This message creates a stream instance with hstream as the handle. The Sync/Stream Manager calls both the source and target stream handlers during an SpiCreateStream call from the application or media driver. The stream handler must pass back a pointer to an SPCB so that the Sync/Stream Manager can negotiate the stream parameters. The Sync/Stream Manager calls SHC_NEGOTIATE_RESULT with the results of the stream negotiation. Device driver stream handlers must perform the OS/2 function AttachDD (DevHelp service), based on the device information in the device control block.
Stream handlers must be able to handle multiple stream instances. These stream instances are created when an SHC_CREATE message is received from the Sync/Stream Manager. The stream handler should create any stream instance control structures at this point.