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Remove a lock acquisition from ProcessWindows::OnExitProcess. 

This was causing a race condition where DoDestroy() would acquire
the lock and then initiate a shutdown and then wait for it to
complete.  But part of the shutdown involved acquiring the same
lock from a different thread.  So the main thread would timeout
waiting for the shutdown to complete and return too soon.

The end result of this is that SBProcess::Kill() was broken on
Windows.

llvm-svn: 225297
This commit is contained in:
Zachary Turner 2015-01-06 20:56:12 +00:00
parent 0f39721261
commit c8761f4807
1 changed files with 12 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
lldb/source/Plugins/Process/Windows/ProcessWindows.cpp
View File

@ -196,6 +196,10 @@ Error
ProcessWindows::DoLaunch(Module *exe_module,
ProcessLaunchInfo &launch_info)
{
// Even though m_session_data is accessed here, it is before a debugger thread has been
// kicked off. So there's no race conditions, and it shouldn't be necessary to acquire
// the mutex.
Error result;
if (!launch_info.GetFlags().Test(eLaunchFlagDebug))
{
@ -367,6 +371,7 @@ ProcessWindows::DoHalt(bool &caused_stop)
caused_stop = false;
else
{
llvm::sys::ScopedLock lock(m_mutex);
caused_stop = ::DebugBreakProcess(m_session_data->m_debugger->GetProcess().GetNativeProcess().GetSystemHandle());
if (!caused_stop)
error.SetError(GetLastError(), eErrorTypeWin32);
@ -391,11 +396,11 @@ ProcessWindows::DoReadMemory(lldb::addr_t vm_addr,
size_t size,
Error &error)
{
llvm::sys::ScopedLock lock(m_mutex);
if (!m_session_data)
return 0;
llvm::sys::ScopedLock lock(m_mutex);
HostProcess process = m_session_data->m_debugger->GetProcess();
void *addr = reinterpret_cast<void *>(vm_addr);
SIZE_T bytes_read = 0;
@ -407,11 +412,11 @@ ProcessWindows::DoReadMemory(lldb::addr_t vm_addr,
size_t
ProcessWindows::DoWriteMemory(lldb::addr_t vm_addr, const void *buf, size_t size, Error &error)
{
llvm::sys::ScopedLock lock(m_mutex);
if (!m_session_data)
return 0;
llvm::sys::ScopedLock lock(m_mutex);
HostProcess process = m_session_data->m_debugger->GetProcess();
void *addr = reinterpret_cast<void *>(vm_addr);
SIZE_T bytes_written = 0;
@ -451,7 +456,7 @@ ProcessWindows::CanDebug(Target &target, bool plugin_specified_by_name)
void
ProcessWindows::OnExitProcess(uint32_t exit_code)
{
llvm::sys::ScopedLock lock(m_mutex);
// No need to acquire the lock since m_session_data isn't accessed.
ModuleSP executable_module = GetTarget().GetExecutableModule();
ModuleList unloaded_modules;
@ -467,8 +472,6 @@ ProcessWindows::OnDebuggerConnected(lldb::addr_t image_base)
{
// Either we successfully attached to an existing process, or we successfully launched a new
// process under the debugger.
llvm::sys::ScopedLock lock(m_mutex);
ModuleSP module = GetTarget().GetExecutableModule();
bool load_addr_changed;
module->SetLoadAddress(GetTarget(), image_base, false, load_addr_changed);
@ -479,6 +482,8 @@ ProcessWindows::OnDebuggerConnected(lldb::addr_t image_base)
loaded_modules.Append(module);
GetTarget().ModulesDidLoad(loaded_modules);
llvm::sys::ScopedLock lock(m_mutex);
DebuggerThreadSP debugger = m_session_data->m_debugger;
const HostThreadWindows &wmain_thread = debugger->GetMainThread().GetNativeThread();
m_session_data->m_new_threads[wmain_thread.GetThreadId()] = debugger->GetMainThread();
@ -566,8 +571,6 @@ ProcessWindows::OnExitThread(const HostThread &exited_thread)
void
ProcessWindows::OnLoadDll(const ModuleSpec &module_spec, lldb::addr_t module_addr)
{
llvm::sys::ScopedLock lock(m_mutex);
// Confusingly, there is no Target::AddSharedModule. Instead, calling GetSharedModule() with
// a new module will add it to the module list and return a corresponding ModuleSP.
Error error;
@ -583,8 +586,6 @@ ProcessWindows::OnLoadDll(const ModuleSpec &module_spec, lldb::addr_t module_add
void
ProcessWindows::OnUnloadDll(lldb::addr_t module_addr)
{
llvm::sys::ScopedLock lock(m_mutex);
Address resolved_addr;
if (GetTarget().ResolveLoadAddress(module_addr, resolved_addr))
{