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>

6 files changed, 35 insertions, 37 deletions

diff --git a/src/gpu-compute/compute_unit.cc b/src/gpu-compute/compute_unit.cc
index 042347cf2..1a174c98b 100644
--- a/src/gpu-compute/compute_unit.cc
+++ b/src/gpu-compute/compute_unit.cc
@@ -655,7 +655,6 @@ ComputeUnit::DataPort::recvTimingResp(PacketPtr pkt)
         }
 
         delete pkt->senderState;
-        delete pkt->req;
         delete pkt;
         return true;
     } else if (pkt->req->isKernel() && pkt->req->isAcquire()) {
@@ -666,7 +665,6 @@ ComputeUnit::DataPort::recvTimingResp(PacketPtr pkt)
         }
 
         delete pkt->senderState;
-        delete pkt->req;
         delete pkt;
         return true;
     }
@@ -916,7 +914,6 @@ ComputeUnit::sendRequest(GPUDynInstPtr gpuDynInst, int index, PacketPtr pkt)
         delete sender_state->tlbEntry;
         delete new_pkt;
         delete pkt->senderState;
-        delete pkt->req;
         delete pkt;
     }
 }
@@ -941,12 +938,13 @@ ComputeUnit::sendSyncRequest(GPUDynInstPtr gpuDynInst, int index, PacketPtr pkt)
 
 void
 ComputeUnit::injectGlobalMemFence(GPUDynInstPtr gpuDynInst, bool kernelLaunch,
-                                  Request* req)
+                                  RequestPtr req)
 {
     assert(gpuDynInst->isGlobalSeg());
 
     if (!req) {
-        req = new Request(0, 0, 0, 0, masterId(), 0, gpuDynInst->wfDynId);
+        req = std::make_shared<Request>(
+            0, 0, 0, 0, masterId(), 0, gpuDynInst->wfDynId);
     }
     req->setPaddr(0);
     if (kernelLaunch) {
@@ -1057,7 +1055,6 @@ ComputeUnit::DataPort::processMemRespEvent(PacketPtr pkt)
     }
 
     delete pkt->senderState;
-    delete pkt->req;
     delete pkt;
 }
 
@@ -1178,11 +1175,11 @@ ComputeUnit::DTLBPort::recvTimingResp(PacketPtr pkt)
             if (!stride)
                 break;
 
-            RequestPtr prefetch_req = new Request(0, vaddr + stride * pf *
-                                                TheISA::PageBytes,
-                                                sizeof(uint8_t), 0,
-                                                computeUnit->masterId(),
-                                                0, 0, 0);
+            RequestPtr prefetch_req = std::make_shared<Request>(
+                0, vaddr + stride * pf * TheISA::PageBytes,
+                sizeof(uint8_t), 0,
+                computeUnit->masterId(),
+                0, 0, nullptr);
 
             PacketPtr prefetch_pkt = new Packet(prefetch_req, requestCmd);
             uint8_t foo = 0;
@@ -1205,7 +1202,6 @@ ComputeUnit::DTLBPort::recvTimingResp(PacketPtr pkt)
 
             delete tlb_state->tlbEntry;
             delete tlb_state;
-            delete prefetch_pkt->req;
             delete prefetch_pkt;
         }
     }
@@ -1801,7 +1797,7 @@ ComputeUnit::sendToLds(GPUDynInstPtr gpuDynInst)
 {
     // this is just a request to carry the GPUDynInstPtr
     // back and forth
-    RequestPtr newRequest = new Request();
+    RequestPtr newRequest = std::make_shared<Request>();
     newRequest->setPaddr(0x0);
 
     // ReadReq is not evaluted by the LDS but the Packet ctor requires this
@@ -1827,7 +1823,6 @@ ComputeUnit::LDSPort::recvTimingResp(PacketPtr packet)
     GPUDynInstPtr gpuDynInst = senderState->getMemInst();
 
     delete packet->senderState;
-    delete packet->req;
     delete packet;
 
     computeUnit->localMemoryPipe.getLMRespFIFO().push(gpuDynInst);
diff --git a/src/gpu-compute/fetch_unit.cc b/src/gpu-compute/fetch_unit.cc
index 36ef1e1e8..a9cea9bf6 100644
--- a/src/gpu-compute/fetch_unit.cc
+++ b/src/gpu-compute/fetch_unit.cc
@@ -145,8 +145,9 @@ FetchUnit::initiateFetch(Wavefront *wavefront)
     }
 
