misc: Using smart pointers for memory Requests

This patch is changing the underlying type for RequestPtr from Request*
to shared_ptr<Request>. Having memory requests being managed by smart
pointers will simplify the code; it will also prevent memory leakage and
dangling pointers.

Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10996
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

src/dev/dma_device.cc

@@ -95,8 +95,7 @@ DmaPort::handleResp(PacketPtr pkt, Tick delay)
         delete state;
     }
 
-    // delete the request that we created and also the packet
-    delete pkt->req;
+    // delete the packet
     delete pkt;
 
     // we might be drained at this point, if so signal the drain event
@@ -165,7 +164,10 @@ DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
             event ? event->scheduled() : -1);
     for (ChunkGenerator gen(addr, size, sys->cacheLineSize());
          !gen.done(); gen.next()) {
-        req = new Request(gen.addr(), gen.size(), flag, masterId);
+
+        req = std::make_shared<Request>(
+            gen.addr(), gen.size(), flag, masterId);
+
         req->taskId(ContextSwitchTaskId::DMA);
         PacketPtr pkt = new Packet(req, cmd);
 

src/dev/x86/i82094aa.cc

@@ -92,7 +92,6 @@ Tick
 X86ISA::I82094AA::recvResponse(PacketPtr pkt)
 {
     // Packet instantiated calling sendMessage() in signalInterrupt()
-    delete pkt->req;
     delete pkt;
     return 0;
 }