Added wxThread::GetMainId().

This is useful for checking if a message was logged from the main thread or not and also allows us to implement IsMain() by comparing GetCurrentId() with GetMainId() in all ports and avoid repetition.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61406 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/thread.h

@@ -447,7 +447,17 @@ public:
     static wxThread *This();
 
         // Returns true if current thread is the main thread.
-    static bool IsMain();
+        //
+        // Notice that it also returns true if main thread id hadn't been
+        // initialized yet on the assumption that it's too early in wx startup
+        // process for any other threads to have been created in this case.
+    static bool IsMain()
+    {
+        return !ms_idMainThread || GetCurrentId() == ms_idMainThread;
+    }
+
+        // Return the main thread id
+    static wxThreadIdType GetMainId() { return ms_idMainThread; }
 
         // Release the rest of our time slice letting the other threads run
     static void Yield();
@@ -466,7 +476,7 @@ public:
         // Get the platform specific thread ID and return as a long.  This
         // can be used to uniquely identify threads, even if they are not
         // wxThreads.  This is used by wxPython.
-   static wxThreadIdType GetCurrentId();
+    static wxThreadIdType GetCurrentId();
 
         // sets the concurrency level: this is, roughly, the number of threads
         // the system tries to schedule to run in parallel. 0 means the
@@ -586,6 +596,11 @@ private:
     virtual void OnExit() { }
 
     friend class wxThreadInternal;
+    friend class wxThreadModule;
+
+
+    // the main thread identifier, should be set on startup
+    static wxThreadIdType ms_idMainThread;
 
     // the (platform-dependent) thread class implementation
     wxThreadInternal *m_internal;

interface/wx/thread.h

@@ -989,7 +989,10 @@ public:
 
     /**
         Returns the platform specific thread ID of the current thread as a long.
+
         This can be used to uniquely identify threads, even if they are not wxThreads.
+
+        @see GetMainId()
     */
     static wxThreadIdType GetCurrentId();
 
@@ -1007,6 +1010,15 @@ public:
     */
     wxThreadKind GetKind() const;
 
+    /**
+        Returns the thread ID of the main thread.
+
+        @see IsMain()
+
+        @since 2.9.1
+     */
+    static wxThreadIdType GetMainId();
+
     /**
         Gets the priority of the thread, between zero and 100.
 
@@ -1035,6 +1047,11 @@ public:
 
     /**
         Returns @true if the calling thread is the main application thread.
+
+        Main thread in the context of wxWidgets is the one which initialized
+        the library.
+
+        @see GetMainId(), GetCurrentId()
     */
     static bool IsMain();
 

src/msw/thread.cpp

@@ -113,7 +113,7 @@ 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;
+wxThreadIdType wxThread::ms_idMainThread = 0;
 
 // if it's false, some secondary thread is holding the GUI lock
 static bool gs_bGuiOwnedByMainThread = true;
@@ -926,11 +926,6 @@ wxThread *wxThread::This()
     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
@@ -1278,8 +1273,7 @@ bool wxThreadModule::OnInit()
 
     gs_critsectThreadDelete = new wxCriticalSection;
 
-    // no error return for GetCurrentThreadId()
+    wxThread::ms_idMainThread = wxThread::GetCurrentId();
-    gs_idMainThread = ::GetCurrentThreadId();
 
     return true;
 }
@@ -1393,7 +1387,7 @@ bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread()
 void WXDLLIMPEXP_BASE wxWakeUpMainThread()
 {
     // sending any message would do - hopefully WM_NULL is harmless enough
-    if ( !::PostThreadMessage(gs_idMainThread, WM_NULL, 0, 0) )
+    if ( !::PostThreadMessage(ms_idMainThread, WM_NULL, 0, 0) )
     {
         // should never happen
         wxLogLastError(wxT("PostThreadMessage(WM_NULL)"));

src/os2/thread.cpp

@@ -57,7 +57,7 @@ enum wxThreadState
 
 // id of the main thread - the one which can call GUI functions without first
 // calling wxMutexGuiEnter()
-static ULONG                        s_ulIdMainThread = 1;
+wxThreadIdType                      wxThread::ms_idMainThread = 0;
 wxMutex*                            p_wxMainMutex;
 
 // OS2 substitute for Tls pointer the current parent thread object
@@ -547,19 +547,6 @@ wxThread *wxThread::This()
     return pThread;
 }
 
