[NativeProcessLinux] Remove the stop callback

[labath]

Summary

The stop callback is a remnant of the ThreadStateCoordinator. We don't need it now that TSC is
gone, as we know exactly which function to call when threads stop. This also removes some
stop-related functions, which were just forwarding calls to one another.

[ovyalov]

Please see my comments.

source/Plugins/Process/Linux/NativeProcessLinux.cpp

4537

Please add a new ThreadContext constructor that takes ThreadState parameter.

4543

If RequestThreadStop fails is it necessary to call m_pending_notification_up->wait_for_stop_tids.insert(tid); ?

4544

Do we need to stop main thread of lldb-server here or RequestThreadStop(tid,.. ) ?

[labath]

source/Plugins/Process/Linux/NativeProcessLinux.cpp

4537

Done.

4543

I would leave this as-is, for now at least, as now I am trying to do cleanups that don't change functionality.

But let's think what are the possible reasons the tgkill may fail:
a) The thread has exited in the meantime.
b) The process has exited.
c) The process has done execve().
d) ???

If everything works as it should, a)-c) should not actually happen, since the thread should stop with PTRACE_EVENT_EXIT before this happens. At this point the thread still exists, and we can send signals to it. If we miss this event for whatever reason, and the thread is really dead, then it could happen that tgkill fails. However, we should still get WIFEXITED event, at which point we will delete the thread and fire the notification (and it wont matter whether we set the flag or not). If we don't get that event also then we will probably hang forever waiting for the thread the stop, but if we end up here, then we are probably in a deep mess anyway.

What do you think?

4544

Good catch. It's tid of course.

[labath]

Address review comments

[ovyalov]

Looks good.

source/Plugins/Process/Linux/NativeProcessLinux.cpp

4543

I was thinking about possible EINTR error that tgkill may raise but it seems "man tgkill" doesn't mention such error as a possible outcome.
Let's leave this flow as-is - since there's logging within RequestThreadStop we'll be able to catch errors if something goes wrong.

source/Plugins/Process/Linux/NativeProcessLinux.h

#endif
 
         /// Single steps the given thread.  If @p signo is anything but
         /// LLDB_INVALID_SIGNAL_NUMBER, deliver that signal to the thread.
         Error
         SingleStep(lldb::tid_t tid, uint32_t signo);
 
         // ThreadStateCoordinator helper methods.
         void
-        NotifyThreadCreateStopped (lldb::tid_t tid);
-
-        void
-        NotifyThreadCreateRunning (lldb::tid_t tid);
-
-        void
         NotifyThreadDeath (lldb::tid_t tid);
 
-        void
-        StopRunningThreads (lldb::tid_t triggering_tid);
-
-        void
-        StopRunningThreadsWithSkipTID (lldb::tid_t deferred_signal_tid,
-                                                lldb::tid_t skip_stop_request_tid);
-
         Error
         Detach(lldb::tid_t tid);
 
-        Error
-        RequestThreadStop (const lldb::pid_t pid, const lldb::tid_t tid);
-
 
     public:
         // Typedefs.
         typedef std::unordered_set<lldb::tid_t> ThreadIDSet;
 
         // Callback/block definitions.
-        typedef std::function<Error (lldb::tid_t tid)> StopThreadFunction;
         typedef std::function<Error (lldb::tid_t tid, bool supress_signal)> ResumeThreadFunction;
 
     private:
-        // Notify the coordinator when a thread is created and/or starting to be
-        // tracked.  is_stopped should be true if the thread is currently stopped;
-        // otherwise, it should be set false if it is already running.  Will
-        // call the error function if the thread id is already tracked.
+        enum class ThreadState
+        {
+            Running,
+            Stopped
+        };
+
+        // Notify that a thread is created and/or starting to be
+        // tracked. The state parameter should reflect whether the thread is created in a running
+        // or stopped state.
         void
-        NotifyThreadCreate(lldb::tid_t tid, bool is_stopped);
+        NotifyThreadCreate(lldb::tid_t tid, ThreadState state);
 
