base,cpu,dev: Add a level of indirection for ListenSockets.

This makes room for there to be different implementations for different
types of sockets.

Change-Id: I8c959e2c3400caec8242e693e11330e072bc2c5f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/69162
Reviewed-by: Yu-hsin Wang <yuhsingw@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>

src/base/remote_gdb.cc

@@ -392,10 +392,11 @@ std::map<Addr, HardBreakpoint *> hardBreakMap;
 
 BaseRemoteGDB::BaseRemoteGDB(System *_system, int _port) :
         incomingConnectionEvent(nullptr), incomingDataEvent(nullptr),
-        listener(_system->name() + ".remote_gdb", _port), fd(-1), sys(_system),
-        connectEvent(*this), disconnectEvent(*this), trapEvent(this),
-        singleStepEvent(*this)
-{}
+        fd(-1), sys(_system), connectEvent(*this), disconnectEvent(*this),
+        trapEvent(this), singleStepEvent(*this)
+{
+    listener = listenSocketInetConfig(_port).build(name());
+}
 
 BaseRemoteGDB::~BaseRemoteGDB()
 {
@@ -417,25 +418,22 @@ BaseRemoteGDB::listen()
         return;
     }
 
-    listener.listen();
+    listener->listen();
 
     incomingConnectionEvent =
-            new IncomingConnectionEvent(this, listener.getfd(), POLLIN);
+            new IncomingConnectionEvent(this, listener->getfd(), POLLIN);
     pollQueue.schedule(incomingConnectionEvent);
-
-    ccprintf(std::cerr, "%d: %s: listening for remote gdb on %s\n",
-             curTick(), name(), listener);
 }
 
 void
 BaseRemoteGDB::connect()
 {
-    panic_if(!listener.islistening(),
+    panic_if(!listener->islistening(),
              "Can't accept GDB connections without any threads!");
 
     pollQueue.remove(incomingConnectionEvent);
 
-    int sfd = listener.accept();
+    int sfd = listener->accept();
 
     if (sfd != -1) {
         if (isAttached())
@@ -448,9 +446,9 @@ BaseRemoteGDB::connect()
 const ListenSocket &
 BaseRemoteGDB::hostSocket() const
 {
-    panic_if(!listener.islistening(),
+    panic_if(!listener->islistening(),
              "Remote GDB socket is unknown until listen() has been called.");
-    return listener;
+    return *listener;
 }
 
 void
@@ -513,7 +511,7 @@ BaseRemoteGDB::addThreadContext(ThreadContext *_tc)
         assert(selectThreadContext(_tc->contextId()));
 
     // Now that we have a thread, we can start listening.
-    if (!listener.islistening())
+    if (!listener->islistening())
         listen();
 }
 

src/base/remote_gdb.hh

@@ -231,7 +231,7 @@ class BaseRemoteGDB
     IncomingConnectionEvent *incomingConnectionEvent;
     IncomingDataEvent *incomingDataEvent;
 
-    ListenSocket listener;
+    ListenSocketPtr listener;
 
     // The socket commands come in through.
     int fd;

src/base/socket.cc

@@ -269,4 +269,12 @@ ListenSocket::accept()
     return sfd;
 }
 
+ListenSocketConfig
+listenSocketInetConfig(int port)
+{
+    return ListenSocketConfig([port](const std::string &name) {
+        return std::make_unique<ListenSocket>(name, port);
+    });
+}
+
 } // namespace gem5

src/base/socket.hh

@@ -33,6 +33,9 @@
 #include <sys/types.h>
 #include <sys/un.h>
 
+#include <cassert>
+#include <functional>
+#include <memory>
 #include <string>
 
 #include "base/named.hh"
@@ -127,6 +130,33 @@ class ListenSocket : public Named
     /** @} */ // end of api_socket
 };
 
+using ListenSocketPtr = std::unique_ptr<ListenSocket>;
+
+class ListenSocketConfig
+{
+  public:
+    using Builder = std::function<ListenSocketPtr(const std::string &name)>;
+
+    ListenSocketConfig() {}
+    ListenSocketConfig(Builder _builder) : builder(_builder) {}
+
+    ListenSocketPtr
+    build(const std::string &name) const
+    {
+        assert(builder);
+        return builder(name);
+    }
+
+    operator bool() const { return (bool)builder; }
+
+  private:
+    Builder builder;
+};
+
+static inline ListenSocketConfig listenSocketEmptyConfig() { return {}; }
+
+ListenSocketConfig listenSocketInetConfig(int port);
+
 inline static std::ostream &
 operator << (std::ostream &os, const ListenSocket &socket)
 {

src/base/vnc/vncserver.cc

@@ -117,8 +117,8 @@ VncServer::DataEvent::process(int revent)
  */
 VncServer::VncServer(const Params &p)
     : VncInput(p), listenEvent(NULL), dataEvent(NULL), number(p.number),
-      listener(p.name, p.port), sendUpdate(false),
-      supportsRawEnc(false), supportsResizeEnc(false)
+      listener(listenSocketInetConfig(p.port).build(p.name)),
+      sendUpdate(false), supportsRawEnc(false), supportsResizeEnc(false)
 {
     if (p.port)
         listen();
@@ -164,9 +164,9 @@ VncServer::listen()
         return;
     }
 
