/////////////////////////////////////////////////////////////////////////////
-// 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"
-#endif
-
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
#pragma hdrstop
#endif
+#if wxUSE_THREADS
+
+#include "wx/thread.h"
+
#ifndef WX_PRECOMP
- #include "wx/wx.h"
+ #include "wx/intl.h"
+ #include "wx/app.h"
#endif
-#if wxUSE_THREADS
-
-#include <stdio.h>
+#include "wx/apptrait.h"
+#include "wx/scopeguard.h"
-#include <windows.h>
+#include "wx/msw/private.h"
+#include "wx/msw/missing.h"
+#include "wx/msw/seh.h"
+#include "wx/except.h"
#include "wx/module.h"
-#include "wx/thread.h"
-enum thread_state
+// must have this symbol defined to get _beginthread/_endthread declarations
+#ifndef _MT
+ #define _MT
+#endif
+
+#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__)
+
+#ifndef __WXWINCE__
+ #undef wxUSE_BEGIN_THREAD
+ #define wxUSE_BEGIN_THREAD
+#endif
+
+#endif
+
+#ifdef wxUSE_BEGIN_THREAD
+ // this is where _beginthreadex() is declared
+ #include <process.h>
+
+ // the return type of the thread function entry point
+ typedef unsigned THREAD_RETVAL;
+
+ // 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_IDLE = 0,
- STATE_RUNNING,
- STATE_CANCELED,
- STATE_EXITED
+ 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
// ----------------------------------------------------------------------------
+// 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 HANDLE s_idMainThread;
+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 *s_critsectGui;
+static wxCriticalSection *gs_critsectGui = NULL;
+
+// critical section which protects gs_nWaitingForGui variable
+static wxCriticalSection *gs_critsectWaitingForGui = NULL;
+
+// critical section which serializes WinThreadStart() and WaitForTerminate()
+// (this is a potential bottleneck, we use a single crit sect for all threads
+// in the system, but normally time spent inside it should be quite short)
+static wxCriticalSection *gs_critsectThreadDelete = 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 classes
+// Windows implementation of thread and related classes
// ============================================================================
// ----------------------------------------------------------------------------
-// wxMutex implementation
+// wxCriticalSection
// ----------------------------------------------------------------------------
+
+wxCriticalSection::wxCriticalSection()
+{
+ wxCOMPILE_TIME_ASSERT( sizeof(CRITICAL_SECTION) <= sizeof(wxCritSectBuffer),
+ wxCriticalSectionBufferTooSmall );
+
+ ::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer);
+}
+
+wxCriticalSection::~wxCriticalSection()
+{
+ ::DeleteCriticalSection((CRITICAL_SECTION *)m_buffer);
+}
+
+void wxCriticalSection::Enter()
+{
+ ::EnterCriticalSection((CRITICAL_SECTION *)m_buffer);
+}
+
+void wxCriticalSection::Leave()
+{
+ ::LeaveCriticalSection((CRITICAL_SECTION *)m_buffer);
+}
+
+// ----------------------------------------------------------------------------
+// wxMutex
+// ----------------------------------------------------------------------------
+
class wxMutexInternal
{
public:
- HANDLE p_mutex;
+ wxMutexInternal(wxMutexType mutexType);
+ ~wxMutexInternal();
+
