From bd3136ca92ef8e46f0bf983b2bb782432af93bae Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Mon, 12 Apr 2021 09:19:03 -0700
Subject: [PATCH] fix stack size assumption at profiler start

---
 .../com/dfsek/terra/profiler/ProfilerImpl.java    | 15 +++++++++++----
 common/src/test/java/profiler/ProfilerTest.java   | 10 +++++++++-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/common/src/main/java/com/dfsek/terra/profiler/ProfilerImpl.java b/common/src/main/java/com/dfsek/terra/profiler/ProfilerImpl.java
index 23f00d495..0ffd824e1 100644
--- a/common/src/main/java/com/dfsek/terra/profiler/ProfilerImpl.java
+++ b/common/src/main/java/com/dfsek/terra/profiler/ProfilerImpl.java
@@ -1,5 +1,6 @@
 package com.dfsek.terra.profiler;
 
+import com.dfsek.terra.api.util.mutable.MutableInteger;
 import com.dfsek.terra.profiler.exception.MalformedStackException;
 
 import java.util.ArrayList;
@@ -15,6 +16,8 @@ public class ProfilerImpl implements Profiler {
     private volatile boolean running = false;
     private static boolean instantiated = false;
 
+    private static final ThreadLocal<Boolean> SAFE = ThreadLocal.withInitial(() -> false);
+    private static final ThreadLocal<MutableInteger> STACK_SIZE = ThreadLocal.withInitial(() -> new MutableInteger(0));
 
     public ProfilerImpl() {
         if(instantiated) throw new IllegalStateException("Only one instance of Profiler may exist!");
@@ -23,15 +26,18 @@ public class ProfilerImpl implements Profiler {
 
     @Override
     public void push(String frame) {
-        if(running) {
+        STACK_SIZE.get().increment();
+        if(running && SAFE.get()) {
             Stack<Frame> stack = THREAD_STACK.get();
-            stack.push(new Frame(stack.size() == 0 ? frame : stack.peek().getId() + "." + frame));
-        }
+            stack.push(new Frame(stack.isEmpty() ? frame : stack.peek().getId() + "." + frame));
+        } else SAFE.set(false);
     }
 
     @Override
     public void pop(String frame) {
-        if(running) {
+        MutableInteger size = STACK_SIZE.get();
+        size.decrement();
+        if(running && SAFE.get()) {
             long time = System.nanoTime();
             Stack<Frame> stack = THREAD_STACK.get();
 
@@ -51,6 +57,7 @@ public class ProfilerImpl implements Profiler {
 
             timings.add(time - top.getStart());
         }
+        if(size.get() == 0) SAFE.set(true);
     }
 
     @Override
diff --git a/common/src/test/java/profiler/ProfilerTest.java b/common/src/test/java/profiler/ProfilerTest.java
index 86ad4e5a1..b4d97856d 100644
--- a/common/src/test/java/profiler/ProfilerTest.java
+++ b/common/src/test/java/profiler/ProfilerTest.java
@@ -7,7 +7,7 @@ public class ProfilerTest {
     private static final Profiler PROFILER = new ProfilerImpl();
     //@Test
     public static void main(String... a) throws InterruptedException {
-        PROFILER.start();
+        //PROFILER.start();
         for(int i = 0; i < 1000; i++) {
             doThing();
         }
@@ -20,6 +20,14 @@ public class ProfilerTest {
             doOtherThing();
         }
         PROFILER.stop();
+        PROFILER.push("thing");
+        PROFILER.push("thing2");
+        PROFILER.start();
+        PROFILER.pop("thing2");
+        PROFILER.pop("thing");
+        PROFILER.push("thing4");
+        PROFILER.pop("thing4");
+
         PROFILER.getTimings().forEach((id, timings) -> {
             System.out.println(id + ": " + timings.toString());
         });