mutex is enough

google · Dec 24, 2023 · 1f0b113 · 1f0b113
1 parent 977ecfa
commit 1f0b113
Showing 1 changed file with 19 additions and 11 deletions.
diff --git a/engine/src/main/java/com/google/android/fhir/sync/FhirSynchronizer.kt b/engine/src/main/java/com/google/android/fhir/sync/FhirSynchronizer.kt
@@ -27,6 +27,8 @@ import java.time.OffsetDateTime
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import org.hl7.fhir.r4.model.ResourceType
 
 enum class SyncOperation {
@@ -83,18 +85,20 @@ internal class FhirSynchronizer(
   }
 
   suspend fun synchronize(): SyncJobStatus {
-    setSyncState(SyncJobStatus.Started)
-
-    return listOf(download(), upload())
-      .filterIsInstance<SyncResult.Error>()
-      .flatMap { it.exceptions }
-      .let {
-        if (it.isEmpty()) {
-          setSyncState(SyncResult.Success())
-        } else {
-          setSyncState(SyncResult.Error(it))
+    mutex.withLock {
+      setSyncState(SyncJobStatus.Started)
+
+      return listOf(download(), upload())
+        .filterIsInstance<SyncResult.Error>()
+        .flatMap { it.exceptions }
+        .let {
+          if (it.isEmpty()) {
+            setSyncState(SyncResult.Success())
+          } else {
+            setSyncState(SyncResult.Error(it))
+          }
         }
-      }
+    }
   }
 
   private suspend fun download(): SyncResult {
@@ -145,4 +149,8 @@ internal class FhirSynchronizer(
       SyncResult.Error(exceptions)
     }
   }
+
+  companion object {
+    private val mutex = Mutex()
+  }
 }