libpri/doc/cc_ptmp_agent.fsm

/*
 * FSM pseudo code used in the design/implementation of the CC PTMP agent.
 */
FSM CC_PTMP_Agent
{
	State CC_STATE_IDLE {
		Init {
		}
		Prolog {
			Action Set_Selfdestruct;
		}
		Stimulus CC_EVENT_AVAILABLE {
			Next_State CC_STATE_PENDING_AVAILABLE;
		}
		Stimulus CC_EVENT_CANCEL {
			Action Set_Selfdestruct;
		}
	}
	State CC_STATE_PENDING_AVAILABLE {
		Stimulus CC_EVENT_MSG_ALERTING {
			Action Send_CC_Available(Q931_ALERTING);
			Next_State CC_STATE_AVAILABLE;
		}
		Stimulus CC_EVENT_MSG_DISCONNECT {
			Action Send_CC_Available(Q931_DISCONNECT);
			Next_State CC_STATE_AVAILABLE;
		}
		Stimulus CC_EVENT_CANCEL {
			Next_State CC_STATE_IDLE;
		}
	}
	State CC_STATE_AVAILABLE {
		Epilog {
			Action Stop_T_RETENTION;
		}
		Stimulus CC_EVENT_MSG_RELEASE {
			Action Stop_T_RETENTION;
			Action Start_T_RETENTION;
		}
		Stimulus CC_EVENT_MSG_RELEASE_COMPLETE {
			Action Stop_T_RETENTION;
			Action Start_T_RETENTION;
		}
		Stimulus CC_EVENT_CC_REQUEST {
			Action Pass_Up_CC_Request;
			Next_State CC_STATE_REQUESTED;
		}
		Stimulus CC_EVENT_TIMEOUT_T_RETENTION {
			Action Send_EraseCallLinkageID;
			Action Release_LinkID;
			Action Pass_Up_CC_Cancel;
			Next_State CC_STATE_IDLE;
		}
		Stimulus CC_EVENT_CANCEL {
			Action Send_EraseCallLinkageID;
			Action Release_LinkID;
			Next_State CC_STATE_IDLE;
		}
	}
	State CC_STATE_REQUESTED {
		Epilog {
			Action Send_EraseCallLinkageID;
			Action Release_LinkID;
		}
		Stimulus CC_EVENT_CC_REQUEST_ACCEPT {
			Next_State CC_STATE_ACTIVATED;
		}
		Stimulus CC_EVENT_CANCEL {
			Next_State CC_STATE_IDLE;
		}
	}
/*
 * Pass_Up_A_Status passes up the current final status of A.
 * Does nothing if status is invalid.
 *
 * Pass_Up_A_Status_Indirect is the same as Pass_Up_A_Status but
 * sets a timer to expire immediately to pass up the event.
 * Does nothing if status is invalid.
 *
 * Pass_Up_Status_Rsp_A passes up the current accumulated status of A.
 * Does nothing if status is invalid.
 *
 * Pass_Up_Status_Rsp_A_Indirect is the same as Pass_Up_Status_Rsp_A but
 * sets a timer to expire immediately to pass up the event.
 * Does nothing if status is invalid.
 */
	State CC_STATE_ACTIVATED {
		Prolog {
			Action Reset_A_Status;
			Action Raw_Status_Count_Reset;
		}
		Stimulus CC_EVENT_RECALL {
			Action Send_Error_Recall(ROSE_ERROR_CCBS_NotReadyForCall);
			Action Set_Call_To_Hangup;
		}
		Stimulus CC_EVENT_B_FREE {
			Action Send_CCBSBFree;
		}
		Stimulus CC_EVENT_REMOTE_USER_FREE {
			Test = Get_A_Status;
			Test == Invalid {
				Next_State CC_STATE_B_AVAILABLE;
			}
			Test == Busy {
				Action Pass_Up_A_Status_Indirect;
				Action Send_CCBSBFree;
				Next_State CC_STATE_SUSPENDED;
			}
			Test == Free {
				//Action Pass_Up_A_Status_Indirect;
				Action Send_RemoteUserFree;
				Next_State CC_STATE_WAIT_CALLBACK;
			}
		}
		Stimulus CC_EVENT_A_STATUS {
			Test = Get_T_CCBS1_Status;
			Test == Active {
				Action Pass_Up_Status_Rsp_A_Indirect;
				Next_State $;
			}
			Test != Active {
				Action Reset_A_Status;
				Action Reset_Raw_A_Status;
				Action Send_CCBSStatusRequest;
				Action Start_T_CCBS1;
