sampling-profiler: initial commit

tools/sampling-profiler/README.md

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+# sampling-profiler
+
+A lightweight profiler that samples Thread/allStackTraces and allows you to filter relevant stack frames.

tools/sampling-profiler/project.clj

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+(defproject house.jux/tools.sampling-profiler "2024.11.05-SNAPSHOT"
+
+  :description "A lightweight profiler that samples Thread/allStackTraces and allows you to filter relevant stack frames."
+  :url "https://github.com/klauswuestefeld/simple-clj/tree/master/tools/sampling-profiler"
+
+  :license {:name "BSD 3-Clause"
+            :url "https://github.com/klauswuestefeld/simple-clj/blob/master/LICENSE"}
+
+  :dependencies []
+
+  :plugins [[lein-parent "0.3.9"]]
+  :parent-project {:coords  [house.jux/parent-project "2024.06.10"]
+                   :inherit [:deploy-repositories :dependencies]})

tools/sampling-profiler/src/house/jux__/tools/sampling_profiler__.clj

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+(ns house.jux--.tools.sampling-profiler--
+  #_(:require [clojure.pprint :refer [pprint]]))
+
+(def summary (atom nil))
+(def running (atom false))
+(defn stop! []
+  (reset! running false))
+
+(defn- tally-classes [summary stack]
+  (->> (seq stack)
+       (remove nil?)
+       (map #(.getClassName %))
+       (reduce (fn [summary class-name]
+                 (update-in summary [:class->count class-name] (fnil inc 0)))
+               summary)))
+
+(defn- summarize [summary thread->stack]
+  (as-> summary _
+    (update _ :sample-count inc)
+    (reduce tally-classes _ (vals thread->stack))))
+
+(defn- summarize-samples! [{:keys [duration-sec interval-ms]}]
+  (let [end-time (+ (System/currentTimeMillis) (* 1000 duration-sec))]
+    (println "before loop")
+    (loop []
+      (println "looping")
+      (Thread/sleep interval-ms)
+      (swap! summary summarize (Thread/getAllStackTraces))
+      (if (and @running
+               (< (System/currentTimeMillis) end-time))
+        (recur)
+        (println "Profiling done.")))))
+
+(defn start! [options]
+  (when @running
+    (throw (IllegalStateException. "Profiler was already running.")))
+  (reset! summary {:sample-count 0})
+  (reset! running true)
+  (println "before future")
+  (future
+    (println "in future")
+    (try
+      (println "before summarize")
+
+      (summarize-samples! options)
+      (catch Exception e
+        (.printStackTrace e)))))
+
+
+(comment
+  ; This will sample all thread stack frames every 20 milliseconds for a duration of 10 seconds. Useful for when the code being profiled hangs.
+  (start! {:interval-ms 20
+           :duration-sec 10})
+
+  ; Run the code you want to profile...
+
+  (stop!)  ; Stops profiling.
+  @summary ; Contains the summary at any moment.
+  )