fix PR

Signed-off-by: adi_holden <[email protected]>

Author: adiholden

src/server/dragonfly_test.cc

@@ -22,7 +22,7 @@ extern "C" {
 
 ABSL_DECLARE_FLAG(float, mem_defrag_threshold);
 ABSL_DECLARE_FLAG(std::vector<std::string>, rename_command);
-ABSL_DECLARE_FLAG(double, maxmemory_ratio);
+ABSL_DECLARE_FLAG(double, oom_deny_ratio);
 
 namespace dfly {
 
@@ -383,7 +383,7 @@ TEST_F(DflyEngineTest, Bug207) {
   shard_set->TEST_EnableHeartBeat();
   shard_set->TEST_EnableCacheMode();
   absl::FlagSaver fs;
-  absl::SetFlag(&FLAGS_maxmemory_ratio, 4);
+  absl::SetFlag(&FLAGS_oom_deny_ratio, 4);
 
   max_memory_limit = 300000;
 
@@ -414,7 +414,7 @@ TEST_F(DflyEngineTest, StickyEviction) {
   shard_set->TEST_EnableHeartBeat();
   shard_set->TEST_EnableCacheMode();
   absl::FlagSaver fs;
-  absl::SetFlag(&FLAGS_maxmemory_ratio, 4);
+  absl::SetFlag(&FLAGS_oom_deny_ratio, 4);
 
   max_memory_limit = 300000;
 

src/server/main_service.cc

@@ -77,10 +77,9 @@ ABSL_FLAG(MaxMemoryFlag, maxmemory, MaxMemoryFlag{},
           "Limit on maximum-memory that is used by the database. "
           "0 - means the program will automatically determine its maximum memory usage. "
           "default: 0");
-ABSL_FLAG(double, maxmemory_ratio, 1.1,
+ABSL_FLAG(double, oom_deny_ratio, 1.1,
           "commands with flag denyoom will return OOM when the ratio between maxmemory and used "
-          "memory is above "
-          "this value");
+          "memory is above this value");
 
 bool AbslParseFlag(std::string_view in, MaxMemoryFlag* flag, std::string* err) {
   int64_t val;
@@ -896,9 +895,9 @@ void Service::DispatchCommand(CmdArgList args, facade::ConnectionContext* cntx)
   }
 
   uint64_t start_ns = ProactorBase::GetMonotonicTimeNs(), end_ns;
-  double maxmemory_ratio = GetFlag(FLAGS_maxmemory_ratio);
-  uint64_t used_memory = ServerState::tlocal()->GetCachedUsedMemory(start_ns);
-  if (used_memory > (max_memory_limit * maxmemory_ratio) && (cid->opt_mask() & CO::DENYOOM)) {
+  double oom_deny_ratio = GetFlag(FLAGS_oom_deny_ratio);
+  uint64_t used_memory = ServerState::tlocal()->GetUsedMemory(start_ns);
+  if (used_memory > (max_memory_limit * oom_deny_ratio) && (cid->opt_mask() & CO::DENYOOM)) {
     return (*cntx)->SendError(kOutOfMemory);
   }
 

src/server/server_state.cc

@@ -71,13 +71,13 @@ void ServerState::Destroy() {
   state_ = nullptr;
 }
 
-uint64_t ServerState::GetCachedUsedMemory(uint64_t now_ns) {
-  uint64_t kCacheEveryNs = 1000;
-  if (now_ns > last_chached_used_current_ + kCacheEveryNs) {
-    last_chached_used_current_ = now_ns;
-    used_mem_ = used_mem_current;
+uint64_t ServerState::GetUsedMemory(uint64_t now_ns) {
+  static constexpr uint64_t kCacheEveryNs = 1000;
+  if (now_ns > used_mem_last_update_ + kCacheEveryNs) {
+    used_mem_last_update_ = now_ns;
+    used_mem_cached_ = used_mem_current.load(memory_order_relaxed);
   }
-  return used_mem_;
+  return used_mem_cached_;
 }
 
 bool ServerState::AllowInlineScheduling() const {

src/server/server_state.h

@@ -130,7 +130,7 @@ class ServerState {  // public struct - to allow initialization.
     gstate_ = s;
   }
 
-  uint64_t GetCachedUsedMemory(uint64_t now_ns);
+  uint64_t GetUsedMemory(uint64_t now_ns);
 
   bool AllowInlineScheduling() const;
 
@@ -228,8 +228,8 @@ class ServerState {  // public struct - to allow initialization.
 
   absl::flat_hash_map<std::string, base::Histogram> call_latency_histos_;
   uint32_t thread_index_ = 0;
-  uint64_t used_mem_ = 0;
-  uint64_t last_chached_used_current_ = 0;
+  uint64_t used_mem_cached_ = 0;  // thread local cache of used_mem_current
+  uint64_t used_mem_last_update_ = 0;
 
   static __thread ServerState* state_;
 };