/*@}*/
+
+
+
+#if defined(THREADS) && !defined(GLX_USE_TLS)
+
+void
+_glapi_init_multithread(void)
+{
+   _glthread_InitTSD(&_gl_DispatchTSD);
+   _glthread_InitTSD(&ContextTSD);
+}
+
+void
+_glapi_destroy_multithread(void)
+{
+#ifdef WIN32_THREADS
+   _glthread_DestroyTSD(&_gl_DispatchTSD);
+   _glthread_DestroyTSD(&ContextTSD);
+#endif
+}
+
+/**
+ * Mutex for multithread check.
+ */
+#ifdef WIN32_THREADS
+/* _glthread_DECLARE_STATIC_MUTEX is broken on windows.  There will be race! */
+#define CHECK_MULTITHREAD_LOCK()
+#define CHECK_MULTITHREAD_UNLOCK()
+#else
+_glthread_DECLARE_STATIC_MUTEX(ThreadCheckMutex);
+#define CHECK_MULTITHREAD_LOCK() _glthread_LOCK_MUTEX(ThreadCheckMutex)
+#define CHECK_MULTITHREAD_UNLOCK() _glthread_UNLOCK_MUTEX(ThreadCheckMutex)
+#endif
+
+/**
+ * We should call this periodically from a function such as glXMakeCurrent
+ * in order to test if multiple threads are being used.
+ */
+PUBLIC void
+_glapi_check_multithread(void)
+{
+   static unsigned long knownID;
+   static GLboolean firstCall = GL_TRUE;
+
+   if (ThreadSafe)
+      return;
+
+   CHECK_MULTITHREAD_LOCK();
+   if (firstCall) {
+      _glapi_init_multithread();
+
+      knownID = _glthread_GetID();
+      firstCall = GL_FALSE;
+   }
+   else if (knownID != _glthread_GetID()) {
+      ThreadSafe = GL_TRUE;
+      _glapi_set_dispatch(NULL);
+      _glapi_set_context(NULL);
+   }
+   CHECK_MULTITHREAD_UNLOCK();
+}
+
+#else
+
+void
+_glapi_init_multithread(void) { }
+
+void
+_glapi_destroy_multithread(void) { }
+
+PUBLIC void
+_glapi_check_multithread(void) { }
+
+#endif
+
+
+
+/**
+ * Set the current context pointer for this thread.
+ * The context pointer is an opaque type which should be cast to
+ * void from the real context pointer type.
+ */
+PUBLIC void
+_glapi_set_context(void *context)
+{
+#if defined(GLX_USE_TLS)
+   _glapi_tls_Context = context;
+#elif defined(THREADS)
+   _glthread_SetTSD(&ContextTSD, context);
+   _glapi_Context = (ThreadSafe) ? NULL : context;
+#else
+   _glapi_Context = context;
+#endif
+}
+
+
+
+/**
+ * Get the current context pointer for this thread.
+ * The context pointer is an opaque type which should be cast from
+ * void to the real context pointer type.
+ */
+PUBLIC void *
+_glapi_get_context(void)
+{
+#if defined(GLX_USE_TLS)
+   return _glapi_tls_Context;
+#elif defined(THREADS)
+   return (ThreadSafe) ? _glthread_GetTSD(&ContextTSD) : _glapi_Context;
+#else
+   return _glapi_Context;
+#endif
+}
+
+
+
+/**
+ * Set the global or per-thread dispatch table pointer.
+ * If the dispatch parameter is NULL we'll plug in the no-op dispatch
+ * table (__glapi_noop_table).
+ */
+PUBLIC void
+_glapi_set_dispatch(struct _glapi_table *dispatch)
+{
+   init_glapi_relocs_once();
+
+   if (dispatch == NULL) {
+      /* use the no-op functions */
+      dispatch = (struct _glapi_table *) __glapi_noop_table;
+   }
+#ifdef DEBUG
+   else {
+      _glapi_check_table_not_null(dispatch);
+      _glapi_check_table(dispatch);
+   }
+#endif
+
+#if defined(GLX_USE_TLS)
+   _glapi_tls_Dispatch = dispatch;
+#elif defined(THREADS)
+   _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
+   _glapi_Dispatch = (ThreadSafe) ? NULL : dispatch;
+#else
+   _glapi_Dispatch = dispatch;
+#endif
+}
+
+
+
+/**
+ * Return pointer to current dispatch table for calling thread.
+ */
+PUBLIC struct _glapi_table *
+_glapi_get_dispatch(void)
+{
+#if defined(GLX_USE_TLS)
+   return _glapi_tls_Dispatch;
+#elif defined(THREADS)
+   return (ThreadSafe)
+     ? (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD)
+     : _glapi_Dispatch;
+#else
+   return _glapi_Dispatch;
+#endif
+}
+
+
+
+
+/*
+ * The dispatch table size (number of entries) is the size of the
+ * _glapi_table struct plus the number of dynamic entries we can add.
+ * The extra slots can be filled in by DRI drivers that register new extension
+ * functions.
+ */
+#define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
+
+
+/**
+ * Return size of dispatch table struct as number of functions (or
+ * slots).
+ */
+PUBLIC GLuint
+_glapi_get_dispatch_table_size(void)
+{
+   return DISPATCH_TABLE_SIZE;
+}
+
+
+/**
+ * Make sure there are no NULL pointers in the given dispatch table.
+ * Intended for debugging purposes.
+ */
+void
+_glapi_check_table_not_null(const struct _glapi_table *table)
+{
+#if 0 /* enable this for extra DEBUG */
+   const GLuint entries = _glapi_get_dispatch_table_size();
+   const void **tab = (const void **) table;
+   GLuint i;
+   for (i = 1; i < entries; i++) {
+      assert(tab[i]);
+   }
+#else
+   (void) table;
+#endif
+}