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core/base/mp_lockanytable.sas
Allan e46165c140 fix: avoid error in mp_lockanytable.sas when unlocking a table that was not locked
This may happen due to the noprint option affecting the sqlobs variable.  Closes #339
2023-06-26 22:02:08 +01:00

251 lines
7.3 KiB
SAS

/**
@file
@brief Mechanism for locking tables to prevent parallel modifications
@details Uses a control table to enable ANY table to be locked for updates
(not just SAS datasets).
Only useful if every update uses the macro! Used heavily within
[Data Controller for SAS](https://datacontroller.io).
@param [in] action The action to be performed. Valid values:
@li LOCK - Sets the lock flag, also confirms if a SAS lock is available
@li UNLOCK - Unlocks the table
@param [in] lib= (WORK) The libref of the table to lock. Should already be
assigned.
@param [in] ds= The dataset to lock
@param [in] ref= A meaningful reference to enable the lock to be traced. Max
length is 200 characters.
@param [out] ctl_ds= (0) The control table which controls the actual locking.
Should already be assigned and available. The definition is available by
running the mddl_dc_locktable.sas macro.
@param [in] loops= (25) Number of times to check for a lock.
@param [in] loop_secs= (1) Seconds to wait between each lock attempt
<h4> SAS Macros </h4>
@li mf_fmtdttm.sas
@li mp_abort.sas
@li mp_lockfilecheck.sas
@li mf_getuser.sas
<h4> Related Macros </h4>
@li mp_lockanytable.test.sas
@version 9.2
**/
%macro mp_lockanytable(
action
,lib= WORK
,ds=0
,ref=
,ctl_ds=0
,loops=25
,loop_secs=1
);
data _null_;
if _n_=1 then putlog "&sysmacroname entry vars:";
set sashelp.vmacro;
where scope="&sysmacroname";
put name '=' value;
run;
%mp_abort(iftrue= ("&ds"="0" and &action ne MAKETABLE)
,mac=&sysmacroname
,msg=%str(dataset was not provided)
)
%mp_abort(iftrue= (&ctl_ds=0)
,mac=&sysmacroname
,msg=%str(Control dataset was not provided)
)
/* set up lib & mac vars */
%let lib=%upcase(&lib);
%let ds=%upcase(&ds);
%let action=%upcase(&action);
%local user x trans msg abortme;
%let user=%mf_getuser();
%let abortme=0;
%mp_abort(iftrue= (&action ne LOCK & &action ne UNLOCK & &action ne MAKETABLE)
,mac=&sysmacroname
,msg=%str(Invalid action (&action) provided)
)
/* if an err condition exists, exit before we even begin */
%mp_abort(iftrue= (&syscc>0 and &action=LOCK)
,mac=&sysmacroname
,msg=%str(aborting due to syscc=&syscc on LOCK entry)
)
/* do not bother locking work tables (else may affect all WORK libraries) */
%if (%upcase(&lib)=WORK or %str(&lib)=%str()) & &action ne MAKETABLE %then %do;
%put NOTE: WORK libraries will not be registered in the locking system.;
%return;
%end;
/* do not proceed if no observations can be processed */
%mp_abort(iftrue= (%sysfunc(getoption(OBS))=0)
,mac=&sysmacroname
,msg=%str(cannot continue when options obs = 0)
)
%if &ACTION=LOCK %then %do;
/* abort if a SAS lock is already in place, or cannot be applied */
%mp_lockfilecheck(&lib..&ds)
/* next, check there is a record for this table */
%local record_exists_check;
proc sql noprint;
select count(*) into: record_exists_check from &ctl_ds
where LOCK_LIB ="&lib" and LOCK_DS="&ds";
quit;
%if &syscc>0 %then %put syscc=&syscc sqlrc=&sqlrc;
%if &record_exists_check=0 %then %do;
data _null_;
putlog "&sysmacroname: adding record to lock table..";
run;
data ;
if 0 then set &ctl_ds;
LOCK_LIB ="&lib";
LOCK_DS="&ds";
LOCK_STATUS_CD='LOCKED';
LOCK_START_DTTM="%sysfunc(datetime(),%mf_fmtdttm())"dt;
LOCK_USER_NM="&user";
LOCK_PID="&sysjobid";
LOCK_REF="&ref";
output;stop;
run;
%let trans=&syslast;
proc append base=&ctl_ds data=&trans;
run;
%end;
/* if record does exist, perform lock attempts */
%else %do x=1 %to &loops;
data _null_;
putlog "&sysmacroname: attempting lock (iteration &x) "@;
putlog "at %sysfunc(datetime(),datetime19.) ..";
run;
proc sql;
update &ctl_ds
set LOCK_STATUS_CD='LOCKED'
, LOCK_START_DTTM="%sysfunc(datetime(),%mf_fmtdttm())"dt
, LOCK_USER_NM="&user"
, LOCK_PID="&sysjobid"
, LOCK_REF="&ref"
where LOCK_LIB ="&lib" and LOCK_DS="&ds";
quit;
/**
* NOTE - occasionally SQL server will return an err code (deadlocked
* transaction). If so, ignore it, keep calm, and carry on..
