MXS-1392 Remove remnats of DCB reference counting

include/maxscale/poll_core.h

@@ -46,23 +46,9 @@ struct mxs_poll_data;
  */
 typedef uint32_t (*mxs_poll_handler_t)(struct mxs_poll_data* data, int wid, uint32_t events);
 
-/**
- * Pointer to function that knows how to free a particular
- * 'struct mxs_poll_data' structure
- *
- * @param data The `mxs_poll_data` instance that contained this function pointer.
- */
-typedef void (*mxs_poll_free_t)(struct mxs_poll_data* data);
-
 typedef struct mxs_poll_data
 {
     mxs_poll_handler_t handler; /*< Handler for this particular kind of mxs_poll_data. */
-    mxs_poll_free_t free;       /*< Optional free function for mxs_poll_data. */
-    uint32_t refcount;          /*< Reference count, optionally used. If 'free' is provided,
-                                    refcount will be incremented before events are delivered
-                                    to the handler and decremented after. If reaches 0, then
-                                    the free function is called.
-                                */
     struct
     {
         int id;                 /*< The id of the worker thread. */
@@ -115,28 +101,4 @@ bool poll_add_fd_to_worker(int wid, int fd, uint32_t events, MXS_POLL_DATA* data
  */
 bool poll_remove_fd_from_worker(int wid, int fd);
 
-/**
- * Increase the reference count of the poll data.
- *
- * @param data  The poll data whose reference count should be increased.
- */
-static inline void poll_inc_ref(MXS_POLL_DATA* data)
-{
-    atomic_add_uint32(&data->refcount, 1);
-}
-
-/**
- * Decrease the reference count of the poll data.
- *
- * @param data  The poll data whose reference count should be decreased.
- *
- * @return The previous reference count. If the returned value is 1, then
- *         the caller should call @c data->free(data) to dispose of the
- *         poll data.
- */
-static inline uint32_t poll_dec_ref(MXS_POLL_DATA* data)
-{
-    return atomic_add_uint32(&data->refcount, -1);
-}
-
 MXS_END_DECLS

include/maxscale/poll_core.hh

@@ -23,14 +23,12 @@ struct MxsPollData : MXS_POLL_DATA
     MxsPollData()
     {
         handler = NULL;
-        free = NULL;
         thread.id = 0;
     }
 
     MxsPollData(mxs_poll_handler_t h)
     {
         handler = h;
-        free = NULL;
         thread.id = 0;
     }
 };

server/core/dcb.cc

@@ -122,12 +122,6 @@ static uint32_t dcb_poll_handler(MXS_POLL_DATA *data, int thread_id, uint32_t ev
 static uint32_t dcb_process_poll_events(DCB *dcb, uint32_t ev);
 static bool dcb_session_check(DCB *dcb, const char *);
 
-static void poll_dcb_free(MXS_POLL_DATA* data)
-{
-    // MXS_POLL_DATA is the first member of DCB.
-    dcb_free_all_memory(reinterpret_cast<DCB*>(data));
-}
-
 void dcb_global_init()
 {
     this_unit.dcb_initialized.dcb_chk_top = CHK_NUM_DCB;
@@ -135,8 +129,6 @@ void dcb_global_init()
     this_unit.dcb_initialized.state = DCB_STATE_ALLOC;
     this_unit.dcb_initialized.ssl_state = SSL_HANDSHAKE_UNKNOWN;
     this_unit.dcb_initialized.poll.handler = dcb_poll_handler;
-    this_unit.dcb_initialized.poll.free = poll_dcb_free;
-    this_unit.dcb_initialized.poll.refcount = 1;
     this_unit.dcb_initialized.dcb_chk_tail = CHK_NUM_DCB;
 
     int nthreads = config_threadcount();

server/core/maxscale/dcb.h

@@ -19,58 +19,4 @@ MXS_BEGIN_DECLS
 void dcb_free_all_memory(DCB *dcb);
 void dcb_final_close(DCB *dcb);
 
-/**
- * @brief Increase the reference count of the DCB
- *
- * @param dcb  The dcb whose reference count should be increased.
- */
-static inline void dcb_inc_ref(DCB* dcb)
-{
-    // A DCB starts out with a refcount of 1.
-    ss_dassert(dcb->poll.refcount >= 1);
-
-    poll_inc_ref(&dcb->poll);
-}
-
-/**
- * @brief Decrease the reference count of the DCB. If it reaches 0,
- *        the DCB will be freed.
- *
- * @param dcb  The dcb whose reference count should be decreased.
- *
- * @return True, if the dcb is still usable after the call, otherwise false.
- *
- * @note If the function returns false, the caller cannot use the dcb
- *       for anything.
- */
-static inline bool dcb_dec_ref(DCB* dcb)
-{
-    // A DCB starts out with a refcount of 1.
-    ss_dassert(dcb->poll.refcount >= 1);
-
-    bool rv = true;
-    if (poll_dec_ref(&dcb->poll) == 1)
-    {
-        dcb_free_all_memory(dcb);
-        rv = false;
-    }
-    return rv;
-}
-
-/**
- * @brief Increase the reference count of the DCB.
- *
- * Convenience function for the situation where a received dcb is stored
- * and the reference count needs to be increased.
- *
- * @param dcb  The dcb whose reference count should be increased.
- *
- * @return The dcb provided as argument.
- */
-static inline DCB* dcb_get_ref(DCB* dcb)
-{
-    dcb_inc_ref(dcb);
-    return dcb;
-}
-
 MXS_END_DECLS

server/core/worker.cc

@@ -163,8 +163,6 @@ Worker::Worker(int id,
     , m_shutdown_initiated(false)
 {
     MXS_POLL_DATA::handler = &Worker::epoll_instance_handler;
-    MXS_POLL_DATA::free = NULL;
-    MXS_POLL_DATA::refcount = 0;
     MXS_POLL_DATA::thread.id = id;
 }