-    listener.listen();
+    listener->listen();
 
-    listenEvent = new ListenEvent(this, listener.getfd(), POLLIN);
+    listenEvent = new ListenEvent(this, listener->getfd(), POLLIN);
     pollQueue.schedule(listenEvent);
 }
 
@@ -179,10 +179,10 @@ VncServer::accept()
     // thread.
     EventQueue::ScopedMigration migrate(eventQueue());
 
-    if (!listener.islistening())
+    if (!listener->islistening())
         panic("%s: cannot accept a connection if not listening!", name());
 
-    int fd = listener.accept();
+    int fd = listener->accept();
     if (fd < 0) {
         warn("%s: failed to accept VNC connection!", name());
         return;

src/base/vnc/vncserver.hh

@@ -180,7 +180,7 @@ class VncServer : public VncInput
     int number;
     int dataFd; // data stream file describer
 
-    ListenSocket listener;
+    ListenSocketPtr listener;
 
     void listen();
     void accept();

src/cpu/nativetrace.cc

@@ -39,14 +39,14 @@ namespace gem5
 namespace trace {
 
 NativeTrace::NativeTrace(const Params &p)
-    : ExeTracer(p), native_listener(p.name, 8000)
+    : ExeTracer(p), native_listener(listenSocketInetConfig(8000).build(p.name))
 {
     if (ListenSocket::allDisabled())
         fatal("All listeners are disabled!");
 
-    native_listener.listen();
+    native_listener->listen();
 
-    fd = native_listener.accept();
+    fd = native_listener->accept();
 }
 
 void

src/cpu/nativetrace.hh

@@ -71,7 +71,7 @@ class NativeTrace : public ExeTracer
   protected:
     int fd;
 
-    ListenSocket native_listener;
+    ListenSocketPtr native_listener;
 
   public:
 

src/dev/net/ethertap.cc

@@ -245,11 +245,12 @@ class TapListener
     void accept();
 
   protected:
-    ListenSocket listener;
+    ListenSocketPtr listener;
     EtherTapStub *tap;
 
   public:
-    TapListener(EtherTapStub *t, int p) : listener(t->name(), p), tap(t) {}
+    TapListener(EtherTapStub *t, int p) :
+        listener(listenSocketInetConfig(p).build(t->name())), tap(t) {}
     ~TapListener() { delete event; }
 
     void listen();
@@ -258,9 +259,9 @@ class TapListener
 void
 TapListener::listen()
 {
-    listener.listen();
+    listener->listen();
 
-    event = new Event(this, listener.getfd(), POLLIN|POLLERR);
+    event = new Event(this, listener->getfd(), POLLIN|POLLERR);
     pollQueue.schedule(event);
 }
 
@@ -272,10 +273,10 @@ TapListener::accept()
     // thread.
     EventQueue::ScopedMigration migrate(tap->eventQueue());
 
-    if (!listener.islistening())
+    if (!listener->islistening())
         panic("TapListener(accept): cannot accept if we're not listening!");
 
-    int sfd = listener.accept();
+    int sfd = listener->accept();
     if (sfd != -1)
         tap->attach(sfd);
 }

src/dev/serial/terminal.cc

@@ -121,7 +121,8 @@ Terminal::DataEvent::process(int revent)
  */
 Terminal::Terminal(const Params &p)
     : SerialDevice(p), listenEvent(NULL), dataEvent(NULL),
-      number(p.number), data_fd(-1), listener(p.name, p.port),
+      number(p.number), data_fd(-1),
+      listener(listenSocketInetConfig(p.port).build(p.name)),
       txbuf(16384), rxbuf(16384), outfile(terminalDump(p))
 #if TRACING_ON == 1
       , linebuf(16384)
@@ -175,19 +176,19 @@ Terminal::listen()
         return;
     }
 
-    listener.listen();
+    listener->listen();
 
-    listenEvent = new ListenEvent(this, listener.getfd(), POLLIN);
+    listenEvent = new ListenEvent(this, listener->getfd(), POLLIN);
     pollQueue.schedule(listenEvent);
 }
 
 void
 Terminal::accept()
 {
-    if (!listener.islistening())
+    if (!listener->islistening())
         panic("%s: cannot accept a connection if not listening!", name());
 
-    int fd = listener.accept();
+    int fd = listener->accept();
     if (data_fd != -1) {
         char message[] = "terminal already attached!\n";
         atomic_write(fd, message, sizeof(message));

src/dev/serial/terminal.hh

@@ -101,7 +101,7 @@ class Terminal : public SerialDevice
     OutputStream * terminalDump(const TerminalParams &p);
 
   protected:
-    ListenSocket listener;
+    ListenSocketPtr listener;
 
     void listen();
     void accept();