size_t
BufferedStream::readInternal(T &buffer, size_t length)
{
if (supportsSeek())
flush(false);
size_t remaining = length;
size_t buffered = std::min(m_readBuffer.readAvailable(), remaining);
m_readBuffer.copyOut(buffer, buffered);
m_readBuffer.consume(buffered);
remaining -= buffered;
MORDOR_LOG_VERBOSE(g_log) << this << " read(" << length << "): "
<< buffered << " read from buffer";
if (remaining == 0)
return length;
if (buffered == 0 || !m_allowPartialReads) {
size_t result;
do {
// Read enough to satisfy this request, plus up to a multiple of
// the buffer size
size_t todo = ((remaining - 1) / m_bufferSize + 1) * m_bufferSize;
try {
MORDOR_LOG_TRACE(g_log) << this << " parent()->read(" << todo
<< ")";
result = parent()->read(m_readBuffer, todo);
MORDOR_LOG_DEBUG(g_log) << this << " parent()->read(" << todo
<< "): " << result;
} catch (...) {
if (remaining == length) {
MORDOR_LOG_VERBOSE(g_log) << this << " forwarding exception";
throw;
} else {
MORDOR_LOG_VERBOSE(g_log) << this << " swallowing exception";
// Swallow the exception
return length - remaining;
}
}
buffered = std::min(m_readBuffer.readAvailable(), remaining);
m_readBuffer.copyOut(buffer, buffered);
m_readBuffer.consume(buffered);
advance(buffer, buffered);
remaining -= buffered;
} while (remaining > 0 && !m_allowPartialReads && result != 0);
}
return length - remaining;
}
void
IOManagerEPoll::tickle()
{
int rc = write(m_tickleFds[1], "T", 1);
MORDOR_LOG_VERBOSE(g_log) << this << " write(" << m_tickleFds[1] << ", 1): "
<< rc << " (" << errno << ")";
MORDOR_VERIFY(rc == 1);
}
IOManagerEPoll::~IOManagerEPoll()
{
stop();
close(m_epfd);
MORDOR_LOG_TRACE(g_log) << this << " close(" << m_epfd << ")";
close(m_tickleFds[0]);
MORDOR_LOG_VERBOSE(g_log) << this << " close(" << m_tickleFds[0] << ")";
close(m_tickleFds[1]);
}
size_t
BufferedStream::flushWrite(size_t length)
{
while (m_writeBuffer.readAvailable() >= m_bufferSize)
{
size_t result;
try {
if (m_readBuffer.readAvailable() && supportsSeek()) {
parent()->seek(-(long long)m_readBuffer.readAvailable(), CURRENT);
m_readBuffer.clear();
}
size_t toWrite = m_writeBuffer.readAvailable();
if (m_flushMultiplesOfBuffer)
toWrite = toWrite / m_bufferSize * m_bufferSize;
MORDOR_LOG_TRACE(g_log) << this << " parent()->write("
<< m_writeBuffer.readAvailable() << ")";
result = parent()->write(m_writeBuffer, toWrite);
MORDOR_LOG_DEBUG(g_log) << this << " parent()->write("
<< m_writeBuffer.readAvailable() << "): " << result;
m_writeBuffer.consume(result);
} catch (...) {
// If this entire write is still in our buffer,
// back it out and report the error
if (m_writeBuffer.readAvailable() >= length) {
MORDOR_LOG_VERBOSE(g_log) << this << " forwarding exception";
Buffer tempBuffer;
tempBuffer.copyIn(m_writeBuffer, m_writeBuffer.readAvailable()
- length);
m_writeBuffer.clear();
m_writeBuffer.copyIn(tempBuffer);
throw;
} else {
// Otherwise we have to say we succeeded,
// because we're not allowed to have a partial
// write, and we can't report an error because
// the caller will think he needs to repeat
// the entire write
MORDOR_LOG_VERBOSE(g_log) << this << " swallowing exception";
return length;
}
}
}
return length;
