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Make main thread wake up code more efficient and less error-prone in wxMSW.

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Use a kernel event object to signal the thread wake up instead of sending
WM_NULL to one of its windows. This is simpler as we don't need to look for
any windows and doesn't suffer from the problem of overflowing the Windows
message queue if we do it too many times as signalling an already signalled
event simply doesn't do anything.

Closes #9053.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78041 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
2014-10-19 12:57:08 +00:00
parent cf61bbb168
commit 6c40531fb7
5 changed files with 82 additions and 85 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
src/msw/evtloopconsole.cpp
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@@ -42,6 +42,17 @@ wxMSWEventLoopBase::wxMSWEventLoopBase()
{
m_shouldExit = false;
m_exitcode = 0;
// Create initially not signalled auto-reset event object.
m_heventWake = ::CreateEvent(NULL, FALSE, FALSE, NULL);
if ( !m_heventWake )
wxLogLastError(wxS("CreateEvent(wake)"));
}
wxMSWEventLoopBase::~wxMSWEventLoopBase()
{
if ( m_heventWake && !::CloseHandle(m_heventWake) )
wxLogLastError(wxS("CloseHandle(wake)"));
}
// ----------------------------------------------------------------------------
@@ -54,26 +65,36 @@ bool wxMSWEventLoopBase::Pending() const
return ::PeekMessage(&msg, 0, 0, 0, PM_NOREMOVE) != 0;
}
void wxMSWEventLoopBase::WakeUp()
{
if ( !::SetEvent(m_heventWake) )
wxLogLastError(wxS("SetEvent(wake)"));
}
#if wxUSE_THREADS
WXDWORD wxMSWEventLoopBase::MSWWaitForThread(WXHANDLE hThread)
{
// The order is important here, the code using this function assumes that
// WAIT_OBJECT_0 indicates the thread termination and anything else -- the
// availability of an input event. So the thread handle must come first.
HANDLE handles[2] = { hThread, m_heventWake };
return ::MsgWaitForMultipleObjects
(
WXSIZEOF(handles), // number of objects to wait for
handles, // the objects
false, // wait for any objects, not all
INFINITE, // no timeout
QS_ALLINPUT | // return as soon as there are any events
QS_ALLPOSTMESSAGE
);
}
#endif // wxUSE_THREADS
bool wxMSWEventLoopBase::GetNextMessage(WXMSG* msg)
{
const BOOL rc = ::GetMessage(msg, NULL, 0, 0);
if ( rc == 0 )
{
// got WM_QUIT
return false;
}
if ( rc == -1 )
{
// should never happen, but let's test for it nevertheless
wxLogLastError(wxT("GetMessage"));
// still break from the loop
return false;
}
return true;
return GetNextMessageTimeout(msg, INFINITE) == TRUE;
}
int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
@@ -86,14 +107,12 @@ int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
// it is not available in very old Windows versions
if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
{
// we use this function just in order to not block longer than the
// given timeout, so we don't pass any handles to it at all
DWORD rc = ::MsgWaitForMultipleObjects
(
0, NULL,
1, &m_heventWake,
FALSE,
timeout,
QS_ALLINPUT
QS_ALLINPUT | QS_ALLPOSTMESSAGE
);
switch ( rc )
@@ -107,6 +126,15 @@ int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
return -1;
case WAIT_OBJECT_0:
// We were woken up by a background thread, which means there
// is no actual input message available, but we should still
// return to the event loop, so pretend there was WM_NULL in
// the queue.
wxZeroMemory(*msg);
break;
case WAIT_OBJECT_0 + 1:
// Some message is supposed to be available.
if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
{
// somehow it may happen that MsgWaitForMultipleObjects()
@@ -127,13 +155,6 @@ int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
#if wxUSE_CONSOLE_EVENTLOOP
void wxConsoleEventLoop::WakeUp()
{
#if wxUSE_THREADS
wxWakeUpMainThread();
#endif
}
void wxConsoleEventLoop::ProcessMessage(WXMSG *msg)
{
::DispatchMessage(msg);