From 8f3222c4eb3ddcc7ec18e1f175e684f2fb862f94 Mon Sep 17 00:00:00 2001
From: Hope Casey-Allen <hcaseyal@google.com>
Date: Thu, 21 Jun 2018 15:25:24 -0700
Subject: [PATCH] Remove allocation in server_auth filter and allocate on the
 arena instead

---
 src/core/lib/security/context/security_context.cc     | 8 ++++----
 src/core/lib/security/context/security_context.h      | 5 ++++-
 src/core/lib/security/transport/server_auth_filter.cc | 2 +-
 src/core/lib/surface/call.cc                          | 2 ++
 src/core/lib/surface/call.h                           | 2 ++
 5 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/core/lib/security/context/security_context.cc b/src/core/lib/security/context/security_context.cc
index 14051a3f008..dbf6e39577b 100644
--- a/src/core/lib/security/context/security_context.cc
+++ b/src/core/lib/security/context/security_context.cc
@@ -21,6 +21,7 @@
 #include <string.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/arena.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/security/context/security_context.h"
 #include "src/core/lib/surface/api_trace.h"
@@ -99,10 +100,10 @@ void grpc_client_security_context_destroy(void* ctx) {
 }
 
 /* --- grpc_server_security_context --- */
-
-grpc_server_security_context* grpc_server_security_context_create(void) {
+grpc_server_security_context* grpc_server_security_context_create(
+    gpr_arena* arena) {
   return static_cast<grpc_server_security_context*>(
-      gpr_zalloc(sizeof(grpc_server_security_context)));
+      gpr_arena_alloc(arena, sizeof(grpc_server_security_context)));
 }
 
 void grpc_server_security_context_destroy(void* ctx) {
@@ -112,7 +113,6 @@ void grpc_server_security_context_destroy(void* ctx) {
   if (c->extension.instance != nullptr && c->extension.destroy != nullptr) {
     c->extension.destroy(c->extension.instance);
   }
-  gpr_free(ctx);
 }
 
 /* --- grpc_auth_context --- */
diff --git a/src/core/lib/security/context/security_context.h b/src/core/lib/security/context/security_context.h
index e782e4f28fe..1e98d169a2d 100644
--- a/src/core/lib/security/context/security_context.h
+++ b/src/core/lib/security/context/security_context.h
@@ -26,6 +26,8 @@
 
 extern grpc_core::DebugOnlyTraceFlag grpc_trace_auth_context_refcount;
 
+struct gpr_arena;
+
 /* --- grpc_auth_context ---
 
    High level authentication context object. Can optionally be chained. */
@@ -101,7 +103,8 @@ typedef struct {
   grpc_security_context_extension extension;
 } grpc_server_security_context;
 
-grpc_server_security_context* grpc_server_security_context_create(void);
+grpc_server_security_context* grpc_server_security_context_create(
+    gpr_arena* arena);
 void grpc_server_security_context_destroy(void* ctx);
 
 /* --- Channel args for auth context --- */
diff --git a/src/core/lib/security/transport/server_auth_filter.cc b/src/core/lib/security/transport/server_auth_filter.cc
index a560a4a02e9..0bf91d219e9 100644
--- a/src/core/lib/security/transport/server_auth_filter.cc
+++ b/src/core/lib/security/transport/server_auth_filter.cc
@@ -214,7 +214,7 @@ static grpc_error* init_call_elem(grpc_call_element* elem,
   // Create server security context.  Set its auth context from channel
   // data and save it in the call context.
   grpc_server_security_context* server_ctx =
-      grpc_server_security_context_create();
+      grpc_server_security_context_create(args->arena);
   server_ctx->auth_context = grpc_auth_context_create(chand->auth_context);
   calld->auth_context = server_ctx->auth_context;
   if (args->context[GRPC_CONTEXT_SECURITY].value != nullptr) {
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 556eb234b44..3f26b05c340 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -1113,6 +1113,8 @@ static void recv_trailing_filter(void* args, grpc_metadata_batch* b) {
   publish_app_metadata(call, b, true);
 }
 
+gpr_arena* grpc_call_get_arena(grpc_call* call) { return call->arena; }
+
 grpc_call_stack* grpc_call_get_call_stack(grpc_call* call) {
   return CALL_STACK_FROM_CALL(call);
 }
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index e000f13e7d3..b3b06059d4d 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -71,6 +71,8 @@ void grpc_call_internal_unref(grpc_call* call);
 #define GRPC_CALL_INTERNAL_UNREF(call, reason) grpc_call_internal_unref(call)
 #endif
 
+gpr_arena* grpc_call_get_arena(grpc_call* call);
+
 grpc_call_stack* grpc_call_get_call_stack(grpc_call* call);
 
 grpc_call_error grpc_call_start_batch_and_execute(grpc_call* call,