tuned error printing and log writing output format
dcb.c :
dcb_connect, check return value of poll_add_dcb and behave accordingly.
dcb_write, in case of SIFPIPE, only write to trace log.
dcb_close, dassert with incorrect dcb states.
gateway.c :
added file_write_header to print header similar than in logs to stderr.
main, add signal handler for SIGPIPE
poll.c :
poll_remove_dcb, don't fail if dcb is in NOPOLLING or in ZOMBIE states.
poll_waitevents, write EPOLLHUPs to trace log, don't even attempt to write to closed socket.
readconnection.h :
shortened comment.
readwritesplit.h :
replaced generic names with more specific ones.
httpd.c :
Check listen return value and behave accordingly.
mysql_backend.c :
Tiny clean up.
mysql_client.c :
gw_MySQLListener, Check listen return value and behave accordingly.
mysql_common.c :
Shortened a header.
telnetd.c :
telnetd_listen, check listen return value and behave accordingly.
readconnroute.c :
Tuned log writing format.
readwritesplit.c :
Added function search_backend_servers, which chooses suitable backend and master server among those known by Maxscale. Fixed clean-up routines. Not ready yet but works somehow.
testroute.c :
Cleanup.
skygw_utils.cc :
Log writing clean up.
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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.