}
long long
HandleStream::size()
{
SchedulerSwitcher switcher(m_scheduler);
long long size;
BOOL ret = GetFileSizeEx(m_hFile, (LARGE_INTEGER*)&size);
DWORD error = GetLastError();
MORDOR_LOG_VERBOSE(g_log) << this << " GetFileSizeEx(" << m_hFile << ", "
<< size << "): " << ret << " (" << error << ")";
if (!ret)
MORDOR_THROW_EXCEPTION_FROM_ERROR_API(error, "GetFileSizeEx");
return size;
}
void
BufferedStream::close(CloseType type)
{
MORDOR_LOG_VERBOSE(g_log) << this << " close(" << type << ")";
if (type & READ)
m_readBuffer.clear();
try {
if ((type & WRITE) && m_writeBuffer.readAvailable())
flush(false);
} catch (...) {
if (ownsParent())
parent()->close(type);
throw;
}
if (ownsParent())
parent()->close(type);
}
void
Scheduler::start()
{
MORDOR_LOG_VERBOSE(g_log) << this << " starting " << m_threadCount << " threads";
boost::mutex::scoped_lock lock(m_mutex);
if (!m_stopping)
return;
// TODO: There may be a race condition here if one thread calls stop(),
// and another thread calls start() before the worker threads for this
// scheduler actually exit; they may resurrect themselves, and the stopping
// thread would block waiting for the thread to exit
m_stopping = false;
MORDOR_ASSERT(m_threads.empty());
m_threads.resize(m_threadCount);
for (size_t i = 0; i < m_threadCount; ++i) {
m_threads[i] = boost::shared_ptr<Thread>(new Thread(
boost::bind(&Scheduler::run, this)));
}
}
void
Scheduler::stop()
{
// Already stopped
if (m_rootFiber &&
m_threadCount == 0 &&
(m_rootFiber->state() == Fiber::TERM || m_rootFiber->state() == Fiber::INIT)) {
MORDOR_LOG_VERBOSE(g_log) << this << " stopped";
m_stopping = true;
// A derived class may inhibit stopping while it has things to do in
// its idle loop, so we can't break early
if (stopping())
return;
}
bool exitOnThisFiber = false;
if (m_rootThread != emptytid()) {
// A thread-hijacking scheduler must be stopped
// from within itself to return control to the
// original thread
MORDOR_ASSERT(Scheduler::getThis() == this);
if (Fiber::getThis() == m_callingFiber) {
exitOnThisFiber = true;
// First switch to the correct thread
MORDOR_LOG_DEBUG(g_log) << this
<< " switching to root thread to stop";
switchTo(m_rootThread);
}
if (!m_callingFiber)
exitOnThisFiber = true;
} else {
// A spawned-threads only scheduler cannot be stopped from within
// itself... who would get control?
MORDOR_ASSERT(Scheduler::getThis() != this);
}
m_stopping = true;
for (size_t i = 0; i < m_threadCount; ++i)
tickle();
if (m_rootFiber && (m_threadCount != 0u || Scheduler::getThis() != this))
tickle();
// Wait for all work to stop on this thread
if (exitOnThisFiber) {
while (!stopping()) {
// Give this thread's run fiber a chance to kill itself off
MORDOR_LOG_DEBUG(g_log) << this
<< " yielding to this thread to stop";
yieldTo(true);
}
}
// Wait for other threads to stop
if (exitOnThisFiber ||
Scheduler::getThis() != this) {
MORDOR_LOG_DEBUG(g_log) << this
<< " waiting for other threads to stop";
std::vector<boost::shared_ptr<Thread> > threads;
{
boost::mutex::scoped_lock lock(m_mutex);
threads.swap(m_threads);
}
for (std::vector<boost::shared_ptr<Thread> >::const_iterator it
(threads.begin());