 
         // Notify the delegate after a given set of threads stops. The triggering_tid will be set
         // as the current thread. The error_function will be fired if either the triggering tid
         // or any of the wait_for_stop_tids are unknown.
         void
-        StopThreads(lldb::tid_t triggering_tid,
-                              const ThreadIDSet &wait_for_stop_tids,
-                              const StopThreadFunction &request_thread_stop_function);
+        StopThreads(lldb::tid_t triggering_tid, const ThreadIDSet &wait_for_stop_tids);
 
         // Notify the delegate after all non-stopped threads stop. The triggering_tid will be set
         // as the current thread. The error_function will be fired if the triggering tid
         // is unknown.
         void
-        StopRunningThreads(lldb::tid_t triggering_tid,
-                                     const StopThreadFunction &request_thread_stop_function);
+        StopRunningThreads(lldb::tid_t triggering_tid);
 
         // Notify the delegate after all non-stopped threads stop. The triggering_tid will be set
         // as the current thread. The error_function will be fired if either the triggering tid
         // or any of the wait_for_stop_tids are unknown.  This variant will send stop requests to
-        // all non-stopped threads except for any contained in skip_stop_request_tids.
+        // all non-stopped threads except skip_stop_request_tid.
         void
-        StopRunningThreadsWithSkipTID(lldb::tid_t triggering_tid,
-                                                 const ThreadIDSet &skip_stop_request_tids,
-                                                 const StopThreadFunction &request_thread_stop_function);
+        StopRunningThreadsWithSkipTID(lldb::tid_t triggering_tid, lldb::tid_t skip_stop_request_tid);
 
         // Notify the thread stopped.  Will trigger error at time of execution if we
         // already think it is stopped.
         Error
         NotifyThreadStop(lldb::tid_t tid, bool initiated_by_llgs);
 
         // Request that the given thread id should have the request_thread_resume_function
         // called. This call signals an error if the thread resume is for
private:
 
         // Indicate the calling process did an exec and that the thread state
         // should be 100% cleared.
         void
         ResetForExec ();
 
     private:
 
-        enum class ThreadState
-        {
-            Running,
-            Stopped
-        };
-
         struct ThreadContext
         {
             ThreadState m_state;
             bool m_stop_requested = false;
             ResumeThreadFunction m_request_resume_function;
+
+            explicit ThreadContext(ThreadState state)
+                : m_state(state)
+            {}
         };
         typedef std::unordered_map<lldb::tid_t, ThreadContext> TIDContextMap;
 
         struct PendingNotification
         {
             PendingNotification (lldb::tid_t triggering_tid,
-                                       const ThreadIDSet &wait_for_stop_tids,
-                                       const StopThreadFunction &request_thread_stop_function):
+                                 const ThreadIDSet &skip_stop_request_tids):
                 triggering_tid (triggering_tid),
                 wait_for_stop_tids (wait_for_stop_tids),
                 original_wait_for_stop_tids (wait_for_stop_tids),
-            request_thread_stop_function (request_thread_stop_function),
                 request_stop_on_all_unstopped_threads (false),
-            skip_stop_request_tids ()
+                skip_stop_request_tids (skip_stop_request_tids)
             {
             }
 
-            PendingNotification (lldb::tid_t triggering_tid,
-                                       const StopThreadFunction &request_thread_stop_function):
+            PendingNotification (lldb::tid_t triggering_tid):
                 triggering_tid (triggering_tid),
                 wait_for_stop_tids (),
                 original_wait_for_stop_tids (),
-            request_thread_stop_function (request_thread_stop_function),
                 request_stop_on_all_unstopped_threads (true),
                 skip_stop_request_tids ()
             {
             }
 