				Action Stop_Extended_T_CCBS1;
				Action Start_Extended_T_CCBS1;
				Next_State $;
			}
		}
		Stimulus CC_EVENT_A_FREE {
			Action Raw_Status_Count_Reset;
			Action Set_Raw_A_Status_Free;
			Action Promote_Raw_A_Status;
			Action Pass_Up_Status_Rsp_A;
			Action Stop_T_CCBS1;
		}
		Stimulus CC_EVENT_A_BUSY {
			Action Add_Raw_A_Status_Busy;
			Action Pass_Up_Status_Rsp_A;
		}
		Stimulus CC_EVENT_TIMEOUT_T_CCBS1 {
			Action Promote_Raw_A_Status;
			Test = Get_A_Status;
			Test != Invalid {
				/* Only received User A busy. */
				Action Raw_Status_Count_Reset;
			}
			Test == Invalid {
				/* Did not get any responses. */
				Action Raw_Status_Count_Increment;
				Test = Get_Raw_Status_Count;
				Test >= RAW_STATUS_COUNT_MAX {
					/* User A no longer present. */
					Action Send_CCBSErase(Normal_Unspecified);
					Action Pass_Up_CC_Cancel;
					Next_State CC_STATE_IDLE;
				}
			}
		}
		Stimulus CC_EVENT_TIMEOUT_EXTENDED_T_CCBS1 {
			Action Reset_A_Status;
			Action Raw_Status_Count_Reset;
		}
	}
	State CC_STATE_B_AVAILABLE {
		/* A status is always invalid on entry. */
		Prolog {
			Test = Get_T_CCBS1_Status;
			Test != Active {
				Action Reset_Raw_A_Status;
				Action Send_CCBSStatusRequest;
				Action Start_T_CCBS1;
			}
		}
		Stimulus CC_EVENT_RECALL {
			Action Send_Error_Recall(ROSE_ERROR_CCBS_NotReadyForCall);
			Action Set_Call_To_Hangup;
		}
		Stimulus CC_EVENT_A_STATUS {
			Action Stop_Extended_T_CCBS1;
			Action Start_Extended_T_CCBS1;
			Action Pass_Up_Status_Rsp_A_Indirect;
		}
		Stimulus CC_EVENT_A_FREE {
			Action Send_RemoteUserFree;
			Action Set_Raw_A_Status_Free;
			//Action Promote_Raw_A_Status;
			//Action Pass_Up_A_Status;
			Test = Get_Extended_T_CCBS1_Status;
			Test == Active {
				Action Pass_Up_Status_Rsp_A;
			}
			Next_State CC_STATE_WAIT_CALLBACK;
		}
		Stimulus CC_EVENT_A_BUSY {
			Action Add_Raw_A_Status_Busy;
			Test = Get_Extended_T_CCBS1_Status;
			Test == Active {
				Action Pass_Up_Status_Rsp_A;
			}
		}
		Stimulus CC_EVENT_TIMEOUT_T_CCBS1 {
			Test = Get_Raw_A_Status;
			Test != Invalid {
				/* Only received User A is busy. */
				Action Raw_Status_Count_Reset;
				Action Send_CCBSBFree;
				Action Promote_Raw_A_Status;
				Action Pass_Up_A_Status;
				Next_State CC_STATE_SUSPENDED;
			}
			Test == Invalid {
				/* Did not get any responses. */
				Action Raw_Status_Count_Increment;
				Test = Get_Raw_Status_Count;
				Test >= RAW_STATUS_COUNT_MAX {
					/* User A no longer present. */
					Action Send_CCBSErase(Normal_Unspecified);
					Action Pass_Up_CC_Cancel;
					Next_State CC_STATE_IDLE;
				}
				//Action Reset_Raw_A_Status;
				Action Send_CCBSStatusRequest;
				Action Start_T_CCBS1;
			}
		}
	}
	State CC_STATE_SUSPENDED {
		Prolog {
			Test = Get_T_CCBS1_Status;
			Test != Active {
				Action Reset_Raw_A_Status;
				Action Send_CCBSStatusRequest;
				Action Start_T_CCBS1;
			}
		}
		Stimulus CC_EVENT_RECALL {
			Action Send_Error_Recall(ROSE_ERROR_CCBS_NotReadyForCall);
			Action Set_Call_To_Hangup;
		}
		Stimulus CC_EVENT_A_STATUS {
			Action Stop_Extended_T_CCBS1;
			Action Start_Extended_T_CCBS1;
			Action Pass_Up_Status_Rsp_A_Indirect;