it != threads.end();
++it) {
(*it)->join();
}
}
MORDOR_LOG_VERBOSE(g_log) << this << " stopped";
}
void
Scheduler::run()
{
t_scheduler = this;
if (gettid() != m_rootThread) {
// Running in own thread
t_fiber = Fiber::getThis().get();
} else {
// Hijacked a thread
MORDOR_ASSERT(t_fiber.get() == Fiber::getThis().get());
}
Fiber::ptr idleFiber(new Fiber(boost::bind(&Scheduler::idle, this)));
MORDOR_LOG_VERBOSE(g_log) << this << " starting thread with idle fiber " << idleFiber;
Fiber::ptr dgFiber;
// use a vector for O(1) .size()
std::vector<FiberAndThread> batch(m_batchSize);
bool isActive = false;
while (true) {
batch.clear();
bool dontIdle = false;
bool tickleMe = false;
{
boost::mutex::scoped_lock lock(m_mutex);
// Kill ourselves off if needed
if (m_threads.size() > m_threadCount && gettid() != m_rootThread) {
// Accounting
if (isActive)
--m_activeThreadCount;
// Kill off the idle fiber
try {
throw boost::enable_current_exception(
OperationAbortedException());
} catch(...) {
idleFiber->inject(boost::current_exception());
}
// Detach our thread
for (std::vector<boost::shared_ptr<Thread> >
::iterator it = m_threads.begin();
it != m_threads.end();
++it)
if ((*it)->tid() == gettid()) {
m_threads.erase(it);
if (m_threads.size() > m_threadCount)
tickle();
return;
}
MORDOR_NOTREACHED();
}
std::list<FiberAndThread>::iterator it(m_fibers.begin());
while (it != m_fibers.end()) {
// If we've met our batch size, and we're not checking to see
// if we need to tickle another thread, then break
if ( (tickleMe || m_activeThreadCount == threadCount()) &&
batch.size() == m_batchSize)
break;
if (it->thread != emptytid() && it->thread != gettid()) {
MORDOR_LOG_DEBUG(g_log) << this
<< " skipping item scheduled for thread "
<< it->thread;
// Wake up another thread to hopefully service this
tickleMe = true;
dontIdle = true;
++it;
continue;
}
MORDOR_ASSERT(it->fiber || it->dg);
// This fiber is still executing; probably just some race
// race condition that it needs to yield on one thread
// before running on another thread
if (it->fiber && it->fiber->state() == Fiber::EXEC) {
MORDOR_LOG_DEBUG(g_log) << this
<< " skipping executing fiber " << it->fiber;
++it;
dontIdle = true;
continue;
}
// We were just checking if there is more work; there is, so
// set the flag and don't actually take this piece of work
if (batch.size() == m_batchSize) {
tickleMe = true;
break;
}
batch.push_back(*it);
it = m_fibers.erase(it);
if (!isActive) {
++m_activeThreadCount;
isActive = true;
}
}
if (batch.empty() && isActive) {
--m_activeThreadCount;
isActive = false;
}
}
if (tickleMe)
tickle();
MORDOR_LOG_DEBUG(g_log) << this
<< " got " << batch.size() << " fiber/dgs to process (max: "
<< m_batchSize << ", active: " << isActive << ")";
MORDOR_ASSERT(isActive == !batch.empty());
if (!batch.empty()) {
std::vector<FiberAndThread>::iterator it;
for (it = batch.begin(); it != batch.end(); ++it) {
Fiber::ptr f = it->fiber;
boost::function<void ()> dg = it->dg;
try {
if (f && f->state() != Fiber::TERM) {
MORDOR_LOG_DEBUG(g_log) << this << " running " << f;
f->yieldTo();
} else if (dg) {
if (!dgFiber)
dgFiber.reset(new Fiber(dg));
dgFiber->reset(dg);
