Author: gclayton
Date: Thu May 26 11:51:23 2016
New Revision: 270869
URL: http://llvm.org/viewvc/llvm-project?rev=270869&view=rev
Log:
Guard against the C++ destructor chain by not letting the debugger list clean
up after itself in the C++ destructor chain.
If users call "static void lldb::SBDebugger::Terminate()" we will clean up the
debugger list, and users can individually destroy debugger instances with
"static void lldb::SBDebugger::Destroy(SBDebugger &)". But if we let the C++
destructor chain tear down this list, other threads that might still be running
as the main thread exits can now crash if they access the debugger list. We
stop this by leaking the debugger list and its mutex.
<rdar://problem/26372169>
Modified:
lldb/trunk/source/Core/Debugger.cpp
Modified: lldb/trunk/source/Core/Debugger.cpp
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Core/Debugger.cpp?rev=270869&r1=270868&r2=270869&view=diff
==============================================================================
--- lldb/trunk/source/Core/Debugger.cpp (original)
+++ lldb/trunk/source/Core/Debugger.cpp Thu May 26 11:51:23 2016
@@ -68,23 +68,9 @@ static size_t g_debugger_event_thread_st
#pragma mark Static Functions
-static std::recursive_mutex &
-GetDebuggerListMutex()
-{
- static std::recursive_mutex g_mutex;
- return g_mutex;
-}
-
typedef std::vector<DebuggerSP> DebuggerList;
-
-static DebuggerList &
-GetDebuggerList()
-{
- // hide the static debugger list inside a singleton accessor to avoid
- // global init constructors
- static DebuggerList g_list;
- return g_list;
-}
+static std::recursive_mutex *g_debugger_list_mutex_ptr = nullptr; // NOTE:
intentional leak to avoid issues with C++ destructor chain
+static DebuggerList *g_debugger_list_ptr = nullptr; // NOTE: intentional leak
to avoid issues with C++ destructor chain
OptionEnumValueElement
g_show_disassembly_enum_values[] =
@@ -454,28 +440,32 @@ Debugger::SetTabSize (uint32_t tab_size)
//}
//
-static bool lldb_initialized = false;
void
Debugger::Initialize(LoadPluginCallbackType load_plugin_callback)
{
- assert(!lldb_initialized && "Debugger::Initialize called more than once!");
-
- lldb_initialized = true;
+ assert(g_debugger_list_ptr == nullptr && "Debugger::Initialize called more
than once!");
+ g_debugger_list_mutex_ptr = new std::recursive_mutex();
+ g_debugger_list_ptr = new DebuggerList();
g_load_plugin_callback = load_plugin_callback;
}
void
Debugger::Terminate ()
{
- assert(lldb_initialized && "Debugger::Terminate called without a matching
Debugger::Initialize!");
+ assert(g_debugger_list_ptr && "Debugger::Terminate called without a
matching Debugger::Initialize!");
- // Clear our master list of debugger objects
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- auto& debuggers = GetDebuggerList();
- for (const auto& debugger: debuggers)
- debugger->Clear();
-
- debuggers.clear();
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
+ {
+ // Clear our master list of debugger objects
+ {
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ for (const auto& debugger: *g_debugger_list_ptr)
+ debugger->Clear();
+ g_debugger_list_ptr->clear();
+ delete g_debugger_list_ptr;
+ g_debugger_list_ptr = nullptr;
+ }
+ }
}
void
@@ -604,10 +594,10 @@ DebuggerSP
Debugger::CreateInstance (lldb::LogOutputCallback log_callback, void *baton)
{
DebuggerSP debugger_sp (new Debugger(log_callback, baton));
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- GetDebuggerList().push_back(debugger_sp);
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ g_debugger_list_ptr->push_back(debugger_sp);
}
debugger_sp->InstanceInitialize ();
return debugger_sp;
@@ -621,16 +611,15 @@ Debugger::Destroy (DebuggerSP &debugger_
debugger_sp->Clear();
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList ();
- DebuggerList::iterator pos, end = debugger_list.end();
- for (pos = debugger_list.begin (); pos != end; ++pos)
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ DebuggerList::iterator pos, end = g_debugger_list_ptr->end();
+ for (pos = g_debugger_list_ptr->begin (); pos != end; ++pos)
{
if ((*pos).get() == debugger_sp.get())
{
- debugger_list.erase (pos);
+ g_debugger_list_ptr->erase (pos);
return;
}
}
@@ -641,13 +630,11 @@ DebuggerSP
Debugger::FindDebuggerWithInstanceName (const ConstString &instance_name)
{
DebuggerSP debugger_sp;
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList();
- DebuggerList::iterator pos, end = debugger_list.end();
-
- for (pos = debugger_list.begin(); pos != end; ++pos)
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ DebuggerList::iterator pos, end = g_debugger_list_ptr->end();
+ for (pos = g_debugger_list_ptr->begin (); pos != end; ++pos)
{
if ((*pos)->m_instance_name == instance_name)
{
@@ -663,12 +650,11 @@ TargetSP
Debugger::FindTargetWithProcessID (lldb::pid_t pid)
{
TargetSP target_sp;
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList();
- DebuggerList::iterator pos, end = debugger_list.end();
- for (pos = debugger_list.begin(); pos != end; ++pos)
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ DebuggerList::iterator pos, end = g_debugger_list_ptr->end();
+ for (pos = g_debugger_list_ptr->begin (); pos != end; ++pos)
{
target_sp = (*pos)->GetTargetList().FindTargetWithProcessID (pid);
if (target_sp)
@@ -682,12 +668,11 @@ TargetSP
Debugger::FindTargetWithProcess (Process *process)
{
TargetSP target_sp;
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList();
- DebuggerList::iterator pos, end = debugger_list.end();
- for (pos = debugger_list.begin(); pos != end; ++pos)
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ DebuggerList::iterator pos, end = g_debugger_list_ptr->end();
+ for (pos = g_debugger_list_ptr->begin (); pos != end; ++pos)
{
target_sp = (*pos)->GetTargetList().FindTargetWithProcess
(process);
if (target_sp)
@@ -1162,10 +1147,10 @@ Debugger::GetAsyncErrorStream ()
size_t
Debugger::GetNumDebuggers()
{
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- return GetDebuggerList().size();
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ return g_debugger_list_ptr->size();
}
return 0;
}
@@ -1175,13 +1160,11 @@ Debugger::GetDebuggerAtIndex (size_t ind
{
DebuggerSP debugger_sp;
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList();
-
- if (index < debugger_list.size())
- debugger_sp = debugger_list[index];
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ if (index < g_debugger_list_ptr->size())
+ debugger_sp = g_debugger_list_ptr->at(index);
}
return debugger_sp;
@@ -1192,12 +1175,11 @@ Debugger::FindDebuggerWithID (lldb::user
{
DebuggerSP debugger_sp;
- if (lldb_initialized)
+ if (g_debugger_list_ptr && g_debugger_list_mutex_ptr)
{
- std::lock_guard<std::recursive_mutex> guard(GetDebuggerListMutex());
- DebuggerList &debugger_list = GetDebuggerList();
- DebuggerList::iterator pos, end = debugger_list.end();
- for (pos = debugger_list.begin(); pos != end; ++pos)
+ std::lock_guard<std::recursive_mutex>
guard(*g_debugger_list_mutex_ptr);
+ DebuggerList::iterator pos, end = g_debugger_list_ptr->end();
+ for (pos = g_debugger_list_ptr->begin (); pos != end; ++pos)
{
if ((*pos)->GetID() == id)
{
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