core: Add benchmarking tools

src/dev/benchmark.nim

@@ -1,5 +1,4 @@
-import strutils, times
+import times, macros, strutils, locks, algorithm
-
 # benchmark measure execution time of block of code.
 # usage:
 #   import os, strutils, times
@@ -15,3 +14,171 @@ template benchmark*(benchmarkName: string, code: untyped) =
     let elapsed = epochTime() - t0
     let elapsedStr = elapsed.formatFloat(format = ffDecimal, precision = 10)
     echo "CPU Time [", benchmarkName, "] ", elapsedStr, "s"
+
+
+# Thread safe benchmarking tools
+# There are two ways to use this module:
+# 1. Use the benchmark benchmarkProc macro to benchmark a block of code. It will automatically call registerDuration with the name of the procedure and the start and end time
+# 2. Manually call registerDuration with name and the start and end time
+
+# The output file is named procBenchmark.csv and is located in the current working directory. It will be created at app exit.
+# The output is sorted by total time in descending order.
+# Output format:
+# Procedure, Number of runs, Total time in ms, Avg time in ms, Weight
+# test*,1,100.00,100.00,50.00%
+# test2*,1,100.00,100.00,50.00%
+
+# usage:
+# proc test() {.benchmarkProc.} =
+#  sleep(1)
+
+# proc test2() {.benchmarkProc.} =
+#  sleep(1)
+
+# proc test3() =
+#  let cpuTime = cpuTime()
+#  defer: registerDuration("custom test3", cpuTime, cpuTime())
+#  sleep(1)
+
+type 
+  ProcBenchmark* = object
+    numRuns*: int
+    totalTime*: float
+    procName*: cstring
+
+  ProcBenchmarkPtr* = ptr ProcBenchmark
+
+  SharedProcBenchmarkArr* = object
+    data: ptr UncheckedArray[ProcBenchmarkPtr]
+    len*: int
+    maxLen*: int
+
+  BenchmarkResult = tuple[procName: string, numRuns: int, totalTime: float, weight: float]
+
+var 
+  lock: Lock
+  benchmarkResults: ptr SharedProcBenchmarkArr
+
+# Forward declarations
+proc registerDuration*(name: string, startTime: float, endTime: float) {.gcsafe.}
+
+proc quitCallback() {.noconv.}
+proc initBenchmarking() {.gcsafe.}
+proc deinitBenchmarking() 
+proc aggregateData(): seq[BenchmarkResult]
+proc writeToFile(resultsToWrite: seq[BenchmarkResult])
+proc resultCmp(x, y: BenchmarkResult): int
+# End of forward declarations
+
+addQuitProc(quitCallback)
+
+macro benchmarkProc*(procDef: untyped): untyped =
+  procDef.expectKind(nnkProcDef)
+
+  let
+    procName = procDef[0].toStrLit
+  
+  let 
+    startingBenchmark = quote do:
+      let startTime = cpuTime()
+      defer: registerDuration(`procName`, startTime, cpuTime())
+
+  procDef.body.insert(0, startingBenchmark)
+  return procDef
+
+proc registerDuration*(name: string, startTime: float, endTime: float) {.gcsafe.} =
+  if(benchmarkResults == nil):
+    initBenchmarking()
+
+  withLock lock:
+    var found = false
+    for i in 0 ..< benchmarkResults.len:
+      if benchmarkResults.data[i].procName == name.cstring:
+        benchmarkResults.data[i].numRuns += 1
+        benchmarkResults.data[i].totalTime += endTime - startTime
+        found = true
+      if found:
+        break
+    
+    if not found:
+      if benchmarkResults.len == benchmarkResults.maxLen:
+        benchmarkResults.maxLen = benchmarkResults.maxLen * 2
+        benchmarkResults.data = cast[ptr UncheckedArray[ProcBenchmarkPtr]](reallocShared(benchmarkResults.data, sizeof(ProcBenchmark) * benchmarkResults.maxLen))
+
+      var newProcBenchmark = cast[ProcBenchmarkPtr](allocShared(sizeof(ProcBenchmark)))
+      var namePtr = cast[cstring](allocShared(name.len+1))
+      copyMem(namePtr, name.cstring, name.len)
+      namePtr[name.len] = '\0'
+
+      newProcBenchmark.procName = namePtr
+      newProcBenchmark.numRuns = 1
+      newProcBenchmark.totalTime = endTime - startTime
+      benchmarkResults.data[benchmarkResults.len] = newProcBenchmark
+      benchmarkResults.len += 1
+      
+proc quitCallback() {.noconv.} =
+  echo "Benchmarking quit callback"
+  var 
+    results = aggregateData()
+  results.writeToFile()
+  deinitBenchmarking()
+
+proc initBenchmarking() {.gcsafe.} =
+  echo "Benchmarking init"
+  initLock(lock)
+
+  withLock lock:
+    if benchmarkResults != nil:
+      return
+
+    benchmarkResults = cast[ptr SharedProcBenchmarkArr](allocShared(sizeof(SharedProcBenchmarkArr)))
+    benchmarkResults.len = 0
+    benchmarkResults.maxLen = 1000
+    benchmarkResults.data = cast[ptr UncheckedArray[ProcBenchmarkPtr]](allocShared(sizeof(ProcBenchmark) * benchmarkResults.maxLen))
+
+proc deinitBenchmarking() =
+  echo "Benchmarking deinit"
+  withLock lock:
+    if benchmarkResults == nil:
+      return
+
+    for i in 0 ..< benchmarkResults.len:
+      deallocShared(benchmarkResults.data[i].procName)
+    
+    deallocShared(benchmarkResults.data)
+    deallocShared(benchmarkResults)
+    benchmarkResults = nil
+
+proc aggregateData(): seq[BenchmarkResult] =
+  result = @[]
+  var totalWeight = 0.0
+
+  withLock lock:
+    for i in 0 ..< benchmarkResults.len:
+      totalWeight += benchmarkResults.data[i].totalTime
+      result.add(($(benchmarkResults.data[i].procName), benchmarkResults.data[i].numRuns, benchmarkResults.data[i].totalTime, 0.0))
+
+  result.sort(resultCmp)
+  for i in 0 ..< result.len:
+    result[i].weight = result[i].totalTime / totalWeight
+
+
+proc writeToFile(resultsToWrite: seq[BenchmarkResult]) =
+  echo "Benchmarking - write to file"
+  var file: File
+  try:
+    file = open("procBenchmark.csv", fmWrite)
+  except:
+    echo "Could not open file procBenchmark.txt for writing"
+    return
+  file.writeLine("Procedure, Number of runs, Total time in ms, Avg time in ms, Weight")
+  for entry in resultsToWrite:
+    file.writeLine(entry.procName & 
+                  "," & $entry.numRuns & 
+                  "," & $(entry.totalTime * 1000) & 
+                  "," & $((entry.totalTime / entry.numRuns.float) * 1000) & 
+                  "," & $(entry.weight * 100) & "%")
+  file.close()
+
+proc resultCmp(x, y: BenchmarkResult): int =
+  cmp(y.totalTime, x.totalTime)