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trycatch the window manager. A lot more going on there.

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This commit is contained in:
Mike Griese 2021-01-27 12:15:06 -06:00
parent d2a34389a8
commit a65f3419e3
2 changed files with 62 additions and 13 deletions
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73
src/cascadia/Remoting/WindowManager.cpp
View file

@ -23,7 +23,24 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
// Register with COM as a server for the Monarch class
_registerAsMonarch();
// Instantiate an instance of the Monarch. This may or may not be in-proc!
_createMonarchAndCallbacks();
bool foundMonarch = false;
while (!foundMonarch)
{
try
{
_createMonarchAndCallbacks();
// _createMonarchAndCallbacks will initialize _isKing
foundMonarch = true;
}
catch (...)
{
// If we fail to find the monarch,
// stay in this jail until we do.
TraceLoggingWrite(g_hRemotingProvider,
"WindowManager_ExceptionInCtor",
TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE));
}
}
}
WindowManager::~WindowManager()
@ -36,6 +53,8 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
_registrationHostClass = 0;
_monarchWaitInterrupt.SetEvent();
// A thread is joinable once it's been started. Basically this just
// makes sure that the thread isn't just default-constructed.
if (_electionThread.joinable())
{
_electionThread.join();
@ -44,15 +63,13 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
void WindowManager::ProposeCommandline(const Remoting::CommandlineArgs& args)
{
const bool isKing = _areWeTheKing();
// If we're the king, we _definitely_ want to process the arguments, we were
// launched with them!
//
// Otherwise, the King will tell us if we should make a new window
_shouldCreateWindow = isKing;
_shouldCreateWindow = _isKing;
std::optional<uint64_t> givenID;
if (!isKing)
if (!_isKing)
{
// The monarch may respond back "you should be a new
// window, with ID,name of (id, name)". Really the responses are:
@ -106,7 +123,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
_createOurPeasant({ givenID });
// Spawn a thread to wait on the monarch, and handle the election
if (!isKing)
if (!_isKing)
{
_createPeasantThread();
}
@ -144,15 +161,25 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
CLSCTX_LOCAL_SERVER);
}
// NOTE: This can throw! Callers include:
// - the constructor, who performs this in a loop until it successfully
// finda a monarch
// - the performElection method, which is called in the waitOnMonarch
// thread. All the calls in that thread are wrapped in try/catch's
// already.
// - _createOurPeasant, who might do this in a loop to establish us with the
// monarch.
void WindowManager::_createMonarchAndCallbacks()
{
_createMonarch();
const auto isKing = _areWeTheKing();
// Save the result of checking if we're the king. We want to avoid
// unnecessary calls back and forth if we can.
_isKing = _areWeTheKing();
TraceLoggingWrite(g_hRemotingProvider,
"WindowManager_ConnectedToMonarch",
TraceLoggingUInt64(_monarch.GetPID(), "monarchPID", "The PID of the new Monarch"),
TraceLoggingBoolean(isKing, "isKing", "true if we are the new monarch"),
TraceLoggingBoolean(_isKing, "isKing", "true if we are the new monarch"),
TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE));
if (_peasant)
@ -161,7 +188,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
_monarch.HandleActivatePeasant(_peasant.GetLastActivatedArgs());
}
if (!isKing)
if (!_isKing)
{
return;
}
@ -176,8 +203,8 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
bool WindowManager::_areWeTheKing()
{
const auto kingPID{ _monarch.GetPID() };
const auto ourPID{ GetCurrentProcessId() };
const auto kingPID{ _monarch.GetPID() };
return (ourPID == kingPID);
}
@ -189,7 +216,28 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
p->AssignID(givenID.value());
}
_peasant = *p;
_monarch.AddPeasant(_peasant);
// Try to add us to the monarch. If that fails, try to find a monarch
// again, until we find one (we will eventually find us)
while (true)
{
try
{
_monarch.AddPeasant(_peasant);
break;
}
catch (...)
{
try
{
// Wrap this in it's own try/catch, beause this can throw.
_createMonarchAndCallbacks();
}
catch (...)
{
}
}
}
TraceLoggingWrite(g_hRemotingProvider,
"WindowManager_CreateOurPeasant",
@ -206,6 +254,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
// - <none>
// Return Value:
// - true iff we're the new monarch process.
// NOTE: This can throw!
bool WindowManager::_performElection()
{
_createMonarchAndCallbacks();
@ -213,7 +262,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
// Tell the new monarch who we are. We might be that monarch!
_monarch.AddPeasant(_peasant);
if (_areWeTheKing())
if (_isKing)
{
// This method is only called when a _new_ monarch is elected. So
// don't do anything here that needs to be done for all monarch

2
src/cascadia/Remoting/WindowManager.h
View file

@ -24,12 +24,12 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
private:
bool _shouldCreateWindow{ false };
bool _isKing{ false };
DWORD _registrationHostClass{ 0 };
winrt::Microsoft::Terminal::Remoting::Monarch _monarch{ nullptr };
winrt::Microsoft::Terminal::Remoting::Peasant _peasant{ nullptr };
wil::unique_event _monarchWaitInterrupt;
std::thread _electionThread;
void _registerAsMonarch();