glWaitSync - instruct the GL server to block until the specified sync object becomes signaled

voidglWaitSync(GLsyncsync,GLbitfieldflags,GLuint64timeout);

       Copyright © 2010-2014 Khronos Group

glWaitSync causes the GL server to block and wait until sync becomes signaled.  sync is the name of an
       existing sync object upon which to wait.  flags and timeout are currently not used and must be set to
       zero and the special value GL_TIMEOUT_IGNORED, respectively[1].  glWaitSync will always wait no longer
       than an implementation-dependent timeout. The duration of this timeout in nanoseconds may be queried by
       calling glGet() with the parameter GL_MAX_SERVER_WAIT_TIMEOUT. There is currently no way to determine
       whether glWaitSync unblocked because the timeout expired or because the sync object being waited on was
       signaled.

       If an error occurs, glWaitSync does not cause the GL server to block.

GL_INVALID_VALUE is generated if sync is not the name of a sync object.

       GL_INVALID_VALUE is generated if flags is not zero.

       GL_INVALID_VALUE is generated if timeout is not GL_TIMEOUT_IGNORED.

       glWaitSync - instruct the GL server to block until the specified sync object becomes signaled

        1. flags  and  timeout  are  placeholders for anticipated future extensions of sync object capabilities.
           They must have these reserved values in order that existing code calling glWaitSync operate  properly
           in the presence of such extensions.

[FIXME: source]                                    11/18/2024                                     GLWAITSYNC(3G)

sync
           Specifies the sync object whose status to wait on.

       flags
           A bitfield controlling the command flushing behavior.  flags may be zero.

       timeout
           Specifies the timeout that the server should wait before continuing.  timeout must be
           GL_TIMEOUT_IGNORED.

glFenceSync(), glClientWaitSync()

       ┌────────────┬───────────────────────────────────────────────────────────────────────┐
       │            │                OpenGLVersion                                         │
       ├────────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤
       │ Function   │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │
       │ /          │     │     │     │     │     │     │     │     │     │     │     │     │
       │ Feature    │     │     │     │     │     │     │     │     │     │     │     │     │
       │ Name       │     │     │     │     │     │     │     │     │     │     │     │     │
       ├────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │ glWaitSync │  -  │  -  │  -  │  -  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │
       └────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