ACB_NULLSH

This data structure allows users of the NULL stream handler to register a callback address. This callback address is used to pass information from the NULL stream handler to the user. There are two stream handler commands (SHC messages) that the NULL stream handler passes to the user (SHC_ENABLE_SYNC and SHC_DISABLE_SYNC). These are required to allow the user to pass back to the Sync/Stream Manager an EVCB and an optional semaphore to be used for synchronization.

The prototype for the callback address is:

ULONG pfnEntry(PVOID pParmin)

where pParmin is a pointer to an SHC message-specific parameter block.

typedef struct _ACB_NULLSH {
  ULONG     ulADBLen;    /*  Structure length. */
  ULONG     ulObjType;   /*  Object type. */
  PFN       pfnEntry;    /*  User callback entry point. */
  ULONG     ulReserved;  /*  Reserved. */
} ACB_NULLSH;

typedef   ACB _ NULLSH   * PACB _ NULLSH ;