X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/054d497f280187c599a6826d950090f72dccdc41..92f5ff59ccde20a9395084bb29c281ed6831b1b1:/include/wx/thread.h

diff --git a/include/wx/thread.h b/include/wx/thread.h
index 1e9d3e09b7..d4af63db35 100644
--- a/include/wx/thread.h
+++ b/include/wx/thread.h
@@ -2,7 +2,8 @@
 // Name:        thread.h
 // Purpose:     Thread API
 // Author:      Guilhem Lavaux
-// Modified by:
+// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
+//              package from Olivetti & Oracle Research Laboratory)
 // Created:     04/13/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
@@ -12,44 +13,63 @@
 #ifndef __THREADH__
 #define __THREADH__
 
-#ifdef __GNUG__
-#pragma interface "thread.h"
-#endif
-
 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------
+
+// get the value of wxUSE_THREADS configuration flag
 #include "wx/setup.h"
 
 #if wxUSE_THREADS
+
+// only for wxUSE_THREADS - otherwise we'd get undefined symbols
+#ifdef __GNUG__
+    #pragma interface "thread.h"
+#endif
+
+// Windows headers define it
+#ifdef Yield
+    #undef Yield
+#endif
+
 #include "wx/module.h"
 
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 
-typedef enum 
+enum wxMutexError
 {
-  wxMUTEX_NO_ERROR = 0,
-  wxMUTEX_DEAD_LOCK,      // Mutex has been already locked by THE CALLING thread 
-  wxMUTEX_BUSY,           // Mutex has been already locked by ONE thread
-  wxMUTEX_UNLOCKED,
-  wxMUTEX_MISC_ERROR
-} wxMutexError;
-
-typedef enum 
+    wxMUTEX_NO_ERROR = 0,
+    wxMUTEX_DEAD_LOCK,      // Mutex has been already locked by THE CALLING thread
+    wxMUTEX_BUSY,           // Mutex has been already locked by ONE thread
+    wxMUTEX_UNLOCKED,
+    wxMUTEX_MISC_ERROR
+};
+
+enum wxThreadError
+{
+    wxTHREAD_NO_ERROR = 0,      // No error
+    wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread
+    wxTHREAD_RUNNING,           // The thread is already running
+    wxTHREAD_NOT_RUNNING,       // The thread isn't running
+    wxTHREAD_KILLED,            // Thread we waited for had to be killed
+    wxTHREAD_MISC_ERROR         // Some other error
+};
+
+enum wxThreadKind
 {
-  wxTHREAD_NO_ERROR = 0,      // No error
-  wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread
-  wxTHREAD_RUNNING,           // The thread is already running
-  wxTHREAD_NOT_RUNNING,       // The thread isn't running
-  wxTHREAD_MISC_ERROR         // Some other error
-} wxThreadError;
-
-/* defines the interval of priority. */
-#define WXTHREAD_MIN_PRIORITY     0
-#define WXTHREAD_DEFAULT_PRIORITY 50
-#define WXTHREAD_MAX_PRIORITY     100
+    wxTHREAD_DETACHED,
+    wxTHREAD_JOINABLE
+};
+
+// defines the interval of priority
+enum
+{
+    WXTHREAD_MIN_PRIORITY      = 0u,
+    WXTHREAD_DEFAULT_PRIORITY  = 50u,
+    WXTHREAD_MAX_PRIORITY      = 100u
+};
 
 // ----------------------------------------------------------------------------
 // A mutex object is a synchronization object whose state is set to signaled
@@ -61,10 +81,10 @@ typedef enum
 // you should consider wxMutexLocker whenever possible instead of directly
 // working with wxMutex class - it is safer
 class WXDLLEXPORT wxMutexInternal;
-class WXDLLEXPORT wxMutex 
+class WXDLLEXPORT wxMutex
 {
 public:
-    // constructor & destructor 
+    // constructor & destructor
     wxMutex();
     ~wxMutex();
 
@@ -86,7 +106,7 @@ protected:
     wxMutex& operator=(const wxMutex&);
 
     int m_locked;
-    wxMutexInternal *p_internal;
+    wxMutexInternal *m_internal;
 };
 