-            PendingNotification (lldb::tid_t triggering_tid,
-                                       const StopThreadFunction &request_thread_stop_function,
-                                       const ThreadIDSet &skip_stop_request_tids):
-            triggering_tid (triggering_tid),
-            wait_for_stop_tids (),
-            original_wait_for_stop_tids (),
-            request_thread_stop_function (request_thread_stop_function),
-            request_stop_on_all_unstopped_threads (true),
-            skip_stop_request_tids (skip_stop_request_tids)
-            {
-            }
-
             const lldb::tid_t  triggering_tid;
             ThreadIDSet        wait_for_stop_tids;
             const ThreadIDSet  original_wait_for_stop_tids;
-            StopThreadFunction request_thread_stop_function;
             const bool         request_stop_on_all_unstopped_threads;
             ThreadIDSet        skip_stop_request_tids;
         };
         typedef std::unique_ptr<PendingNotification> PendingNotificationUP;
 
         // Fire pending notification if no pending thread stops remain.
         void SignalIfRequirementsSatisfied();
 
         bool
         RequestStopOnAllSpecifiedThreads();
 
         void
         RequestStopOnAllRunningThreads();
 
-        void
+        Error
         RequestThreadStop (lldb::tid_t tid, ThreadContext& context);
 
         std::mutex m_event_mutex; // Serializes execution of ProcessEvent. XXX
 
         Error
         ThreadDidStop(lldb::tid_t tid, bool initiated_by_llgs);
 
         Error
         DoResume(lldb::tid_t tid, ResumeThreadFunction request_thread_resume_function,
                 bool error_when_already_running);
 
         void
         DoStopThreads(PendingNotificationUP &&notification_up);
 
         void
-        ThreadWasCreated (lldb::tid_t tid, bool is_stopped);
+        ThreadWasCreated (lldb::tid_t tid, ThreadState state);
 
         void
         ThreadDidDie (lldb::tid_t tid);
 
         bool
         IsKnownThread(lldb::tid_t tid) const;
 
         // Member variables.

source/Plugins/Process/Linux/NativeProcessLinux.cpp

if (error.Fail())
         return -1;
     }
 
     if (log)
         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
 
     thread_sp = AddThread (pid);
     assert (thread_sp && "AddThread() returned a nullptr thread");
-    NotifyThreadCreateStopped (pid);
+    NotifyThreadCreate (pid, ThreadState::Stopped);
     std::static_pointer_cast<NativeThreadLinux> (thread_sp)->SetStoppedBySignal (SIGSTOP);
 
     // Let our process instance know the thread has stopped.
     SetCurrentThreadID (thread_sp->GetID ());
     SetState (StateType::eStateStopped);
 
     if (log)
     {
while (Host::FindProcessThreads(pid, tids_to_attach))
 
                 it->second = true;
 
                 // Create the thread, mark it as stopped.
                 NativeThreadProtocolSP thread_sp (AddThread (static_cast<lldb::tid_t> (tid)));
                 assert (thread_sp && "AddThread() returned a nullptr");
 
                 // This will notify this is a new thread and tell the system it is stopped.
-                NotifyThreadCreateStopped (tid);
+                NotifyThreadCreate (tid, ThreadState::Stopped);
                 std::static_pointer_cast<NativeThreadLinux> (thread_sp)->SetStoppedBySignal (SIGSTOP);
                 SetCurrentThreadID (thread_sp->GetID ());
             }
 
             // move the loop forward
             ++it;
         }
     }
NativeProcessLinux::WaitForNewThread(::pid_t tid)
 
     if (log)
         log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 ": tracking new thread tid %" PRIu32,
                  __FUNCTION__, GetID (), tid);
 
     new_thread_sp = AddThread(tid);
     std::static_pointer_cast<NativeThreadLinux> (new_thread_sp)->SetRunning ();
     Resume (tid, LLDB_INVALID_SIGNAL_NUMBER);
-    NotifyThreadCreate (tid, false);
+    NotifyThreadCreate (tid, ThreadState::Running);
 }
 
 void
 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
 {
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
     const bool is_main_thread = (pid == GetID ());
 
case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
         {
             SetCurrentThreadID (LLDB_INVALID_THREAD_ID);
             if (log)
                 log->Printf ("NativeProcessLinux::%s pid %" PRIu64 "no main thread found, discarded all threads, we're in a no-thread state!", __FUNCTION__, GetID ());
         }
 
