X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/d524867f4cd44178f8e6d22f37ade851918de628..993eebf1bae0a595540cb282342e894f23fbb1ee:/src/msw/thread.cpp diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp index 56fe00d322..d93d017704 100644 --- a/src/msw/thread.cpp +++ b/src/msw/thread.cpp @@ -1,398 +1,1355 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: thread.cpp +// Name: src/msw/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 (1999-2002) // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// #ifdef __GNUG__ -#pragma implementation "thread.h" + #pragma implementation "thread.h" #endif -// this is here to regen the precompiled header in the ide compile otherwise the -// compiler crashes in vc5 (nfi why) +// ---------------------------------------------------------------------------- +// 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 "wx/msw/missing.h" -#include #include "wx/module.h" #include "wx/thread.h" -enum thread_state { - STATE_IDLE = 0, - STATE_RUNNING, - STATE_CANCELED, - STATE_EXITED -}; +// must have this symbol defined to get _beginthread/_endthread declarations +#ifndef _MT + #define _MT +#endif -///////////////////////////////////////////////////////////////////////////// -// Static variables -///////////////////////////////////////////////////////////////////////////// +#if defined(__BORLANDC__) + #if !defined(__MT__) + // I can't set -tWM in the IDE (anyone?) so have to do this + #define __MT__ + #endif + + #if !defined(__MFC_COMPAT__) + // Needed to know about _beginthreadex etc.. + #define __MFC_COMPAT__ + #endif +#endif // BC++ + +// define wxUSE_BEGIN_THREAD if the compiler has _beginthreadex() function +// which should be used instead of Win32 ::CreateThread() if possible +#if defined(__VISUALC__) || \ + (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \ + (defined(__GNUG__) && defined(__MSVCRT__)) || \ + defined(__WATCOMC__) || defined(__MWERKS__) + + #undef wxUSE_BEGIN_THREAD + #define wxUSE_BEGIN_THREAD +#endif -static HANDLE p_mainid; -wxMutex *wxMainMutex; // controls access to all GUI functions +#ifdef wxUSE_BEGIN_THREAD + // this is where _beginthreadex() is declared + #include -///////////////////////////////////////////////////////////////////////////// -// Windows implementation -///////////////////////////////////////////////////////////////////////////// + // the return type of the thread function entry point + typedef unsigned THREAD_RETVAL; -class wxMutexInternal { -public: - HANDLE p_mutex; + // the calling convention of the thread function entry point + #define THREAD_CALLCONV __stdcall +#else + // the settings for CreateThread() + typedef DWORD THREAD_RETVAL; + #define THREAD_CALLCONV WINAPI +#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 }; -wxMutex::wxMutex() +// ---------------------------------------------------------------------------- +// this module globals +// ---------------------------------------------------------------------------- + +// TLS index of the slot where we store the pointer to the current thread +static DWORD gs_tlsThisThread = 0xFFFFFFFF; + +// 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; + +// are we waiting for a thread termination? +static bool gs_waitingForThread = FALSE; + +// ============================================================================ +// Windows implementation of thread and related classes +// ============================================================================ + +// ---------------------------------------------------------------------------- +// wxCriticalSection +// ---------------------------------------------------------------------------- + +wxCriticalSection::wxCriticalSection() { - p_internal = new wxMutexInternal; - p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL); - if ( !p_internal->p_mutex ) - { - wxLogSysError(_("Can not create mutex.")); - } + wxCOMPILE_TIME_ASSERT( sizeof(CRITICAL_SECTION) <= sizeof(wxCritSectBuffer), + wxCriticalSectionBufferTooSmall ); + + ::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer); +} - m_locked = 0; +wxCriticalSection::~wxCriticalSection() +{ + ::DeleteCriticalSection((CRITICAL_SECTION *)m_buffer); } -wxMutex::~wxMutex() +void wxCriticalSection::Enter() { - if (m_locked > 0) - wxLogDebug("Warning: freeing a locked mutex (%d locks).", m_locked); - CloseHandle(p_internal->p_mutex); + ::EnterCriticalSection((CRITICAL_SECTION *)m_buffer); } -wxMutexError wxMutex::Lock() +void wxCriticalSection::Leave() { - DWORD ret; + ::LeaveCriticalSection((CRITICAL_SECTION *)m_buffer); +} + +// ---------------------------------------------------------------------------- +// wxMutex +// ---------------------------------------------------------------------------- + +class wxMutexInternal +{ +public: + wxMutexInternal(wxMutexType mutexType); + ~wxMutexInternal(); + + bool IsOk() const { return m_mutex != NULL; } - ret = WaitForSingleObject(p_internal->p_mutex, INFINITE); - if (ret == WAIT_ABANDONED) - return wxMUTEX_BUSY; + wxMutexError Lock() { return LockTimeout(INFINITE); } + wxMutexError TryLock() { return LockTimeout(0); } + wxMutexError Unlock(); - m_locked++; - return wxMUTEX_NO_ERROR; +private: + wxMutexError LockTimeout(DWORD milliseconds); + + HANDLE m_mutex; +}; + +// all mutexes are recursive under Win32 so we don't use mutexType +wxMutexInternal::wxMutexInternal(wxMutexType WXUNUSED(mutexType)) +{ + // create a nameless (hence intra process and always private) mutex + m_mutex = ::CreateMutex + ( + NULL, // default secutiry attributes + FALSE, // not initially locked + NULL // no name + ); + + if ( !m_mutex ) + { + wxLogLastError(_T("CreateMutex()")); + } } -wxMutexError wxMutex::TryLock() +wxMutexInternal::~wxMutexInternal() { - DWORD ret; + if ( m_mutex ) + { + if ( !::CloseHandle(m_mutex) ) + { + wxLogLastError(_T("CloseHandle(mutex)")); + } + } +} - ret = WaitForSingleObject(p_internal->p_mutex, 0); - if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED) - return wxMUTEX_BUSY; +wxMutexError wxMutexInternal::LockTimeout(DWORD milliseconds) +{ + DWORD rc = ::WaitForSingleObject(m_mutex, milliseconds); + if ( rc == WAIT_ABANDONED ) + { + // the previous caller died without releasing the mutex, but now we can + // really lock it + wxLogDebug(_T("WaitForSingleObject() returned WAIT_ABANDONED")); - m_locked++; - return wxMUTEX_NO_ERROR; + // use 0 timeout, normally we should always get it + rc = ::WaitForSingleObject(m_mutex, 0); + } + + switch ( rc ) + { + case WAIT_OBJECT_0: + // ok + break; + + case WAIT_TIMEOUT: + return wxMUTEX_BUSY; + + case WAIT_ABANDONED: // checked for above + default: + wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock")); + // fall through + + case WAIT_FAILED: + wxLogLastError(_T("WaitForSingleObject(mutex)")); + return wxMUTEX_MISC_ERROR; + } + + return wxMUTEX_NO_ERROR; } -wxMutexError wxMutex::Unlock() +wxMutexError wxMutexInternal::Unlock() { - if (m_locked > 0) - m_locked--; + if ( !::ReleaseMutex(m_mutex) ) + { + wxLogLastError(_("ReleaseMutex()")); - BOOL ret = ReleaseMutex(p_internal->p_mutex); - if ( ret != 0 ) - { - wxLogSysError(_("Couldn't release a mutex")); - return wxMUTEX_MISC_ERROR; - } + return wxMUTEX_MISC_ERROR; + } - return wxMUTEX_NO_ERROR; + return wxMUTEX_NO_ERROR; } -class wxConditionInternal { +// -------------------------------------------------------------------------- +// wxSemaphore +// -------------------------------------------------------------------------- + +// a trivial wrapper around Win32 semaphore +class wxSemaphoreInternal +{ public: - HANDLE event; - int waiters; + wxSemaphoreInternal(int initialcount, int