 // a helper class which locks the mutex in the ctor and unlocks it in the dtor:
@@ -96,14 +116,16 @@ class WXDLLEXPORT wxMutexLocker
 {
 public:
     // lock the mutex in the ctor
-    wxMutexLocker(wxMutex *mutex)
-        { m_isOk = mutex && ((m_mutex = mutex)->Lock() == wxMUTEX_NO_ERROR); }
+    wxMutexLocker(wxMutex& mutex) : m_mutex(mutex)
+        { m_isOk = m_mutex.Lock() == wxMUTEX_NO_ERROR; }
 
     // returns TRUE if mutex was successfully locked in ctor
-    bool IsOk() const { return m_isOk; }
+    bool IsOk() const
+        { return m_isOk; }
 
     // unlock the mutex in dtor
-    ~wxMutexLocker() { if ( IsOk() ) m_mutex->Unlock(); }
+    ~wxMutexLocker()
+        { if ( IsOk() ) m_mutex.Unlock(); }
 
 private:
     // no assignment operator nor copy ctor
@@ -111,24 +133,35 @@ private:
     wxMutexLocker& operator=(const wxMutexLocker&);
 
     bool     m_isOk;
-    wxMutex *m_mutex;
+    wxMutex& m_mutex;
 };
 
 // ----------------------------------------------------------------------------
 // Critical section: this is the same as mutex but is only visible to the
 // threads of the same process. For the platforms which don't have native
 // support for critical sections, they're implemented entirely in terms of
-// mutexes
+// mutexes.
+//
+// NB: wxCriticalSection object does not allocate any memory in its ctor
+//     which makes it possible to have static globals of this class
 // ----------------------------------------------------------------------------
 
-// you should consider wxCriticalSectionLocker whenever possible instead of
-// directly working with wxCriticalSection class - it is safer
-#ifdef __WXMSW__
-    class WXDLLEXPORT wxCriticalSectionInternal;
-    #define WXCRITICAL_INLINE
-#else // !MSW
+class WXDLLEXPORT wxCriticalSectionInternal;
+
+// in order to avoid any overhead under platforms where critical sections are
+// just mutexes make all wxCriticalSection class functions inline
+#if !defined(__WXMSW__) && !defined(__WXPM__)
     #define WXCRITICAL_INLINE   inline
+
+    #define wxCRITSECT_IS_MUTEX 1
+#else // MSW || OS2
+    #define WXCRITICAL_INLINE
+
+    #define wxCRITSECT_IS_MUTEX 0
 #endif // MSW/!MSW
+
+// you should consider wxCriticalSectionLocker whenever possible instead of
+// directly working with wxCriticalSection class - it is safer
 class WXDLLEXPORT wxCriticalSection
 {
 public:
@@ -137,31 +170,39 @@ public:
     WXCRITICAL_INLINE ~wxCriticalSection();
 
     // enter the section (the same as locking a mutex)
-    void WXCRITICAL_INLINE Enter();
+    WXCRITICAL_INLINE void Enter();
     // leave the critical section (same as unlocking a mutex)
-    void WXCRITICAL_INLINE Leave();
+    WXCRITICAL_INLINE void Leave();
 
 private:
     // no assignment operator nor copy ctor
     wxCriticalSection(const wxCriticalSection&);
     wxCriticalSection& operator=(const wxCriticalSection&);
 
-#ifdef __WXMSW__
-    wxCriticalSectionInternal *m_critsect;
-#else // !MSW
+#if wxCRITSECT_IS_MUTEX
     wxMutex m_mutex;
-#endif // MSW/!MSW
+#elif defined(__WXMSW__)
+    // we can't allocate any memory in the ctor, so use placement new -
+    // unfortunately, we have to hardcode the sizeof() here because we can't
+    // include windows.h from this public header
+    char m_buffer[24];
+#elif !defined(__WXPM__)
+    wxCriticalSectionInternal *m_critsect;
+#else
+    // nothing for OS/2
+#endif // !Unix/Unix
 };
 
+// keep your preprocessor name space clean
+#undef WXCRITICAL_INLINE
+
 // wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
 // to th mutexes
 class WXDLLEXPORT wxCriticalSectionLocker
 {
 public:
-    wxCriticalSectionLocker(wxCriticalSection& critsect) : m_critsect(critsect)
-        { m_critsect.Enter(); }
-    ~wxCriticalSectionLocker()
-        { m_critsect.Leave(); }
+    inline wxCriticalSectionLocker(wxCriticalSection& critsect);
+    inline ~wxCriticalSectionLocker();
 
 private:
     // no assignment operator nor copy ctor
@@ -172,98 +213,200 @@ private:
 };
 
