Cleanup of wxSocket::_Wait():

- Rename to DoWait() to avoid symbols starting with underscores.
 - Added comments explaining how does it work.
 - Remove the pointless timeout manipulations: GSocket::Select() doesn't
   use timeout (any more?) anyhow.

Also pass GSOCK_LOST_FLAG to DoWait() from WaitForWrite() for the same reasons
it is done in WaitForRead().


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56275 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
2008-10-13 13:00:49 +00:00
parent 551266a969
commit 60ee017274
2 changed files with 120 additions and 113 deletions

View File

@@ -137,12 +137,26 @@ public:
wxSocketBase& Write(const void *buffer, wxUint32 nbytes);
wxSocketBase& WriteMsg(const void *buffer, wxUint32 nbytes);
void InterruptWait() { m_interrupt = true; }
// all Wait() functions wait until their condition is satisfied or the
// timeout expires; if seconds == -1 (default) then m_timeout value is used
//
// it is also possible to call InterruptWait() to cancel any current Wait()
// wait for anything at all to happen with this socket
bool Wait(long seconds = -1, long milliseconds = 0);
// wait until we can read from or write to the socket without blocking
// (notice that this does not mean that the operation will succeed but only
// that it will return immediately)
bool WaitForRead(long seconds = -1, long milliseconds = 0);
bool WaitForWrite(long seconds = -1, long milliseconds = 0);
// wait until the connection is terminated
bool WaitForLost(long seconds = -1, long milliseconds = 0);
void InterruptWait() { m_interrupt = true; }
wxSocketFlags GetFlags() const { return m_flags; }
void SetFlags(wxSocketFlags flags);
void SetTimeout(long seconds);
@@ -182,7 +196,17 @@ private:
// low level IO
wxUint32 _Read(void* buffer, wxUint32 nbytes);
wxUint32 _Write(const void *buffer, wxUint32 nbytes);
bool _Wait(long seconds, long milliseconds, wxSocketEventFlags flags);
// wait until the given flags are set for this socket or the given timeout
// (or m_timeout) expires
//
// notice that GSOCK_LOST_FLAG is always taken into account but the return
// value depends on whether it is included in flags or not: if it is, and the
// connection is indeed lost, true is returned, but if it isn't then the
// function returns false in this case
//
// false is always returned if we returned because of the timeout expiration
bool DoWait(long seconds, long milliseconds, wxSocketEventFlags flags);
// pushback buffer
void Pushback(const void *buffer, wxUint32 size);
@@ -203,7 +227,7 @@ private:
bool m_closed; // was the other end closed?
// (notice that m_error is also set then)
wxUint32 m_lcount; // last IO transaction size
unsigned long m_timeout; // IO timeout value
unsigned long m_timeout; // IO timeout value in seconds
wxList m_states; // stack of states
bool m_interrupt; // interrupt ongoing wait operations?
bool m_beingDeleted; // marked for delayed deletion?