         // Tell coordinator about about the "new" (since exec) stopped main thread.
         const lldb::tid_t main_thread_tid = GetID ();
-        NotifyThreadCreateStopped (main_thread_tid);
+        NotifyThreadCreate (main_thread_tid, ThreadState::Stopped);
 
         // NOTE: ideally these next statements would execute at the same time as the coordinator thread create was executed.
         // Consider a handler that can execute when that happens.
         // Let our delegate know we have just exec'd.
         NotifyDidExec ();
 
         // If we have a main thread, indicate we are stopped.
         assert (main_thread_sp && "exec called during ptraced process but no main thread metadata tracked");
if ((info->si_pid == 0) && (info->si_code == SI_USER))
             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
                      __FUNCTION__, GetID (), pid);
 
         thread_sp = AddThread(pid);
         assert (thread_sp.get() && "failed to create the tracking data for newly created inferior thread");
         // We can now resume the newly created thread.
         std::static_pointer_cast<NativeThreadLinux> (thread_sp)->SetRunning ();
         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
-        NotifyThreadCreate (pid, false);
+        NotifyThreadCreate (pid, ThreadState::Running);
         // Done handling.
         return;
     }
 
     // Check for thread stop notification.
     if (is_from_llgs && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
     {
         // This is a tgkill()-based stop.
if (error.Fail ())
         if (log)
             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_sp->GetID (), error.AsCString ());
         return error;
     }
 
     return error;
 }
 
-void
-NativeProcessLinux::NotifyThreadCreateStopped (lldb::tid_t tid)
-{
-    const bool is_stopped = true;
-    NotifyThreadCreate (tid, is_stopped);
-}
-
-void
-NativeProcessLinux::StopRunningThreads(lldb::tid_t trigerring_tid)
-{
-    Log *const log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
-    if (log)
-        log->Printf("NativeProcessLinux::%s tid %" PRIu64, __FUNCTION__, trigerring_tid);
-
-    const lldb::pid_t pid = GetID ();
-    StopRunningThreads(trigerring_tid,
-            [=](lldb::tid_t request_stop_tid) { return RequestThreadStop(pid, request_stop_tid); });
-}
-
-void
-NativeProcessLinux::StopRunningThreadsWithSkipTID(lldb::tid_t deferred_signal_tid,
-                                                  lldb::tid_t skip_stop_request_tid)
-{
-    Log *const log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
-    if (log)
-        log->Printf("NativeProcessLinux::%s deferred_signal_tid %" PRIu64 ", skip_stop_request_tid %" PRIu64, __FUNCTION__, deferred_signal_tid, skip_stop_request_tid);
-
-    const lldb::pid_t pid = GetID ();
-    StopRunningThreadsWithSkipTID(deferred_signal_tid,
-            skip_stop_request_tid != LLDB_INVALID_THREAD_ID ? NativeProcessLinux::ThreadIDSet {skip_stop_request_tid} : NativeProcessLinux::ThreadIDSet (),
-            [=](lldb::tid_t request_stop_tid) { return RequestThreadStop(pid, request_stop_tid); });
-}
-
-Error
-NativeProcessLinux::RequestThreadStop (const lldb::pid_t pid, const lldb::tid_t tid)
-{
-    Log* log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
-    if (log)
-        log->Printf ("NativeProcessLinux::%s requesting thread stop(pid: %" PRIu64 ", tid: %" PRIu64 ")", __FUNCTION__, pid, tid);
-
-    Error err;
-    errno = 0;
-    if (::tgkill (pid, tid, SIGSTOP) != 0)
-    {
-        err.SetErrorToErrno ();
-        if (log)
-            log->Printf ("NativeProcessLinux::%s tgkill(%" PRIu64 ", %" PRIu64 ", SIGSTOP) failed: %s", __FUNCTION__, pid, tid, err.AsCString ());
-    }
-
-    return err;
-}
-
 Error
 NativeProcessLinux::GetLoadedModuleFileSpec(const char* module_path, FileSpec& file_spec)
 {
     char maps_file_name[32];
     snprintf(maps_file_name, sizeof(maps_file_name), "/proc/%" PRIu64 "/maps", GetID());
 
