On Windows, shutdown the pipe server when an unrecoverable error occurs.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@31296 a592a061-630c-0410-9148-cb99ea01b6c8
This commit is contained in:
Enrico Forestieri 2009-09-05 16:39:33 +00:00
parent d7e7780f02
commit 9919ec3625
2 changed files with 124 additions and 76 deletions

View File

@ -93,43 +93,59 @@ private:
namespace {
char * errormsg()
string errormsg(DWORD const error)
{
void * msgbuf;
DWORD error = GetLastError();
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, error, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &msgbuf, 0, NULL);
return static_cast<char *>(msgbuf);
}
extern "C" {
DWORD WINAPI pipeServerWrapper(void * arg)
{
LyXComm * lyxcomm = reinterpret_cast<LyXComm *>(arg);
lyxcomm->pipeServer();
return 1;
}
string message;
if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, error,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &msgbuf, 0, NULL)) {
message = static_cast<char *>(msgbuf);
LocalFree(msgbuf);
} else
message = "Unknown error";
return message;
}
} // namespace anon
DWORD WINAPI pipeServerWrapper(void * arg)
{
LyXComm * lyxcomm = reinterpret_cast<LyXComm *>(arg);
if (!lyxcomm->pipeServer()) {
// Error exit; perform cleanup.
lyxcomm->ready_ = false;
lyxcomm->closeHandles();
CloseHandle(lyxcomm->server_thread_);
CloseHandle(lyxcomm->stopserver_);
CloseHandle(lyxcomm->outbuf_mutex_);
lyxerr << "LyXComm: Closing connection" << endl;
}
return 1;
}
LyXComm::LyXComm(string const & pip, Server * cli, ClientCallbackfct ccb)
: pipename_(pip), client_(cli), clientcb_(ccb), stopserver_(0)
{
for (int i = 0; i < MAX_PIPES; ++i) {
event_[i] = 0;
pipe_[i].handle = INVALID_HANDLE_VALUE;
}
ready_ = false;
openConnection();
}
void LyXComm::pipeServer()
bool LyXComm::pipeServer()
{
DWORD i;
DWORD error;
for (i = 0; i < MAX_PIPES; ++i) {
bool const is_outpipe = i >= MAX_CLIENTS;
@ -140,11 +156,11 @@ void LyXComm::pipeServer()
// Manual-reset event, initial state = signaled
event_[i] = CreateEvent(NULL, TRUE, TRUE, NULL);
if (!event_[i]) {
error = GetLastError();
lyxerr << "LyXComm: Could not create event for pipe "
<< pipename.c_str() << "\nLyXComm: "
<< errormsg() << endl;
closeHandles(i);
return;
<< pipename << "\nLyXComm: "
<< errormsg(error) << endl;
return false;
}
pipe_[i].overlap.hEvent = event_[i];
@ -155,14 +171,15 @@ void LyXComm::pipeServer()
PIPE_TIMEOUT, NULL);
if (pipe_[i].handle == INVALID_HANDLE_VALUE) {
error = GetLastError();
lyxerr << "LyXComm: Could not create pipe "
<< pipename.c_str() << "\nLyXComm: "
<< errormsg() << endl;
closeHandles(i);
return;
<< pipename << "\nLyXComm: "
<< errormsg(error) << endl;
return false;
}
startPipe(i);
if (!startPipe(i))
return false;
pipe_[i].state = pipe_[i].pending_io ?
CONNECTING_STATE : (is_outpipe ? WRITING_STATE
: READING_STATE);
@ -203,9 +220,11 @@ void LyXComm::pipeServer()
case CONNECTING_STATE:
// Pending connect operation
if (!success) {
error = GetLastError();
lyxerr << "LyXComm: "
<< errormsg() << endl;
resetPipe(i, true);
<< errormsg(error) << endl;
if (!resetPipe(i, true))
return false;
continue;
}
pipe_[i].state = is_outpipe ? WRITING_STATE
@ -216,7 +235,8 @@ void LyXComm::pipeServer()
// Pending read operation
LASSERT(!is_outpipe, /**/);
if (!success || status == 0) {
resetPipe(i);
if (!resetPipe(i, !success))
return false;
continue;
}
pipe_[i].nbytes = status;
@ -267,24 +287,28 @@ void LyXComm::pipeServer()
continue;
}
if (!success && GetLastError() == ERROR_IO_PENDING) {
error = GetLastError();
if (!success && error == ERROR_IO_PENDING) {
// The read operation is still pending.
pipe_[i].pending_io = true;
continue;
}
success = error == ERROR_BROKEN_PIPE;
// Client closed connection (ERROR_BROKEN_PIPE) or
// an error occurred; in either case, reset the pipe.
