redhat man page for glfinish

GLFINISH(3G)															      GLFINISH(3G)

NAME
       glFinish - block until all GL execution is complete

C SPECIFICATION
       void glFinish( void )

DESCRIPTION
       glFinish  does  not  return  until  the	effects of all previously called GL commands are complete.  Such effects include all changes to GL
       state, all changes to connection state, and all changes to the frame buffer contents.

NOTES
       glFinish requires a round trip to the server.

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

SEE ALSO
       glFlush(3G)

																      GLFINISH(3G)