+ bool IsOk() const { return m_mutex != NULL; }
+
+ wxMutexError Lock() { return LockTimeout(INFINITE); }
+ wxMutexError TryLock() { return LockTimeout(0); }
+ wxMutexError Unlock();
+
+private:
+ wxMutexError LockTimeout(DWORD milliseconds);
+
+ HANDLE m_mutex;
+
+ DECLARE_NO_COPY_CLASS(wxMutexInternal)
};
-wxMutex::wxMutex()
+// all mutexes are recursive under Win32 so we don't use mutexType
+wxMutexInternal::wxMutexInternal(wxMutexType WXUNUSED(mutexType))
{
- p_internal = new wxMutexInternal;
- p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL);
- if ( !p_internal->p_mutex )
+ // 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 )
{
- wxLogSysError(_("Can not create mutex."));
+ wxLogLastError(_T("CreateMutex()"));
}
-
- m_locked = 0;
}
-wxMutex::~wxMutex()
+wxMutexInternal::~wxMutexInternal()
{
- if (m_locked > 0)
- wxLogDebug("Warning: freeing a locked mutex (%d locks).", m_locked);
- CloseHandle(p_internal->p_mutex);
+ if ( m_mutex )
+ {
+ if ( !::CloseHandle(m_mutex) )
+ {
+ wxLogLastError(_T("CloseHandle(mutex)"));
+ }
+ }
}
-wxMutexError wxMutex::Lock()
+wxMutexError wxMutexInternal::LockTimeout(DWORD milliseconds)
{
- DWORD ret;
-
- ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
- switch ( ret )
+ DWORD rc = ::WaitForSingleObject(m_mutex, milliseconds);
+ if ( rc == WAIT_ABANDONED )
{
- case WAIT_ABANDONED:
- return wxMUTEX_BUSY;
+ // the previous caller died without releasing the mutex, but now we can
+ // really lock it
+ wxLogDebug(_T("WaitForSingleObject() returned WAIT_ABANDONED"));
+
+ // use 0 timeout, normally we should always get it
+ rc = ::WaitForSingleObject(m_mutex, 0);
+ }
+ switch ( rc )
+ {
case WAIT_OBJECT_0:
// ok
break;
- case WAIT_FAILED:
- wxLogSysError(_("Couldn't acquire a mutex lock"));
- return wxMUTEX_MISC_ERROR;
-
case WAIT_TIMEOUT:
+ return wxMUTEX_BUSY;
+
+ case WAIT_ABANDONED: // checked for above
default:
- wxFAIL_MSG("impossible return value in wxMutex::Lock");
+ wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
+ // fall through
+
+ case WAIT_FAILED:
+ wxLogLastError(_T("WaitForSingleObject(mutex)"));
+ return wxMUTEX_MISC_ERROR;
}
- m_locked++;
return wxMUTEX_NO_ERROR;
}
-wxMutexError wxMutex::TryLock()
+wxMutexError wxMutexInternal::Unlock()
{
- DWORD ret;
+ if ( !::ReleaseMutex(m_mutex) )
+ {
+ wxLogLastError(_T("ReleaseMutex()"));
- ret = WaitForSingleObject(p_internal->p_mutex, 0);
- if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED)
- return wxMUTEX_BUSY;
+ return wxMUTEX_MISC_ERROR;
+ }
- m_locked++;
return wxMUTEX_NO_ERROR;
}
-wxMutexError wxMutex::Unlock()
+// --------------------------------------------------------------------------
+// wxSemaphore
+// --------------------------------------------------------------------------
+
+// a trivial wrapper around Win32 semaphore
+class wxSemaphoreInternal
{
- if (m_locked > 0)
- m_locked--;
+public:
+ wxSemaphoreInternal(int initialcount, int maxcount);
+ ~wxSemaphoreInternal();
+
+ bool IsOk() const { return m_semaphore != NULL; }
- BOOL ret = ReleaseMutex(p_internal->p_mutex);
- if ( ret == 0 )
+ wxSemaError Wait() { return WaitTimeout(INFINITE); }
+
+ wxSemaError TryWait()
{
- wxLogSysError(_("Couldn't release a mutex"));
- return wxMUTEX_MISC_ERROR;
