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>
llvm-svn: 270869
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index d5727ef..dfff06d 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -68,23 +68,9 @@
#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 @@
//}
//
-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 @@
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_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 @@
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 @@
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 @@
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 @@
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 @@
{
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 @@
{
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)
{