     // set up virtual request
-    RequestPtr req = new Request(0, vaddr, size, Request::INST_FETCH,
-                               computeUnit->masterId(), 0, 0, 0);
+    RequestPtr req = std::make_shared<Request>(
+        0, vaddr, size, Request::INST_FETCH,
+        computeUnit->masterId(), 0, 0, nullptr);
 
     PacketPtr pkt = new Packet(req, MemCmd::ReadReq);
     // This fetchBlock is kind of faux right now - because the translations so
@@ -306,7 +307,6 @@ FetchUnit::processFetchReturn(PacketPtr pkt)
     wavefront->pendingFetch = false;
 
     delete pkt->senderState;
-    delete pkt->req;
     delete pkt;
 }
 
diff --git a/src/gpu-compute/gpu_tlb.cc b/src/gpu-compute/gpu_tlb.cc
index 8b9bd4320..fea6183ed 100644
--- a/src/gpu-compute/gpu_tlb.cc
+++ b/src/gpu-compute/gpu_tlb.cc
@@ -287,7 +287,7 @@ namespace X86ISA
     }
 
     Fault
-    GpuTLB::translateInt(RequestPtr req, ThreadContext *tc)
+    GpuTLB::translateInt(const RequestPtr &req, ThreadContext *tc)
     {
         DPRINTF(GPUTLB, "Addresses references internal memory.\n");
         Addr vaddr = req->getVaddr();
@@ -662,7 +662,8 @@ namespace X86ISA
      * On a hit it will update the LRU stack.
      */
     bool
-    GpuTLB::tlbLookup(RequestPtr req, ThreadContext *tc, bool update_stats)
+    GpuTLB::tlbLookup(const RequestPtr &req,
+                      ThreadContext *tc, bool update_stats)
     {
         bool tlb_hit = false;
     #ifndef NDEBUG
@@ -710,7 +711,7 @@ namespace X86ISA
     }
 
     Fault
-    GpuTLB::translate(RequestPtr req, ThreadContext *tc,
+    GpuTLB::translate(const RequestPtr &req, ThreadContext *tc,
                       Translation *translation, Mode mode,
                       bool &delayedResponse, bool timing, int &latency)
     {
@@ -913,8 +914,8 @@ namespace X86ISA
     };
 
     Fault
-    GpuTLB::translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode,
-                            int &latency)
+    GpuTLB::translateAtomic(const RequestPtr &req, ThreadContext *tc,
+                            Mode mode, int &latency)
     {
         bool delayedResponse;
 
@@ -923,7 +924,7 @@ namespace X86ISA
     }
 
     void
-    GpuTLB::translateTiming(RequestPtr req, ThreadContext *tc,
+    GpuTLB::translateTiming(const RequestPtr &req, ThreadContext *tc,
             Translation *translation, Mode mode, int &latency)
     {
         bool delayedResponse;
@@ -1069,7 +1070,7 @@ namespace X86ISA
         }
 
         tlbOutcome lookup_outcome = TLB_MISS;
-        RequestPtr tmp_req = pkt->req;
+        const RequestPtr &tmp_req = pkt->req;
 
         // Access the TLB and figure out if it's a hit or a miss.
         bool success = tlbLookup(tmp_req, tmp_tc, update_stats);
diff --git a/src/gpu-compute/gpu_tlb.hh b/src/gpu-compute/gpu_tlb.hh
index f479eb6ce..04d9bfce8 100644
--- a/src/gpu-compute/gpu_tlb.hh
+++ b/src/gpu-compute/gpu_tlb.hh
@@ -113,8 +113,8 @@ namespace X86ISA
              * may be responsible for cleaning itslef up which will happen in
              * this function. Once it's called the object is no longer valid.
              */
-            virtual void finish(Fault fault, RequestPtr req, ThreadContext *tc,
-                    Mode mode) = 0;
+            virtual void finish(Fault fault, const RequestPtr &req,
+                                ThreadContext *tc, Mode mode) = 0;
         };
 
         void dumpAll();
@@ -177,9 +177,9 @@ namespace X86ISA
          */
         std::vector<EntryList> entryList;
 