+ wxSemaError rc = WaitTimeout(0);
+ if ( rc == wxSEMA_TIMEOUT )
+ rc = wxSEMA_BUSY;
+
+ return rc;
}
- return wxMUTEX_NO_ERROR;
-}
+ wxSemaError WaitTimeout(unsigned long milliseconds);
-// ----------------------------------------------------------------------------
-// wxCondition implementation
-// ----------------------------------------------------------------------------
+ wxSemaError Post();
-class wxConditionInternal
-{
-public:
- HANDLE event;
- int waiters;
+private:
+ HANDLE m_semaphore;
+
+ DECLARE_NO_COPY_CLASS(wxSemaphoreInternal)
};
-wxCondition::wxCondition()
+wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
{
- p_internal = new wxConditionInternal;
- p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL);
- if ( !p_internal->event )
+#if !defined(_WIN32_WCE) || (_WIN32_WCE >= 300)
+ if ( maxcount == 0 )
{
- wxLogSysError(_("Can not create event object."));
+ // make it practically infinite
+ maxcount = INT_MAX;
}
- p_internal->waiters = 0;
+ m_semaphore = ::CreateSemaphore
+ (
+ NULL, // default security attributes
+ initialcount,
+ maxcount,
+ NULL // no name
+ );
+#endif
+ 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 );
-bool wxCondition::Wait(wxMutex& mutex,
- unsigned long sec,
- unsigned long nsec)
-{
- DWORD ret;
+ switch ( rc )
+ {
+ case WAIT_OBJECT_0:
+ return wxSEMA_NO_ERROR;
- mutex.Unlock();
- p_internal->waiters++;
- ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000));
- p_internal->waiters--;
- mutex.Lock();
+ case WAIT_TIMEOUT:
+ return wxSEMA_TIMEOUT;
- return (ret != WAIT_TIMEOUT);
-}
+ default:
+ wxLogLastError(_T("WaitForSingleObject(semaphore)"));
+ }
-void wxCondition::Signal()
-{
- SetEvent(p_internal->event);
+ return wxSEMA_MISC_ERROR;
}
-void wxCondition::Broadcast()
+wxSemaError wxSemaphoreInternal::Post()
{
- int i;
-
- for (i=0;i<p_internal->waiters;i++)
+#if !defined(_WIN32_WCE) || (_WIN32_WCE >= 300)
+ if ( !::ReleaseSemaphore(m_semaphore, 1, NULL /* ptr to previous count */) )
+#endif
{
- if ( SetEvent(p_internal->event) == 0 )
- {
- wxLogSysError(_("Couldn't change the state of event object."));
- }
+ wxLogLastError(_T("ReleaseSemaphore"));
+
+ return wxSEMA_MISC_ERROR;
}
+
+ return wxSEMA_NO_ERROR;
}
// ----------------------------------------------------------------------------
-// wxCriticalSection implementation
+// wxThread implementation
// ----------------------------------------------------------------------------
-class wxCriticalSectionInternal
+// wxThreadInternal class
+// ----------------------
+
+class wxThreadInternal
{
public:
- // init the critical section object
- wxCriticalSectionInternal()
- { ::InitializeCriticalSection(&m_data); }
+ wxThreadInternal(wxThread *thread)
+ {
+ m_thread = thread;
+ m_hThread = 0;
+ m_state = STATE_NEW;
+ m_priority = WXTHREAD_DEFAULT_PRIORITY;
+ m_nRef = 1;
+ }
+
+ ~wxThreadInternal()
+ {
+ Free();
+ }
+
+ void Free()
+ {
+ if ( m_hThread )
+ {
+ if ( !::CloseHandle(m_hThread) )
+ {
+ wxLogLastError(wxT("CloseHandle(thread)"));
+ }
- // implicit cast to the associated data
- operator CRITICAL_SECTION *() { return &m_data; }
+ m_hThread = 0;
+ }
+ }
+
+ // create a new (suspended) thread (for the given thread object)
