Search Top Index
HELP POPGCTRACE Steven Hardy, March 1982 Revised A.Sloman, April 1989 <boolean|integer> -> popgctrace; If POPGCTRACE is set to TRUE then a message is output after each garbage collection, giving the GC time and the memory allocation in the form ;;; GC-<code>(X) TIME: <t> MEM: used <u> + free <f> + stack <s> = <m> where <code> is a 4-letter code indicating why the GC happened, <t> is the time for the GC in 1/100ths sec, <u> is the number of words used in the heap, <f> the number free, <s> the number taken by the userstack, and <m> the total (note that these values include structures locked in with -sys_lock_heap-). X is a letter indicating which garbage collection algorithm was used (C = copying, N = non-copying). The characters of the message are output through -cucharout-. An example printout with POPGCTRACE set to be TRUE might be ;;; GC-auto(C) TIME: 0.99, MEM: used 239006 + free 121442 + stack 0 = 360448 If the value of POPGCTRACE is an integer then information about PROLOG memory usage is also printed. For example:- ;;; GC-user(C) TIME: 0.53, MEM: used 9729 + free 94719 + stack 0 = 104448 ;;; CALLSTACK: 79;;; ;;; PROLOG: trail 7 + free 2008 + contn 33 = 2048 This indicates that the collection took 0.53 seconds, and afterwards there were 9729 words used, and 94719 free, with a total of 104448. The number for STACK shows how much space is taken on the POP-11 user stack. The third line shows how space is used on Prolog's variable trail and continuation stacks. The value of POPGCTRACE is user-assignable, and the default is FALSE. See also HELP *SYS_LOCK_HEAP - locks the heap *POPMEMLIM - on setting the maximum memory size *POPMEMUSED - holds total memory used at last garbage collection *SYSGARBAGE - causes a garbage collection *POPGCRATIO - helps determine memory allocation for the system *POPGCTIME - holds the CPU time spent on garbage collections *SYSTIME - holds total CPU time for current run of POP system PLOGHELP *SYSTEM - on predicates that control the PROLOG system REF *SYSTEM/popgctrace - for more detail --- C.all/help/popgctrace ---------------------------------------------- --- Copyright University of Sussex 1989. All rights reserved. ----------