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8.24 System statistics
8.24.1 statistics/0,
statistics/2
Templates
-
statistics
statistics(?atom, ?list)
Description
statistics displays statistics about memory usage and run times.
statistics(Key, Value) unifies Value with the current
value of the statistics key Key. Value a list of two
elements. Times are in milliseconds, sizes of areas in bytes.
Key Description Value
user_time user CPU time [SinceStart, SinceLast]
system_time system CPU time [SinceStart, SinceLast]
cpu_time total CPU time (user + system) [SinceStart,
SinceLast]
real_time absolute time [SinceStart, SinceLast]
local_stack local stack sizes (control, environments, choices) [UsedSize, FreeSize]
global_stack global stack sizes (compound terms) [UsedSize, FreeSize]
trail_stack trail stack sizes (variable bindings to undo) [UsedSize, FreeSize]
cstr_stack constraint trail sizes (finite domain constraints) [UsedSize, FreeSize]
atoms atom table [NumberOfAtoms, FreeNumberOfAtoms]
Note that the key runtime is recognized as user_time for
compatibility purpose.
Errors
Key is neither a variable nor a valid key domain_error(statistics_key, Key)
Value is neither a variable nor a list of two elements domain_error(statistics_value, Value)
Value is a list of two elements and an element E
is neither a variable nor an integer type_error(integer, E)
Portability
GNU Prolog predicates.
8.24.2 user_time/1,
system_time/1,
cpu_time/1,
real_time/1
Templates
-
user_time(?integer)
system_time(?integer)
cpu_time(?integer)
real_time(?integer)
Description
user_time(Time) unifies Time with the user
CPU time elapsed since the start of Prolog.
system_time(Time) unifies Time with the
system CPU time elapsed since the start of Prolog.
cpu_time(Time) unifies Time with the CPU
time (user + system) elapsed since the start of Prolog.
real_time(Time) unifies Time with the
absolute time elapsed since the start of Prolog.
Errors
Time is neither a variable nor an integer type_error(integer, Time)
Portability
GNU Prolog predicates.
Copyright (C) 1999-2021 Daniel Diaz
Verbatim copying and distribution of this entire article is permitted in any
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