[virtual machine] reverted back the commit "move the lock into the ch…

…eck_state_for_shutdown function since the state variable is the only one needs to be protected, also convert unique_lock to scoped_lock because manual unlock/ lock is no longer needed."

src/platform/backends/qemu/qemu_virtual_machine.cpp

@@ -346,6 +346,8 @@ void mp::QemuVirtualMachine::start()
 
 void mp::QemuVirtualMachine::shutdown(const bool force)
 {
+    std::unique_lock<std::mutex> lock{state_mutex};
+
     try
     {
         check_state_for_shutdown(force);
@@ -363,6 +365,7 @@ void mp::QemuVirtualMachine::shutdown(const bool force)
         if (vm_process)
         {
             mpl::log(mpl::Level::info, vm_name, "Killing process");
+            lock.unlock();
             vm_process->kill();
             vm_process->wait_for_finished(timeout);
         }
@@ -371,7 +374,6 @@ void mp::QemuVirtualMachine::shutdown(const bool force)
             mpl::log(mpl::Level::debug, vm_name, "No process to kill");
         }
 
-        std::scoped_lock lock{state_mutex};
         if (state == State::suspended || mp::backend::instance_image_has_snapshot(desc.image.image_path, suspend_tag))
         {
             mpl::log(mpl::Level::info, vm_name, "Deleting suspend image");
@@ -382,6 +384,8 @@ void mp::QemuVirtualMachine::shutdown(const bool force)
     }
     else
     {
+        lock.unlock();
+
         drop_ssh_session();
 
         if (vm_process && vm_process->running())

src/platform/backends/shared/base_virtual_machine.cpp

@@ -192,7 +192,7 @@ void mp::BaseVirtualMachine::check_state_for_shutdown(const bool force)
 {
     const std::string force_statement{"Use --force to override."};
 
-    std::scoped_lock lock{state_mutex};
+    // A mutex should already be locked by the caller here
     if (state == State::off || state == State::stopped)
     {
         throw VMStateIdempotentException{"Ignoring shutdown since instance is already stopped."};