From 15184db09217553490750c5cbd03498fd38b0ac6 Mon Sep 17 00:00:00 2001
From: Greg Clayton <gclayton@apple.com>
Date: Sun, 29 May 2011 23:07:38 +0000
Subject: [PATCH] Protect the input reader stack with a recursive mutex.

llvm-svn: 132301
---
 lldb/include/lldb/Core/Debugger.h | 1 +
 lldb/source/Core/Debugger.cpp     | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/lldb/include/lldb/Core/Debugger.h b/lldb/include/lldb/Core/Debugger.h
index 433732d32ab7..d337a71262f2 100644
--- a/lldb/include/lldb/Core/Debugger.h
+++ b/lldb/include/lldb/Core/Debugger.h
@@ -451,6 +451,7 @@ protected:
     SourceManager m_source_manager;
     std::auto_ptr<CommandInterpreter> m_command_interpreter_ap;
 
+    Mutex m_input_readers_mutex;
     std::stack<lldb::InputReaderSP> m_input_readers;
     std::string m_input_reader_data;
 
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 6cbc92ed3aaa..80035363650e 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -230,6 +230,7 @@ Debugger::Debugger () :
     m_listener ("lldb.Debugger"),
     m_source_manager (),
     m_command_interpreter_ap (new CommandInterpreter (*this, eScriptLanguageDefault, false)),
+    m_input_readers_mutex (Mutex::eMutexTypeRecursive),
     m_input_readers (),
     m_input_reader_data ()
 {
@@ -356,6 +357,7 @@ Debugger::GetCurrentInputReader ()
 {
     InputReaderSP reader_sp;
     
+    Mutex::Locker locker (m_input_readers_mutex);
     if (!m_input_readers.empty())
     {
         // Clear any finished readers from the stack
@@ -422,6 +424,7 @@ Debugger::CleanUpInputReaders ()
 {
     m_input_reader_data.clear();
     
+    Mutex::Locker locker (m_input_readers_mutex);
     // The bottom input reader should be the main debugger input reader.  We do not want to close that one here.
     while (m_input_readers.size() > 1)
     {
@@ -476,6 +479,7 @@ Debugger::WriteToDefaultReader (const char *bytes, size_t bytes_len)
     if (m_input_reader_data.empty())
         return;
 
+    Mutex::Locker locker (m_input_readers_mutex);
     while (!m_input_readers.empty() && !m_input_reader_data.empty())
     {
         // Get the input reader from the top of the stack
@@ -515,6 +519,7 @@ Debugger::PushInputReader (const InputReaderSP& reader_sp)
     if (top_reader_sp)
         top_reader_sp->Notify (eInputReaderDeactivate);
 
+    Mutex::Locker locker (m_input_readers_mutex);
     m_input_readers.push (reader_sp);
     reader_sp->Notify (eInputReaderActivate);
     ActivateInputReader (reader_sp);
@@ -527,6 +532,7 @@ Debugger::PopInputReader (const lldb::InputReaderSP& pop_reader_sp)
 
     // The reader on the stop of the stack is done, so let the next
     // read on the stack referesh its prompt and if there is one...
+    Mutex::Locker locker (m_input_readers_mutex);
     if (!m_input_readers.empty())
     {
         // Cannot call GetCurrentInputReader here, as that would cause an infinite loop.
@@ -557,6 +563,7 @@ bool
 Debugger::CheckIfTopInputReaderIsDone ()
 {
     bool result = false;
+    Mutex::Locker locker (m_input_readers_mutex);
     if (!m_input_readers.empty())
     {
         // Cannot call GetCurrentInputReader here, as that would cause an infinite loop.