if (GetLastError() != ERROR_BROKEN_PIPE) {
lyxerr << "LyXComm: " << errormsg() << endl;
if (!success) {
lyxerr << "LyXComm: " << errormsg(error) << endl;
if (!pipe_[i].iobuf.empty()) {
lyxerr << "LyXComm: truncated command: "
<< pipe_[i].iobuf << endl;
pipe_[i].iobuf.erase();
}
resetPipe(i, true);
} else
resetPipe(i);
}
if (!resetPipe(i, !success))
return false;
break;
case WRITING_STATE:
@ -318,11 +342,14 @@ void LyXComm::pipeServer()
// The write operation completed successfully.
pipe_[i].iobuf.erase();
pipe_[i].pending_io = false;
resetPipe(i);
if (!resetPipe(i))
return false;
continue;
}
if (GetLastError() == ERROR_IO_PENDING) {
error = GetLastError();
if (success && error == ERROR_IO_PENDING) {
// The write operation is still pending.
// We get here when a reader is started
// well before a reply is ready, so delay
@ -332,33 +359,39 @@ void LyXComm::pipeServer()
continue;
}
success = error == ERROR_NO_DATA;
// Client closed connection (ERROR_NO_DATA) or
// an error occurred; in either case, reset the pipe.
if (GetLastError() != ERROR_NO_DATA) {
if (!success) {
lyxerr << "LyXComm: Error sending message: "
<< pipe_[i].iobuf << "\nLyXComm: "
<< errormsg() << endl;
resetPipe(i, true);
} else
resetPipe(i);
<< errormsg(error) << endl;
}
if (!resetPipe(i, !success))
return false;
break;
}
}
ready_ = false;
closeHandles(MAX_PIPES - 1);
closeHandles();
return true;
}
void LyXComm::closeHandles(DWORD index)
void LyXComm::closeHandles()
{
for (int i = 0; i <= int(index); ++i) {
for (int i = 0; i < MAX_PIPES; ++i) {
if (event_[i]) {
ResetEvent(event_[i]);
CloseHandle(event_[i]);
event_[i] = 0;
}
if (pipe_[i].handle != INVALID_HANDLE_VALUE)
if (pipe_[i].handle != INVALID_HANDLE_VALUE) {
CloseHandle(pipe_[i].handle);
pipe_[i].handle = INVALID_HANDLE_VALUE;
}
}
}
@ -373,23 +406,23 @@ bool LyXComm::event(QEvent * e)
}
BOOL LyXComm::checkStopServer()
bool LyXComm::checkStopServer()
{
return WaitForSingleObject(stopserver_, 0) == WAIT_OBJECT_0;
}
void LyXComm::startPipe(DWORD index)
bool LyXComm::startPipe(DWORD index)
{
pipe_[index].pending_io = false;
// Overlapped ConnectNamedPipe should return zero.
if (ConnectNamedPipe(pipe_[index].handle, &pipe_[index].overlap)) {
// FIXME: What to do? Maybe the pipe server should be reset.
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not connect pipe "
<< external_path(pipeName(index))
<< "\nLyXComm: " << errormsg() << endl;
return;
<< "\nLyXComm: " << errormsg(error) << endl;
return false;
}
switch (GetLastError()) {
@ -402,26 +435,31 @@ void LyXComm::startPipe(DWORD index)
// Client is already connected, so signal an event.
if (SetEvent(pipe_[index].overlap.hEvent))
break;
// fall through
default:
// Anything else is an error.
// FIXME: What to do? Maybe the pipe server should be reset.
DWORD const error = GetLastError();
lyxerr << "LyXComm: An error occurred while connecting pipe "
<< external_path(pipeName(index))
<< "\nLyXComm: " << errormsg() << endl;
<< "\nLyXComm: " << errormsg(error) << endl;
return false;
}
return true;
}
void LyXComm::resetPipe(DWORD index, bool close_handle)
bool LyXComm::resetPipe(DWORD index, bool close_handle)
{
// This method is called when an error occurs or when a client
// closes the connection. We first disconnect the pipe instance,
// then reconnect it, ready to wait for another client.
if (!DisconnectNamedPipe(pipe_[index].handle)) {
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not disconnect pipe "
<< external_path(pipeName(index))
<< "\nLyXComm: " << errormsg() << endl;
<< "\nLyXComm: " << errormsg(error) << endl;
// What to do now? Let's try whether re-creating the pipe helps.
close_handle = true;
}
@ -442,16 +480,19 @@ void LyXComm::resetPipe(DWORD index, bool close_handle)
PIPE_TIMEOUT, NULL);
if (pipe_[index].handle == INVALID_HANDLE_VALUE) {
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not reset pipe " << name
<< "\nLyXComm: " << errormsg() << endl;
return;
<< "\nLyXComm: " << errormsg(error) << endl;
return false;
}
}
startPipe(index);
if (!startPipe(index))
return false;
pipe_[index].state = pipe_[index].pending_io ?