View File

@@ -714,75 +714,65 @@ wxSocketBase& wxSocketBase::Discard()
// timeout elapses. The polling loop runs the event loop so that
// this won't block the GUI.
bool wxSocketBase::_Wait(long seconds,
long milliseconds,
wxSocketEventFlags flags)
bool
wxSocketBase::DoWait(long seconds, long milliseconds, wxSocketEventFlags flags)
{
GSocketEventFlags result;
long timeout; // in ms
wxCHECK_MSG( m_socket, false, "can't wait on invalid socket" );
// Set this to true to interrupt ongoing waits
// This can be set to true from Interrupt() to exit this function a.s.a.p.
m_interrupt = false;
// Check for valid socket
if (!m_socket)
return false;
// Check for valid timeout value.
if (seconds != -1)
timeout = seconds * 1000 + milliseconds;
else
timeout = m_timeout * 1000;
// Use either the provided timeout or the default timeout value associated
// with this socket.
//
// TODO: allow waiting forever, see #9443
const long timeout = seconds == -1 ? m_timeout * 1000
: seconds * 1000 + milliseconds;
const wxMilliClock_t timeEnd = wxGetLocalTimeMillis() + timeout;
// Get the active event loop
wxEventLoopBase * const eventLoop = wxEventLoop::GetActive();
// Get the active event loop which we'll use for the message dispatching
// when running in the main thread
wxEventLoopBase *eventLoop;
if ( wxIsMainThread() )
{
eventLoop = wxEventLoop::GetActive();
#ifdef __WXMSW__
wxASSERT_MSG( !wxIsMainThread() || eventLoop,
wxASSERT_MSG( eventLoop,
"Sockets won't work without a running event loop" );
#endif // __WXMSW__
// Wait in an active polling loop.
//
// NOTE: We duplicate some of the code in OnRequest, but this doesn't
// hurt. It has to be here because the (GSocket) event might arrive
// a bit delayed, and it has to be in OnRequest as well because we
// don't know whether the Wait functions are being used.
//
// Do this at least once (important if timeout == 0, when
// we are just polling). Also, if just polling, do not yield.
const wxMilliClock_t time_limit = wxGetLocalTimeMillis() + timeout;
bool done = false;
bool valid_result = false;
if (!eventLoop)
}
else // in worker thread
{
// This is used to avoid a busy loop on wxBase - having a select
// timeout of 50 ms per iteration should be enough.
if (timeout > 50)
m_socket->SetTimeout(50);
else
m_socket->SetTimeout(timeout);
// We never dispatch messages from threads other than the main one.
eventLoop = NULL;
}
while (!done)
// Wait in an active polling loop: notice that the loop is executed at
// least once, even if timeout is 0 (i.e. polling).
bool gotEvent = false;
for ( ;; )
{
// We always stop waiting when the connection is lost as it doesn't
// make sense to continue further, even if GSOCK_LOST_FLAG is not
// specified in flags to wait for.
const GSocketEventFlags
result = m_socket->Select(flags | GSOCK_LOST_FLAG);
// Incoming connection (server) or connection established (client)
// Incoming connection (server) or connection established (client)?
if ( result & GSOCK_CONNECTION_FLAG )
{
m_connected = true;
m_establishing = false;
valid_result = true;
gotEvent = true;
break;
}
// Data available or output buffer ready
// Data available or output buffer ready?
if ( (result & GSOCK_INPUT_FLAG) || (result & GSOCK_OUTPUT_FLAG) )
{
valid_result = true;
gotEvent = true;
break;
}
@@ -791,83 +781,73 @@ bool wxSocketBase::_Wait(long seconds,
{
m_connected = false;
m_establishing = false;
valid_result = ((flags & GSOCK_LOST_FLAG) != 0);
if ( flags & GSOCK_LOST_FLAG )
gotEvent = true;
break;
}
if ( m_interrupt )
break;
// Wait more?
long time_left = wxMilliClockToLong(time_limit - wxGetLocalTimeMillis());
if ((!timeout) || (time_left <= 0) || (m_interrupt))
done = true;
else
{
const wxMilliClock_t timeNow = wxGetLocalTimeMillis();
if ( timeNow >= timeEnd )
break;
if ( eventLoop )
{
// from the main thread itself we have to run the event loop to
// let the events (including the GUI events and the low-level
// (not wxWidgets) events from GSocket) be processed but from
// another thread it is enough to just call wxThread::Yield()
// which will give away the rest of our time slice: the
// explanation is that the events will be processed by the main
