2002-09-17 Robert Collins <rbtcollins@hotmail.com>

This work inspires by Thomas Pfaff's pthread_fork patch (1).
        * fork.cc (fork_child): Remove MTinterface fixup call, it's
        adsorbed by pthread::atforkchild.
        Rename __pthread_atforkchild to pthread::atforkchild to give
        access to private members.
        (fork_parent): Rename __pthread_atforkparent to
        pthread::atforkparent to give it access to private members.
        Ditto for __pthread_atforkprepare.
        * thread.cc: Fix some formatting problems throughout.
        (MTinterface::fixup_before_fork): Implement.
        (MTinterface::fixup_after_fork): Fix pthread_keys.
        (pthread_key::keys): Implement.
        (pthread_key::fixup_before_fork): Ditto.
        (pthread_key::fixup_after_fork): Ditto.
        (pthread_key::pthread_key): Add to pthread_key::keys.
        (pthread_key::~pthread_key): Remove from pthread_key::keys.
        (pthread_key::saveKeyToBuffer): Implement.
        (pthread_key::recreateKeyFromBuffer): Ditto.
        (pthread::atforkprepare): Prepare all MT classes for fork.
        (pthread::atforkchild): And fix them up afterwards.
        * thread.h (pthread_key): Buffer the key value during
        fork in fork_buf.
        List the keys needing to be fixed up in a linked list with
        head pthread_key::keys.
        (pthread): Move atfork cygwin internal calls into the class.
        (MTInterface): Provide a fixup_before_fork for objecst that
        need to save state.
        (__pthread_atforkprepare): Remove.
        (__pthread_atforkparent): Remove.
        (__pthread_atforkchild): Remove.

winsup/cygwin/ChangeLog

@@ -1,3 +1,36 @@
+2002-09-17  Robert Collins  <rbtcollins@hotmail.com>
+
+	This work inspires by Thomas Pfaff's pthread_fork patch (1).
+	* fork.cc (fork_child): Remove MTinterface fixup call, it's
+	adsorbed by pthread::atforkchild.
+	Rename __pthread_atforkchild to pthread::atforkchild to give
+	access to private members.
+	(fork_parent): Rename __pthread_atforkparent to 
+	pthread::atforkparent to give it access to private members.
+	Ditto for __pthread_atforkprepare.
+	* thread.cc: Fix some formatting problems throughout.
+	(MTinterface::fixup_before_fork): Implement.
+	(MTinterface::fixup_after_fork): Fix pthread_keys.
+	(pthread_key::keys): Implement.
+	(pthread_key::fixup_before_fork): Ditto.
+	(pthread_key::fixup_after_fork): Ditto.
+	(pthread_key::pthread_key): Add to pthread_key::keys.
+	(pthread_key::~pthread_key): Remove from pthread_key::keys.
+	(pthread_key::saveKeyToBuffer): Implement.
+	(pthread_key::recreateKeyFromBuffer): Ditto.
+	(pthread::atforkprepare): Prepare all MT classes for fork.
+	(pthread::atforkchild): And fix them up afterwards.
+	* thread.h (pthread_key): Buffer the key value during
+	fork in fork_buf.
+	List the keys needing to be fixed up in a linked list with
+	head pthread_key::keys.
+	(pthread): Move atfork cygwin internal calls into the class.
+	(MTInterface): Provide a fixup_before_fork for objecst that
+	need to save state.
+	(__pthread_atforkprepare): Remove.
+	(__pthread_atforkparent): Remove.
+	(__pthread_atforkchild): Remove.
+
 2002-09-16  Christopher Faylor  <cgf@redhat.com>
 
 	* init.cc: Cleanup slightly and remove obsolete code.

winsup/cygwin/fork.cc

@@ -313,10 +313,8 @@ fork_child (HANDLE& hParent, dll *&first_dll, bool& load_dlls)
     if ((*t)->clear_on_fork ())
       (*t)->set ();
 
-  user_data->threadinterface->fixup_after_fork ();
-
   wait_for_sigthread ();
-  __pthread_atforkchild ();
+  pthread::atforkchild ();
   cygbench ("fork-child");
   return 0;
 }
@@ -354,8 +352,7 @@ fork_parent (HANDLE& hParent, dll *&first_dll,
   DWORD rc;
   PROCESS_INFORMATION pi = {0, NULL, 0, 0};
 
-  /* call the pthread_atfork prepare functions */
+  pthread::atforkprepare ();
-  __pthread_atforkprepare ();
 
   subproc_init ();
 
@@ -601,7 +598,7 @@ fork_parent (HANDLE& hParent, dll *&first_dll,
   ForceCloseHandle (forker_finished);
   forker_finished = NULL;
   pi.hThread = NULL;
-  __pthread_atforkparent ();
+  pthread::atforkparent ();
 
   return forked->pid;
 

winsup/cygwin/thread.cc

@@ -314,10 +314,17 @@ MTinterface::Init (int forked)
 #endif
 }
 
+void
+MTinterface::fixup_before_fork (void)
+{
+  pthread_key::fixup_before_fork ();
+}
+
 /* This function is called from a single threaded process */
 void
 MTinterface::fixup_after_fork (void)
 {
+  pthread_key::fixup_after_fork ();
   pthread_mutex *mutex = mutexs;
   debug_printf ("mutexs is %x",mutexs);
   while (mutex)
@@ -375,6 +382,8 @@ pthread::setTlsSelfPointer(pthread *thisThread)
   TlsSetValue (MT_INTERFACE->thread_self_dwTlsIndex, thisThread);
 }
 