+ bool Create(wxThread *thread, unsigned int stackSize);
+
+ // wait for the thread to terminate, either by itself, or by asking it
+ // (politely, this is not Kill()!) to do it
+ wxThreadError WaitForTerminate(wxCriticalSection& cs,
+ wxThread::ExitCode *pRc,
+ wxThread *threadToDelete = NULL);
+
+ // kill the thread unconditionally
+ wxThreadError Kill();
+
+ // 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; }
- // free the associated ressources
- ~wxCriticalSectionInternal()
- { ::DeleteCriticalSection(&m_data); }
+ // 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; }
+
+ // the thread function forwarding to DoThreadStart
+ static THREAD_RETVAL THREAD_CALLCONV WinThreadStart(void *thread);
+
+ // really start the thread (if it's not already dead)
+ static THREAD_RETVAL DoThreadStart(wxThread *thread);
+
+ // call OnExit() on the thread
+ static void DoThreadOnExit(wxThread *thread);
+
+
+ void KeepAlive()
+ {
+ if ( m_thread->IsDetached() )
+ ::InterlockedIncrement(&m_nRef);
+ }
+
+ void LetDie()
+ {
+ if ( m_thread->IsDetached() && !::InterlockedDecrement(&m_nRef) )
+ delete m_thread;
+ }
private:
- CRITICAL_SECTION m_data;
+ // the thread we're associated with
+ wxThread *m_thread;
+
+ 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
+
+ // number of threads which need this thread to remain alive, when the count
+ // reaches 0 we kill the owning wxThread -- and die ourselves with it
+ LONG m_nRef;
+
+ DECLARE_NO_COPY_CLASS(wxThreadInternal)
};
-wxCriticalSection::wxCriticalSection()
+// small class which keeps a thread alive during its lifetime
+class wxThreadKeepAlive
{
- m_critsect = new wxCriticalSectionInternal;
-}
+public:
+ wxThreadKeepAlive(wxThreadInternal& thrImpl) : m_thrImpl(thrImpl)
+ { m_thrImpl.KeepAlive(); }
+ ~wxThreadKeepAlive()
+ { m_thrImpl.LetDie(); }
-wxCriticalSection::~wxCriticalSection()
+private:
+ wxThreadInternal& m_thrImpl;
+};
+
+/* static */
+void wxThreadInternal::DoThreadOnExit(wxThread *thread)
{
- delete m_critsect;
+ wxTRY
+ {
+ thread->OnExit();
+ }
+ wxCATCH_ALL( wxTheApp->OnUnhandledException(); )
}
-void wxCriticalSection::Enter()
+/* static */
+THREAD_RETVAL wxThreadInternal::DoThreadStart(wxThread *thread)
{
- ::EnterCriticalSection(*m_critsect);
+ wxON_BLOCK_EXIT1(DoThreadOnExit, thread);
+
+ THREAD_RETVAL rc = (THREAD_RETVAL)-1;
+
+ wxTRY
+ {
+ // store the thread object in the TLS
+ if ( !::TlsSetValue(gs_tlsThisThread, thread) )
+ {
+ wxLogSysError(_("Can not start thread: error writing TLS."));
+
+ return (THREAD_RETVAL)-1;
+ }
+
+ rc = (THREAD_RETVAL)thread->Entry();
+ }
+ wxCATCH_ALL( wxTheApp->OnUnhandledException(); )
+
+ return rc;
}
-void wxCriticalSection::Leave()
+/* static */
+THREAD_RETVAL THREAD_CALLCONV wxThreadInternal::WinThreadStart(void *param)
{
- ::LeaveCriticalSection(*m_critsect);
-}
+ THREAD_RETVAL rc = (THREAD_RETVAL)-1;
-// ----------------------------------------------------------------------------
-// wxThread implementation
-// ----------------------------------------------------------------------------
+ wxThread * const thread = (wxThread *)param;
-class wxThreadInternal
-{
-public:
- static DWORD WinThreadStart(LPVOID arg);
+ // each thread has its own SEH translator so install our own a.s.a.p.
