Merge "minadbd sends heartbeat to rescue service for getprop command."

install/adb_install.cpp

@@ -367,11 +367,13 @@ InstallResult ApplyFromAdb(Device* device, bool rescue_mode, Device::BuiltinActi
         "\n\nNow send the package you want to apply\n"
         "to the device with \"adb sideload <filename>\"...\n");
   } else {
-    ui->Print("\n\nWaiting for rescue commands...\n");
     command_map.emplace(MinadbdCommand::kWipeData, [&device]() {
       bool result = WipeData(device, false);
       return std::make_pair(result, true);
     });
+    command_map.emplace(MinadbdCommand::kNoOp, []() { return std::make_pair(true, true); });
+
+    ui->Print("\n\nWaiting for rescue commands...\n");
   }
 
   CreateMinadbdServiceAndExecuteCommands(ui, command_map, rescue_mode);

minadbd/minadbd_services.cpp

@@ -189,6 +189,14 @@ static void RescueGetpropHostService(unique_fd sfd, const std::string& prop) {
   if (!android::base::WriteFully(sfd, result.data(), result.size())) {
     exit(kMinadbdHostSocketIOError);
   }
+
+  // Send heartbeat signal to keep the rescue service alive.
+  if (!WriteCommandToFd(MinadbdCommand::kNoOp, minadbd_socket)) {
+    exit(kMinadbdSocketIOError);
+  }
+  if (MinadbdCommandStatus status; !WaitForCommandStatus(minadbd_socket, &status)) {
+    exit(kMinadbdMessageFormatError);
+  }
 }
 
 // Reboots into the given target. We don't reboot directly from minadbd, but going through recovery

minadbd/minadbd_types.h

@@ -53,6 +53,7 @@ enum class MinadbdCommand : uint32_t {
   kRebootRescue = 6,
   kWipeCache = 7,
   kWipeData = 8,
+  kNoOp = 9,
 
   // Last but invalid command.
   kError,