X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/ee4f8c2af9c6c5458e488db10aef7d00a89ace25..aa50e893ee119e4c66414d7f194d89a3d9a23819:/src/msw/thread.cpp diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp index 86bbcfea6f..f76f9a4c7b 100644 --- a/src/msw/thread.cpp +++ b/src/msw/thread.cpp @@ -2,319 +2,1222 @@ // Name: thread.cpp // Purpose: wxThread Implementation // Author: Original from Wolfram Gloger/Guilhem Lavaux -// Modified by: +// Modified by: Vadim Zeitlin to make it work :-) // Created: 04/22/98 // RCS-ID: $Id$ -// Copyright: (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998) +// Copyright: (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998), +// Vadim Zeitlin (1999) // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// #ifdef __GNUG__ -#pragma implementation "thread.h" + #pragma implementation "thread.h" #endif +// ---------------------------------------------------------------------------- +// headers +// ---------------------------------------------------------------------------- + +// For compilers that support precompilation, includes "wx.h". #include "wx/wxprec.h" #if defined(__BORLANDC__) -#pragma hdrstop + #pragma hdrstop #endif #ifndef WX_PRECOMP -#include "wx/wx.h" +# include "wx/wx.h" #endif -#include +#if wxUSE_THREADS + +#include "wx/msw/private.h" -#include #include "wx/module.h" #include "wx/thread.h" -enum thread_state { - STATE_IDLE = 0, - STATE_RUNNING, - STATE_CANCELED, - STATE_EXITED +#ifdef Yield +# undef Yield +#endif + +// must have this symbol defined to get _beginthread/_endthread declarations +#ifndef _MT + #define _MT +#endif + +#if defined(__VISUALC__) || \ + (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \ + (defined(__GNUG__) && defined(__MSVCRT__)) + +#if defined(__BORLANDC__) && !defined(__MT__) +// I can't set -tWM in the IDE (anyone?) so have to do this +#define __MT__ +#endif + +#if defined(__BORLANDC__) && !defined(__MFC_COMPAT__) +// Needed to know about _beginthreadex etc.. +#define __MFC_COMPAT__ +#endif + + #include +#endif + +// ---------------------------------------------------------------------------- +// constants +// ---------------------------------------------------------------------------- + +// the possible states of the thread ("=>" shows all possible transitions from +// this state) +enum wxThreadState +{ + STATE_NEW, // didn't start execution yet (=> RUNNING) + STATE_RUNNING, // thread is running (=> PAUSED, CANCELED) + STATE_PAUSED, // thread is temporarily suspended (=> RUNNING) + STATE_CANCELED, // thread should terminate a.s.a.p. (=> EXITED) + STATE_EXITED // thread is terminating }; -///////////////////////////////////////////////////////////////////////////// -// Static variables -///////////////////////////////////////////////////////////////////////////// +// ---------------------------------------------------------------------------- +// this module globals +// ---------------------------------------------------------------------------- -static HANDLE p_mainid; -wxMutex wxMainMutex; // controls access to all GUI functions +// TLS index of the slot where we store the pointer to the current thread +static DWORD gs_tlsThisThread = 0xFFFFFFFF; -///////////////////////////////////////////////////////////////////////////// -// Windows implementation -///////////////////////////////////////////////////////////////////////////// +// id of the main thread - the one which can call GUI functions without first +// calling wxMutexGuiEnter() +static DWORD gs_idMainThread = 0; + +// if it's FALSE, some secondary thread is holding the GUI lock +static bool gs_bGuiOwnedByMainThread = TRUE; + +// critical section which controls access to all GUI functions: any secondary +// thread (i.e. except the main one) must enter this crit section before doing +// any GUI calls +static wxCriticalSection *gs_critsectGui = NULL; + +// critical section which protects gs_nWaitingForGui variable +static wxCriticalSection *gs_critsectWaitingForGui = NULL; + +// number of threads waiting for GUI in wxMutexGuiEnter() +static size_t gs_nWaitingForGui = 0; -class wxMutexInternal { +// are we waiting for a thread termination? +static bool gs_waitingForThread = FALSE; + +// ============================================================================ +// Windows implementation of thread classes +// ============================================================================ + +// ---------------------------------------------------------------------------- +// wxMutex implementation +// ---------------------------------------------------------------------------- + +class wxMutexInternal +{ public: - HANDLE p_mutex; + wxMutexInternal() + { + m_mutex = ::CreateMutex(NULL, FALSE, NULL); + if ( !m_mutex ) + { + wxLogSysError(_("Can not create mutex")); + } + } + + ~wxMutexInternal() { if ( m_mutex ) CloseHandle(m_mutex); } + +public: + HANDLE m_mutex; }; wxMutex::wxMutex() { - p_internal = new wxMutexInternal; - p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL); - m_locked = 0; + m_internal = new wxMutexInternal; + + m_locked = 0; } wxMutex::~wxMutex() { - CloseHandle(p_internal->p_mutex); + if ( m_locked > 0 ) + { + wxLogDebug(_T("Warning: freeing a locked mutex (%d locks)."), m_locked); + } + + delete m_internal; } wxMutexError wxMutex::Lock() { - DWORD ret; + DWORD ret; + + ret = WaitForSingleObject(m_internal->m_mutex, INFINITE); + switch ( ret ) + { + case WAIT_ABANDONED: + return wxMUTEX_BUSY; + + case WAIT_OBJECT_0: + // ok + break; - ret = WaitForSingleObject(p_internal->p_mutex, INFINITE); - if (ret == WAIT_ABANDONED) - return MUTEX_BUSY; + case WAIT_FAILED: + wxLogSysError(_("Couldn't acquire a mutex lock")); + return wxMUTEX_MISC_ERROR; - m_locked++; - return MUTEX_NO_ERROR; + case WAIT_TIMEOUT: + default: + wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock")); + } + + m_locked++; + return wxMUTEX_NO_ERROR; } wxMutexError wxMutex::TryLock() { - DWORD ret; + DWORD ret; - ret = WaitForSingleObject(p_internal->p_mutex, 0); - if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED) - return MUTEX_BUSY; + ret = WaitForSingleObject(m_internal->m_mutex, 0); + if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED) + return wxMUTEX_BUSY; - m_locked++; - return MUTEX_NO_ERROR; + m_locked++; + return wxMUTEX_NO_ERROR; } wxMutexError wxMutex::Unlock() { - BOOL ret; + if (m_locked > 0) + m_locked--; - if (m_locked > 0) - m_locked--; + BOOL ret = ReleaseMutex(m_internal->m_mutex); + if ( ret == 0 ) + { + wxLogSysError(_("Couldn't release a mutex")); + return wxMUTEX_MISC_ERROR; + } - // Why does this have 3 args? The redundant ones removed by JACS -// ret = ReleaseMutex(p_internal->p_mutex, 1, NULL); - ret = ReleaseMutex(p_internal->p_mutex); - return MUTEX_NO_ERROR; + return wxMUTEX_NO_ERROR; } -class wxConditionInternal { +// ---------------------------------------------------------------------------- +// wxCondition implementation +// ---------------------------------------------------------------------------- + +class wxConditionInternal +{ public: - HANDLE event; - int waiters; + wxConditionInternal() + { + m_hEvent = ::CreateEvent( + NULL, // default secutiry + FALSE, // not manual reset + FALSE, // nonsignaled initially + NULL // nameless event + ); + if ( !m_hEvent ) + { + wxLogSysError(_("Can not create event object.")); + } + + // nobody waits for us yet + m_nWaiters = 0; + } + + bool Wait(DWORD timeout) + { + // as m_nWaiters variable is accessed from multiple waiting threads + // (and possibly from the broadcasting thread), we need to change its + // value atomically + ::InterlockedIncrement(&m_nWaiters); + + // FIXME this should be MsgWaitForMultipleObjects() as we want to keep + // processing Windows messages while waiting (or don't we?) + DWORD rc = ::WaitForSingleObject(m_hEvent, timeout); + + ::InterlockedDecrement(&m_nWaiters); + + return rc != WAIT_TIMEOUT; + } + + void Signal() + { + // set the event to signaled: if a thread is already waiting on it, it + // will be woken up, otherwise the event will remain in the signaled + // state until someone waits on it. In any case, the system will return + // it to a non signalled state afterwards. If multiple threads are + // waiting, only one will be woken up. + if ( !::SetEvent(m_hEvent) ) + { + wxLogLastError(wxT("SetEvent")); + } + } + + void Broadcast() + { + // we need to save the original value as m_nWaiters