Vlv2TbltDevicePkg/PlatformDxe/Observable/Observable.h

   1 /*++
   2
   3   Copyright (c) 2004  - 2014, Intel Corporation. All rights reserved.<BR>
   4
   5   This program and the accompanying materials are licensed and made available under
   6   the terms and conditions of the BSD License that accompanies this distribution.
   7   The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13
  14 Module Name:
  15
  16   Observable.h
  17
  18 Abstract:
  19
  20   Prototypes for Observable protocol implementation
  21 --*/
  22
  23 #ifndef _OBSERVABLE_H_
  24 #define _OBSERVABLE_H_
  25 #include "PlatformDxe.h"
  26 #include "Protocol/Observable.h"
  27
  28 //
  29 // Prototypes
  30 //
  31
  32 /** Install observable protocol.
  33  *
  34  * Install interface and initialize the observable protocol.
  35  *
  36  * @param   VOID          No parameters.
  37  *
  38  * @return  EFI_SUCCESS   Successfully installed and initialized the protocol.
  39  **/
  40 EFI_STATUS
  41 InitializeObservableProtocol(
  42   VOID
  43   );
  44
  45 /** Remove all observables.
  46  *
  47  * Remove all observable guids and all interfaces subscribed to them.
  48  *
  49  * @param   VOID          No parameters.
  50  *
  51  * @return  EFI_SUCCESS   Successfully removed all observables and subscribed interfaces.
  52  **/
  53 EFI_STATUS
  54 EFIAPI
  55 RemoveAllObservables(
  56   VOID
  57   );
  58
  59 /** Subscribe an interface with an observable guid.
  60  *
  61  * Use this to register a callback function with a guid. The function provided by CallbackInterface will be executed
  62  * whenever the appropriate observable instance specified by ReferenceGuid calls Publish.
  63  *
  64  * @param   EFI_GUID              ReferenceGuid       The observable guid that the callback interface will subscribe to.
  65  *          OBS_CALLBACK          CallbackInterface   A pointer to the function that is subscribing to the observable.
  66  *
  67  * @return  EFI_SUCCESS           Successfully subscribed the interface to the observable guid.
  68  *          EFI_NOT_FOUND         No match could be found between the provided guid and existing observables.
  69  *          EFI_OUT_OF_RESOURCES  Could not subscribe to this observer due to resource limitations.
  70  *          EFI_INVALID_PARAMETER Interface is already subscribed to this observer.
  71  **/
  72 EFI_STATUS
  73 EFIAPI
  74 Subscribe (
  75   IN      EFI_GUID        ReferenceGuid,
  76   IN      OBS_CALLBACK    CallbackInterface
  77   );
  78
  79 /** Unsubscribe an interface with an observable guid.
  80  *
  81  * Use this to remove an interface from the callback list associated with an observable guid.
  82  *
  83  * @param   EFI_GUID              ReferenceGuid      The observable guid to unsubscribe the interface from.
  84  *          OBS_CALLBACK          CallbackInterface  A pointer to the interface that is being unsubscribed.
  85  *
  86  * @return  EFI_SUCCESS           Successfully unsubscribed the interface from the observable guid.
  87  **/
  88 EFI_STATUS
  89 EFIAPI
  90 Unsubscribe (
  91   IN      EFI_GUID            ReferenceGuid,
  92   IN      OBS_CALLBACK    CallbackInterface
  93   );
  94
  95 /** Notify observing functions.
  96  *
  97  * Use this to notify all functions who are subscribed to the guid specified by ReferenceGuid.
  98  *
  99  * @param   EFI_GUID          ReferenceGuid   The observable guid that contains the list of interfaces to be notified.
 100  *          VOID*             Data            Parameter context to be passed to the subscribed function.
 101  *
 102  * @return  EFI_SUCCESS       Successfully notified all observers listening to this guid.
 103  *          EFI_NOT_FOUND     No match could be found between the provided guid and existing observables.
 104  **/
 105 EFI_STATUS
 106 EFIAPI
 107 Publish (
 108   IN      EFI_GUID        ReferenceGuid,
 109   IN  OUT VOID*           Data
 110   );
 111
 112 /** Creates a new observable.
 113  *
 114  * Create a new observable that can be observed with the use of Subscribe function.
 115  *
 116  * @param   EFI_GUID              ReferenceGuid   The observable guid to add.
 117  *
 118  * @return  EFI_SUCCESS           Successfully added observable.
 119  *          EFI_INVALID_PARAMETER Observable already exists.
 120  **/
 121 EFI_STATUS
 122 EFIAPI
 123 AddObservable (
 124   IN      EFI_GUID        ReferenceGuid
 125   );
 126
 127 /** Remove an observable.
 128  *
 129  * Remove an observable so that it can no longer be subscribed to. In addition, unsubscribe any functions
 130  * that are subscribed to this guid.
 131  *
 132  * @param   EFI_GUID              ReferenceGuid   The observable guid to remove.
 133  *
 134  * @return  EFI_SUCCESS           Successfully removed observable.
 135  **/
 136 EFI_STATUS
 137 EFIAPI
 138 RemoveObservable (
 139   IN      EFI_GUID        ReferenceGuid
 140   );
 141
 142 #endif