*/
%if &syscc>0 %then %do;
data _null_;
putlog 'NOTE-' / 'NOTE-';
putlog "NOTE- &sysmacroname: Update failed. "@;
putlog "Resetting err conditions and re-attempting.";
putlog "NOTE- syscc=&syscc syserr=&syserr sqlrc=&sqlrc";
putlog 'NOTE-' / 'NOTE-';
run;
%let syscc=0;
%let sqlrc=0;
%end;
/* now check if the record was successfully updated */
%local success_check;
proc sql noprint;
select count(*) into: success_check from &ctl_ds
where LOCK_LIB ="&lib" and LOCK_DS="&ds"
and LOCK_PID="&sysjobid" and LOCK_STATUS_CD='LOCKED';
quit;
%if &success_check=0 %then %do;
%if &x < &loops %then %do;
/* pause before next check */
data _null_;
putlog 'NOTE-' / 'NOTE-';
putlog "NOTE- &sysmacroname: table locked, waiting "@;
putlog "%sysfunc(sleep(&loop_secs)) seconds.. ";
putlog "NOTE- (iteration &x of &loops)";
putlog 'NOTE-' / 'NOTE-';
run;
%end;
%else %do;
%let msg=Unable to lock &lib..&ds via &ctl_ds after &loops attempts.\n
Please ask your administrator to investigate!;
%let abortme=1;
%end;
%end;
%else %do;
data _null_;
putlog 'NOTE-' / 'NOTE-';
putlog "NOTE- &sysmacroname: Table &lib..&ds locked at "@;
putlog " %sysfunc(datetime(),datetime19.) (iteration &x)"@;
putlog 'NOTE-' / 'NOTE-';
run;
%if &syscc>0 %then %do;
%put setting syscc(&syscc) back to 0;
%let syscc=0;
%end;
%let x=&loops; /* no more iterations needed */
%end;
%end;
%end;
%else %if &ACTION=UNLOCK %then %do;
%local status cnt;
%let cnt=0;
proc sql noprint;
select count(*) into: cnt from &ctl_ds where LOCK_LIB ="&lib" & LOCK_DS="&ds";
%if &cnt=0 %then %do;
%put %str(WAR)NING: &lib..&ds was not previously locked in &ctl_ds!;
%end;
%else %do;
select LOCK_STATUS_CD into: status from &ctl_ds
where LOCK_LIB ="&lib" and LOCK_DS="&ds";
quit;
%if &syscc>0 %then %put syscc=&syscc sqlrc=&sqlrc;
%if &status=LOCKED %then %do;
data _null_;
putlog "&sysmacroname: unlocking &lib..&ds:";
run;
proc sql;
update &ctl_ds
set LOCK_STATUS_CD='UNLOCKED'
, LOCK_END_DTTM="%sysfunc(datetime(),%mf_fmtdttm())"dt
, LOCK_USER_NM="&user"
, LOCK_PID="&sysjobid"
, LOCK_REF="&ref"
where LOCK_LIB ="&lib" and LOCK_DS="&ds";
quit;
%end;
%else %if &status=UNLOCKED %then %do;
%put %str(WAR)NING: &lib..&ds is already unlocked!;
%end;
%else %do;
%put NOTE: Unrecognised STATUS_CD (&status) in &ctl_ds;
%let abortme=1;
%end;
%end;
%end;
%else %do;
%let msg=lock_anytable given unsupported action (&action);
%let abortme=1;
%end;
/* catch errs - mp_abort must be called outside of a logic block */
%mp_abort(iftrue=(&abortme=1),
msg=%superq(msg),
mac=&sysmacroname
)
%exit_macro:
data _null_;
put "&sysmacroname: Exit vars: action=&action lib=&lib ds=&ds";
put " syscc=&syscc sqlrc=&sqlrc syserr=&syserr";
run;
%mend mp_lockanytable;