xref: /third_party/mesa3d/src/glx/create_context.c (revision bf215546)
1/*
2 * Copyright © 2011 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#include <limits.h>
25#include "glxclient.h"
26#include "glx_error.h"
27#include <xcb/glx.h>
28#include <X11/Xlib-xcb.h>
29
30#include <assert.h>
31
32#if INT_MAX != 2147483647
33#error This code requires sizeof(uint32_t) == sizeof(int).
34#endif
35
36/* An "Atrribs/Attribs" typo was fixed in glxproto.h in Nov 2014.
37 * This is in case we don't have the updated header.
38 */
39#if !defined(X_GLXCreateContextAttribsARB) && \
40     defined(X_GLXCreateContextAtrribsARB)
41#define X_GLXCreateContextAttribsARB X_GLXCreateContextAtrribsARB
42#endif
43
44_X_HIDDEN GLXContext
45glXCreateContextAttribsARB(Display *dpy, GLXFBConfig config,
46			   GLXContext share_context, Bool direct,
47			   const int *attrib_list)
48{
49   xcb_connection_t *const c = XGetXCBConnection(dpy);
50   struct glx_config *const cfg = (struct glx_config *) config;
51   struct glx_context *const share = (struct glx_context *) share_context;
52   struct glx_context *gc = NULL;
53   unsigned num_attribs = 0;
54   struct glx_screen *psc;
55   xcb_generic_error_t *err;
56   xcb_void_cookie_t cookie;
57   unsigned dummy_err = 0;
58   uint32_t xid, share_xid;
59   int screen = -1;
60
61   if (dpy == NULL)
62      return NULL;
63
64   /* Count the number of attributes specified by the application.  All
65    * attributes appear in pairs, except the terminating None.
66    */
67   if (attrib_list != NULL) {
68      for (/* empty */; attrib_list[num_attribs * 2] != 0; num_attribs++)
69	 /* empty */ ;
70   }
71
72   if (cfg) {
73      screen = cfg->screen;
74   } else {
75      for (unsigned int i = 0; i < num_attribs; i++) {
76         if (attrib_list[i * 2] == GLX_SCREEN)
77            screen = attrib_list[i * 2 + 1];
78      }
79      if (screen == -1) {
80         __glXSendError(dpy, BadValue, 0, X_GLXCreateContextAttribsARB, True);
81         return NULL;
82      }
83   }
84
85   /* This means that either the caller passed the wrong display pointer or
86    * one of the internal GLX data structures (probably the fbconfig) has an
87    * error.  There is nothing sensible to do, so return an error.
88    */
89   psc = GetGLXScreenConfigs(dpy, screen);
90   if (psc == NULL)
91      return NULL;
92
93   assert(screen == psc->scr);
94
95   /* Some application may request an indirect context but we may want to force a direct
96    * one because Xorg only allows indirect contexts if they were enabled.
97    */
98   if (!direct &&
99       psc->force_direct_context) {
100      direct = true;
101   }
102
103
104   if (direct && psc->vtable->create_context_attribs) {
105      /* GLX drops the error returned by the driver.  The expectation is that
106       * an error will also be returned by the server.  The server's error
107       * will be delivered to the application.
108       */
109      gc = psc->vtable->create_context_attribs(psc, cfg, share, num_attribs,
110					       (const uint32_t *) attrib_list,
111					       &dummy_err);
112   }
113
114   if (gc == NULL) {
115#ifdef GLX_USE_APPLEGL
116      gc = applegl_create_context(psc, cfg, share, 0);
117#else
118      gc = indirect_create_context_attribs(psc, cfg, share, num_attribs,
119              (const uint32_t *) attrib_list,
120              &dummy_err);
121#endif
122   }
123
124   xid = xcb_generate_id(c);
125   share_xid = (share != NULL) ? share->xid : 0;
126
127   /* The manual pages for glXCreateContext and glXCreateNewContext say:
128    *
129    *     "NULL is returned if execution fails on the client side."
130    *
131    * If the server generates an error, the application is supposed to catch
132    * the protocol error and handle it.  Part of handling the error is freeing
133    * the possibly non-NULL value returned by this function.
134    */
135   cookie =
136      xcb_glx_create_context_attribs_arb_checked(c,
137						 xid,
138						 cfg ? cfg->fbconfigID : 0,
139						 screen,
140						 share_xid,
141						 gc ? gc->isDirect : direct,
142						 num_attribs,
143						 (const uint32_t *)
144						 attrib_list);
145   err = xcb_request_check(c, cookie);
146   if (err != NULL) {
147      if (gc)
148         gc->vtable->destroy(gc);
149      gc = NULL;
150
151      __glXSendErrorForXcb(dpy, err);
152      free(err);
153   } else if (!gc) {
154      /* the server thought the context description was okay, but we failed
155       * somehow on the client side. clean up the server resource and panic.
156       */
157      xcb_glx_destroy_context(c, xid);
158      /* increment dpy->request in order to give a unique serial number to the
159       * error */
160      XNoOp(dpy);
161      __glXSendError(dpy, GLXBadFBConfig, xid, 0, False);
162   } else {
163      gc->xid = xid;
164      gc->share_xid = share_xid;
165   }
166
167   return (GLXContext) gc;
168}
169