From b2faf6300a1183613bdce54edf6a46cdaf9ed8f9 Mon Sep 17 00:00:00 2001
From: Timm Fitschen <t.fitschen@indiscale.com>
Date: Fri, 5 Mar 2021 10:44:27 +0100
Subject: [PATCH] Revert DatabaseAccessManager to buggy implementation
---
.../caosdb/server/database/DatabaseAccessManager.java | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/src/main/java/org/caosdb/server/database/DatabaseAccessManager.java b/src/main/java/org/caosdb/server/database/DatabaseAccessManager.java
index f12c78e3..196a9fb2 100644
--- a/src/main/java/org/caosdb/server/database/DatabaseAccessManager.java
+++ b/src/main/java/org/caosdb/server/database/DatabaseAccessManager.java
@@ -26,7 +26,6 @@
package org.caosdb.server.database;
import java.util.concurrent.Semaphore;
-import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.ReentrantLock;
import org.caosdb.server.database.access.Access;
import org.caosdb.server.database.access.AccessControlAccess;
@@ -57,7 +56,7 @@ import org.caosdb.server.utils.Releasable;
class ReadAccessSemaphore extends Semaphore implements Releasable {
private static final long serialVersionUID = 4384921156838881337L;
- private AtomicInteger acquired = new AtomicInteger(0); // how many threads have read access
+ private int acquired = 0; // how many threads have read access
Semaphore writersBlock =
new Semaphore(1, true); // This semaphore is blocked as long as there are any
// unreleased read permits.
@@ -74,9 +73,10 @@ class ReadAccessSemaphore extends Semaphore implements Releasable {
@Override
public void acquire() throws InterruptedException {
super.acquire(); // Protect the next few lines
- if (this.acquired.getAndIncrement() == 0) {
+ if (this.acquired == 0) {
this.writersBlock.acquire();
}
+ this.acquired++;
super.release();
}
@@ -87,7 +87,9 @@ class ReadAccessSemaphore extends Semaphore implements Releasable {
*/
@Override
public void release() {
- if (this.acquired.decrementAndGet() == 0) { // Last permit: release
+ this.acquired--;
+ if (this.acquired <= 0) { // Last permit: release
+ this.acquired = 0;
if (this.writersBlock.availablePermits() <= 0) {
this.writersBlock.release();
}
--
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