+ DisableAutomaticSETranslator();
- HANDLE thread_id;
- int state;
- int prio, defer;
- DWORD tid;
-};
+ // first of all, check whether we hadn't been cancelled already and don't
+ // start the user code at all then
+ const bool hasExited = thread->m_internal->GetState() == STATE_EXITED;
-DWORD wxThreadInternal::WinThreadStart(LPVOID arg)
-{
- wxThread *ptr = (wxThread *)arg;
- DWORD ret;
+ // run the thread function itself inside a SEH try/except block
+ wxSEH_TRY
+ {
+ if ( hasExited )
+ DoThreadOnExit(thread);
+ else
+ rc = DoThreadStart(thread);
+ }
+ wxSEH_HANDLE((THREAD_RETVAL)-1)
+
+
+ // save IsDetached because thread object can be deleted by joinable
+ // threads after state is changed to STATE_EXITED.
+ const bool isDetached = thread->IsDetached();
+ if ( !hasExited )
+ {
+ // enter m_critsect before changing the thread state
+ //
+ // NB: can't use wxCriticalSectionLocker here as we use SEH and it's
+ // incompatible with C++ object dtors
+ thread->m_critsect.Enter();
+ thread->m_internal->SetState(STATE_EXITED);
+ thread->m_critsect.Leave();
+ }
- ret = (DWORD)ptr->Entry();
- ptr->p_internal->state = STATE_EXITED;
+ // the thread may delete itself now if it wants, we don't need it any more
+ if ( isDetached )
+ thread->m_internal->LetDie();
- return ret;
+ return rc;
}
-wxThreadError wxThread::Create()
+void wxThreadInternal::SetPriority(unsigned int priority)
{
- int prio = p_internal->prio;
+ m_priority = priority;
+
+ // translate wxWidgets 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 )
+bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize)
+{
+ wxASSERT_MSG( m_state == STATE_NEW && !m_hThread,
+ _T("Create()ing thread twice?") );
+
+ // 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"));
- return wxTHREAD_NO_RESOURCE;
+
+ return false;
}
- 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
+ if ( m_priority != WXTHREAD_DEFAULT_PRIORITY )
{
- wxFAIL_MSG("invalid value of thread priority parameter");
- win_prio = THREAD_PRIORITY_NORMAL;
+ SetPriority(m_priority);
}
- SetThreadPriority(p_internal->thread_id, win_prio);
+ return true;
+}
- ResumeThread(p_internal->thread_id);
- p_internal->state = STATE_RUNNING;
+wxThreadError wxThreadInternal::Kill()
+{
+ if ( !::TerminateThread(m_hThread, (DWORD)-1) )
+ {
+ wxLogSysError(_("Couldn't terminate thread"));
+
+ return wxTHREAD_MISC_ERROR;
+ }
+
+ Free();
return wxTHREAD_NO_ERROR;
}
-wxThreadError wxThread::Destroy()
+wxThreadError
+wxThreadInternal::WaitForTerminate(wxCriticalSection& cs,
+ wxThread::ExitCode *pRc,
+ wxThread *threadToDelete)
{
- if (p_internal->state != STATE_RUNNING)
- return wxTHREAD_NOT_RUNNING;
+ // prevent the thread C++ object from disappearing as long as we are using
+ // it here
+ wxThreadKeepAlive keepAlive(*this);
- if ( p_internal->defer )
- // soft termination: just set the flag and wait until the thread
- // auto terminates
- p_internal->state = STATE_CANCELED;
- else
- // kill the thread
- TerminateThread(p_internal->thread_id, 0);
- return wxTHREAD_NO_ERROR;
+ // we may either wait passively for the thread to terminate (when called
+ // from Wait()) or ask it to terminate (when called from Delete())
+ bool shouldDelete = threadToDelete != NULL;
+
+ wxThread::ExitCode rc = 0;
+
+ // we might need to resume the thread if it's currently stopped
+ bool shouldResume = false;
+
+ // as Delete() (which calls us) is always safe to call we need to consider
+ // all possible states
+ {
+ wxCriticalSectionLocker lock(cs);
+
+ if ( m_state == STATE_NEW )
+ {
+ if ( shouldDelete )
+ {
+ // 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_state = STATE_EXITED;
+
+ // we must call Resume() as the thread hasn't been initially
+ // resumed yet (and as Resume() it knows about STATE_EXITED
+ // special case, it won't touch it and WinThreadStart() will
+ // just exit immediately)
+ shouldResume = true;
+ shouldDelete = false;
+ }
+ //else: shouldResume is correctly set to false here, wait until
+ // someone else runs the thread and it finishes
+ }
+ else // running, paused, cancelled or even exited
+ {
+ shouldResume = m_state == STATE_PAUSED;
+ }
+ }
+
+ // resume the thread if it is paused
+ if ( shouldResume )
+ Resume();
+
+ // ask the thread to terminate
+ if ( shouldDelete )
+ {
+ wxCriticalSectionLocker lock(cs);
+
+ Cancel();
+ }
+
+
+ // now wait for thread to finish
+ if ( wxThread::IsMain() )
+ {
+ // set flag for wxIsWaitingForThread()
+ gs_waitingForThread = true;
+ }
+
+ // 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
+ // (note that even in console applications we might have to process
+ // messages if we use wxExecute() or timers or ...)