is goign to be + // decreased by the signalled thread resulting in the loop being + // executed less times than needed + LONG nWaiters = m_nWaiters; + + // this works because all these threads are already waiting and so each + // SetEvent() inside Signal() is really a PulseEvent() because the + // event state is immediately returned to non-signaled + for ( LONG n = 0; n < nWaiters; n++ ) + { + Signal(); + } + } + + ~wxConditionInternal() + { + if ( m_hEvent ) + { + if ( !::CloseHandle(m_hEvent) ) + { + wxLogLastError(wxT("CloseHandle(event)")); + } + } + } + +private: + // the Win32 synchronization object corresponding to this event + HANDLE m_hEvent; + + // number of threads waiting for this condition + LONG m_nWaiters; }; wxCondition::wxCondition() { - p_internal = new wxConditionInternal; - p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL); - p_internal->waiters = 0; + m_internal = new wxConditionInternal; } wxCondition::~wxCondition() { - CloseHandle(p_internal->event); + delete m_internal; } -void wxCondition::Wait(wxMutex& mutex) +void wxCondition::Wait() { - mutex.Unlock(); - p_internal->waiters++; - WaitForSingleObject(p_internal->event, INFINITE); - p_internal->waiters--; - mutex.Lock(); + (void)m_internal->Wait(INFINITE); } -bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, +bool wxCondition::Wait(unsigned long sec, unsigned long nsec) { - DWORD ret; - - mutex.Unlock(); - p_internal->waiters++; - ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000)); - p_internal->waiters--; - mutex.Lock(); - - return (ret != WAIT_TIMEOUT); + return m_internal->Wait(sec*1000 + nsec/1000000); } void wxCondition::Signal() { - SetEvent(p_internal->event); + m_internal->Signal(); } void wxCondition::Broadcast() { - int i; + m_internal->Broadcast(); +} - for (i=0;iwaiters;i++) - SetEvent(p_internal->event); +// ---------------------------------------------------------------------------- +// wxCriticalSection implementation +// ---------------------------------------------------------------------------- + +wxCriticalSection::wxCriticalSection() +{ +#ifdef __WXDEBUG__ + // Done this way to stop warnings during compilation about statement + // always being false + int csSize = sizeof(CRITICAL_SECTION); + int bSize = sizeof(m_buffer); + wxASSERT_MSG( csSize <= bSize, + _T("must increase buffer size in wx/thread.h") ); +#endif + + ::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer); } -class wxThreadInternal { -public: - static DWORD WinThreadStart(LPVOID arg); +wxCriticalSection::~wxCriticalSection() +{ + ::DeleteCriticalSection((CRITICAL_SECTION *)m_buffer); +} + +void wxCriticalSection::Enter() +{ + ::EnterCriticalSection((CRITICAL_SECTION *)m_buffer); +} + +void wxCriticalSection::Leave() +{ + ::LeaveCriticalSection((CRITICAL_SECTION *)m_buffer); +} + +// ---------------------------------------------------------------------------- +// wxThread implementation +// ---------------------------------------------------------------------------- - HANDLE thread_id; - int state; - int prio, defer; - DWORD tid; +// wxThreadInternal class +// ---------------------- + +class wxThreadInternal +{ +public: + wxThreadInternal() + { + m_hThread = 0; + m_state = STATE_NEW; + m_priority = WXTHREAD_DEFAULT_PRIORITY; + } + + ~wxThreadInternal() + { + Free(); + } + + void Free() + { + if ( m_hThread ) + { + if ( !::CloseHandle(m_hThread) ) + { + wxLogLastError(wxT("CloseHandle(thread)")); + } + + m_hThread = 0; + } + } + + // create a new (suspended) thread (for the given thread object) + bool Create(wxThread *thread); + + // suspend/resume/terminate + bool Suspend(); + bool Resume(); + void Cancel() { m_state = STATE_CANCELED; } + + // thread state + void SetState(wxThreadState state) { m_state = state; } + wxThreadState GetState() const { return m_state; } + + // thread priority + void SetPriority(unsigned int priority); + unsigned int GetPriority() const { return m_priority; } + + // thread handle and id + HANDLE GetHandle() const { return m_hThread; } + DWORD GetId() const { return m_tid; } + + // thread function + static DWORD WinThreadStart(wxThread *thread); + +private: + HANDLE m_hThread; // handle of the thread + wxThreadState