NAME

       TSLifecycleHookAdd -

SYNOPSIS

       #include <ts/ts.h>

       void TSLifecycleHookAdd(TSLifecycleHookID id, TSCont contp)

DESCRIPTION

       TSLifecycleHookAdd() adds contp to the list of lifecycle hooks specified by id. Lifecycle hooks are based
       on the Traffic Server process, not on any specific transaction or session. These will typically be called
       only  once  during  the  execution  of  the  Traffic  Server  process  and  therefore  should be added in
       TSPluginInit() (which could itself be considered a lifecyle hook). Unlike other  hooks,  lifecycle  hooks
       may  not  have  a well defined ordering and use of them should not assume that one of the hooks is always
       called before another unless specifically mentioned.

       TS_LIFECYCLE_PORTS_INITIALIZED_HOOK
              Called after the proxy server port data structures have been initialized  but  before  connections
              are  accepted  on  those  ports.  The  sockets  corresponding  to the ports may or may not be open
              depending on how the traffic_server process was invoked. Other API functions that depend on server
              ports should be called from this hook and not TSPluginInit().

              Invoked with the event TS_EVENT_LIFECYCLE_PORTS_INITIALIZED and NULL data.

       TS_LIFECYCLE_PORTS_READY_HOOK
              Called after enabling connections on the proxy server ports. Because Traffic  Server  is  threaded
              this  may  or may not be called before any connections are accepted. The hook code may assume that
              any connection to Traffic Server started after this hook is called will  be  accepted  by  Traffic
              Server, making this a convenient place to signal external processes of that.

              Invoked with the event TS_EVENT_LIFECYCLE_PORTS_READY and NULL data.

       TS_LIFECYCLE_CACHE_READY_HOOK
              Called after Traffic Server cache initialization has finished.

              Invoked with the event TS_EVENT_LIFECYCLE_CACHE_READY and NULL data.

ORDERING

       TS_LIFECYCLE_PORTS_INITIALIZED_HOOK will always be called before TS_LIFECYCLE_PORTS_READY_HOOK.

EXAMPLES

       The  following  example  demonstrates how to correctly use TSNetAcceptNamedProtocol(), which requires the
       proxy ports to be initialized and therefore does not work if called from TSPluginInit() directly.

          #include <ts/ts.h>

          #define SSL_PROTOCOL_NAME "whatever"

          static int
          ssl_proto_handler(TSCont contp, TSEvent event, void* data)
          {
             /// Do named protocol handling.
          }

          static int
          local_ssl_init(TSCont contp, TSEvent event, void *edata)
          {
             if (TS_EVENT_LIFECYCLE_PORTS_INITIALIZED == event) { // just to be safe.
                TSNetAcceptNamedProtocol(
                   TSContCreate(ssl_proto_handler, TSMutexCreate()),
                   SSL_PROTOCOL_NAME
                );
             }
             return 0;
          }

          void
          TSPluginInit (int argc, const char *argv[])
          {
             TSLifecycleHookAdd(TS_LIFECYCLE_PORTS_INITIALIZED_HOOK, TSContCreate(local_ssl_init, NULL));
          }

HISTORY

       Lifecycle hooks were introduced to solve process initialization ordering issues (TS-1487). Different  API
       calls required different modules of Traffic Server to be initialized for the call to work, but others did
       not work that late in initialization, which was problematic because all of them could effectively only be
       called  from TSPluginInit() . The solution was to move TSPluginInit() as early as possible in the process
       initialization and provide hooks for API calls that needed to be invoked later which  served  essentially
       as additional pluging initialization points.

SEE ALSO

       TSAPI(3ts), TSContCreate(3ts)

COPYRIGHT

       2014, dev@trafficserver.apache.org

5.3                                              April 18, 2016                          TSLIFECYCLEHOOKADD(3ts)