		}
		Stimulus CC_EVENT_A_FREE {
			Action Set_Raw_A_Status_Free;
			Action Promote_Raw_A_Status;
			Action Pass_Up_A_Status;
			Test = Get_Extended_T_CCBS1_Status;
			Test == Active {
				Action Pass_Up_Status_Rsp_A;
			}
			Action Stop_T_CCBS1;
			Action Stop_Extended_T_CCBS1;
			Next_State CC_STATE_ACTIVATED;
		}
		Stimulus CC_EVENT_A_BUSY {
			Action Add_Raw_A_Status_Busy;
			Test = Get_Extended_T_CCBS1_Status;
			Test == Active {
				Action Pass_Up_Status_Rsp_A;
			}
		}
		Stimulus CC_EVENT_TIMEOUT_T_CCBS1 {
			Test = Get_Raw_A_Status;
			Test != Invalid {
				/* Only received User A is busy. */
				Action Raw_Status_Count_Reset;
			}
			Test == Invalid {
				/* Did not get any responses. */
				Action Raw_Status_Count_Increment;
				Test = Get_Raw_Status_Count;
				Test >= RAW_STATUS_COUNT_MAX {
					/* User A no longer present. */
					Action Send_CCBSErase(Normal_Unspecified);
					Action Pass_Up_CC_Cancel;
					Next_State CC_STATE_IDLE;
				}
			}
			Action Reset_Raw_A_Status;
			Action Send_CCBSStatusRequest;
			Action Start_T_CCBS1;
		}
	}
	State CC_STATE_WAIT_CALLBACK {
		Prolog {
			/* Start T_CCBS3 */
			Action Start_T_RECALL;
		}
		Epilog {
			Action Stop_T_RECALL;
		}
		Stimulus CC_EVENT_TIMEOUT_T_RECALL {
			Action Pass_Up_CC_Cancel;
			Action Send_CCBSErase(T_CCBS3_TIMEOUT);
			Next_State CC_STATE_IDLE;
		}
		Stimulus CC_EVENT_STOP_ALERTING {
			/*
			 * If an earlier link can send us this event then we
			 * really should be configured for globalRecall like
			 * the earlier link.
			 */
			Test = Get_Recall_Mode;
			Test == globalRecall {
				Action Send_CCBSStopAlerting;
			}
			Next_State CC_STATE_ACTIVATED;
		}
		Stimulus CC_EVENT_RECALL {
			Action Pass_Up_CC_Call;
			Action Set_Original_Call_Parameters;
			Test = Get_Recall_Mode;
			Test == globalRecall {
				Action Send_CCBSStopAlerting;
			}
			Next_State CC_STATE_CALLBACK;
		}
		Stimulus CC_EVENT_A_STATUS {
			Action Set_Raw_A_Status_Free;
			Action Pass_Up_Status_Rsp_A_Indirect;
		}
	}
	State CC_STATE_CALLBACK {
		Stimulus CC_EVENT_RECALL {
			Action Send_Error_Recall(ROSE_ERROR_CCBS_AlreadyAccepted);
			Action Set_Call_To_Hangup;
		}
		Stimulus CC_EVENT_A_STATUS {
			Action Set_Raw_A_Status_Free;
			Action Pass_Up_Status_Rsp_A_Indirect;
		}
	}
	Superstate CC_ACTIVE(CC_STATE_ACTIVATED, CC_STATE_B_AVAILABLE, CC_STATE_SUSPENDED, CC_STATE_WAIT_CALLBACK, CC_STATE_CALLBACK) {
		Prolog {
			/* Start T_CCBS2 or T_CCNR2 depending upon CC mode. */
			Action Start_T_SUPERVISION;
		}
		Epilog {
			Action Stop_T_SUPERVISION;
		}
		Stimulus CC_EVENT_TIMEOUT_T_SUPERVISION {
			Action Pass_Up_CC_Cancel;
			Action Send_CCBSErase(T_CCBS2_TIMEOUT);
			Next_State CC_STATE_IDLE;
		}
		Stimulus CC_EVENT_LINK_CANCEL {
			Action Pass_Up_CC_Cancel;
			Action Send_CCBSErase(Normal_Unspecified);
			Next_State CC_STATE_IDLE;
		}
		Stimulus CC_EVENT_CANCEL {
			Action Send_CCBSErase(Normal_Unspecified);
			Next_State CC_STATE_IDLE;
		}
	}
	Superstate CC_STATUS(CC_STATE_ACTIVATED, CC_STATE_B_AVAILABLE, CC_STATE_SUSPENDED) {
		Epilog {
			Action Stop_T_CCBS1;
			Action Stop_Extended_T_CCBS1;
		}
	}
}