m_state; // state, see wxThreadState enum + unsigned int m_priority; // thread priority in "wx" units + DWORD m_tid; // thread id }; -DWORD wxThreadInternal::WinThreadStart(LPVOID arg) +DWORD wxThreadInternal::WinThreadStart(wxThread *thread) { - wxThread *ptr = (wxThread *)arg; - DWORD ret; + DWORD rc; + bool wasCancelled; + + // first of all, check whether we hadn't been cancelled already and don't + // start the user code at all then + if ( thread->m_internal->GetState() == STATE_EXITED ) + { + rc = (DWORD)-1; + wasCancelled = TRUE; + } + else // do run thread + { + // store the thread object in the TLS + if ( !::TlsSetValue(gs_tlsThisThread, thread) ) + { + wxLogSysError(_("Can not start thread: error writing TLS.")); + + return (DWORD)-1; + } + + rc = (DWORD)thread->Entry(); + + // enter m_critsect before changing the thread state + thread->m_critsect.Enter(); + wasCancelled = thread->m_internal->GetState() == STATE_CANCELED; + thread->m_internal->SetState(STATE_EXITED); + thread->m_critsect.Leave(); + } + + thread->OnExit(); + + // if the thread was cancelled (from Delete()), then its handle is still + // needed there + if ( thread->IsDetached() && !wasCancelled ) + { + // auto delete + delete thread; + } + //else: the joinable threads handle will be closed when Wait() is done + + return rc; +} + +void wxThreadInternal::SetPriority(unsigned int priority) +{ + m_priority = priority; + + // translate wxWindows priority to the Windows one + int win_priority; + if (m_priority <= 20) + win_priority = THREAD_PRIORITY_LOWEST; + else if (m_priority <= 40) + win_priority = THREAD_PRIORITY_BELOW_NORMAL; + else if (m_priority <= 60) + win_priority = THREAD_PRIORITY_NORMAL; + else if (m_priority <= 80) + win_priority = THREAD_PRIORITY_ABOVE_NORMAL; + else if (m_priority <= 100) + win_priority = THREAD_PRIORITY_HIGHEST; + else + { + wxFAIL_MSG(wxT("invalid value of thread priority parameter")); + win_priority = THREAD_PRIORITY_NORMAL; + } + + if ( !::SetThreadPriority(m_hThread, win_priority) ) + { + wxLogSysError(_("Can't set thread priority")); + } +} - ret = (DWORD)ptr->Entry(); - ptr->p_internal->state = STATE_EXITED; +bool wxThreadInternal::Create(wxThread *thread) +{ + // for compilers which have it, we should use C RTL function for thread + // creation instead of Win32 API one because otherwise we will have memory + // leaks if the thread uses C RTL (and most threads do) +#if defined(__VISUALC__) || \ + (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \ + (defined(__GNUG__) && defined(__MSVCRT__)) + typedef unsigned (__stdcall *RtlThreadStart)(void *); + + m_hThread = (HANDLE)_beginthreadex(NULL, 0, + (RtlThreadStart) + wxThreadInternal::WinThreadStart, + thread, CREATE_SUSPENDED, + (unsigned int *)&m_tid); +#else // compiler doesn't have _beginthreadex + m_hThread = ::CreateThread + ( + NULL, // default security + 0, // default stack size + (LPTHREAD_START_ROUTINE) // thread entry point + wxThreadInternal::WinThreadStart, // + (LPVOID)thread, // parameter + CREATE_SUSPENDED, // flags + &m_tid // [out] thread id + ); +#endif // _beginthreadex/CreateThread + + if ( m_hThread == NULL ) + { + wxLogSysError(_("Can't create thread")); + + return FALSE; + } + + if ( m_priority != WXTHREAD_DEFAULT_PRIORITY ) + { + SetPriority(m_priority); + } - return ret; + return TRUE; } -wxThreadError wxThread::Create() +bool wxThreadInternal::Suspend() { - int win_prio, prio = p_internal->prio; + DWORD nSuspendCount = ::SuspendThread(m_hThread); + if ( nSuspendCount == (DWORD)-1 ) + { + wxLogSysError(_("Can not suspend thread %x"), m_hThread); - p_internal->thread_id = CreateThread(NULL, 0, - (LPTHREAD_START_ROUTINE)wxThreadInternal::WinThreadStart, - (void *)this, CREATE_SUSPENDED, &p_internal->tid); - if (p_internal->thread_id == NULL) { - printf("Error = %d\n", GetLastError()); - return THREAD_NO_RESOURCE; - } + return FALSE; + } - if (prio <= 20) - win_prio = THREAD_PRIORITY_LOWEST; - else if (prio <= 40) - win_prio = THREAD_PRIORITY_BELOW_NORMAL; - else if (prio <= 60) - win_prio = THREAD_PRIORITY_NORMAL; - else if (prio <= 80) - win_prio = THREAD_PRIORITY_ABOVE_NORMAL; - else if (prio <= 100) - win_prio = THREAD_PRIORITY_HIGHEST; + m_state = STATE_PAUSED; - SetThreadPriority(p_internal->thread_id, win_prio); + return TRUE; +} + +bool wxThreadInternal::Resume() +{ + DWORD nSuspendCount = ::ResumeThread(m_hThread); + if ( nSuspendCount == (DWORD)-1 ) + { + wxLogSysError(_("Can not resume thread %x"), m_hThread); + + return FALSE; + } + + // don't change the state from STATE_EXITED because it's special and means + // we are going to terminate without running any user code - if we did it, + // the codei n Delete() wouldn't work + if ( m_state != STATE_EXITED ) + { + m_state = STATE_RUNNING; + } - ResumeThread(p_internal->thread_id); - p_internal->state = STATE_RUNNING; - - return THREAD_NO_ERROR; + return TRUE; } -wxThreadError wxThread::Destroy() +// static functions +// ---------------- + +wxThread *wxThread::This() { - if (p_internal->state != STATE_RUNNING) - return THREAD_NOT_RUNNING; + wxThread *thread = (wxThread *)::TlsGetValue(gs_tlsThisThread); + + // be careful, 0 may be a valid return value as well + if ( !thread && (::GetLastError() != NO_ERROR) ) + { + wxLogSysError(_("Couldn't get the current thread pointer")); - if (p_internal->defer == FALSE) - TerminateThread(p_internal->thread_id, 0); - else - p_internal->state = STATE_CANCELED; + // return NULL... + } - return THREAD_NO_ERROR; + return thread; } -void wxThread::Exit(void *status) +bool wxThread::IsMain() { - p_internal->state = STATE_EXITED; - ExitThread((DWORD)status); + return ::GetCurrentThreadId() == gs_idMainThread; } -void wxThread::SetPriority(int prio) +#ifdef Yield +#undef Yield +#endif + +void wxThread::Yield() { - p_internal->prio = prio; + // 0 argument to Sleep() is special and means to just give away the rest of + // our timeslice + ::Sleep(0); } -int wxThread::GetPriority() +void wxThread::Sleep(unsigned long milliseconds) { - return p_internal->prio; + ::Sleep(milliseconds); } -void wxThread::DeferDestroy(bool on) +int wxThread::GetCPUCount() { - p_internal->defer = on; + SYSTEM_INFO si; + GetSystemInfo(&si); + + return si.dwNumberOfProcessors; } -void wxThread::TestDestroy() +bool wxThread::SetConcurrency(size_t level) { - if (p_internal->state == STATE_CANCELED) - ExitThread(0); + wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") ); + + // ok only for the default one + if ( level == 0 ) + return 0; + + // get system affinity mask first + HANDLE hProcess = ::GetCurrentProcess(); + DWORD dwProcMask, dwSysMask; + if ( ::GetProcessAffinityMask(hProcess, &dwProcMask, &dwSysMask) == 0 ) + { + wxLogLastError(_T("GetProcessAffinityMask")); + + return FALSE; + } + + // how many CPUs have we got? + if ( dwSysMask == 1 ) + { + // don't bother with all this complicated stuff - on a single + // processor system it doesn't make much sense anyhow + return level == 1; + } + + // calculate the process mask: it's a bit vector with one bit per + // processor; we want to schedule the process to run on first level + // CPUs + DWORD bit = 1; + while ( bit ) + { + if ( dwSysMask & bit ) + { + // ok, we can set this bit + dwProcMask |= bit; + + // another process added + if ( !--level ) + { + // and that's enough + break; + } + } + + // next bit + bit <<= 1; + } + + // could we set all bits? + if ( level != 0 ) + { + wxLogDebug(_T("bad level %u in wxThread::SetConcurrency()"), level); + + return FALSE; + } + + // set it: we can't link to SetProcessAffinityMask() because it doesn't + // exist in Win9x, use RT binding instead + + typedef BOOL (*SETPROCESSAFFINITYMASK)(HANDLE, DWORD); + + // can use static var because we're always in the main thread here + static SETPROCESSAFFINITYMASK pfnSetProcessAffinityMask = NULL; + + if ( !pfnSetProcessAffinityMask ) + { + HMODULE hModKernel = ::LoadLibrary(_T("kernel32")); + if ( hModKernel ) + { + pfnSetProcessAffinityMask = (SETPROCESSAFFINITYMASK) + ::GetProcAddress(hModKernel, "SetProcessAffinityMask"); + } + + // we've discovered a MT version of Win9x! + wxASSERT_MSG( pfnSetProcessAffinityMask, + _T("this system has several CPUs but no SetProcessAffinityMask function?") ); + } + + if ( !pfnSetProcessAffinityMask ) + { + // msg given above - do it only once + return FALSE; + } + + if ( pfnSetProcessAffinityMask(hProcess, dwProcMask) == 0 ) + { + wxLogLastError(_T("SetProcessAffinityMask")); + + return FALSE; + } + + return TRUE; } -void *wxThread::Join() +// ctor and dtor +// ------------- + +wxThread::wxThread(wxThreadKind kind) { - DWORD exit_code; + m_internal = new wxThreadInternal(); + + m_isDetached = kind == wxTHREAD_DETACHED; +} - if (p_internal->state == STATE_IDLE) - return NULL; +wxThread::~wxThread() +{ + delete m_internal; +} - if (wxThread::IsMain()) - wxMainMutex.Unlock(); - WaitForSingleObject(p_internal->thread_id, INFINITE); - if (wxThread::IsMain()) - wxMainMutex.Lock(); +// create/start thread +// ------------------- - GetExitCodeThread(p_internal->thread_id, &exit_code); - CloseHandle(p_internal->thread_id); +wxThreadError wxThread::Create() +{ + wxCriticalSectionLocker lock(m_critsect); - p_internal->state = STATE_IDLE; + if ( !m_internal->Create(this) ) + return wxTHREAD_NO_RESOURCE; - return (void *)exit_code; + return wxTHREAD_NO_ERROR; } -unsigned long wxThread::GetID() const +wxThreadError wxThread::Run() { - return (unsigned long)p_internal->tid; + wxCriticalSectionLocker lock(m_critsect); + + if ( m_internal->GetState() != STATE_NEW ) + { + // actually, it may be almost any state at all, not only STATE_RUNNING + return wxTHREAD_RUNNING; + } + + // the thread has just been created and is still suspended - let it run + return Resume(); } -bool wxThread::IsMain() const +// suspend/resume thread +// --------------------- + +wxThreadError wxThread::Pause() { - return (GetCurrentThread() == p_mainid); + wxCriticalSectionLocker lock(m_critsect); + + return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR; } -wxThread::wxThread() +wxThreadError wxThread::Resume() { - p_internal = new wxThreadInternal(); + wxCriticalSectionLocker lock(m_critsect); - p_internal->defer = FALSE; - p_internal->prio = WXTHREAD_DEFAULT_PRIORITY; - p_internal->state = STATE_IDLE; + return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR; } -wxThread::~wxThread() +// stopping thread +// --------------- + +wxThread::ExitCode wxThread::Wait() { - Destroy(); - Join(); - delete p_internal; + // although under Windows we can wait for any thread, it's an error to + // wait for a detached one in wxWin API + wxCHECK_MSG( !IsDetached(), (ExitCode)-1, + _T("can't wait for detached thread") ); + + ExitCode rc = (ExitCode)-1; + + (void)Delete(&rc); + + m_internal->Free(); + + return rc; +} + +wxThreadError wxThread::Delete(ExitCode *pRc) +{ + ExitCode rc = 0; + + // Delete() is always safe to call, so consider all possible states + + // we might need to resume the thread, but we might also not need to cancel + // it if it doesn't run yet + bool shouldResume = FALSE, + shouldCancel = TRUE, + isRunning = FALSE; + + // check if the thread already started to run + { + wxCriticalSectionLocker lock(m_critsect); + + if ( m_internal->GetState() == STATE_NEW ) + { + // WinThreadStart() will see it and terminate immediately, no need + // to cancel the thread - but we still need to resume it to let it + // run + m_internal->SetState(STATE_EXITED); + + Resume(); // it knows about STATE_EXITED special case + + shouldCancel = FALSE; + isRunning = TRUE; + + // shouldResume is correctly set to FALSE here + } + else + { + shouldResume = IsPaused(); + } + } + + // resume the thread if it is paused + if ( shouldResume ) + Resume(); + + HANDLE hThread = m_internal->GetHandle(); + + // does is still run? + if ( isRunning || IsRunning() ) + { + if ( IsMain() ) + { + // set flag for wxIsWaitingForThread() + gs_waitingForThread = TRUE; + +#if wxUSE_GUI + wxBeginBusyCursor(); +#endif // wxUSE_GUI + } + + // ask the thread to terminate + if ( shouldCancel ) + { + wxCriticalSectionLocker lock(m_critsect); + + m_internal->Cancel(); + } + +#if wxUSE_GUI + // we can't just wait for the thread to terminate because it might be + // calling some GUI functions and so it will never terminate before we + // process the Windows messages that result from these functions + DWORD result; + do + { + result = ::MsgWaitForMultipleObjects + ( + 1, // number of objects to wait for + &hThread, // the objects + FALSE, // don't wait for all objects + INFINITE, // no timeout + QS_ALLEVENTS // return as soon as there are any