From f9298d8e85bd9ba44f76d16009cdc868ed4a3082 Mon Sep 17 00:00:00 2001
From: Ilya Kirillov <ilya.kirillov@jetbrains.com>
Date: Tue, 13 Dec 2022 14:02:59 +0100
Subject: [PATCH] [LL FIR] try to check for PCE in ValueWithPostCompute to
 avoid possible deadlocks

---
 .../level/api/fir/caches/ValueWithPostCompute.kt    | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/caches/ValueWithPostCompute.kt b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/caches/ValueWithPostCompute.kt
index 848bf272302..833b1ae9951 100644
--- a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/caches/ValueWithPostCompute.kt
+++ b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/caches/ValueWithPostCompute.kt
@@ -5,7 +5,9 @@
 
 package org.jetbrains.kotlin.analysis.low.level.api.fir.fir.caches
 
+import org.jetbrains.kotlin.analysis.low.level.api.fir.util.lockWithPCECheck
 import org.jetbrains.kotlin.util.shouldIjPlatformExceptionBeRethrown
+import java.util.concurrent.locks.ReentrantLock
 
 /**
  * Lazily calculated value which runs postCompute in the same thread,
@@ -24,6 +26,7 @@ internal class ValueWithPostCompute<KEY, VALUE, DATA>(
 ) {
     private var _calculate: ((KEY) -> Pair<VALUE, DATA>)? = calculate
     private var _postCompute: ((KEY, VALUE, DATA) -> Unit)? = postCompute
+    private val lock = ReentrantLock()
 
     /**
      * can be in one of the following three states:
@@ -58,7 +61,7 @@ internal class ValueWithPostCompute<KEY, VALUE, DATA>(
                 if (stateSnapshot.threadId == Thread.currentThread().id) {
                     return stateSnapshot.value as VALUE
                 } else {
-                    synchronized(this) { // wait until other thread which holds the lock now computes the value
+                    lock.lockWithPCECheck(LOCKING_INTERVAL_MS) { // wait until other thread which holds the lock now computes the value
                         when (val newStateSnapshot = value) {
                             ValueIsNotComputed -> {
                                 // if we have a PCE during value computation, then we will enter the critical section with `value == ValueIsNotComputed`
@@ -77,7 +80,7 @@ internal class ValueWithPostCompute<KEY, VALUE, DATA>(
                     }
                 }
             }
-            ValueIsNotComputed -> synchronized(this) {
+            ValueIsNotComputed -> lock.lockWithPCECheck(LOCKING_INTERVAL_MS) {
                 return computeValueWithoutLock()
             }
             is ExceptionWasThrownDuringValueComputation -> {
@@ -92,7 +95,7 @@ internal class ValueWithPostCompute<KEY, VALUE, DATA>(
     @Suppress("UNCHECKED_CAST")
     // should be called under a synchronized section
     private fun computeValueWithoutLock(): VALUE {
-        require(Thread.holdsLock(this))
+        require(lock.isHeldByCurrentThread)
         // if we entered synchronized section that's mean that the value is not yet calculated and was not started to be calculated
         // or the some other thread calculated the value while we were waiting to acquire the lock
 
@@ -146,4 +149,6 @@ internal class ValueWithPostCompute<KEY, VALUE, DATA>(
     private class ValueIsPostComputingNow(val value: Any?, val threadId: Long)
     private class ExceptionWasThrownDuringValueComputation(val error: Throwable)
     private object ValueIsNotComputed
-}
\ No newline at end of file
+}
+
+private const val LOCKING_INTERVAL_MS = 50L
\ No newline at end of file