+ DWORD result wxDUMMY_INITIALIZE(0);
+ do
+ {
+ if ( wxThread::IsMain() )
+ {
+ // give the thread we're waiting for chance to do the GUI call
+ // it might be in
+ if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
+ {
+ wxMutexGuiLeave();
+ }
+ }
+
+#if !defined(QS_ALLPOSTMESSAGE)
+#define QS_ALLPOSTMESSAGE 0
+#endif
+
+ result = ::MsgWaitForMultipleObjects
+ (
+ 1, // number of objects to wait for
+ &m_hThread, // the objects
+ false, // don't wait for all objects
+ INFINITE, // no timeout
+ QS_ALLINPUT|QS_ALLPOSTMESSAGE // 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 -- but only if we're the
+ // main thread as we don't support processing messages in
+ // the other ones
+ //
+ // NB: we still must include QS_ALLINPUT even when waiting
+ // in a secondary thread because if it had created some
+ // window somehow (possible not even using wxWidgets)
+ // the system might dead lock then
+ if ( wxThread::IsMain() )
+ {
+ wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits()
+ : NULL;
+
+ if ( traits && !traits->DoMessageFromThreadWait() )
+ {
+ // WM_QUIT received: kill the thread
+ Kill();
+
+ return wxTHREAD_KILLED;
+ }
+ }
+ break;
+
+ default:
+ wxFAIL_MSG(wxT("unexpected result of MsgWaitForMultipleObject"));
+ }
+ } while ( result != WAIT_OBJECT_0 );
+
+ if ( wxThread::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
+ for ( ;; )
+ {
+ if ( !::GetExitCodeThread(m_hThread, (LPDWORD)&rc) )
+ {
+ wxLogLastError(wxT("GetExitCodeThread"));
+
+ rc = (wxThread::ExitCode)-1;
+
+ break;
+ }
+
+ if ( (DWORD)rc != STILL_ACTIVE )
+ break;
+
+ // give the other thread some time to terminate, otherwise we may be
+ // starving it
+ ::Sleep(1);
+ }
+
+ if ( pRc )
+ *pRc = rc;
+
+ // we don't need the thread handle any more in any case
+ Free();
+
+
+ return rc == (wxThread::ExitCode)-1 ? wxTHREAD_MISC_ERROR
+ : wxTHREAD_NO_ERROR;
}
-wxThreadError wxThread::Pause()
+bool wxThreadInternal::Suspend()
{
- DWORD nSuspendCount = ::SuspendThread(p_internal->thread_id);
+ DWORD nSuspendCount = ::SuspendThread(m_hThread);
if ( nSuspendCount == (DWORD)-1 )
{
- wxLogSysError(_("Can not suspend thread %x"), p_internal->thread_id);
+ wxLogSysError(_("Can not suspend thread %x"), m_hThread);
- return wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
+ return false;
}
- return wxTHREAD_NO_ERROR;
+ m_state = STATE_PAUSED;
+
+ return true;
}
-wxThreadError wxThread::Resume()
+bool wxThreadInternal::Resume()
{
- DWORD nSuspendCount = ::ResumeThread(p_internal->thread_id);
+ DWORD nSuspendCount = ::ResumeThread(m_hThread);
if ( nSuspendCount == (DWORD)-1 )
{
- wxLogSysError(_("Can not resume thread %x"), p_internal->thread_id);
+ 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 code in WaitForTerminate() wouldn't work
+ if ( m_state != STATE_EXITED )
+ {
+ m_state = STATE_RUNNING;
+ }
+
+ return true;
+}
+
+// static functions
+// ----------------
+
+wxThread *wxThread::This()
+{
+ 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"));
+
+ // return NULL...