events + ); + + switch ( result ) + { + case 0xFFFFFFFF: + // error + wxLogSysError(_("Can not wait for thread termination")); + Kill(); + return wxTHREAD_KILLED; + + case WAIT_OBJECT_0: + // thread we're waiting for terminated + break; + + case WAIT_OBJECT_0 + 1: + // new message arrived, process it + if ( !wxTheApp->DoMessage() ) + { + // WM_QUIT received: kill the thread + Kill(); + + return wxTHREAD_KILLED; + } + + if ( IsMain() ) + { + // give the thread we're waiting for chance to exit + // from the GUI call it might have been in + if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() ) + { + wxMutexGuiLeave(); + } + } + + break; + + default: + wxFAIL_MSG(wxT("unexpected result of MsgWaitForMultipleObject")); + } + } while ( result != WAIT_OBJECT_0 ); +#else // !wxUSE_GUI + // simply wait for the thread to terminate + // + // OTOH, even console apps create windows (in wxExecute, for WinSock + // &c), so may be use MsgWaitForMultipleObject() too here? + if ( WaitForSingleObject(hThread, INFINITE) != WAIT_OBJECT_0 ) + { + wxFAIL_MSG(wxT("unexpected result of WaitForSingleObject")); + } +#endif // wxUSE_GUI/!wxUSE_GUI + + if ( IsMain() ) + { + gs_waitingForThread = FALSE; + +#if wxUSE_GUI + wxEndBusyCursor(); +#endif // wxUSE_GUI + } + } + + if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) ) + { + wxLogLastError(wxT("GetExitCodeThread")); + + rc = (ExitCode)-1; + } + + if ( IsDetached() ) + { + // if the thread exits normally, this is done in WinThreadStart, but in + // this case it would have been too early because + // MsgWaitForMultipleObject() would fail if the thread handle was + // closed while we were waiting on it, so we must do it here + delete this; + } + + wxASSERT_MSG( (DWORD)rc != STILL_ACTIVE, + wxT("thread must be already terminated.") ); + + if ( pRc ) + *pRc = rc; + + return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR; } -// The default callback just joins the thread and throws away the result. -void wxThread::OnExit() +wxThreadError wxThread::Kill() { - Join(); + if ( !IsRunning() ) + return wxTHREAD_NOT_RUNNING; + + if ( !::TerminateThread(m_internal->GetHandle(), (DWORD)-1) ) + { + wxLogSysError(_("Couldn't terminate thread")); + + return wxTHREAD_MISC_ERROR; + } + + m_internal->Free(); + + if ( IsDetached() ) + { + delete this; + } + + return wxTHREAD_NO_ERROR; } -// Automatic initialization -class wxThreadModule : public wxModule { - DECLARE_DYNAMIC_CLASS(wxThreadModule) +void wxThread::Exit(ExitCode status) +{ + m_internal->Free(); + + if ( IsDetached() ) + { + delete this; + } + +#if defined(__VISUALC__) || \ + (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \ + (defined(__GNUG__) && defined(__MSVCRT__)) + _endthreadex((unsigned)status); +#else // !VC++ + ::ExitThread((DWORD)status); +#endif // VC++/!VC++ + + wxFAIL_MSG(wxT("Couldn't return from ExitThread()!")); +} + +// priority setting +// ---------------- + +void wxThread::SetPriority(unsigned int prio) +{ + wxCriticalSectionLocker lock(m_critsect); + + m_internal->SetPriority(prio); +} + +unsigned int wxThread::GetPriority() const +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetPriority(); +} + +unsigned long wxThread::GetId() const +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return (unsigned long)m_internal->GetId(); +} + +bool wxThread::IsRunning() const +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetState() == STATE_RUNNING; +} + +bool wxThread::IsAlive() const +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return (m_internal->GetState() == STATE_RUNNING) || + (m_internal->GetState() == STATE_PAUSED); +} + +bool wxThread::IsPaused() const +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetState() == STATE_PAUSED; +} + +bool wxThread::TestDestroy() +{ + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetState() == STATE_CANCELED; +} + +// ---------------------------------------------------------------------------- +// Automatic initialization for thread module +// ---------------------------------------------------------------------------- + +class wxThreadModule : public wxModule +{ public: - virtual bool OnInit() { - p_mainid = GetCurrentThread(); - wxMainMutex.Lock(); - return