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#
#
# Nimrod's Runtime Library
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## Profiling support for Nimrod. This is an embedded profiler that requires
## ``--profiler:on``. You only need to import this module to get a profiling
## report at program exit.
when not defined(profiler):
{.warning: "Profiling support is turned off!".}
# We don't want to profile the profiling code ...
{.push profiler: off.}
import hashes, algorithm, strutils, tables, sets
include "system/timers"
const
withThreads = compileOption("threads")
tickCountCorrection = 50_000
when not defined(system.TStackTrace):
type TStackTrace = array [0..20, cstring]
# We use a simple hash table of bounded size to keep track of the stack traces:
type
TProfileEntry = object
total: int
st: TStackTrace
TProfileData = array [0..64*1024-1, ptr TProfileEntry]
proc `==`(a, b: TStackTrace): bool =
for i in 0 .. high(a):
if a[i] != b[i]: return false
result = true
# XXX extract this data structure; it is generally useful ;-)
# However a chain length of over 3000 is suspicious...
var
profileData: TProfileData
emptySlots = profileData.len * 3 div 2
maxChainLen = 0
totalCalls = 0
var
interval: TNanos = 5_000_000 - tickCountCorrection # 5ms
proc setSamplingFrequency*(intervalInUs: int) =
## set this to change the sampling frequency. Default value is 5ms.
## Set it to 0 to disable time based profiling; it uses an imprecise
## instruction count measure instead then.
if intervalInUs <= 0: interval = 0
else: interval = intervalInUs * 1000 - tickCountCorrection
when withThreads:
var
profilingLock: TLock
InitLock profilingLock
proc hookAux(st: TStackTrace) =
# this is quite performance sensitive!
when withThreads: Acquire profilingLock
inc totalCalls
var last = high(st)
while last > 0 and isNil(st[last]): dec last
var h = hash(pointer(st[last])) and high(profileData)
# we use probing for maxChainLen entries and replace the encountered entry
# with the minimal 'total' value:
if emptySlots == 0:
var minIdx = h
var probes = maxChainLen
while probes >= 0:
if profileData[h].st == st:
# wow, same entry found:
inc profileData[h].total
return
if profileData[minIdx].total < profileData[h].total:
minIdx = h
h = ((5 * h) + 1) and high(profileData)
dec probes
profileData[minIdx].total = 1
profileData[minIdx].st = st
else:
var chain = 0
while true:
if profileData[h] == nil:
profileData[h] = cast[ptr TProfileEntry](
allocShared0(sizeof(TProfileEntry)))
profileData[h].total = 1
profileData[h].st = st
dec emptySlots
break
if profileData[h].st == st:
# wow, same entry found:
inc profileData[h].total
break
h = ((5 * h) + 1) and high(profileData)
inc chain
maxChainLen = max(maxChainLen, chain)
when withThreads: Release profilingLock
var
t0 {.threadvar.}: TTicks
proc hook(st: TStackTrace) {.nimcall.} =
if interval == 0:
hookAux(st)
elif getticks() - t0 > interval:
hookAux(st)
t0 = getticks()
proc getTotal(x: ptr TProfileEntry): int =
result = if isNil(x): 0 else: x.total
proc cmpEntries(a, b: ptr TProfileEntry): int =
result = b.getTotal - a.getTotal
proc `//`(a, b: int): string =
result = format("$1/$2 = $3%", a, b, formatFloat(a / b * 100.0, ffDefault, 2))
proc writeProfile() {.noconv.} =
when defined(system.TStackTrace):
system.profilerHook = nil
const filename = "profile_results.txt"
echo "writing " & filename & "..."
var f: TFile
if open(f, filename, fmWrite):
sort(profileData, cmpEntries)
writeln(f, "total executions of each stack trace:")
var entries = 0
for i in 0..high(profileData):
if profileData[i] != nil: inc entries
var perProc = initCountTable[string]()
for i in 0..entries-1:
var dups = initSet[string]()
for ii in 0..high(TStackTrace):
let procname = profileData[i].st[ii]
if isNil(procname): break
let p = $procname
if not containsOrIncl(dups, p):
perProc.inc(p, profileData[i].total)
var sum = 0
# only write the first 100 entries:
for i in 0..min(100, entries-1):
if profileData[i].total > 1:
inc sum, profileData[i].total
writeln(f, "Entry: ", i+1, "/", entries, " Calls: ",
profileData[i].total // totalCalls, " [sum: ", sum, "; ",
sum // totalCalls, "]")
for ii in 0..high(TStackTrace):
let procname = profileData[i].st[ii]
if isNil(procname): break
writeln(f, " ", procname, " ", perProc[$procname] // totalCalls)
close(f)
echo "... done"
else:
echo "... failed"
var
disabled: int
proc disableProfiling*() =
atomicDec disabled
system.profilerHook = nil
proc enableProfiling*() =
if atomicInc(disabled) >= 0:
system.profilerHook = hook
when defined(system.TStackTrace):
system.profilerHook = hook
addQuitProc(writeProfile)
{.pop.}
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