Resolve #1211 | Thread-safe version

allegro · Jun 10, 2020 · d54d18a · d54d18a
1 parent 23ebfaa
commit d54d18a
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Showing 2 changed files with 9 additions and 10 deletions.
diff --git a/...gement/src/main/java/pl/allegro/tech/hermes/management/domain/health/HealthCheckTask.java b/...gement/src/main/java/pl/allegro/tech/hermes/management/domain/health/HealthCheckTask.java
@@ -57,13 +57,10 @@ private HealthCheckResult doHealthCheck(ZookeeperClient zookeeperClient) {
     }
 
     private void updateMode(List<HealthCheckResult> healthCheckResults) {
-        /* ReadOnly set by admin can be changed to ReadWrite only by admin */
-        if (!modeService.isReadOnlySetByAdmin()) {
-            if (healthCheckResults.contains(HealthCheckResult.UNHEALTHY)) {
-                modeService.setMode(ModeService.ManagementMode.READ_ONLY);
-            } else {
-                modeService.setMode(ModeService.ManagementMode.READ_WRITE);
-            }
+        if (healthCheckResults.contains(HealthCheckResult.UNHEALTHY)) {
+            modeService.compareAndSwapMode(ModeService.ManagementMode.READ_WRITE, ModeService.ManagementMode.READ_ONLY);
+        } else {
+            modeService.compareAndSwapMode(ModeService.ManagementMode.READ_ONLY, ModeService.ManagementMode.READ_WRITE);
         }
     }
 

diff --git a/...s-management/src/main/java/pl/allegro/tech/hermes/management/domain/mode/ModeService.java b/...s-management/src/main/java/pl/allegro/tech/hermes/management/domain/mode/ModeService.java
@@ -32,15 +32,17 @@ public ManagementMode getMode() {
         return mode;
     }
 
-    public void setMode(ManagementMode mode) {
+    public synchronized void setMode(ManagementMode mode) {
         this.mode = mode;
     }
 
     public boolean isReadOnlyEnabled() {
         return mode == ManagementMode.READ_ONLY || mode == ManagementMode.READ_ONLY_ADMIN;
     }
 
-    public boolean isReadOnlySetByAdmin() {
-        return mode == ManagementMode.READ_ONLY_ADMIN;
+    public synchronized void compareAndSwapMode(ManagementMode expectedMode, ManagementMode newMode) {
+        if (mode.equals(expectedMode)) {
+            setMode(newMode);
+        }
     }
 }