Closing ticket #4465:

Net_server starts services by invoking fork() followed by exec(). If the latter
fails (for instance because the service isn't installed), the forked child is
invoking exit(). This in turn unloads libbe, triggering static cleanup code in 
BMessage, which deletes a couple of message ports that were inherited from the
parent during the fork. After that, net_server was desparately missing those
ports and no longer worked reliably.
* in InitTerminateLibBe, we now register an atfork-(child-)handler, which
  takes care to re-initialize the static reply ports used by BMessage code
* added BMessage::Private::StaticReInitForkedChild wrapper and 
  BMessage::_StaticReInitForkedChild() implementation which overwrites the
  inherited port IDs with a set of own ports


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33050 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/app/Message.h

@@ -339,6 +339,7 @@ class BMessage {
 							port_id port, int32 token, bigtime_t timeout);
 
 		static void		_StaticInit();
+		static void		_StaticReInitForkedChild();
 		static void		_StaticCleanup();
 		static void		_StaticCacheCleanup();
 		static int32	_StaticGetCachedReplyPort();

headers/private/app/MessagePrivate.h

@@ -207,6 +207,12 @@ class BMessage::Private {
 			BMessage::_StaticInit();
 		}
 
+		static void
+		StaticReInitForkedChild()
+		{
+			BMessage::_StaticReInitForkedChild();
+		}
+
 		static void
 		StaticCleanup()
 		{

src/kits/app/InitTerminateLibBe.cpp

@@ -10,6 +10,7 @@
 
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include <ClipboardPrivate.h>
 #include <MessagePrivate.h>
@@ -22,6 +23,17 @@
 #define OUT	printf
 
 
+static void
+initialize_forked_child()
+{
+	DBG(OUT("initialize_forked_child()\n"));
+
+	BMessage::Private::StaticReInitForkedChild();
+
+	DBG(OUT("initialize_forked_child() done\n"));
+}
+
+
 extern "C" void
 initialize_before()
 {
@@ -30,6 +42,8 @@ initialize_before()
 	BMessage::Private::StaticInit();
 	BRoster::Private::InitBeRoster();
 
+	atfork(initialize_forked_child);
+
 	DBG(OUT("initialize_before() done\n"));
 }
 

src/kits/app/Message.cpp

@@ -1971,6 +1971,22 @@ BMessage::_StaticInit()
 }
 
 
+void
+BMessage::_StaticReInitForkedChild()
+{
+	DEBUG_FUNCTION_ENTER2;
+
+	// overwrite the inherited ports with a set of our own
+	sReplyPorts[0] = create_port(1, "tmp_rport0");
+	sReplyPorts[1] = create_port(1, "tmp_rport1");
+	sReplyPorts[2] = create_port(1, "tmp_rport2");
+
+	sReplyPortInUse[0] = 0;
+	sReplyPortInUse[1] = 0;
+	sReplyPortInUse[2] = 0;
+}
+
+
 void
 BMessage::_StaticCleanup()
 {