maxcount); + ~wxSemaphoreInternal(); + + bool IsOk() const { return m_semaphore != NULL; } + + wxSemaError Wait() { return WaitTimeout(INFINITE); } + wxSemaError TryWait() { return WaitTimeout(0); } + wxSemaError WaitTimeout(unsigned long milliseconds); + + wxSemaError Post(); + +private: + HANDLE m_semaphore; }; -wxCondition::wxCondition() +wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount) { - p_internal = new wxConditionInternal; - p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL); - if ( !p_internal->event ) - { - wxLogSysError(_("Can not create event object.")); - } + if ( maxcount == 0 ) + { + // make it practically infinite + maxcount = INT_MAX; + } + + m_semaphore = ::CreateSemaphore + ( + NULL, // default security attributes + initialcount, + maxcount, + NULL // no name + ); - p_internal->waiters = 0; + if ( !m_semaphore ) + { + wxLogLastError(_T("CreateSemaphore()")); + } } -wxCondition::~wxCondition() +wxSemaphoreInternal::~wxSemaphoreInternal() { - CloseHandle(p_internal->event); + if ( m_semaphore ) + { + if ( !::CloseHandle(m_semaphore) ) + { + wxLogLastError(_T("CloseHandle(semaphore)")); + } + } } -void wxCondition::Wait(wxMutex& mutex) +wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long milliseconds) { - mutex.Unlock(); - p_internal->waiters++; - WaitForSingleObject(p_internal->event, INFINITE); - p_internal->waiters--; - mutex.Lock(); + DWORD rc = ::WaitForSingleObject( m_semaphore, milliseconds ); + + switch ( rc ) + { + case WAIT_OBJECT_0: + return wxSEMA_NO_ERROR; + + case WAIT_TIMEOUT: + return wxSEMA_BUSY; + + default: + wxLogLastError(_T("WaitForSingleObject(semaphore)")); + } + + return wxSEMA_MISC_ERROR; } -bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, - unsigned long nsec) +wxSemaError wxSemaphoreInternal::Post() { - DWORD ret; + if ( !::ReleaseSemaphore(m_semaphore, 1, NULL /* ptr to previous count */) ) + { + wxLogLastError(_T("ReleaseSemaphore")); - mutex.Unlock(); - p_internal->waiters++; - ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000)); - p_internal->waiters--; - mutex.Lock(); + return wxSEMA_MISC_ERROR; + } - return (ret != WAIT_TIMEOUT); + return wxSEMA_NO_ERROR; } -void wxCondition::Signal() +// -------------------------------------------------------------------------- +// wxCondition +// -------------------------------------------------------------------------- + +// Win32 doesn't have explicit support for the POSIX condition variables and +// the Win32 events have quite different semantics, so we reimplement the +// conditions from scratch using the mutexes and semaphores +class wxConditionInternal +{ +public: + wxConditionInternal(wxMutex& mutex); + + bool IsOk() const { return m_mutex.IsOk() && m_semaphore.IsOk(); } + + wxCondError Wait(); + wxCondError WaitTimeout(unsigned long milliseconds); + + wxCondError Signal(); + wxCondError Broadcast(); + +private: + // the number of threads currently waiting for this condition + LONG m_numWaiters; + + // the critical section protecting m_numWaiters + wxCriticalSection m_csWaiters; + + wxMutex& m_mutex; + wxSemaphore m_semaphore; +}; + +wxConditionInternal::wxConditionInternal(wxMutex& mutex) + : m_mutex(mutex) { - SetEvent(p_internal->event); + // another thread can't access it until we return from ctor, so no need to + // protect access to m_numWaiters here + m_numWaiters = 0; } -void wxCondition::Broadcast() +wxCondError wxConditionInternal::Wait() { - int i; + // increment the number of waiters + ::InterlockedIncrement(&m_numWaiters); + + m_mutex.Unlock(); + + // a potential race condition can occur here + // + // after a thread increments nwaiters, and unlocks the mutex and before the + // semaphore.Wait() is called, if another thread can cause a signal to be + // generated + // + // this race condition is handled by using a