 // ----------------------------------------------------------------------------
-// Condition handler.
+// Condition variable: allows to block the thread execution until something
+// happens (== condition is signaled)
 // ----------------------------------------------------------------------------
 
 class wxConditionInternal;
-class WXDLLEXPORT wxCondition 
+class WXDLLEXPORT wxCondition
 {
 public:
-  // constructor & destructor
-  wxCondition();
-  ~wxCondition();
-
-  // Waits indefinitely.
-  void Wait(wxMutex& mutex);
-  // Waits until a signal is raised or the timeout is elapsed.
-  bool Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec);
-  // Raises a signal: only one "Waiter" is released.
-  void Signal();
-  // Broadcasts to all "Waiters".
-  void Broadcast();
+    // constructor & destructor
+    wxCondition();
+    ~wxCondition();
+
+    // wait until the condition is signaled
+        // waits indefinitely.
+    void Wait();
+        // waits until a signal is raised or the timeout elapses
+    bool Wait(unsigned long sec, unsigned long nsec);
+
+    // signal the condition
+        // wakes up one (and only one) of the waiting threads
+    void Signal();
+        // wakes up all threads waiting onthis condition
+    void Broadcast();
 
 private:
-  wxConditionInternal *p_internal;
+    wxConditionInternal *m_internal;
 };
 
 // ----------------------------------------------------------------------------
-// Thread management class
+// Thread class
 // ----------------------------------------------------------------------------
 
+// there are two different kinds of threads: joinable and detached (default)
+// ones. Only joinable threads can return a return code and only detached
+// threads auto-delete themselves - the user should delete the joinable
+// threads manually.
+
+// NB: in the function descriptions the words "this thread" mean the thread
+//     created by the wxThread object while "main thread" is the thread created
+//     during the process initialization (a.k.a. the GUI thread)
+
 class wxThreadInternal;
-class WXDLLEXPORT wxThread 
+class WXDLLEXPORT wxThread
 {
 public:
-  // constructor & destructor.
-  wxThread();
-  virtual ~wxThread();
-
-  // Create a new thread, this method should check there is only one thread
-  // running by object.
-  wxThreadError Create();
-
-  // Destroys the thread immediately if the defer flag isn't true.
-  wxThreadError Destroy();
-
-  // Pause a running thread
-  wxThreadError Pause();
+    // the return type for the thread function
+    typedef void *ExitCode;
+
+    // static functions
+        // Returns the wxThread object for the calling thread. NULL is returned
+        // if the caller is the main thread (but it's recommended to use
+        // IsMain() and only call This() for threads other than the main one
+        // because NULL is also returned on error). If the thread wasn't
+        // created with wxThread class, the returned value is undefined.
+    static wxThread *This();
+
+        // Returns true if current thread is the main thread.
+    static bool IsMain();
+
+        // Release the rest of our time slice leting the other threads run
+    static void Yield();
+
+        // Sleep during the specified period of time in milliseconds
+        //
+        // NB: at least under MSW worker threads can not call ::wxSleep()!
+    static void Sleep(unsigned long milliseconds);
+
+        // get the number of system CPUs - useful with SetConcurrency()
+        // (the "best" value for it is usually number of CPUs + 1)
+        //
+        // Returns -1 if unknown, number of CPUs otherwise
+    static int GetCPUCount();
+
+        // sets the concurrency level: this is, roughly, the number of threads
+        // the system tries to schedule to run in parallel. 0 means the
+        // default value (usually acceptable, but may not yield the best
+        // performance for this process)
+        //
+        // Returns TRUE on success, FALSE otherwise (if not implemented, for
+        // example)
+    static bool SetConcurrency(size_t level);
+
+    // constructor only creates the C++ thread object and doesn't create (or
+    // start) the real thread
+    wxThread(wxThreadKind kind = wxTHREAD_DETACHED);
+
+    // functions that change the thread state: all these can only be called
+    // from _another_ thread (typically the thread that created this one, e.g.
+    // the main thread), not from the thread itself
+
+        // create a new thread - call Run() to start it
+    wxThreadError Create();
+
+        // starts execution of the thread - from the moment Run() is called
+        // the execution of wxThread::Entry() may start at any moment, caller
+        // shouldn't suppose that it starts after (or before) Run() returns.
+    wxThreadError Run();
+
+        // stops the thread if it's running and deletes the wxThread object if
+        // this is a detached thread freeing its memory - otherwise (for
+        // joinable threads) you still need to delete wxThread object
+        // yourself.
+        //
+        // this function only works if the thread calls TestDestroy()
+        // periodically - the thread will only be deleted the next time it
+        // does it!
+        //
+        // will fill the rc pointer with the thread exit code if it's !NULL
+    wxThreadError Delete(ExitCode *rc = (ExitCode *)NULL);
+
+        // waits for a joinable thread to finish and returns its exit code
+        //
+        // Returns (ExitCode)-1 on error (for example, if the thread is not
+        // joinable)
+    ExitCode Wait();
+
+        // kills the thread without giving it any chance to clean up - should
+        // not be used in normal circumstances, use Delete() instead. It is a
+        // dangerous function that should only be used in the most extreme
+        // cases!
+        //
+        // The wxThread object is deleted by Kill() if the thread is
+        // detachable, but you still have to delete it manually for joinable
+        // threads.
+    wxThreadError Kill();
+
+        // pause a running thread: as Delete(), this only works if the thread
+        // calls TestDestroy() regularly
+    wxThreadError Pause();
+
+        // resume a paused thread
+    wxThreadError Resume();
+
+    // priority
+        // Sets the priority to "prio": see WXTHREAD_XXX_PRIORITY constants
+        //
+        // NB: the priority can only be set before the thread is created
+    void SetPriority(unsigned int prio);
+
+        // Get the current priority.
+    unsigned int GetPriority() const;
+
+    // thread status inquiries
+        // Returns true if the thread is alive: i.e. running or suspended
+    bool IsAlive() const;
+        // Returns true if the thread is running (not paused, not killed).
+    bool IsRunning() const;
+        // Returns true if the thread is suspended
+    bool IsPaused() const;
+
+        // is the thread of detached kind?
+    bool IsDetached() const { return m_isDetached; }
+
+    // Get the thread ID - a platform dependent number which uniquely
+    // identifies a thread inside a process
+    unsigned long GetId() const;
+
+    // called when the thread exits - in the context of this thread
+    //
+    // NB: this function will not be called if the thread is Kill()ed
+    virtual void OnExit() { }
+
+    // dtor is public, but the detached threads should never be deleted - use
+    // Delete() instead (or leave the thread terminate by itself)
+    virtual ~wxThread();
 
