Name

barrier — synchronize execution of multiple shader invocations

Declaration

void barrier(void);

Description

Available only in the Tessellation Control Shader, barrier provides a partially defined order of execution between shader invocations. For any given static instance of barrier, all tessellation control shader invocations for a single input patch must enter it before any will be allowed to continue beyond it. This ensures that values written by one invocation prior to a given static instance of barrier can be safely read by other invocations after their call to the same static instance of barrier. Because invocations may execute in undefined order between these barrier calls, the values of a per-vertex or per-patch output variable will be undefined in a number of cases.

barrier may only be placed inside the function main() of the tessellation control shader and may not be called within any control flow. Barriers are also disallowed after a return statement in the function main().

Version Support

FunctionVersion 1.10Version 1.20Version 1.30Version 1.40Version 1.50Version 3.30Version 4.00Version 4.10Version 4.20Version 4.30
barrier------YYYY

Copyright

Copyright © 2011 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.