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