semaphore and incrementing the + // semaphore only if 'nwaiters' is greater that zero since the semaphore, + // can 'remember' signals the race condition will not occur + + // wait ( if necessary ) and decrement semaphore + wxSemaError err = m_semaphore.Wait(); + m_mutex.Lock(); + + return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR : wxCOND_MISC_ERROR; +} - for (i=0;iwaiters;i++) - { - if ( SetEvent(p_internal->event) == 0 ) +wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) +{ + ::InterlockedIncrement(&m_numWaiters); + + m_mutex.Unlock(); + + // a race condition can occur at this point in the code + // + // please see the comments in Wait(), for details + + wxSemaError err = m_semaphore.WaitTimeout(milliseconds); + + if ( err == wxSEMA_BUSY ) + { + // another potential race condition exists here it is caused when a + // 'waiting' thread timesout, and returns from WaitForSingleObject, but + // has not yet decremented 'nwaiters'. + // + // at this point if another thread calls signal() then the semaphore + // will be incremented, but the waiting thread will miss it. + // + // to handle this particular case, the waiting thread calls + // WaitForSingleObject again with a timeout of 0, after locking + // 'nwaiters_mutex'. this call does not block because of the zero + // timeout, but will allow the waiting thread to catch the missed + // signals. + wxCriticalSectionLocker lock(m_csWaiters); + + err = m_semaphore.WaitTimeout(0); + + if ( err != wxSEMA_NO_ERROR ) + { + m_numWaiters--; + } + } + + m_mutex.Lock(); + + return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR : wxCOND_MISC_ERROR; +} + +wxCondError wxConditionInternal::Signal() +{ + wxCriticalSectionLocker lock(m_csWaiters); + + if ( m_numWaiters > 0 ) { - wxLogSysError(_("Couldn't change the state of event object.")); + // increment the semaphore by 1 + if ( m_semaphore.Post() != wxSEMA_NO_ERROR ) + return wxCOND_MISC_ERROR; + + m_numWaiters--; } - } + + return wxCOND_NO_ERROR; +} + +wxCondError wxConditionInternal::Broadcast() +{ + wxCriticalSectionLocker lock(m_csWaiters); + + while ( m_numWaiters > 0 ) + { + if ( m_semaphore.Post() != wxSEMA_NO_ERROR ) + return wxCOND_MISC_ERROR; + + m_numWaiters--; + } + + return wxCOND_NO_ERROR; } -class wxThreadInternal { +// ---------------------------------------------------------------------------- +// wxThread implementation +// ---------------------------------------------------------------------------- + +// wxThreadInternal class +// ---------------------- + +class wxThreadInternal +{ public: - static DWORD WinThreadStart(LPVOID arg); + 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; + } + } - HANDLE thread_id; - int state; - int prio, defer; - DWORD tid; + // create a new (suspended) thread (for the given thread object) + bool Create(wxThread *thread, unsigned int stackSize); + + // 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 THREAD_RETVAL THREAD_CALLCONV WinThreadStart(void *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) +THREAD_RETVAL THREAD_CALLCONV wxThreadInternal::WinThreadStart(void *param) { - wxThread *ptr = (wxThread *)arg; - DWORD ret; + THREAD_RETVAL rc; + bool wasCancelled; + + // first of all, check whether we hadn't been cancelled already and don't + // start the user code at all then + wxThread *thread = (wxThread *)param; + if ( thread->m_internal->GetState() == STATE_EXITED ) + { + rc = (THREAD_RETVAL)-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; + } - ret = (DWORD)ptr->Entry(); - ptr->p_internal->state = STATE_EXITED; + rc = (THREAD_RETVAL)thread->Entry(); - return ret; + // 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; } -wxThreadError wxThread::Create() +void wxThreadInternal::SetPriority(unsigned int priority) { - int prio = p_internal->prio; + 