TRUE; - } + virtual bool OnInit(); + virtual void OnExit(); - // Global cleanup - virtual void OnExit() { - wxMainMutex.Unlock(); - } +private: + DECLARE_DYNAMIC_CLASS(wxThreadModule) }; IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule) +bool wxThreadModule::OnInit() +{ + // allocate TLS index for storing the pointer to the current thread + gs_tlsThisThread = ::TlsAlloc(); + if ( gs_tlsThisThread == 0xFFFFFFFF ) + { + // in normal circumstances it will only happen if all other + // TLS_MINIMUM_AVAILABLE (>= 64) indices are already taken - in other + // words, this should never happen + wxLogSysError(_("Thread module initialization failed: impossible to allocate index in thread local storage")); + + return FALSE; + } + + // main thread doesn't have associated wxThread object, so store 0 in the + // TLS instead + if ( !::TlsSetValue(gs_tlsThisThread, (LPVOID)0) ) + { + ::TlsFree(gs_tlsThisThread); + gs_tlsThisThread = 0xFFFFFFFF; + + wxLogSysError(_("Thread module initialization failed: can not store value in thread local storage")); + + return FALSE; + } + + gs_critsectWaitingForGui = new wxCriticalSection(); + + gs_critsectGui = new wxCriticalSection(); + gs_critsectGui->Enter(); + + // no error return for GetCurrentThreadId() + gs_idMainThread = ::GetCurrentThreadId(); + + return TRUE; +} + +void wxThreadModule::OnExit() +{ + if ( !::TlsFree(gs_tlsThisThread) ) + { + wxLogLastError(wxT("TlsFree failed.")); + } + + if ( gs_critsectGui ) + { + gs_critsectGui->Leave(); + delete gs_critsectGui; + gs_critsectGui = NULL; + } + + delete gs_critsectWaitingForGui; + gs_critsectWaitingForGui = NULL; +} + +// ---------------------------------------------------------------------------- +// under Windows, these functions are implemented using a critical section and +// not a mutex, so the names are a bit confusing +// ---------------------------------------------------------------------------- + +void WXDLLEXPORT wxMutexGuiEnter() +{ + // this would dead lock everything... + wxASSERT_MSG( !wxThread::IsMain(), + wxT("main thread doesn't want to block in wxMutexGuiEnter()!") ); + + // the order in which we enter the critical sections here is crucial!! + + // set the flag telling to the main thread that we want to do some GUI + { + wxCriticalSectionLocker enter(*gs_critsectWaitingForGui); + + gs_nWaitingForGui++; + } + + wxWakeUpMainThread(); + + // now we may block here because the main thread will soon let us in + // (during the next iteration of OnIdle()) + gs_critsectGui->Enter(); +} + +void WXDLLEXPORT wxMutexGuiLeave() +{ + wxCriticalSectionLocker enter(*gs_critsectWaitingForGui); + + if ( wxThread::IsMain() ) + { + gs_bGuiOwnedByMainThread = FALSE; + } + else + { + // decrement the number of threads waiting for GUI access now + wxASSERT_MSG( gs_nWaitingForGui > 0, + wxT("calling wxMutexGuiLeave() without entering it first?") ); + + gs_nWaitingForGui--; + + wxWakeUpMainThread(); + } + + gs_critsectGui->Leave(); +} + +void WXDLLEXPORT wxMutexGuiLeaveOrEnter() +{ + wxASSERT_MSG( wxThread::IsMain(), + wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") ); + + wxCriticalSectionLocker enter(*gs_critsectWaitingForGui); + + if ( gs_nWaitingForGui == 0 ) + { + // no threads are waiting for GUI - so we may acquire the lock without + // any danger (but only if we don't already have it) + if ( !wxGuiOwnedByMainThread() ) + { + gs_critsectGui->Enter(); + + gs_bGuiOwnedByMainThread = TRUE; + } + //else: already have it, nothing to do + } + else + { + // some threads are waiting, release the GUI lock if we have it + if ( wxGuiOwnedByMainThread() ) + { + wxMutexGuiLeave(); + } + //else: some other worker thread is doing GUI + } +} + +bool WXDLLEXPORT wxGuiOwnedByMainThread() +{ + return gs_bGuiOwnedByMainThread; +} + +// wake up the main thread if it's in ::GetMessage() +void WXDLLEXPORT wxWakeUpMainThread() +{ + // sending any message would do - hopefully WM_NULL is harmless enough + if ( !::PostThreadMessage(gs_idMainThread, WM_NULL, 0, 0) ) + { + // should never happen + wxLogLastError(wxT("PostThreadMessage(WM_NULL)")); + } +} + +bool WXDLLEXPORT wxIsWaitingForThread() +{ + return gs_waitingForThread; +} + +#endif // wxUSE_THREADS