+ }
+
+ return thread;
+}
+
+bool wxThread::IsMain()
+{
+ return ::GetCurrentThreadId() == gs_idMainThread || gs_idMainThread == 0;
+}
+
+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 WXUNUSED_IN_WINCE(level))
+{
+#ifdef __WXWINCE__
+ return false;
+#else
+ 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_PTR 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 == 0 )
+ {
+ // 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 wxTHREAD_MISC_ERROR; // no idea what might provoke this error...
+ 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;
+#endif // __WXWINCE__/!__WXWINCE__
+}
+
+// ctor and dtor
+// -------------
+
+wxThread::wxThread(wxThreadKind kind)
+{
+ m_internal = new wxThreadInternal(this);
+
+ 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()
{
- p_internal->prio = prio;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-int wxThread::GetPriority() const
+wxThreadError wxThread::Resume()
{
- return p_internal->prio;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
}
-void wxThread::DeferDestroy(bool on)
+// stopping thread
+// ---------------
+
+wxThread::ExitCode wxThread::Wait()
{
- p_internal->defer = on;
+ // 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("wxThread::Wait(): can't wait for detached thread") );
+
+ ExitCode rc = (ExitCode)-1;
+
+ (void)m_internal->WaitForTerminate(m_critsect, &rc);
+
+ return rc;
}
-bool wxThread::TestDestroy()
+wxThreadError wxThread::Delete(ExitCode *pRc)
{
- return p_internal->state == STATE_CANCELED;
+ return m_internal->WaitForTerminate(m_critsect, pRc, this);
}
-void *wxThread::Join()
+wxThreadError wxThread::Kill()
{
- DWORD exit_code;
+ if ( !IsRunning() )
+ return wxTHREAD_NOT_RUNNING;
+
+ wxThreadError rc = m_internal->Kill();
- if (p_internal->state == STATE_IDLE)
- return NULL;
+ if ( IsDetached() )
+ {
+ delete this;
+ }
+ else // joinable
+ {
+ // update the status of the joinable thread
+ wxCriticalSectionLocker lock(m_critsect);
+ m_internal->SetState(STATE_EXITED);
+ }
- if (wxThread::IsMain())
- s_critsectGui->Leave();
- WaitForSingleObject(p_internal->thread_id, INFINITE);
- if (wxThread::IsMain())
- s_critsectGui->Enter();
+ return rc;
+}
- GetExitCodeThread(p_internal->thread_id, &exit_code);
- CloseHandle(p_internal->thread_id);
+void wxThread::Exit(ExitCode status)
+{
+ m_internal->Free();
- p_internal->state = STATE_IDLE;
+ if ( IsDetached() )
+ {
+ delete this;
+ }
+ else // joinable
+ {
+ // update the status of the joinable thread
+ wxCriticalSectionLocker lock(m_critsect);
+ m_internal->SetState(STATE_EXITED);
+ }
- return (void *)exit_code;
+#ifdef wxUSE_BEGIN_THREAD
+ _endthreadex((unsigned)status);
+#else // !VC++
+ ::ExitThread((DWORD)status);
+#endif // VC++/!VC++
+
+ wxFAIL_MSG(wxT("Couldn't return from ExitThread()!"));
}
-unsigned long wxThread::GetID() const
+// priority setting
+// ----------------
+
+void wxThread::SetPriority(unsigned int prio)
{
- return (unsigned long)p_internal->tid;
+ wxCriticalSectionLocker lock(m_critsect);
+
+ m_internal->SetPriority(prio);
}
-bool wxThread::IsRunning() const
+unsigned int wxThread::GetPriority() const
{
- return (p_internal->state == STATE_RUNNING);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
+
+ return m_internal->GetPriority();
}