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; + } - p_internal->thread_id = CreateThread(NULL, 0, - (LPTHREAD_START_ROUTINE)wxThreadInternal::WinThreadStart, - (void *)this, CREATE_SUSPENDED, &p_internal->tid); + if ( !::SetThreadPriority(m_hThread, win_priority) ) + { + wxLogSysError(_("Can't set thread priority")); + } +} - if ( p_internal->thread_id == NULL ) - { - wxLogSysError(_("Can't create thread")); - return wxTHREAD_NO_RESOURCE; - } +bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize) +{ + // 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) +#ifdef wxUSE_BEGIN_THREAD + + // Watcom is reported to not like 0 stack size (which means "use default" + // for the other compilers and is also the default value for stackSize) +#ifdef __WATCOMC__ + if ( !stackSize ) + stackSize = 10240; +#endif // __WATCOMC__ + + m_hThread = (HANDLE)_beginthreadex + ( + NULL, // default security + stackSize, + wxThreadInternal::WinThreadStart, // entry point + thread, + CREATE_SUSPENDED, + (unsigned int *)&m_tid + ); +#else // compiler doesn't have _beginthreadex + m_hThread = ::CreateThread + ( + NULL, // default security + stackSize, // stack size + wxThreadInternal::WinThreadStart, // thread entry point + (LPVOID)thread, // parameter + CREATE_SUSPENDED, // flags + &m_tid // [out] thread id + ); +#endif // _beginthreadex/CreateThread + + if ( m_hThread == NULL ) + { + wxLogSysError(_("Can't create thread")); - int win_prio; - 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; - else - { - wxFAIL_MSG("invalid value of thread priority parameter"); - win_prio = THREAD_PRIORITY_NORMAL; - } + return FALSE; + } - SetThreadPriority(p_internal->thread_id, win_prio); + if ( m_priority != WXTHREAD_DEFAULT_PRIORITY ) + { + SetPriority(m_priority); + } - ResumeThread(p_internal->thread_id); - p_internal->state = STATE_RUNNING; - - return wxTHREAD_NO_ERROR; + return TRUE; } -wxThreadError wxThread::Destroy() +bool wxThreadInternal::Suspend() { - if (p_internal->state != STATE_RUNNING) - return wxTHREAD_NOT_RUNNING; + DWORD nSuspendCount = ::SuspendThread(m_hThread); + if ( nSuspendCount == (DWORD)-1 ) + { + wxLogSysError(_("Can not suspend thread %x"), m_hThread); - if (p_internal->defer == FALSE) - TerminateThread(p_internal->thread_id, 0); - else - p_internal->state = STATE_CANCELED; + return FALSE; + } - return wxTHREAD_NO_ERROR; + m_state = STATE_PAUSED; + + return TRUE; } -wxThreadError wxThread::Pause() +bool wxThreadInternal::Resume() { - DWORD nSuspendCount = ::SuspendThread(p_internal->thread_id); + DWORD nSuspendCount = ::ResumeThread(m_hThread); if ( nSuspendCount == (DWORD)-1 ) { - wxLogSysError(_("Can not suspend thread %x"), p_internal->thread_id); + wxLogSysError(_("Can not resume thread %x"), m_hThread); - return wxTHREAD_MISC_ERROR; // no idea what might provoke this error... + return FALSE; } - return wxTHREAD_NO_ERROR; + // 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; + } + + return TRUE; } -wxThreadError wxThread::Resume() +// static functions +// ---------------- + +wxThread *wxThread::This() { - DWORD nSuspendCount = ::ResumeThread(p_internal->thread_id); - if ( nSuspendCount == (DWORD)-1 ) + wxThread *thread = (wxThread *)::TlsGetValue(gs_tlsThisThread); + + // be careful, 0 may be a valid return value as well + if ( !thread && (::GetLastError() != NO_ERROR) ) { - wxLogSysError(_("Can not resume thread %x"), p_internal->thread_id); + wxLogSysError(_("Couldn't get the current thread pointer")); - return wxTHREAD_MISC_ERROR; // no idea what might provoke this error... + // return NULL... } + return thread; +} + +bool wxThread::IsMain() +{ + return ::GetCurrentThreadId() == gs_idMainThread; +} + +#ifdef Yield +#undef Yield +#endif + +void wxThread::Yield() +{ + // 0 argument to Sleep() is special and means to just give away the rest of + // our timeslice + ::Sleep(0); +} + +void wxThread::Sleep(unsigned long milliseconds) +{ + ::Sleep(milliseconds); +} + +int wxThread::GetCPUCount() +{ + SYSTEM_INFO si; + GetSystemInfo(&si); + + return si.dwNumberOfProcessors; +} + +unsigned long wxThread::GetCurrentId() +{ + return (unsigned long)::GetCurrentThreadId(); +} + +bool wxThread::SetConcurrency(size_t level) +{ + 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; +} + +// ctor and dtor +// ------------- + +wxThread::wxThread(wxThreadKind kind) +{ + m_internal = new wxThreadInternal(); + + m_isDetached = kind == wxTHREAD_DETACHED; +} + +wxThread::~wxThread() +{ + delete m_internal; +} + +// create/start thread +// ------------------- + +wxThreadError wxThread::Create(unsigned int stackSize) +{ + wxCriticalSectionLocker lock(m_critsect); + + if ( !m_internal->Create(this, stackSize) ) + return wxTHREAD_NO_RESOURCE; + return wxTHREAD_NO_ERROR; } -void wxThread::Exit(void *status) +wxThreadError wxThread::Run() { - p_internal->state = STATE_EXITED; - ExitThread((DWORD)status); + 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(); } -void wxThread::SetPriority(int prio) +// suspend/resume thread +// --------------------- + +wxThreadError wxThread::Pause() +{ + wxCriticalSectionLocker lock(m_critsect); + + return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR; +} + +wxThreadError wxThread::Resume() { - p_internal->prio = prio; + wxCriticalSectionLocker lock(m_critsect); + + return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR; } -int wxThread::GetPriority() const +// stopping thread +// --------------- + +wxThread::ExitCode wxThread::Wait() { - return p_internal->prio; + // 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; } -void wxThread::DeferDestroy(bool on) +wxThreadError wxThread::Delete(ExitCode *pRc) { - p_internal->defer = on; + 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; + } + + // 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 = 0; // suppress warnings from broken compilers + do + { + if ( IsMain() ) + { + // give the thread we're waiting for chance to do the GUI call + // it might be in + if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() ) + { + wxMutexGuiLeave(); + } + } + + result = ::MsgWaitForMultipleObjects + ( + 1, // number of objects to wait for + &hThread, // the objects + FALSE, // don't wait for all objects + INFINITE, // no timeout + QS_ALLINPUT | // return as soon as there are any events + QS_ALLPOSTMESSAGE + ); + + 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; + } + 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; + } + } + + // although the thread might be already in the EXITED state it might not + // have terminated yet and so we are not sure that it has actually + // terminated if the "if" above hadn't been taken + do + { + if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) ) + { + wxLogLastError(wxT("GetExitCodeThread")); + + rc = (ExitCode)-1; + } + } while ( (DWORD)rc == STILL_ACTIVE ); + + 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; + } + + if ( pRc ) + *pRc = rc; + + return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR; } -void wxThread::TestDestroy() +wxThreadError wxThread::Kill() { - if (p_internal->state == STATE_CANCELED) - ExitThread(0); + 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; } -void *wxThread::Join() +void wxThread::Exit(ExitCode status) { - DWORD exit_code; + m_internal->Free(); + + if ( IsDetached() ) + { + delete this; + } - if (p_internal->state == STATE_IDLE) - return NULL; +#ifdef wxUSE_BEGIN_THREAD + _endthreadex((unsigned)status); +#else // !VC++ + ::ExitThread((DWORD)status); +#endif // VC++/!VC++ - if (wxThread::IsMain()) - wxMainMutex->Unlock(); - WaitForSingleObject(p_internal->thread_id, INFINITE); - if (wxThread::IsMain()) - wxMainMutex->Lock(); + wxFAIL_MSG(wxT("Couldn't return from ExitThread()!")); +} - GetExitCodeThread(p_internal->thread_id, &exit_code); - CloseHandle(p_internal->thread_id); +// priority setting +// ---------------- - p_internal->state = STATE_IDLE; +void wxThread::SetPriority(unsigned int prio) +{ + wxCriticalSectionLocker lock(m_critsect); - return (void *)exit_code; + m_internal->SetPriority(prio); } -unsigned long wxThread::GetID() const +unsigned int wxThread::GetPriority() const { - return (unsigned long)p_internal->tid; + 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 { - return (p_internal->state == STATE_RUNNING); + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetState() == STATE_RUNNING; } bool wxThread::IsAlive() const { - return (p_internal->state == STATE_RUNNING); + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return (m_internal->GetState() == STATE_RUNNING) || + (m_internal->GetState() == STATE_PAUSED); } -bool wxThread::IsMain() +bool wxThread::IsPaused() const { - return (GetCurrentThread() == p_mainid); + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast + + return m_internal->GetState() == STATE_PAUSED; } -wxThread::wxThread() +bool wxThread::TestDestroy() { - p_internal = new wxThreadInternal(); + wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast - p_internal->defer = FALSE; - p_internal->prio = WXTHREAD_DEFAULT_PRIORITY; - p_internal->state = STATE_IDLE; + return m_internal->GetState() == STATE_CANCELED; } -wxThread::~wxThread() +// ---------------------------------------------------------------------------- +// Automatic initialization for thread module +// ---------------------------------------------------------------------------- + +class wxThreadModule : public wxModule +{ +public: + virtual bool OnInit(); + virtual void OnExit(); + +private: + DECLARE_DYNAMIC_CLASS(wxThreadModule) +}; + +IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule) + +bool wxThreadModule::OnInit() { - Destroy(); - Join(); - delete p_internal; + // 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; } -// The default callback just joins the thread and throws away the result. -void wxThread::OnExit() +void wxThreadModule::OnExit() { - Join(); + 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; } -// GUI mutex functions +// ---------------------------------------------------------------------------- +// under Windows, these functions are implemented using a critical section and +// not a mutex, so the names are a bit confusing +// ---------------------------------------------------------------------------- void WXDLLEXPORT wxMutexGuiEnter() { - wxFAIL_MSG("not implemented"); + // 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() { - wxFAIL_MSG("not implemented"); + 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(); } -// Automatic initialization +void WXDLLEXPORT wxMutexGuiLeaveOrEnter() +{ + wxASSERT_MSG( wxThread::IsMain(), + wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") ); -IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule) + 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 wxThreadModule::OnInit() +bool WXDLLEXPORT wxGuiOwnedByMainThread() { - wxMainMutex = new wxMutex(); - p_mainid = GetCurrentThread(); - wxMainMutex->Lock(); - return TRUE; + return gs_bGuiOwnedByMainThread; } -void wxThreadModule::OnExit() +// wake up the main thread if it's in ::GetMessage() +void WXDLLEXPORT wxWakeUpMainThread() { - wxMainMutex->Unlock(); - delete wxMainMutex; -}; + // 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; +} + +// ---------------------------------------------------------------------------- +// include common implementation code +// ---------------------------------------------------------------------------- + +#include "wx/thrimpl.cpp" + +#endif // wxUSE_THREADS