darwin之回调

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在darwin中定义了一个全局变量(结构体)sCallbacks,而这个结构体只有一个成员addr(数组),addr的每一个元素代表一个回调指针.

QTSS_Callbacks  QTSServer::sCallbacks;

typedef struct {    // Callback function pointer array    QTSS_CallbackProcPtr addr [kLastCallback];} QTSS_Callbacks, *QTSS_CallbacksPtr;

typedef QTSS_Error  (*QTSS_CallbackProcPtr)(...);

enum{    // Indexes for each callback routine. Addresses of the callback routines get    // placed in an array.     // IMPORTANT: When adding new callbacks, add only to the end of the list and increment the     //            kLastCallback value. Inserting or changing the index order will break dynamic modules    //            built with another release.        kNewCallback                    = 0,    kDeleteCallback                 = 1,    kMillisecondsCallback           = 2,    kConvertToUnixTimeCallback      = 3,    kAddRoleCallback                = 4,    kAddAttributeCallback           = 5,    kIDForTagCallback               = 6,    kGetAttributePtrByIDCallback    = 7,    kGetAttributeByIDCallback       = 8,    kSetAttributeByIDCallback       = 9,    kWriteCallback                  = 10,    kWriteVCallback                 = 11,    kFlushCallback                  = 12,    kAddServiceCallback             = 13,    kIDForServiceCallback           = 14,    kDoServiceCallback              = 15,    kSendRTSPHeadersCallback        = 16,    kAppendRTSPHeadersCallback      = 17,    kSendStandardRTSPCallback       = 18,    kAddRTPStreamCallback           = 19,    kPlayCallback                   = 20,    kPauseCallback                  = 21,    kTeardownCallback               = 22,    kRequestEventCallback           = 23,    kSetIdleTimerCallback           = 24,    kOpenFileObjectCallback         = 25,    kCloseFileObjectCallback        = 26,    kReadCallback                   = 27,    kSeekCallback                   = 28,    kAdviseCallback                 = 29,    kGetNumValuesCallback           = 30,    kGetNumAttributesCallback       = 31,    kSignalStreamCallback           = 32,    kCreateSocketStreamCallback     = 33,    kDestroySocketStreamCallback    = 34,    kAddStaticAttributeCallback     = 35,    kAddInstanceAttributeCallback   = 36,    kRemoveInstanceAttributeCallback= 37,    kGetAttrInfoByIndexCallback     = 38,    kGetAttrInfoByNameCallback      = 39,    kGetAttrInfoByIDCallback        = 40,    kGetValueAsStringCallback       = 41,    kTypeToTypeStringCallback       = 42,    kTypeStringToTypeCallback       = 43,    kStringToValueCallback          = 44,           kValueToStringCallback          = 45,           kRemoveValueCallback            = 46,    kRequestGlobalLockCallback      = 47,     kIsGlobalLockedCallback         = 48,     kUnlockGlobalLock               = 49,     kAuthenticateCallback           = 50,    kAuthorizeCallback              = 51,       kRefreshTimeOutCallback         = 52,    kCreateObjectValueCallback      = 53,    kCreateObjectTypeCallback       = 54,    kLockObjectCallback             = 55,    kUnlockObjectCallback           = 56,    kSetAttributePtrCallback        = 57,    kSetIntervalRoleTimerCallback   = 58,    kLockStdLibCallback             = 59,    kUnlockStdLibCallback           = 60,kGetRTSPPushSessionsCallback= 61,kRelayRTPCallback               = 62,kLastCallback                   = 63};

1.这个数组什么时候初始化呢?在InitCallbacks函数中对数组的每一个元素初始化