     FileSpec maps_file_spec(maps_file_name, false);
     if (!maps_file_spec.Exists()) {
NativeProcessLinux::DoResume(
 
     return error;
 }
 
 //===----------------------------------------------------------------------===//
 
 void
 NativeProcessLinux::StopThreads(const lldb::tid_t triggering_tid,
-                                              const ThreadIDSet &wait_for_stop_tids,
-                                              const StopThreadFunction &request_thread_stop_function)
+                                          const ThreadIDSet &wait_for_stop_tids)
 {
     Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
     std::lock_guard<std::mutex> lock(m_event_mutex);
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s about to process event: (triggering_tid: %" PRIu64 ", wait_for_stop_tids.size(): %zd)",
                 __FUNCTION__, triggering_tid, wait_for_stop_tids.size());
     }
 
     DoStopThreads(PendingNotificationUP(new PendingNotification(
-                triggering_tid, wait_for_stop_tids, request_thread_stop_function)));
+                triggering_tid, wait_for_stop_tids, ThreadIDSet())));
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s event processing done", __FUNCTION__);
     }
 }
 
 void
-NativeProcessLinux::StopRunningThreads(const lldb::tid_t triggering_tid,
-                                                     const StopThreadFunction &request_thread_stop_function)
+NativeProcessLinux::StopRunningThreads(const lldb::tid_t triggering_tid)
 {
     Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
     std::lock_guard<std::mutex> lock(m_event_mutex);
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s about to process event: (triggering_tid: %" PRIu64 ")",
                 __FUNCTION__, triggering_tid);
     }
 
-    DoStopThreads(PendingNotificationUP(new PendingNotification(
-                triggering_tid,
-                request_thread_stop_function)));
+    DoStopThreads(PendingNotificationUP(new PendingNotification(triggering_tid)));
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s event processing done", __FUNCTION__);
     }
 }
 
 void
 NativeProcessLinux::StopRunningThreadsWithSkipTID(lldb::tid_t triggering_tid,
-                                                                 const ThreadIDSet &skip_stop_request_tids,
-                                                                 const StopThreadFunction &request_thread_stop_function)
+                                                  lldb::tid_t skip_stop_request_tid)
 {
     Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
     std::lock_guard<std::mutex> lock(m_event_mutex);
 
     if (log)
     {
-        log->Printf("NativeProcessLinux::%s about to process event: (triggering_tid: %" PRIu64 ", skip_stop_request_tids.size(): %zd)",
-                __FUNCTION__, triggering_tid, skip_stop_request_tids.size());
+        log->Printf("NativeProcessLinux::%s about to process event: (triggering_tid: %" PRIu64 ", skip_stop_request_tid: %" PRIu64 ")",
+                __FUNCTION__, triggering_tid, skip_stop_request_tid);
     }
 
     DoStopThreads(PendingNotificationUP(new PendingNotification(
                 triggering_tid,
-                request_thread_stop_function,
-                skip_stop_request_tids)));
+                ThreadIDSet(),
+                skip_stop_request_tid != LLDB_INVALID_THREAD_ID ? NativeProcessLinux::ThreadIDSet {skip_stop_request_tid} : ThreadIDSet ())));
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s event processing done", __FUNCTION__);
     }
 }
 
 void
for (auto it = m_tid_map.begin(); it != m_tid_map.end(); ++it)
             sent_tids.insert (tid);
         }
     }
 
     // Set the wait list to the set of tids for which we requested stops.
     m_pending_notification_up->wait_for_stop_tids.swap (sent_tids);
 }
 
