There seems to be some odd corner case where we shut down the ProcessGDBRemote, but we haven't managed to shut down the async thread. That causes the ProcessGDBRemote::AsyncThread to crash when it wakes up. So I changed StartAsyncThread and StopAsyncThread to be callable multiple times (only the first one does anything) so that we can just shut it down unequivocally in the ProcessGDBRemote destructor.
<rdar://problem/12602981>
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@167197 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 7f38cb6..1bfbb7a 100644
--- a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -188,6 +188,8 @@
m_register_info (),
m_async_broadcaster (NULL, "lldb.process.gdb-remote.async-broadcaster"),
m_async_thread (LLDB_INVALID_HOST_THREAD),
+ m_async_thread_state(eAsyncThreadNotStarted),
+ m_async_thread_state_mutex(Mutex::eMutexTypeRecursive),
m_thread_ids (),
m_continue_c_tids (),
m_continue_C_tids (),
@@ -220,6 +222,12 @@
// destruct this class, then Process::~Process() might have problems
// trying to fully destroy the broadcaster.
Finalize();
+
+ // The general Finalize is going to try to destroy the process and that SHOULD
+ // shut down the async thread. However, if we don't kill it it will get stranded and
+ // its connection will go away so when it wakes up it will crash. So kill it for sure here.
+ StopAsyncThread();
+ KillDebugserverProcess();
}
//----------------------------------------------------------------------
@@ -2713,11 +2721,32 @@
if (log)
log->Printf ("ProcessGDBRemote::%s ()", __FUNCTION__);
-
- // Create a thread that watches our internal state and controls which
- // events make it to clients (into the DCProcess event queue).
- m_async_thread = Host::ThreadCreate ("<lldb.process.gdb-remote.async>", ProcessGDBRemote::AsyncThread, this, NULL);
- return IS_VALID_LLDB_HOST_THREAD(m_async_thread);
+
+ Mutex::Locker start_locker(m_async_thread_state_mutex);
+ if (m_async_thread_state == eAsyncThreadNotStarted)
+ {
+ // Create a thread that watches our internal state and controls which
+ // events make it to clients (into the DCProcess event queue).
+ m_async_thread = Host::ThreadCreate ("<lldb.process.gdb-remote.async>", ProcessGDBRemote::AsyncThread, this, NULL);
+ if (IS_VALID_LLDB_HOST_THREAD(m_async_thread))
+ {
+ m_async_thread_state = eAsyncThreadRunning;
+ return true;
+ }
+ else
+ return false;
+ }
+ else
+ {
+ // Somebody tried to start the async thread while it was either being started or stopped. If the former, and
+ // it started up successfully, then say all's well. Otherwise it is an error, since we aren't going to restart it.
+ if (log)
+ log->Printf ("ProcessGDBRemote::%s () - Called when Async thread was in state: %d.", __FUNCTION__, m_async_thread_state);
+ if (m_async_thread_state == eAsyncThreadRunning)
+ return true;
+ else
+ return false;
+ }
}
void
@@ -2728,15 +2757,25 @@
if (log)
log->Printf ("ProcessGDBRemote::%s ()", __FUNCTION__);
- m_async_broadcaster.BroadcastEvent (eBroadcastBitAsyncThreadShouldExit);
-
- // This will shut down the async thread.
- m_gdb_comm.Disconnect(); // Disconnect from the debug server.
-
- // Stop the stdio thread
- if (IS_VALID_LLDB_HOST_THREAD(m_async_thread))
+ Mutex::Locker start_locker(m_async_thread_state_mutex);
+ if (m_async_thread_state == eAsyncThreadRunning)
{
- Host::ThreadJoin (m_async_thread, NULL, NULL);
+ m_async_broadcaster.BroadcastEvent (eBroadcastBitAsyncThreadShouldExit);
+
+ // This will shut down the async thread.
+ m_gdb_comm.Disconnect(); // Disconnect from the debug server.
+
+ // Stop the stdio thread
+ if (IS_VALID_LLDB_HOST_THREAD(m_async_thread))
+ {
+ Host::ThreadJoin (m_async_thread, NULL, NULL);
+ }
+ m_async_thread_state = eAsyncThreadDone;
+ }
+ else
+ {
+ if (log)
+ log->Printf ("ProcessGDBRemote::%s () - Called when Async thread was in state: %d.", __FUNCTION__, m_async_thread_state);
}
}