From 1b68e10f1740cac5085f0a90b89cfcdf797445fd Mon Sep 17 00:00:00 2001
From: Philipp Moritz <pcmoritz@gmail.com>
Date: Thu, 16 Jun 2016 16:10:09 -0700
Subject: [PATCH] Revert "fix bug in which object is deallocated before
 objready is called" (#119)

---
 src/objstore.cc  |  2 +-
 src/scheduler.cc | 30 ------------------------------
 src/scheduler.h  |  7 ++-----
 3 files changed, 3 insertions(+), 36 deletions(-)

diff --git a/src/objstore.cc b/src/objstore.cc
index 286ef229c..2c24ba79a 100644
--- a/src/objstore.cc
+++ b/src/objstore.cc
@@ -75,7 +75,7 @@ Status ObjStoreService::StartDelivery(ServerContext* context, const StartDeliver
     if (memory_[objref].second == MemoryStatusType::NOT_PRESENT) {
     }
     else {
-      RAY_CHECK_NEQ(memory_[objref].second, MemoryStatusType::DEALLOCATED, "Objstore " << objstoreid_ << " is attempting to get objref " << objref << ", but memory_[objref] == DEALLOCATED.");
+      RAY_CHECK_NEQ(memory_[objref].second, MemoryStatusType::DEALLOCATED, "Objstore " << objstoreid_ << " is attempting to get objref " << objref << ", but memory_[objref] == DEALLOCATED."); 
       RAY_LOG(RAY_DEBUG, "Objstore " << objstoreid_ << " already has objref " << objref << " or it is already being shipped, so no need to pull it again.");
       return Status::OK;
     }
diff --git a/src/scheduler.cc b/src/scheduler.cc
index 05f6f2963..845aa647e 100644
--- a/src/scheduler.cc
+++ b/src/scheduler.cc
@@ -95,11 +95,6 @@ Status SchedulerService::AliasObjRefs(ServerContext* context, const AliasObjRefs
     std::lock_guard<std::mutex> reverse_target_objrefs_lock(reverse_target_objrefs_lock_);
     reverse_target_objrefs_[target_objref].push_back(alias_objref);
   }
-
-  std::vector<ObjRef> objref_vector;
-  objref_vector.push_back(alias_objref);
-  decrement_ref_count(objref_vector); // The corresponding increment is done in register_new_object in the scheduler.
-
   schedule();
   return Status::OK;
 }
@@ -137,21 +132,8 @@ Status SchedulerService::RegisterFunction(ServerContext* context, const Register
 Status SchedulerService::ObjReady(ServerContext* context, const ObjReadyRequest* request, AckReply* reply) {
   ObjRef objref = request->objref();
   RAY_LOG(RAY_DEBUG, "object " << objref << " ready on store " << request->objstoreid());
-  bool first_time_objready_called = false;
-  {
-    std::lock_guard<std::mutex> lock(target_objrefs_lock_);
-    if (target_objrefs_[objref] == UNITIALIZED_ALIAS) {
-      first_time_objready_called = true;
-    }
-  }
   add_canonical_objref(objref);
   add_location(objref, request->objstoreid());
-  // Only decrement the reference count the first time ObjReady is called.
-  if (first_time_objready_called) {
-    std::vector<ObjRef> objref_vector;
-    objref_vector.push_back(objref);
-    decrement_ref_count(objref_vector); // The corresponding increment is done in register_new_object in the scheduler.
-  }
   schedule();
   return Status::OK;
 }
@@ -344,23 +326,11 @@ ObjRef SchedulerService::register_new_object() {
   reverse_target_objrefs_.push_back(std::vector<ObjRef>());
   reference_counts_.push_back(0);
   contained_objrefs_.push_back(std::vector<ObjRef>());
-
-  // We increment once so the objref doesn't go out of scope before the ObjReady
-  // method is called. The corresponding decrement will happen either in
-  // ObjReady in the scheduler or in AliasObjRefs in the scheduler.
-  std::vector<ObjRef> objref_vector;
-  objref_vector.push_back(objtable_size);
-  increment_ref_count(objref_vector);
-
   return objtable_size;
 }
 
 void SchedulerService::add_location(ObjRef canonical_objref, ObjStoreId objstoreid) {
   // add_location must be called with a canonical objref
-  {
-    std::lock_guard<std::mutex> reference_counts_lock(reference_counts_lock_);
-    RAY_CHECK_NEQ(reference_counts_[canonical_objref], DEALLOCATED, "Calling ObjReady with canonical_objref " << canonical_objref << ", but this objref has already been deallocated");
-  }
   RAY_CHECK(is_canonical(canonical_objref), "Attempting to call add_location with a non-canonical objref (objref " << canonical_objref << ")");
   std::lock_guard<std::mutex> objtable_lock(objtable_lock_);
   RAY_CHECK_LT(canonical_objref, objtable_.size(), "trying to put an object in the object store that was not registered with the scheduler (objref " << canonical_objref << ")");
diff --git a/src/scheduler.h b/src/scheduler.h
index 76e7b8192..a74298af9 100644
--- a/src/scheduler.h
+++ b/src/scheduler.h
@@ -158,11 +158,8 @@ private:
   // List of pending alias notifications. Each element consists of (objstoreid, (alias_objref, canonical_objref)).
   std::vector<std::pair<ObjStoreId, std::pair<ObjRef, ObjRef> > > alias_notification_queue_;
   std::mutex alias_notification_queue_lock_;
-  // Reference counts. Currently, reference_counts_[objref] is the number of
-  // existing references held to objref. This is done for all objrefs, not just
-  // canonical_objrefs. This data structure completely ignores aliasing. If the
-  // object corresponding to objref has been deallocated, then
-  // reference_counts[objref] will equal DEALLOCATED.
+  // Reference counts. Currently, reference_counts_[objref] is the number of existing references
+  // held to objref. This is done for all objrefs, not just canonical_objrefs. This data structure completely ignores aliasing.
   std::vector<RefCount> reference_counts_;
   std::mutex reference_counts_lock_;
   // contained_objrefs_[objref] is a vector of all of the objrefs contained inside the object referred to by objref