-bool wxThread::IsAlive() const
+unsigned long wxThread::GetId() const
{
- return (p_internal->state == STATE_RUNNING);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
+
+ return (unsigned long)m_internal->GetId();
}
-bool wxThread::IsMain()
+bool wxThread::IsRunning() const
{
- return (GetCurrentThread() == s_idMainThread);
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
+
+ return m_internal->GetState() == STATE_RUNNING;
}
-wxThread::wxThread()
+bool wxThread::IsAlive() const
{
- 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_RUNNING) ||
+ (m_internal->GetState() == STATE_PAUSED);
}
-wxThread::~wxThread()
+bool wxThread::IsPaused() const
{
- Destroy();
- Join();
- delete p_internal;
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
+
+ return m_internal->GetState() == STATE_PAUSED;
}
-void wxThread::OnExit()
+bool wxThread::TestDestroy()
{
+ wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
+
+ return m_internal->GetState() == STATE_CANCELED;
}
// ----------------------------------------------------------------------------
bool wxThreadModule::OnInit()
{
- s_critsectGui = new wxCriticalSection();
- s_critsectGui->Enter();
- s_idMainThread = GetCurrentThread();
+ // 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();
+
+ gs_critsectThreadDelete = new wxCriticalSection;
+
+ // no error return for GetCurrentThreadId()
+ gs_idMainThread = ::GetCurrentThreadId();
- return TRUE;
+ return true;
}
void wxThreadModule::OnExit()
{
- if ( s_critsectGui )
+ if ( !::TlsFree(gs_tlsThisThread) )
{
- s_critsectGui->Leave();
- delete s_critsectGui;
- s_critsectGui = NULL;
+ wxLogLastError(wxT("TlsFree failed."));
}
+
+ delete gs_critsectThreadDelete;
+ gs_critsectThreadDelete = NULL;
+
+ if ( gs_critsectGui )
+ {
+ gs_critsectGui->Leave();
+ delete gs_critsectGui;
+ gs_critsectGui = NULL;
+ }
+
+ delete gs_critsectWaitingForGui;
+ gs_critsectWaitingForGui = NULL;
}
-// under Windows, these functions are implemented usign a critical section and
+// ----------------------------------------------------------------------------
+// under Windows, these functions are implemented using a critical section and
// not a mutex, so the names are a bit confusing
-void WXDLLEXPORT wxMutexGuiEnter()
+// ----------------------------------------------------------------------------
+
+void WXDLLIMPEXP_BASE 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 WXDLLIMPEXP_BASE 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 WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter()
{
- //s_critsectGui->Enter();
+ 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
+ }
}
-void WXDLLEXPORT wxMutexGuiLeave()
+bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread()
{
- //s_critsectGui->Leave();
+ return gs_bGuiOwnedByMainThread;
}
+// wake up the main thread if it's in ::GetMessage()
+void WXDLLIMPEXP_BASE 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 WXDLLIMPEXP_BASE wxIsWaitingForThread()
+{
+ return gs_waitingForThread;
+}
+
+// ----------------------------------------------------------------------------
+// include common implementation code
+// ----------------------------------------------------------------------------
+
+#include "wx/thrimpl.cpp"
+
#endif // wxUSE_THREADS
projects / wxWidgets.git / blobdiff