-void
+Error
 NativeProcessLinux::RequestThreadStop (lldb::tid_t tid, ThreadContext& context)
 {
-    const auto error = m_pending_notification_up->request_thread_stop_function (tid);
-    if (error.Success ())
-        context.m_stop_requested = true;
-    else
+    Log* log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
+
+    lldb::pid_t pid = GetID();
+
+    if (log)
+        log->Printf ("NativeProcessLinux::%s requesting thread stop(pid: %" PRIu64 ", tid: %" PRIu64 ")", __FUNCTION__, pid, tid);
+
+    Error err;
+    errno = 0;
+    if (::tgkill (pid, tid, SIGSTOP) != 0)
     {
-        Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
+        err.SetErrorToErrno ();
         if (log)
-            log->Printf("NativeProcessLinux::%s failed to request thread stop tid  %" PRIu64 ": %s",
-                         __FUNCTION__, tid, error.AsCString ());
+            log->Printf ("NativeProcessLinux::%s tgkill(%" PRIu64 ", %" PRIu64 ", SIGSTOP) failed: %s", __FUNCTION__, pid, tid, err.AsCString ());
     }
+    else
+        context.m_stop_requested = true;
+
+    return err;
 }
 
 
 Error
 NativeProcessLinux::ThreadDidStop (lldb::tid_t tid, bool initiated_by_llgs)
 {
     // Ensure we know about the thread.
     auto find_it = m_tid_map.find (tid);
else
         if (!RequestStopOnAllSpecifiedThreads())
             return;
     }
 
     SignalIfRequirementsSatisfied();
 }
 
 void
-NativeProcessLinux::ThreadWasCreated (lldb::tid_t tid, bool is_stopped)
+NativeProcessLinux::ThreadWasCreated (lldb::tid_t tid, ThreadState state)
 {
     // Ensure we don't already know about the thread.
     lldbassert(m_tid_map.find(tid) == m_tid_map.end());
 
     // Add the new thread to the stop map.
-    ThreadContext ctx;
-    ctx.m_state = (is_stopped) ? ThreadState::Stopped : ThreadState::Running;
-    m_tid_map[tid] = std::move(ctx);
+    auto tid_it = m_tid_map.emplace(tid, ThreadContext(state)).first;
 
-    if (m_pending_notification_up && !is_stopped)
+    if (m_pending_notification_up && state == ThreadState::Running)
     {
         // We will need to wait for this new thread to stop as well before firing the
         // notification.
         m_pending_notification_up->wait_for_stop_tids.insert(tid);
-        m_pending_notification_up->request_thread_stop_function(tid);
+        RequestThreadStop(tid, tid_it->second);
     }
 }
 
 void
 NativeProcessLinux::ThreadDidDie (lldb::tid_t tid)
 {
     // Ensure we know about the thread.
     auto find_it = m_tid_map.find (tid);
NativeProcessLinux::RequestThreadResumeAsNeeded (lldb::tid_t tid,
     {
         log->Printf("NativeProcessLinux::%s event processing done", __FUNCTION__);
     }
 
     return error;
 }
 
 void
-NativeProcessLinux::NotifyThreadCreate (lldb::tid_t tid,
-                                            bool is_stopped)
+NativeProcessLinux::NotifyThreadCreate (lldb::tid_t tid, ThreadState state)
 {
     Log *const log = GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD);
     std::lock_guard<std::mutex> lock(m_event_mutex);
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s about to process event: (tid: %" PRIu64 ", is %sstopped)",
-                __FUNCTION__, tid, is_stopped?"":"not ");
+                __FUNCTION__, tid, state==ThreadState::Stopped?"":"not ");
     }
 
-    ThreadWasCreated (tid, is_stopped);
+    ThreadWasCreated (tid, state);
 
     if (log)
     {
         log->Printf("NativeProcessLinux::%s event processing done", __FUNCTION__);
     }
 }
 
 void