-  // Resume a paused thread
-  wxThreadError Resume();
-
-  // Switches on the defer flag.
-  void DeferDestroy(bool on);
-
-  // Waits for the termination of the thread.
-  void *Join();
-
-  // Sets the priority to "prio". (Warning: The priority can only be set before
-  // the thread is created)
-  void SetPriority(int prio);
-  // Get the current priority.
-  int GetPriority() const;
-
-  // Get the thread ID
-  unsigned long GetID() const;
-
-  // Returns true if the thread is alive.
-  bool IsAlive() const;
-  // Returns true if the thread is running (not paused, not killed).
-  bool IsRunning() const;
-  // Returns true if the thread is suspended
-  bool IsPaused() const { return IsAlive() && !IsRunning(); }
+protected:
+    // Returns TRUE if the thread was asked to terminate: this function should
+    // be called by the thread from time to time, otherwise the main thread
+    // will be left forever in Delete()!
+    bool TestDestroy();
 
-  // Returns true if current thread is the main thread (aka the GUI thread)
-  static bool IsMain();
+    // exits from the current thread - can be called only from this thread
+    void Exit(ExitCode exitcode = 0);
 
-  // Called when thread exits.
-  virtual void OnExit();
+    // entry point for the thread - called by Run() and executes in the context
+    // of this thread.
+    virtual void *Entry() = 0;
 
-protected:
-  // Returns TRUE if the thread was asked to terminate
-  bool TestDestroy();
+private:
+    // no copy ctor/assignment operator
+    wxThread(const wxThread&);
+    wxThread& operator=(const wxThread&);
 
-  // Exits from the current thread.
-  void Exit(void *status = NULL);
+    friend class wxThreadInternal;
 
-private:
-  // Entry point for the thread.
-  virtual void *Entry() = 0;
+    // the (platform-dependent) thread class implementation
+    wxThreadInternal *m_internal;
 
-private:
-  friend class wxThreadInternal;
+    // protects access to any methods of wxThreadInternal object
+    wxCriticalSection m_critsect;
 
-  wxThreadInternal *p_internal;
+    // true if the thread is detached, false if it is joinable
+    bool m_isDetached;
 };
 