MORDOR_LOG_DEBUG(g_log) << this << " running " << dg;
dgFiber->yieldTo();
if (dgFiber->state() != Fiber::TERM)
dgFiber.reset();
else
dgFiber->reset(NULL);
}
} catch (...) {
MORDOR_LOG_FATAL(Log::root())
<< boost::current_exception_diagnostic_information();
throw;
}
}
continue;
}
if (dontIdle)
continue;
if (idleFiber->state() == Fiber::TERM) {
MORDOR_LOG_DEBUG(g_log) << this << " idle fiber terminated";
if (gettid() == m_rootThread)
m_callingFiber.reset();
// Unblock the next thread
if (threadCount() > 1)
tickle();
return;
}
MORDOR_LOG_DEBUG(g_log) << this << " idling";
idleFiber->call();
}
}
Result
PreparedStatement::execute()
{
PGconn *conn = m_conn.lock().get();
boost::shared_ptr<PGresult> result, next;
int nParams = (int)m_params.size();
Oid *paramTypes = NULL;
int *paramLengths = NULL, *paramFormats = NULL;
const char **params = NULL;
if (nParams) {
if (m_name.empty())
paramTypes = &m_paramTypes[0];
params = &m_params[0];
paramLengths = &m_paramLengths[0];
paramFormats = &m_paramFormats[0];
}
const char *api = NULL;
#ifndef WINDOWS
SchedulerSwitcher switcher(m_scheduler);
#endif
if (m_name.empty()) {
#ifndef WINDOWS
if (m_scheduler) {
api = "PQsendQueryParams";
if (!PQsendQueryParams(conn, m_command.c_str(),
nParams, paramTypes, params, paramLengths, paramFormats, m_resultFormat))
throwException(conn);
flush(conn, m_scheduler);
next.reset(nextResult(conn, m_scheduler), &PQclear);
while (next) {
result = next;
next.reset(nextResult(conn, m_scheduler), &PQclear);
if (next) {
ExecStatusType status = PQresultStatus(next.get());
MORDOR_LOG_VERBOSE(g_log) << conn << "PQresultStatus(" <<
next.get() << "): " << PQresStatus(status);
switch (status) {
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
break;
default:
throwException(next.get());
MORDOR_NOTREACHED();
}
}
}
} else
#endif
{
api = "PQexecParams";
result.reset(PQexecParams(conn, m_command.c_str(),
nParams, paramTypes, params, paramLengths, paramFormats, m_resultFormat),
&PQclear);
}
} else {
#ifndef WINDOWS
if (m_scheduler) {
api = "PQsendQueryPrepared";
if (!PQsendQueryPrepared(conn, m_name.c_str(),
nParams, params, paramLengths, paramFormats, 1))
throwException(conn);
flush(conn, m_scheduler);
next.reset(nextResult(conn, m_scheduler), &PQclear);
while (next) {
result = next;
next.reset(nextResult(conn, m_scheduler), &PQclear);
if (next) {
ExecStatusType status = PQresultStatus(next.get());
MORDOR_LOG_VERBOSE(g_log) << conn << "PQresultStatus(" <<
next.get() << "): " << PQresStatus(status);
switch (status) {
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
break;
default:
throwException(next.get());
MORDOR_NOTREACHED();
}
}
}
} else
#endif
{
api = "PQexecPrepared";
result.reset(PQexecPrepared(conn, m_name.c_str(),
nParams, params, paramLengths, paramFormats, m_resultFormat),
&PQclear);
}
}
if (!result)
throwException(conn);
ExecStatusType status = PQresultStatus(result.get());
MORDOR_ASSERT(api);
MORDOR_LOG_VERBOSE(g_log) << conn << " " << api << "(\"" << m_command
<< m_name << "\", " << nParams << "), PQresultStatus(" << result.get()
<< "): " << PQresStatus(status);
switch (status) {
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
return Result(result);
