sockets: Add a function to disable all listening sockets.

When invoking several copies of m5 on the same machine at the same
time, there can be a race for TCP ports for the terminal connections
or remote gdb.  Expose a function to disable those ports, and have the
regression scripts disable them.  There are some SimObjects that have
no other function than to be used with ports (NativeTrace and
EtherTap), so they will panic if the ports are disabled.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/dev/ethertap.cc b/src/dev/ethertap.cc
index 81b84d179..c7b292c8a 100644
--- a/src/dev/ethertap.cc
+++ b/src/dev/ethertap.cc
@@ -130,6 +130,9 @@ EtherTap::EtherTap(const Params *p)
     : EtherObject(p), event(NULL), socket(-1), buflen(p->bufsz), dump(p->dump),
       interface(NULL), txEvent(this)
 {
+    if (ListenSocket::allDisabled())
+        fatal("All listeners are disabled! EtherTap can't work!");
+
     buffer = new char[buflen];
     listener = new TapListener(this, p->port);
     listener->listen();