OpenGL-es 2.0 代码中的内存错误

Question

我已经在 Ubuntu 10.10 中使用 PVRSDK 在 OpenGL-ES 2.0 中编写了代码，现在的问题是，无论我想要什么输出，我都能得到它，但它出现了，然后窗口消失了， 如果我设置一个断点，我就会得到我想要的。但我不明白为什么窗口消失了。

当我用 valgrind 进行内存检查时，我得到了这些错误：

==5997== Memcheck, a memory error detector
==5997== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==5997== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==5997== Command: ./cube
==5997== 
libEGL warning: use software fallback
==5997== 
==5997== HEAP SUMMARY:
==5997==     in use at exit: 12,126 bytes in 94 blocks
==5997==   total heap usage: 97,499 allocs, 97,405 frees, 197,353,970 bytes allocated
==5997== 
==5997== 8 bytes in 1 blocks are definitely lost in loss record 3 of 57
==5997==    at 0x4024F12: calloc (vg_replace_malloc.c:467)
==5997==    by 0x486CE90: __glXInitialize (glxinit.c:584)
==5997==    by 0x486AA61: x11_screen_support (x11_screen.c:133)
==5997==    by 0x486DEEB: x11_create_dri2_display (native_dri2.c:700)
==5997==    by 0x4869AEA: native_create_display (native_x11.c:42)
==5997==    by 0x4866A2A: egl_g3d_initialize (egl_g3d.c:498)
==5997==    by 0x4176F36: _eglMatchDriver (egldriver.c:580)
==5997==    by 0x4170BBF: eglInitialize (eglapi.c:294)
==5997==    by 0x8049EFF: main (Hello.cpp:231)
==5997== 
==5997== 40 bytes in 1 blocks are definitely lost in loss record 31 of 57
==5997==    at 0x4026351: operator new(unsigned int) (vg_replace_malloc.c:255)
==5997==    by 0x8049CE3: main (Hello.cpp:206)
==5997== 
==5997== 72 bytes in 1 blocks are definitely lost in loss record 34 of 57
==5997==    at 0x4024F12: calloc (vg_replace_malloc.c:467)
==5997==    by 0x4A50C7C: st_bufferobj_alloc (st_cb_bufferobjects.c:56)
==5997==    by 0x49A1B78: _mesa_alloc_shared_state (shared.c:94)
==5997==    by 0x498860F: _mesa_initialize_context_for_api (context.c:904)
==5997==    by 0x49886DB: _mesa_create_context_for_api (context.c:1050)
==5997==    by 0x49C7479: st_create_context (st_context.c:176)
==5997==    by 0x4985A80: st_api_create_context (st_manager.c:646)
==5997==    by 0x4868843: egl_g3d_create_context (egl_g3d_api.c:131)
==5997==    by 0x4173127: eglCreateContext (eglapi.c:413)
==5997==    by 0x804A039: main (Hello.cpp:261)
==5997== 
==5997== 1,546 (48 direct, 1,498 indirect) bytes in 1 blocks are definitely lost in loss record 55 of 57
==5997==    at 0x4025BD3: malloc (vg_replace_malloc.c:236)
==5997==    by 0x4BABD13: talloc_enable_null_tracking (in /usr/lib/libtalloc.so.2.0.1)
==5997==    by 0x4BABE28: talloc_init (in /usr/lib/libtalloc.so.2.0.1)
==5997==    by 0x49F48B5: glsl_symbol_table::glsl_symbol_table() (glsl_symbol_table.cpp:60)
==5997==    by 0x49F2566: _mesa_glsl_parse_state::_mesa_glsl_parse_state(__GLcontextRec*, unsigned int, void*) (glsl_parser_extras.cpp:50)
==5997==    by 0x49D68B3: _mesa_glsl_compile_shader (ir_to_mesa.cpp:2815)
==5997==    by 0x49A0486: _mesa_CompileShaderARB (shaderapi.c:807)
==5997==    by 0x804A0E1: main (Hello.cpp:280)
==5997== 
==5997== LEAK SUMMARY:
==5997==    definitely lost: 168 bytes in 4 blocks
==5997==    indirectly lost: 1,498 bytes in 28 blocks
==5997==      possibly lost: 0 bytes in 0 blocks
==5997==    still reachable: 10,460 bytes in 62 blocks
==5997==         suppressed: 0 bytes in 0 blocks
==5997== Reachable blocks (those to which a pointer was found) are not shown.
==5997== To see them, rerun with: --leak-check=full --show-reachable=yes
==5997== 
==5997== For counts of detected and suppressed errors, rerun with: -v
==5997== ERROR SUMMARY: 4 errors from 4 contexts (suppressed: 54 from 11)

现在他们提到的那些行：

206         x11Visual = new XVisualInfo;
207         XMatchVisualInfo( x11Display, x11Screen, i32Depth, TrueColor, x11Vis    ual);
208         if (!x11Visual)
209         {
210                 printf("Error: Unable to acquire visual\n");
211                 goto cleanup;
212         }

===========================================================================================

230         EGLint iMajorVersion, iMinorVersion;
231         if (!eglInitialize(eglDisplay, &iMajorVersion, &iMinorVersion))
232         {
233                 printf("Error: eglInitialize() failed.\n");
234         }

==========================================================================================

 eglContext = eglCreateContext(eglDisplay, eglConfig, NULL, ai32Conte    xtAttribs);
262         if (!TestEGLError("eglCreateContext"))
263         {
264                 goto cleanup;
265         }

============================================================================================

279         glShaderSource(uiFragShader, 1, (const char**)&pszFragShader, NULL);
280         glCompileShader(uiFragShader);

所以我只想知道，由于这些错误，我得到的屏幕消失了，或者其他原因可能是原因。

Answer 1

我只是想知道，由于这些错误，我的屏幕消失了，或者可能是其他原因

后者的原因。泄漏不会影响程序运行时（除非它们太大以至于程序在需要时无法分配更多内存；但泄漏很小）。

您是否忘记进入 X 事件循环？

更新：

int i32NumMessages = XPending( x11Display );
for( int i = 0; i < i32NumMessages; i++ )
{
    XEvent  event;
    XNextEvent( x11Display, &event );
}

该循环实际上

• 显然是错误的
• ，这是您的应用程序（几乎）立即退出的原因

您只处理到目前为止排队的事件（这可能是极少数的事件）事件）。而你实际上正在丢弃它们。您可能需要编写类似于 this 的内容。