// thread anyhow, but we don't want to eat the CPU time
// uselessly while sitting in the loop waiting for the data
if ( wxIsMainThread() )
{
// Dispatch the events when we run in the main thread and have an
// active event loop: without this sockets don't work at all under
// MSW as socket flags are only updated when socket messages are
// processed.
if ( eventLoop->Pending() )
eventLoop->Dispatch();
}
#if wxUSE_THREADS
else
else // no event loop or waiting in another thread
{
// We're busy waiting but at least give up the rest of our current
// time slice.
wxThread::Yield();
}
#endif // wxUSE_THREADS
}
else
{
// If there's less than 50 ms left, just call select with that timeout.
if (time_left < 50)
m_socket->SetTimeout(time_left);
}
}
}
// Set timeout back to original value (we overwrote it for polling)
if (!eventLoop)
m_socket->SetTimeout(m_timeout*1000);
return valid_result;
return gotEvent;
}
bool wxSocketBase::Wait(long seconds, long milliseconds)
{
return _Wait(seconds, milliseconds, GSOCK_INPUT_FLAG |
return DoWait(seconds, milliseconds,
GSOCK_INPUT_FLAG |
GSOCK_OUTPUT_FLAG |
GSOCK_CONNECTION_FLAG |
GSOCK_LOST_FLAG);
GSOCK_LOST_FLAG
);
}
bool wxSocketBase::WaitForRead(long seconds, long milliseconds)
{
// Check pushback buffer before entering _Wait
// Check pushback buffer before entering DoWait
if ( m_unread )
return true;
// Note that GSOCK_INPUT_LOST has to be explicitly passed to
// _Wait because of the semantics of WaitForRead: a return
// value of true means that a GSocket_Read call will return
// immediately, not that there is actually data to read.
return _Wait(seconds, milliseconds, GSOCK_INPUT_FLAG | GSOCK_LOST_FLAG);
// Note that GSOCK_INPUT_LOST has to be explicitly passed to DoWait
// because of the semantics of WaitForRead: a return value of true means
// that a GSocket_Read call will return immediately, not that there is
// actually data to read.
return DoWait(seconds, milliseconds, GSOCK_INPUT_FLAG | GSOCK_LOST_FLAG);
}
bool wxSocketBase::WaitForWrite(long seconds, long milliseconds)
{
return _Wait(seconds, milliseconds, GSOCK_OUTPUT_FLAG);
return DoWait(seconds, milliseconds, GSOCK_OUTPUT_FLAG | GSOCK_LOST_FLAG);
}
bool wxSocketBase::WaitForLost(long seconds, long milliseconds)
{
return _Wait(seconds, milliseconds, GSOCK_LOST_FLAG);
return DoWait(seconds, milliseconds, GSOCK_LOST_FLAG);
}
// --------------------------------------------------------------------------
@@ -1002,11 +982,6 @@ void LINKAGEMODE wx_socket_callback(GSocket * WXUNUSED(socket),
void wxSocketBase::OnRequest(wxSocketNotify notification)
{
// NOTE: We duplicate some of the code in _Wait, but this doesn't
// hurt. It has to be here because the (GSocket) event might arrive
// a bit delayed, and it has to be in _Wait as well because we don't
// know whether the Wait functions are being used.
switch(notification)
{
case wxSOCKET_CONNECTION:
@@ -1241,7 +1216,7 @@ wxSocketBase *wxSocketServer::Accept(bool wait)
bool wxSocketServer::WaitForAccept(long seconds, long milliseconds)
{
return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG);
return DoWait(seconds, milliseconds, GSOCK_CONNECTION_FLAG);
}
bool wxSocketBase::GetOption(int level, int optname, void *optval, int *optlen)
@@ -1411,14 +1386,22 @@ bool wxSocketClient::Connect(const wxSockAddress& addr_man,
bool wxSocketClient::WaitOnConnect(long seconds, long milliseconds)
{
if (m_connected) // Already connected
if ( m_connected )
{
// this happens if the initial attempt to connect succeeded without
// blocking
return true;
}
if (!m_establishing || !m_socket) // No connection in progress
return false;
wxCHECK_MSG( m_establishing && m_socket, false,
"No connection establishment attempt in progress" );
return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG |
GSOCK_LOST_FLAG);
// we must specify GSOCK_LOST_FLAG here explicitly because we must return
// true if the connection establishment process is finished, whether it is
// over because we successfully connected or because we were not able to
// connect
return DoWait(seconds, milliseconds,
GSOCK_CONNECTION_FLAG | GSOCK_LOST_FLAG);
}
// ==========================================================================