fglFinishAsyncSGIX(3G) OpenGL Reference fglFinishAsyncSGIX(3G)NAMEfglFinishAsyncSGIX - wait for completion of an asynchronous command
FORTRAN SPECIFICATION
INTEGER*4 fglFinishAsyncSGIX( CHARACTER*8 markerp )
PARAMETERS
markerp Returns a marker for a completed asynchronous command.
DESCRIPTIONfglFinishAsyncSGIX is part of the SGIX_async extension. This extension
provides a framework within which particular sets of OpenGL commands can
become "asynchronous" via specific further OpenGL extensions. Currently
the SGIX_async_pixel extension is the only such defined extension.
Asynchronous commands are commands that may complete out-of-order with
respect to other OpenGL commands. An asynchronous command samples the
OpenGL state vector when it is issued. The sampled state includes the
results from the complete execution of all synchronous (normal) commands
issued prior to the asynchronous command. However, the results of an
asynchronous command (state changes or framebuffer updates) are not
necessarily committed in order. An asynchronous command may commit its
results any time after the completion of all synchronous commands issued
prior to the asynchronous command. An implementation may choose to
execute asynchronous commands in parallel with subsequent commands or at
some convenient time in the future.
Implementations of asynchronous commands may also be non-blocking. For
example, a non-blocking query command returns control to the program
immediately rather than stalling the program until the results of the
query are available.
Note that this language allows any particular asynchronous command to
behave exactly as if it were not asynchronous, if the implementation
chooses.
fglFinishAsyncSGIX returns 1 when an asynchronous command has completed;
in this case it writes the marker associated with the completed command
into the integer referred to by markerp. If there are pending
asynchronous commands but none have completed, fglFinishAsyncSGIX blocks
waiting for one. If there are no pending asynchronous commands,
fglFinishAsyncSGIX returns 0 immediately and does not modify the integer
referred to by markerp.
Once OpenGL has reported the completion of an asynchronous command via
either fglFinishAsyncSGIX or fglPollAsyncSGIX, the completion status of
the command will not be reported again. If several commands have the
same marker associated with them, the completion status of each command
will be reported separately, although these reports will be
indistinguishable. The order in which asynchronous commands are reported
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fglFinishAsyncSGIX(3G) OpenGL Reference fglFinishAsyncSGIX(3G)
is undefined.
A program may guarantee that all outstanding asynchronous commands have
completed by calling fglFinish. A call to fglFinish does not cause the
completion status of outstanding commands to be reported, so subsequent
calls to fglFinishAsyncSGIX or fglPollAsyncSGIX will report the status of
such commands.
ERRORS
GL_INVALID_OPERATION is generated if fglFinishAsyncSGIX is executed
between the execution of fglBegin and the corresponding execution of
fglEnd.
MACHINE DEPENDENCIES
The SGIX_async and SGIX_async_pixel extensions are implemented only on
Octane2 VPro systems.
SEE ALSO
fglAsyncMarkerSGIX, fglDeleteAsyncMarkersSGIX, fglGenAsyncMarkersSGIX,
fglIsAsyncMarkerSGIX, fglPollAsyncSGIX, fglDrawPixels, fglGet,
fglReadPixels, fglTexImage1D, fglTexImage2D, fglTexImage3D,
fglTexSubImage1D, fglTexSubImage2D, fglTexSubImage3D
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