Wrote a opengles application in carrying out

GlClearColor (0.0 f, f, 0.0 0.0 f, 0.0 f);
GlClear (GL_COLOR_BUFFER_BIT);
Encountered the following error:
PVR (Error) : KEGLGetDrawableParameters: No Current thread [0]
PVR (Error) : PrepareToDraw: Invalid drawable [0]
PVR (Error) : glClear: Can 't prepare to draw [0]

EGL initialization is as follows:
(opengles version is 2.0, EGL version is 1.4, the initialization is performed successfully)

 static const EGLint context_attribs []={
EGL_CONTEXT_CLIENT_VERSION, 2, 
EGL_NONE 
}; 

The static const EGLint config_attribs []={
EGL_SURFACE_TYPE EGL_WINDOW_BIT, 
EGL_RED_SIZE, 8, 
EGL_GREEN_SIZE, 8, 
EGL_BLUE_SIZE, 8, 
EGL_ALPHA_SIZE, 8, 
EGL_RENDERABLE_TYPE EGL_OPENGL_ES2_BIT, 
EGL_NONE 
}; 

S_egl_info. Display=eglGetDisplay (pGbmSurfInfo - & gt; PDev); 

EGLint major, minor, n. 
if (! EglInitialize (s_egl_info. Display, & amp; Major, & amp; Minor)) {
Printf (" failed to initialize \ n "); 
return -1; 
} 

Printf (" Using the display version % % p with EGL d. % d \ n ", s_egl_info. Display, major, minor); 

Printf (" EGL Version \ "% s \ " n ", eglQueryString (s_egl_info. Display, EGL_VERSION)); 
Printf (" EGL Vendor \ "% s \ " n ", eglQueryString (s_egl_info. Display, EGL_VENDOR)); 
Printf (" EGL Extensions \ "% s \ " n ", eglQueryString (s_egl_info. Display, EGL_EXTENSIONS)); 

if (! EglBindAPI (EGL_OPENGL_ES_API)) {
Printf (" failed to bind API EGL_OPENGL_ES_API \ n "); 
return -1; 
} 

if (! EglChooseConfig (s_egl_info. Display, config_attribs, & amp; S_egl_info. Config, 1, & amp; N) | | n!=1) {
Printf (" failed to choose the config: % d \ n ", n); 
return -1; 
} 

S_egl_info. Context=eglCreateContext (s_egl_info. Display, s_egl_info. Config, EGL_NO_CONTEXT context_attribs); 
If (s_egl_info context==NULL) {
Printf (" failed to create the context \ n "); 
return -1; 
} 

S_egl_info. Surface=eglCreateWindowSurface (s_egl_info. Display, s_egl_info config, pGbmSurfInfo - & gt; PSurface, NULL); 
If (s_egl_info. Surface==EGL_NO_SURFACE) {
Printf (" failed to create egl surface \ n "); 
return -1; 
} 

/* connect the context to the surface */
EglMakeCurrent (s_egl_info. Display, s_egl_info surface, s_egl_info. Surface, s_egl_info. Context). 

S_egl_info. UserData. WinWidth=width; 
S_egl_info. UserData. WinHeight=height; 

Char vShaderStr []=
"The attribute vec4 a_position; 
 \ n""The attribute vec2 a_texCoord; 
 \ n""Varying vec2 v_texCoord; 
 \ n""Void main () \ n" 
"{\ n 
""Gl_Position=a_position; 
 \ n""V_texCoord=a_texCoord; 
 \ n""} \ n "; 


Char fShaderStr []=
"Precision mediump float; 
 \ n""Varying vec2 v_texCoord; 
 \ n""Uniform sampler2D s_sampler; 
 \ n""Void main () \ n" 
"{\ n 
""Gl_FragColor=texture2D (s_sampler v_texCoord); 
 \ n""} \ n "; 

//Load the shaders and get a linked program object 
S_egl_info. UserData. ProgramObject=esLoadProgram (vShaderStr fShaderStr); 
If (s_egl_info. UserData. ProgramObject==0) {
EGL_LOG_ERR (" EGL load shader fail... "); 
return -1; 
} 

GlBindAttribLocation (s_egl_info userData. ProgramObject, 0, "a_position"); 
GlBindAttribLocation (s_egl_info. UserData. ProgramObject, 1, "a_texCoord"); 

//Get the sampler location 
S_egl_info. UserData. SamplerLoc=glGetUniformLocation (s_egl_info. UserData. ProgramObject, "s_sampler"); 

//* * Load indice data * * 
GLushort indices []={0, 1, 2, 0, 2, 3}; 
GLushort indicesSize=sizeof (indices); 
S_egl_info. UserData. Indices=(GLushort *) malloc (indicesSize); 
Memcpy (s_egl_info. UserData. Indices, indices, indicesSize); 
Memset (s_egl_info userData. TextureNumPerLayer, 0, sizeof (s_egl_info. UserData. TextureNumPerLayer)); 
Memset (s_egl_info userData. TextureIds, 0, MAX_TEXTURE_PER_LAYER LAYER_MAX * * sizeof (GLuint)); 
S_egl_info. UserData. IndiceNum=6; 
S_egl_info. HasInit=1; 

GlUseProgram (s_egl_info. UserData. ProgramObject); 
GlViewport (0, 0, s_egl_info. UserData. WinWidth, s_egl_info. UserData. WinHeight); 

GlEnable (GL_BLEND); 
GlBlendFunc (GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA); 

Printf (" egl init finish [% d % d x]... . \ n ", s_egl_info userData. WinWidth s_egl_info. UserData. WinHeight); 

Anyone know what the problem with the initialization?