default:
throwException(result.get());
MORDOR_NOTREACHED();
}
}
void
IOManagerEPoll::idle()
{
epoll_event events[64];
while (true) {
unsigned long long nextTimeout;
if (stopping(nextTimeout))
return;
int rc = -1;
errno = EINTR;
while (rc < 0 && errno == EINTR) {
int timeout = -1;
if (nextTimeout != ~0ull)
timeout = (int)(nextTimeout / 1000) + 1;
rc = epoll_wait(m_epfd, events, 64, timeout);
if (rc < 0 && errno == EINTR)
nextTimeout = nextTimer();
}
MORDOR_LOG_LEVEL(g_log, rc < 0 ? Log::ERROR : Log::VERBOSE) << this
<< " epoll_wait(" << m_epfd << "): " << rc << " (" << errno << ")";
if (rc < 0)
MORDOR_THROW_EXCEPTION_FROM_LAST_ERROR_API("epoll_wait");
std::vector<boost::function<void ()> > expired = processTimers();
schedule(expired.begin(), expired.end());
for(int i = 0; i < rc; ++i) {
epoll_event &event = events[i];
if (event.data.fd == m_tickleFds[0]) {
unsigned char dummy;
int rc2 = read(m_tickleFds[0], &dummy, 1);
MORDOR_VERIFY(rc2 == 1);
MORDOR_LOG_VERBOSE(g_log) << this << " received tickle";
continue;
}
bool err = event.events & (EPOLLERR | EPOLLHUP);
boost::mutex::scoped_lock lock(m_mutex);
std::map<int, AsyncEvent>::iterator it =
m_pendingEvents.find(event.data.fd);
if (it == m_pendingEvents.end())
continue;
AsyncEvent &e = it->second;
MORDOR_LOG_TRACE(g_log) << " epoll_event {"
<< (epoll_events_t)event.events << ", " << event.data.fd
<< "}, registered for " << (epoll_events_t)e.event.events;
if ((event.events & EPOLLERR) && (e.event.events & EPOLLERR)) {
if (e.m_dgError)
e.m_schedulerError->schedule(e.m_dgError);
else
e.m_schedulerError->schedule(e.m_fiberError);
// Block other events from firing
e.m_dgError = NULL;
e.m_fiberError.reset();
e.m_dgIn = NULL;
e.m_fiberIn.reset();
e.m_dgOut = NULL;
e.m_fiberOut.reset();
event.events = 0;
e.event.events = 0;
}
if ((event.events & EPOLLHUP) && (e.event.events & EPOLLHUP)) {
if (e.m_dgClose)
e.m_schedulerError->schedule(e.m_dgClose);
else
e.m_schedulerError->schedule(e.m_fiberClose);
// Block write event from firing
e.m_dgOut = NULL;
e.m_fiberOut.reset();
e.m_dgClose = NULL;
e.m_fiberClose.reset();
event.events &= EPOLLOUT;
e.event.events &= EPOLLOUT;
err = false;
}
if (((event.events & EPOLLIN) ||
err) && (e.event.events & EPOLLIN)) {
if (e.m_dgIn)
e.m_schedulerIn->schedule(e.m_dgIn);
else
e.m_schedulerIn->schedule(e.m_fiberIn);
e.m_dgIn = NULL;
e.m_fiberIn.reset();
event.events |= EPOLLIN;
}
if (((event.events & EPOLLOUT) ||
err) && (e.event.events & EPOLLOUT)) {
if (e.m_dgOut)
e.m_schedulerOut->schedule(e.m_dgOut);
else
e.m_schedulerOut->schedule(e.m_fiberOut);
e.m_dgOut = NULL;
e.m_fiberOut.reset();
event.events |= EPOLLOUT;
}
e.event.events &= ~event.events;
int op = e.event.events == 0 ? EPOLL_CTL_DEL : EPOLL_CTL_MOD;
int rc2 = epoll_ctl(m_epfd, op, event.data.fd,
&e.event);
MORDOR_LOG_LEVEL(g_log, rc2 ? Log::ERROR : Log::VERBOSE) << this
<< " epoll_ctl(" << m_epfd << ", " << (epoll_ctl_op_t)op << ", "
<< event.data.fd << ", " << (epoll_events_t)e.event.events << "): " << rc2
<< " (" << errno << ")";
if (rc2)
MORDOR_THROW_EXCEPTION_FROM_LAST_ERROR_API("epoll_ctl");
if (op == EPOLL_CTL_DEL)
m_pendingEvents.erase(it);
}
Fiber::yield();
}
}