+
+
 /* member methods */
 pthread::pthread ():verifyable_object (PTHREAD_MAGIC), win32_obj_id (0),
                     cancelstate (0), canceltype (0), cancel_event (0),
@@ -1018,6 +1027,35 @@ pthread_cond::fixup_after_fork ()
 #endif
 }
 
+/* pthread_key */
+/* static members */
+pthread_key *pthread_key::keys = NULL;
+
+void
+pthread_key::fixup_before_fork ()
+{
+  pthread_key *key = keys;
+  debug_printf ("keys is %x",keys);
+  while (key)
+    {
+      key->saveKeyToBuffer ();
+      key = key->next;
+    }
+}
+
+void
+pthread_key::fixup_after_fork ()
+{
+  pthread_key *key = keys;
+  debug_printf ("keys is %x",keys);
+  while (key)
+    {
+      key->recreateKeyFromBuffer ();
+      key = key->next;
+    }
+}
+
+/* non-static members */
 
 pthread_key::pthread_key (void (*destructor) (void *)):verifyable_object (PTHREAD_KEY_MAGIC)
 {
@@ -1029,6 +1067,8 @@ pthread_key::pthread_key (void (*destructor) (void *)):verifyable_object (PTHREA
       MT_INTERFACE->destructors.
 	Insert (new pthread_key_destructor (destructor, this));
     }
+  /* threadsafe addition is easy */
+  next = (pthread_key *) InterlockedExchangePointer (&keys, this);
 }
 
 pthread_key::~pthread_key ()
@@ -1036,6 +1076,18 @@ pthread_key::~pthread_key ()
   if (pthread_key_destructor *dest = MT_INTERFACE->destructors.Remove (this))
     delete dest;
   TlsFree (dwTlsIndex);
+
+  /* I'm not 100% sure the next bit is threadsafe. I think it is... */
+  if (keys == this)
+    InterlockedExchangePointer (keys, this->next);
+  else
+    {
+      pthread_key *tempkey = keys;
+      while (tempkey->next && tempkey->next != this)
+        tempkey = tempkey->next;
+      /* but there may be a race between the loop above and this statement */
+      InterlockedExchangePointer (&tempkey->next, this->next);
+    }
 }
 
 int
@@ -1053,6 +1105,21 @@ pthread_key::get ()
   return TlsGetValue (dwTlsIndex);
 }
 
+void
+pthread_key::saveKeyToBuffer ()
+{
+  fork_buf = get ();
+}
+
+void
+pthread_key::recreateKeyFromBuffer ()
+{
+  dwTlsIndex = TlsAlloc ();
+  if (dwTlsIndex == TLS_OUT_OF_INDEXES)
+    api_fatal ("pthread_key::recreateKeyFromBuffer () failed to reallocate Tls storage");
+  set (fork_buf);
+}
+
 /*pshared mutexs:
 
  * REMOVED FROM CURRENT. These can be reinstated with the daemon, when all the
@@ -1448,8 +1515,10 @@ __pthread_cancel (pthread_t thread)
  *If yes, we're safe, if no, we're not.
  */
 void
-__pthread_atforkprepare (void)
+pthread::atforkprepare (void)
 {
+  MT_INTERFACE->fixup_before_fork ();
+
   callback *cb = MT_INTERFACE->pthread_prepare;
   while (cb)
     {
@@ -1459,7 +1528,7 @@ __pthread_atforkprepare (void)
 }
 
 void
-__pthread_atforkparent (void)
+pthread::atforkparent (void)
 {
   callback *cb = MT_INTERFACE->pthread_parent;
   while (cb)
@@ -1470,8 +1539,10 @@ __pthread_atforkparent (void)
 }
 
 void
-__pthread_atforkchild (void)
+pthread::atforkchild (void)
 {
+  MT_INTERFACE->fixup_after_fork ();
+
   callback *cb = MT_INTERFACE->pthread_child;
   while (cb)
     {

winsup/cygwin/thread.h

@@ -178,11 +178,21 @@ class pthread_key:public verifyable_object
 public:
 
   DWORD dwTlsIndex;
+  void *fork_buf;
+  class pthread_key *next;
+
   int set (const void *);
   void *get ();
 
     pthread_key (void (*)(void *));
    ~pthread_key ();
+  static void fixup_before_fork();
+  static void fixup_after_fork();
+private:
+  // lists of objects. USE THREADSAFE INSERTS AND DELETES.
+  static pthread_key * keys;
+  void saveKeyToBuffer ();
+  void recreateKeyFromBuffer ();
 };
 
 /* FIXME: test using multiple inheritance and merging key_destructor into pthread_key
@@ -281,6 +291,9 @@ public:
 
    static void initMainThread(pthread *, HANDLE);
    static bool isGoodObject(pthread_t *);
+   static void atforkprepare();
+   static void atforkparent();
+   static void atforkchild();
 
    virtual void exit (void *value_ptr);
 
@@ -421,12 +434,13 @@ public:
   callback *pthread_child;
   callback *pthread_parent;
 
-  // list of mutex's. USE THREADSAFE INSERTS AND DELETES.
+  // lists of pthread objects. USE THREADSAFE INSERTS AND DELETES.
   class pthread_mutex * mutexs;
   class pthread_cond  * conds;
   class semaphore     * semaphores;
 
   void Init (int);
+  void fixup_before_fork (void);
   void fixup_after_fork (void);
 
   MTinterface ():reent_index (0), indexallocated (0), threadcount (1)
@@ -437,10 +451,6 @@ public:
     }
 };
 
-void __pthread_atforkprepare(void);
-void __pthread_atforkparent(void);
-void __pthread_atforkchild(void);
-
 /* Cancellation */
 int __pthread_cancel (pthread_t thread);