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Removed DCB states DCB_STATE_IDLE, and DCB_STATE_PROCESSING.
Added DCB_STATE_UNDEFINED for initial content for state variable which doesn't have any specific value set, and DCB_STATE_NOPOLLING to indicate that dcb has been removed from poll set.
Added following dcb roles: DCB_ROLE_SERVICE_LISTENER for listeners of services, and DCB_ROLE_REQUEST_HANDLER for client/backend dcbs. Listeners may have state DCB_STATE_LISTENING, but not DCB_STATE_POLLING. Request handlers may have DCB_STATE_POLLING but not DCB_STATE_LISTENING. Role is passed as an argument to dcb.c:dcb_alloc.
From now on, struct check numbers of DCB are included and checked in DEBUG build only.
Added dcb_role_t dcb_role-member to DCB as well as SPINLOCK dcb_initlock, which protects state changes.
Removed extern keyword from function declarations because functions are by default externally visible if they are declared in header.
dcb.b
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Function dcb_set_state, and dcb_set_state_nomutex provide functions for changing dcb states. Latter implements a state machine for dcb.
Function dcb_add_to_zombieslist replaces dcb_free. It adds in atomic step dcb to zombieslist and changes state to DCB_STATE_ZOMBIE.
Function dcb_final_free removes dcb from allDCBs list, terminates router and client sessions, and frees dcb and related memory.
Function dcb_process_zombies removes executing thread from dcb's bitmask, and it there are no further thread bits, moves dcb to a victim list, and finally, for each dcb on victim list, closes fd and sets state to DCB_STATE_DISCONNECTED.
Function dcb_close sets dcb state to DCB_STATE_NOPOLLIN, removes dcb from poll set and sets bit to bitmask for each server thread in an atomic step.
poll.c
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Function poll_add_dcb sets either DCB_STATE_LISTENING or DCB_STATE_POLLING state for newly created dcb, depending whether the role of dcb is DCB_ROLE_SERVICE_LISTENER, or DCB_ROLE_REQUEST_HANDLER, respectively. Then dcb is set to poll set.
poll_waitevents : commented out code which skipped event if dcb was added to zombieslist or if fd was closed. Added state checks.
service.c : Minor changes.
httpd.c : Removed dcb state changes. They are done in core.
mysql_backend.c : Added checks, removed dcb state changes.
mysql_client.c : Removed dcb state changes. Added checks.
mysql_common.c : Minor changes
telnetd.c : Removed state changes. Replaced some typecasts and pointer references with local variable reads.
skygw_debug.h : Removed two states, and added two to state printing macro.
Changed log header text, replaced SkySQL GAteway with SkySQL MaxScale.
Fixed bug in log flushing. skygw_log_write_flush didn't cause call of fsync, which suspended file writing.
/** No change in these */
bool skygw_logmanager_init(void** buf, int argc, char* argv[]);
void skygw_logmanager_done(void** buf);
void skygw_logmanager_exit(void);
int skygw_log_flush(logfile_id_t id);
/** writebuf remains unused, but formatted string is now possible and in case
* of formatted string, arbitrary long argument list is supported too. Max
* length for a log string is defined to BUFSIZ, whose value depends on the
* system but typically is 4/8KB.
*/
int skygw_log_write(void* writebuf, logfile_id_t id, char* format, ...);
int skygw_log_write_flush(void* writebuf, logfile_id_t id, char* format, ...);
makefile.inc includes new CFLAG : SS_PROF, which is set if PROF=Y on make command line or in build_gateway.inc .
ss_debug.h includes corresponding ss_prof(exp) macro which equals to exp if SS_PROF is defined and to empty if in other case.
mlist_t now includes datadel function which is a callback and it is executed for mlnode_data on node exit.
skygw_logmanager_init is still useful because it allows for providing memory address for log manager where it can store a list of preallocated write buffers. TBD.
Logmanager access is now protected with spinlock familiar from epoll/core/spinlock.c . It is modified to avoid trashing; misses are counted and every tenth subsequent lock acquiring attempt triggers short random sleep.