 // ----------------------------------------------------------------------------
@@ -274,12 +417,28 @@ private:
 void WXDLLEXPORT wxMutexGuiEnter();
 void WXDLLEXPORT wxMutexGuiLeave();
 
+// macros for entering/leaving critical sections which may be used without
+// having to take them inside "#if wxUSE_THREADS"
+#define wxENTER_CRIT_SECT(cs)   (cs).Enter()
+#define wxLEAVE_CRIT_SECT(cs)   (cs).Leave()
+#define wxCRIT_SECT_DECLARE(cs) static wxCriticalSection cs
+#define wxCRIT_SECT_LOCKER(name, cs)  wxCriticalSectionLocker name(cs)
+
 #else // !wxUSE_THREADS
 
+#include "wx/defs.h" // for WXDLLEXPORT
+
 // no thread support
 inline void WXDLLEXPORT wxMutexGuiEnter() { }
 inline void WXDLLEXPORT wxMutexGuiLeave() { }
 
+// macros for entering/leaving critical sections which may be used without
+// having to take them inside "#if wxUSE_THREADS"
+#define wxENTER_CRIT_SECT(cs)
+#define wxLEAVE_CRIT_SECT(cs)
+#define wxCRIT_SECT_DECLARE(cs)
+#define wxCRIT_SECT_LOCKER(name, cs)
+
 #endif // wxUSE_THREADS
 
 // automatically unlock GUI mutex in dtor
@@ -293,19 +452,57 @@ public:
 // -----------------------------------------------------------------------------
 // implementation only until the end of file
 // -----------------------------------------------------------------------------
-#ifdef wxUSE_THREADS
-#ifdef __WXMSW__
+
+#if wxUSE_THREADS
+
+#if defined(__WXMSW__)
     // unlock GUI if there are threads waiting for and lock it back when
     // there are no more of them - should be called periodically by the main
     // thread
-    void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
+    extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
 
     // returns TRUE if the main thread has GUI lock
-    bool WXDLLEXPORT wxGuiOwnedByMainThread();
+    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
 
     // wakes up the main thread if it's sleeping inside ::GetMessage()
-    void WXDLLEXPORT wxWakeUpMainThread();
-#else // !MSW
+    extern void WXDLLEXPORT wxWakeUpMainThread();
+
+    // return TRUE if the main thread is waiting for some other to terminate:
+    // wxApp then should block all "dangerous" messages
+    extern bool WXDLLEXPORT wxIsWaitingForThread();
+#elif defined(__WXMAC__)
+   extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
+
+    // returns TRUE if the main thread has GUI lock
+    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+
+    // wakes up the main thread if it's sleeping inside ::GetMessage()
+    extern void WXDLLEXPORT wxWakeUpMainThread();
+
+    // return TRUE if the main thread is waiting for some other to terminate:
+    // wxApp then should block all "dangerous" messages
+    extern bool WXDLLEXPORT wxIsWaitingForThread();
+
+    // implement wxCriticalSection using mutexes
+    inline wxCriticalSection::wxCriticalSection() { }
+    inline wxCriticalSection::~wxCriticalSection() { }
+
+    inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
+    inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
+#elif defined(__WXPM__)
+    // unlock GUI if there are threads waiting for and lock it back when
+    // there are no more of them - should be called periodically by the main
+    // thread
+    extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
+
+    // returns TRUE if the main thread has GUI lock
+    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+
+    // return TRUE if the main thread is waiting for some other to terminate:
+    // wxApp then should block all "dangerous" messages
+    extern bool WXDLLEXPORT wxIsWaitingForThread();
+
+#else // !MSW && !PM
     // implement wxCriticalSection using mutexes
     inline wxCriticalSection::wxCriticalSection() { }
     inline wxCriticalSection::~wxCriticalSection() { }
@@ -313,6 +510,14 @@ public:
     inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
     inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
 #endif // MSW/!MSW
+
+    // we can define these inline functions now (they should be defined after
+    // wxCriticalSection::Enter/Leave)
+    inline
+    wxCriticalSectionLocker:: wxCriticalSectionLocker(wxCriticalSection& cs)
+        : m_critsect(cs) { m_critsect.Enter(); }
+    inline
+    wxCriticalSectionLocker::~wxCriticalSectionLocker() { m_critsect.Leave(); }
 #endif // wxUSE_THREADS
 
 #endif // __THREADH__