redhat man page for glflush

GLFLUSH(3G)															       GLFLUSH(3G)

NAME
       glFlush - force execution of GL commands in finite time

C SPECIFICATION
       void glFlush( void )

DESCRIPTION
       Different GL implementations buffer commands in several different locations, including network buffers and the graphics accelerator itself.
       glFlush empties all of these buffers, causing all issued commands to be executed as quickly as they are accepted by  the  actual  rendering
       engine.	Though this execution may not be completed in any particular time period, it does complete in finite time.

       Because any GL program might be executed over a network, or on an accelerator that buffers commands, all programs should call glFlush when-
       ever they count on having all of their previously issued commands completed.  For example, call glFlush before waiting for user input  that
       depends on the generated image.

NOTES
       glFlush can return at any time.	It does not wait until the execution of all previously issued GL commands is complete.

ERRORS
       GL_INVALID_OPERATION is generated if glFlush is executed between the execution of glBegin and the corresponding execution of glEnd.

SEE ALSO
       glFinish(3G)

																       GLFLUSH(3G)