constantine/metering/tracer.nim

153 lines
5.0 KiB
Nim

# Constantine
# Copyright (c) 2018-2019 Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import
std/[macros, times, monotimes],
../benchmarks/platforms
# ############################################################
#
# Trace operations
#
# ############################################################
# Utils
# --------------------------------------------------
const someGcc = defined(gcc) or defined(llvm_gcc) or defined(clang) or defined(icc)
const hasThreadSupport = defined(threads)
proc atomicInc*(memLoc: var int64, x = 1'i64): int64 =
when someGcc and hasThreadSupport:
result = atomicAddFetch(memLoc.addr, x, ATOMIC_RELAXED)
elif defined(vcc) and hasThreadSupport:
result = addAndFetch(memLoc.addr, x)
result += x
else:
memloc += x
result = memLoc
# Types
# --------------------------------------------------
type
Metadata* = object
procName*: string
module: string
package: string
tag: string # Can be change to multi-tags later
numCalls*: int64
cumulatedTimeNs*: int64 # in microseconds
when SupportsGetTicks:
cumulatedCycles*: int64
var ctMetrics{.compileTime.}: seq[Metadata]
## Metrics are collected here, this is just a temporary holder of compileTime values
## Unfortunately the "seq" is emptied when passing the compileTime/runtime boundaries
## due to Nim bugs
var Metrics*: seq[Metadata]
## We can't directly use it at compileTime because it doesn't exist.
## We need `Metrics = static(ctMetrics)`
## To transfer the compileTime content to runtime at an opportune time.
template mtag(tagname: string){.pragma.}
## This will allow tagging proc in the future with
## "Fp", "ec", "polynomial"
proc resetMetering*() =
Metrics = static(ctMetrics)
const CttMeter {.booldefine.} = off
const CttTrace {.booldefine.} = off # For manual "debug-echo"-style timing.
when CttTrace:
# strformat doesn't work in templates.
from strutils import alignLeft, formatFloat
# Symbols
# --------------------------------------------------
template fnEntry(name: string, id: int, startTime, startCycle: untyped): untyped =
## Bench tracing to insert on function entry
{.noSideEffect, gcsafe.}:
discard Metrics[id].numCalls.atomicInc()
let startTime = getMonoTime()
when SupportsGetTicks:
let startCycle = getTicks()
else:
let startCycle = 0
template fnExit(name: string, id: int, startTime, startCycle: untyped): untyped =
## Bench tracing to insert before each function exit
{.noSideEffect, gcsafe.}:
when SupportsGetTicks:
let stopCycle = getTicks()
let stopTime = getMonoTime()
when SupportsGetTicks:
let elapsedCycles = stopCycle - startCycle
let elapsedTime = inMicroseconds(stopTime - startTime)
discard Metrics[id].cumulatedTimeNs.atomicInc(elapsedTime)
when SupportsGetTicks:
discard Metrics[id].cumulatedCycles.atomicInc(elapsedCycles)
when CttTrace:
# Advice: Use "when name == relevantProc" to isolate specific procedures.
# strformat doesn't work in templates.
when SupportsGetTicks:
echo static(alignLeft(name, 50)),
"Time (µs): ", alignLeft(formatFloat(elapsedTime.float64 * 1e-3, precision=3), 10),
"Cycles (billions): ", formatFloat(elapsedCycles.float64 * 1e-9, precision=3)
else:
echo static(alignLeft(name, 50)),
"Time (µs): ", alignLeft(formatFloat(elapsedTime.float64 * 1e-3, precision=3), 10)
macro meterAnnotate(procAst: untyped): untyped =
procAst.expectKind({nnkProcDef, nnkFuncDef})
let id = ctMetrics.len
let name = procAst[0].repr
# TODO, get the module and the package the proc is coming from
# and the tag "Fp", "ec", "polynomial" ...
ctMetrics.add Metadata(procName: name)
var newBody = newStmtList()
let startTime = genSym(nskLet, "metering_" & name & "_startTime_")
let startCycle = genSym(nskLet, "metering_" & name & "_startCycles_")
newBody.add getAst(fnEntry(name, id, startTime, startCycle))
newbody.add nnkDefer.newTree(getAst(fnExit(name, id, startTime, startCycle)))
newBody.add procAst.body
procAst.body = newBody
result = procAst
template meter*(procBody: untyped): untyped =
when CttMeter or CttTrace:
meterAnnotate(procBody)
else:
procBody
# Sanity checks
# ---------------------------------------------------
when isMainModule:
static: doAssert CttMeter or CttTrace, "CttMeter or CttTrace must be on for tracing"
expandMacros:
proc foo(x: int): int{.meter.} =
echo "Hey hey hey"
result = x
resetMetering()
echo Metrics
discard foo(10)
echo Metrics
doAssert Metrics[0].numCalls == 1