Note: This feature is available in Web Workers.
The WebGL2RenderingContext.fenceSync() method of the WebGL 2 API creates a new WebGLSync object and inserts it into the GL command stream.
fenceSync(condition, flags)conditionA GLenum specifying the condition that must be met to set the sync object's state to signaled. Must be gl.SYNC_GPU_COMMANDS_COMPLETE.
flagsA GLbitfield specifying a bitwise combination of flags controlling the behavior of the sync object. Must be 0 (exists for extensions only).
A WebGLSync object.
gl must be a WebGL2RenderingContext. WebGLSync objects are not available in WebGL 1.
const sync = gl.fenceSync(gl.SYNC_GPU_COMMANDS_COMPLETE, 0);