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Development of Tuxedo – Various APIs
Tuxedo provides an event-broker server called TMUSREVT. It helps to store the
subscription information as tpsubscribe() is being called; similarly, tppost()
invokes it to post an event for the subscriber(s). In the case of unsolicited
subscription, this server creates a message using tppost() and sends an unsolicited
message to the clients that subscribed to that unsolicited event. Let us look at how
we can subscribe, post, and unsubscribe from an event:
• Subscribe to an event by name using the tpsubscribe() function. The
event-expr argument is the name of one or more events, filterptr is the
rule to select the specific event, ctlptr is the pointer to an event-control
structure (it is NULL for unsolicited notifications), and the flags parameter is
TPEVSERVICE, TPEVQUEUE, TPEVTRAN, or TPEVPERSIST. The tpsubscribe()
function returns a handler for a specific subscription, which should be used
for unsubscription.
tpsubscribe – long tpsubscribe (char *event-expr, char
*filterptr, TPEVCTL *ctlptr, long flags)
• Post (initiate or notify) an event by using tppost(). It posts an event
identified by event-name; indata is the message you would like to pass to
its subscriber(s), length is the message length, and flags can have values
TPSIGRSTRT, TPNOTRAN, TPNOREPLY, TPNOBLOCK, and TPNOTIME.
tppost – tppost(char *event-name, char *indata, long length,
long flags)
• Unsubscribe from the event by using tpunsubscribe(). The subscription is
a valid handler returned by tpsubscribe(). A client must use this function
before it calls tpterm().
tpunsubscribe –int tpunsubscribe (long subscription-name,
long flags)
So, there are two ways to use event-based communication, namely unsolicited client
notification by using the tpnotify() and tpbroadcast() functions, and eventbroker
server by using the tppost() and tpsubscribe() functions.
Transaction in Tuxedo
This is one of the most important sections in client/server architecture. The
foundation of Tuxedo ATMI is a proven, reliable transaction processor, also known
as a Transaction Processing (TP) monitor. This transaction processing has very
unique characteristics consisting Atomicity, Consistency, Isolation, and Durability,
also known as ACID.
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