Fix incorrect transaction batching during conversation delete.

benchmark/src/main/java/org/thoughtcrime/benchmark/BenchmarkMetrics.kt

@@ -47,4 +47,10 @@ object BenchmarkMetrics {
     get() = listOf(
       TraceSectionMetric("ReceiptMessageProcessor#incrementReadReceiptCounts", Mode.Average)
     )
+
+  val threadDeletion: List<TraceSectionMetric>
+    get() = listOf(
+      TraceSectionMetric("ThreadTable#deleteConversations", Mode.Sum),
+      TraceSectionMetric("MessageTable#deleteMessagesInThread", Mode.Sum)
+    )
 }

benchmark/src/main/java/org/thoughtcrime/benchmark/BenchmarkSetup.kt

@@ -8,10 +8,10 @@ object BenchmarkSetup {
   private const val TARGET_PACKAGE = "org.thoughtcrime.securesms.benchmark"
   private const val RECEIVER = "org.signal.benchmark.BenchmarkCommandReceiver"
 
-  fun setup(type: String, device: UiDevice) {
+  fun setup(type: String, device: UiDevice, timeout: Long = 25_000L) {
     device.executeShellCommand("pm clear $TARGET_PACKAGE")
     device.executeShellCommand("am start -W -n $TARGET_PACKAGE/org.signal.benchmark.BenchmarkSetupActivity --es setup-type $type")
-    device.wait(Until.hasObject(By.textContains("done")), 25_000L)
+    device.wait(Until.hasObject(By.textContains("done")), timeout)
   }
 
   fun setupIndividualSend(device: UiDevice) {
@@ -34,6 +34,10 @@ object BenchmarkSetup {
     device.benchmarkCommandBroadcast("release-messages")
   }
 
+  fun deleteThread(device: UiDevice) {
+    device.benchmarkCommandBroadcast("delete-thread")
+  }
+
   private fun UiDevice.benchmarkCommandBroadcast(command: String) {
     executeShellCommand("am broadcast -a org.signal.benchmark.action.COMMAND -e command $command -n $TARGET_PACKAGE/$RECEIVER")
   }

benchmark/src/main/java/org/thoughtcrime/benchmark/ThreadDeletionBenchmarks.kt

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.benchmark
+
+import androidx.annotation.RequiresApi
+import androidx.benchmark.macro.CompilationMode
+import androidx.benchmark.macro.ExperimentalMetricApi
+import androidx.benchmark.macro.junit4.MacrobenchmarkRule
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.uiautomator.By
+import androidx.test.uiautomator.Until
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * Macrobenchmark for measuring thread deletion performance.
+ *
+ * Inserts 20,000 messages into a conversation, then measures the time
+ * to delete the entire thread using per-batch transactions.
+ *
+ * Two variants:
+ * - [deleteThread20kMessages]: 1:1 conversation with attachments and reactions
+ * - [deleteGroupThread20kMessages]: Group conversation with attachments, reactions,
+ *   group receipts (5 members x 20k = 100k rows), and mentions
+ */
+@OptIn(ExperimentalMetricApi::class)
+@RunWith(AndroidJUnit4::class)
+@RequiresApi(31)
+class ThreadDeletionBenchmarks {
+  @get:Rule
+  val benchmarkRule = MacrobenchmarkRule()
+
+  @Test
+  fun deleteThread20kMessages() {
+    benchmarkRule.measureRepeated(
+      packageName = "org.thoughtcrime.securesms.benchmark",
+      metrics = BenchmarkMetrics.threadDeletion,
+      iterations = 1,
+      compilationMode = CompilationMode.Partial(),
+      setupBlock = {
+        BenchmarkSetup.setup("thread-delete", device, timeout = 120_000L)
+        killProcess()
+        startActivityAndWait()
+        device.waitForIdle()
+        device.wait(Until.findObject(By.textContains("Buddy")), 10_000)
+      }
+    ) {
+      BenchmarkSetup.deleteThread(device)
+      device.wait(Until.gone(By.textContains("Buddy")), 300_000L)
+    }
+  }
+
+  @Test
+  fun deleteGroupThread20kMessages() {
+    benchmarkRule.measureRepeated(
+      packageName = "org.thoughtcrime.securesms.benchmark",
+      metrics = BenchmarkMetrics.threadDeletion,
+      iterations = 1,
+      compilationMode = CompilationMode.Partial(),
+      setupBlock = {
+        BenchmarkSetup.setup("thread-delete-group", device, timeout = 180_000L)
+        killProcess()
+        startActivityAndWait()
+        device.waitForIdle()
+        device.wait(Until.findObject(By.textContains("Title")), 10_000)
+      }
+    ) {
+      BenchmarkSetup.deleteThread(device)
+      device.wait(Until.gone(By.textContains("Title")), 300_000L)
+    }
+  }
+}