CONNECTING_STATE : (is_outpipe ? WRITING_STATE
: READING_STATE);
return true;
}
@ -464,8 +505,6 @@ void LyXComm::openConnection()
LYXERR(Debug::LYXSERVER, "LyXComm: Already connected");
return;
}
// We assume that we don't make it
ready_ = false;
if (pipename_.empty()) {
LYXERR(Debug::LYXSERVER, "LyXComm: server is disabled, nothing to do");
@ -484,8 +523,9 @@ void LyXComm::openConnection()
// Mutex with no initial owner for synchronized access to outbuf_
outbuf_mutex_ = CreateMutex(NULL, FALSE, NULL);
if (!outbuf_mutex_) {
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not create output buffer mutex"
<< "\nLyXComm: " << errormsg() << endl;
<< "\nLyXComm: " << errormsg(error) << endl;
pipename_.erase();
return;
}
@ -493,8 +533,9 @@ void LyXComm::openConnection()
// Manual-reset event, initial state = not signaled
stopserver_ = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!stopserver_) {
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not create stop server event"
<< "\nLyXComm: " << errormsg() << endl;
<< "\nLyXComm: " << errormsg(error) << endl;
pipename_.erase();
CloseHandle(outbuf_mutex_);
return;
@ -503,8 +544,9 @@ void LyXComm::openConnection()
server_thread_ = CreateThread(NULL, 0, pipeServerWrapper,
static_cast<void *>(this), 0, NULL);
if (!server_thread_) {
DWORD const error = GetLastError();
lyxerr << "LyXComm: Could not create pipe server thread"
<< "\nLyXComm: " << errormsg() << endl;
<< "\nLyXComm: " << errormsg(error) << endl;
pipename_.erase();
CloseHandle(stopserver_);
CloseHandle(outbuf_mutex_);
@ -544,8 +586,11 @@ void LyXComm::emergencyCleanup()
SetEvent(stopserver_);
// Forcibly terminate the pipe server thread if it does
// not finish quickly.
if (WaitForSingleObject(server_thread_, 200) != WAIT_OBJECT_0)
if (WaitForSingleObject(server_thread_, 200) != WAIT_OBJECT_0) {
TerminateThread(server_thread_, 0);
ready_ = false;
closeHandles();
}
CloseHandle(server_thread_);
ResetEvent(stopserver_);
CloseHandle(stopserver_);
@ -613,9 +658,10 @@ void LyXComm::send(string const & msg)
ReleaseMutex(outbuf_mutex_);
} else {
// Something is fishy, better resetting the connection.
DWORD const error = GetLastError();
lyxerr << "LyXComm: Error sending message: " << msg
<< "\nLyXComm: " << errormsg()
<< "LyXComm: Resetting connection" << endl;
<< "\nLyXComm: " << errormsg(error)
<< "\nLyXComm: Resetting connection" << endl;
ReleaseMutex(outbuf_mutex_);
closeConnection();
if (!checkStopServer())

View File

@ -42,6 +42,8 @@ class LyXComm : public boost::signals::trackable {
class LyXComm : public QObject {
Q_OBJECT
friend DWORD pipeServerWrapper(void *);
public:
/// Max number of clients
enum { MAX_CLIENTS = 10 };
@ -98,9 +100,6 @@ public:
void read_ready();
#else
void read_ready(DWORD);
/// The pipe server
void pipeServer();
#endif
private:
@ -129,20 +128,23 @@ private:
/// This is -1 if not open
int outfd_;
#else
/// The pipe server returns false when exiting due to an error
bool pipeServer();
/// Start an overlapped connection
void startPipe(DWORD);
bool startPipe(DWORD);
/// Reset an overlapped connection
void resetPipe(DWORD, bool close_handle = false);
bool resetPipe(DWORD, bool close_handle = false);
/// Close event and pipe handles
void closeHandles(DWORD);
void closeHandles();
/// Catch pipe ready-to-be-read notification
bool event(QEvent *);
/// Check whether the pipe server must be stopped
BOOL checkStopServer();
bool checkStopServer();
/// The filename of a (in or out) pipe instance
std::string const pipeName(DWORD) const;