-bool wxThread::IsMain()
-{
-    PTIB ptib;
-    PPIB ppib;
-
-    ::DosGetInfoBlocks(&ptib, &ppib);
-
-    if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
-        return true;
-
-    return false;
-}
-
 #ifdef Yield
     #undef Yield
 #endif
@@ -582,13 +569,13 @@ int wxThread::GetCPUCount()
     return CPUCount;
 }
 
-unsigned long wxThread::GetCurrentId()
+wxThreadIdType wxThread::GetCurrentId()
 {
     PTIB                            ptib;
     PPIB                            ppib;
 
     ::DosGetInfoBlocks(&ptib, &ppib);
-    return (unsigned long) ptib->tib_ptib2->tib2_ultid;
+    return (wxThreadIdType) ptib->tib_ptib2->tib2_ultid;
 }
 
 bool wxThread::SetConcurrency(size_t level)
@@ -937,12 +924,8 @@ bool wxThreadModule::OnInit()
     gs_pCritsectGui = new wxCriticalSection();
     gs_pCritsectGui->Enter();
 
-    PTIB ptib;
+    wxThread::ms_idMainThread = wxThread::GetCurrentId();
-    PPIB ppib;
 
-    ::DosGetInfoBlocks(&ptib, &ppib);
-
-    s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
     return true;
 }
 

src/osx/carbon/thread.cpp

@@ -49,7 +49,7 @@ enum wxThreadState
 // ----------------------------------------------------------------------------
 
 // the task ID of the main thread
-static wxThreadIdType gs_idMainThread = kInvalidID;
+wxThreadIdType wxThread::ms_idMainThread = kInvalidID;
 
 // this is the Per-Task Storage for the pointer to the appropriate wxThread
 TaskStorageIndex gs_tlsForWXThread = 0;
@@ -796,11 +796,6 @@ wxThread *wxThread::This()
     return thr;
 }
 
-bool wxThread::IsMain()
-{
-    return GetCurrentId() == gs_idMainThread || gs_idMainThread == kInvalidID ;
-}
-
 #ifdef Yield
 #undef Yield
 #endif
@@ -1214,7 +1209,7 @@ bool wxThreadModule::OnInit()
     verify_noerr( MPAllocateTaskStorageIndex( &gs_tlsForWXThread ) ) ;
     verify_noerr( MPSetTaskStorageValue( gs_tlsForWXThread, 0 ) ) ;
 
-    gs_idMainThread = wxThread::GetCurrentId();
+    wxThread::ms_idMainThread = wxThread::GetCurrentId();
     gs_critsectWaitingForGui = new wxCriticalSection();
 
     gs_critsectGui = new wxCriticalSection();

src/unix/threadpsx.cpp

@@ -118,7 +118,11 @@ static wxArrayThread gs_allThreads;
 static wxMutex *gs_mutexAllThreads = NULL;
 
 // the id of the main thread
-static pthread_t gs_tidMain = (pthread_t)-1;
+//
+// we suppose that 0 is not a valid pthread_t value but in principle this might
+// be false (e.g. if it's a selector-like value), wxThread::IsMain() would need
+// to be updated in such case
+wxThreadIdType wxThread::ms_idMainThread = 0;
 
 // the key for the pointer to the associated wxThread object
 static pthread_key_t gs_keySelf;
@@ -1057,11 +1061,6 @@ wxThread *wxThread::This()
     return (wxThread *)pthread_getspecific(gs_keySelf);
 }
 
-bool wxThread::IsMain()
-{
-    return (bool)pthread_equal(pthread_self(), gs_tidMain) || gs_tidMain == (pthread_t)-1;
-}
-
 void wxThread::Yield()
 {
 #ifdef HAVE_SCHED_YIELD
@@ -1110,23 +1109,11 @@ int wxThread::GetCPUCount()
     return -1;
 }
 
-// VMS is a 64 bit system and threads have 64 bit pointers.
+wxThreadIdType wxThread::GetCurrentId()
-// FIXME: also needed for other systems????
-#ifdef __VMS
-unsigned long long wxThread::GetCurrentId()
 {
-    return (unsigned long long)pthread_self();
+    return (wxThreadIdType)pthread_self();
 }
 
-#else // !__VMS
-
-unsigned long wxThread::GetCurrentId()
-{
-    return (unsigned long)pthread_self();
-}
-
-#endif // __VMS/!__VMS
-
 
 bool wxThread::SetConcurrency(size_t level)
 {
@@ -1705,7 +1692,7 @@ bool wxThreadModule::OnInit()
         return false;
     }
 
-    gs_tidMain = pthread_self();
+    wxThread::ms_idMainThread = wxThread::GetCurrentId();
 
     gs_mutexAllThreads = new wxMutex();