-        Fault translateInt(RequestPtr req, ThreadContext *tc);
+        Fault translateInt(const RequestPtr &req, ThreadContext *tc);
 
-        Fault translate(RequestPtr req, ThreadContext *tc,
+        Fault translate(const RequestPtr &req, ThreadContext *tc,
                 Translation *translation, Mode mode, bool &delayedResponse,
                 bool timing, int &latency);
 
@@ -222,10 +222,10 @@ namespace X86ISA
         void printAccessPattern();
 
 
-        Fault translateAtomic(RequestPtr req, ThreadContext *tc, Mode mode,
-                              int &latency);
+        Fault translateAtomic(const RequestPtr &req, ThreadContext *tc,
+                              Mode mode, int &latency);
 
-        void translateTiming(RequestPtr req, ThreadContext *tc,
+        void translateTiming(const RequestPtr &req, ThreadContext *tc,
                              Translation *translation, Mode mode,
                              int &latency);
 
@@ -239,7 +239,8 @@ namespace X86ISA
         virtual void unserialize(CheckpointIn& cp);
         void issueTranslation();
         enum tlbOutcome {TLB_HIT, TLB_MISS, PAGE_WALK, MISS_RETURN};
-        bool tlbLookup(RequestPtr req, ThreadContext *tc, bool update_stats);
+        bool tlbLookup(const RequestPtr &req,
+                       ThreadContext *tc, bool update_stats);
 
         void handleTranslationReturn(Addr addr, tlbOutcome outcome,
                                      PacketPtr pkt);
diff --git a/src/gpu-compute/shader.cc b/src/gpu-compute/shader.cc
index 8e7ba9ad5..d0bd41a0d 100644
--- a/src/gpu-compute/shader.cc
+++ b/src/gpu-compute/shader.cc
@@ -226,7 +226,7 @@ Shader::handshake(GpuDispatcher *_dispatcher)
 }
 
 void
-Shader::doFunctionalAccess(RequestPtr req, MemCmd cmd, void *data,
+Shader::doFunctionalAccess(const RequestPtr &req, MemCmd cmd, void *data,
                            bool suppress_func_errors, int cu_id)
 {
     int block_size = cuList.at(cu_id)->cacheLineSize();
@@ -338,12 +338,13 @@ Shader::AccessMem(uint64_t address, void *ptr, uint32_t size, int cu_id,
 
     for (ChunkGenerator gen(address, size, cuList.at(cu_id)->cacheLineSize());
          !gen.done(); gen.next()) {
-        RequestPtr req = new Request(0, gen.addr(), gen.size(), 0,
-                                   cuList[0]->masterId(), 0, 0, 0);
+
+        RequestPtr req = std::make_shared<Request>(
+            0, gen.addr(), gen.size(), 0,
+            cuList[0]->masterId(), 0, 0, nullptr);
 
         doFunctionalAccess(req, cmd, data_buf, suppress_func_errors, cu_id);
         data_buf += gen.size();
-        delete req;
     }
 }
 
diff --git a/src/gpu-compute/shader.hh b/src/gpu-compute/shader.hh
index f9c1ad4b2..5c14d9898 100644
--- a/src/gpu-compute/shader.hh
+++ b/src/gpu-compute/shader.hh
@@ -181,7 +181,7 @@ class Shader : public ClockedObject
     void WriteMem(uint64_t address, void *ptr, uint32_t sz, int cu_id,
                   bool suppress_func_errors);
 
-    void doFunctionalAccess(RequestPtr req, MemCmd cmd, void *data,
+    void doFunctionalAccess(const RequestPtr &req, MemCmd cmd, void *data,
                             bool suppress_func_errors, int cu_id);
 
     void