more stuff

src/core/ext/transport/chttp2/transport/chttp2_transport.cc

@@ -236,6 +236,7 @@ static void init_transport(grpc_chttp2_transport* t,
   size_t i;
   int j;
 
+  grpc_tcp_set_write_timestamps_callback(ContextList::Execute);
   GPR_ASSERT(strlen(GRPC_CHTTP2_CLIENT_CONNECT_STRING) ==
              GRPC_CHTTP2_CLIENT_CONNECT_STRLEN);
 
@@ -1026,11 +1027,13 @@ static void write_action_begin_locked(void* gt, grpc_error* error_ignored) {
 static void write_action(void* gt, grpc_error* error) {
   GPR_TIMER_SCOPE("write_action", 0);
   grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(gt);
+  void *cl = t->cl;
+  t->cl = nullptr;
   grpc_endpoint_write(
       t->ep, &t->outbuf,
       GRPC_CLOSURE_INIT(&t->write_action_end_locked, write_action_end_locked, t,
-                        grpc_combiner_scheduler(t->combiner)),
-      nullptr);
+                        grpc_combiner_scheduler(t->combiner)), cl
+      );
 }
 
 /* Callback from the grpc_endpoint after bytes have been written by calling
@@ -1354,6 +1357,7 @@ static void perform_stream_op_locked(void* stream_op,
 
   GRPC_STATS_INC_HTTP2_OP_BATCHES();
 
+  s->context = op->context;
   if (grpc_http_trace.enabled()) {
     char* str = grpc_transport_stream_op_batch_string(op);
     gpr_log(GPR_INFO, "perform_stream_op_locked: %s; on_complete = %p", str,

src/core/ext/transport/chttp2/transport/context_list.cc

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/transport/chttp2/transport/context_list.h"
+
+namespace {
+void (*cb)(void *, grpc_core::Timestamps*);
+}
+
+void ContextList::Execute(ContextList *head, grpc_core::Timestamps *ts, grpc_error* error) {
+  ContextList *ptr;
+  while(head != nullptr) {
+    if(error == GRPC_ERROR_NONE) {
+      cb(head->context, ts);
+    }
+    ptr = head;
+    head_ = head->next;
+    gpr_free(ptr);
+  }
+}
+
+
+grpc_http2_set_write_timestamps_callback(void (*fn)(void *, grpc_core::Timestamps *)) {
+  cb = fn;
+}

src/core/ext/transport/chttp2/transport/context_list.h

@@ -22,26 +22,26 @@
 #include <grpc/support/port_platform.h>
 
 /** A list of RPC Contexts */
-class ContextList {
-  struct ContextListElement {
-    void *context;
-    ContextListElement *next;
-  };
-
+class ContextList {\
  public:
-  ContextList() : head_(nullptr);
-
-  /* Creates a new element with \a context as the value and appends it to the 
+  /* Creates a new element with \a context as the value and appends it to the
    * list. */
-  void Append(void *context) {
-    ContextListElement *elem = static_cast<ContextListElement *>(gpr_malloc(sizeof(ContextlistELement)));
+  void Append(ContextList **head, void *context) {
+    /* Make sure context is not already present */
+    ContextList *ptr = *head;
+    while(ptr != nullptr) {
+      if(ptr->context == context) {
+        GPR_ASSERT(false);
+      }
+    }
+    ContextList *elem = static_cast<ContextListElement *>(gpr_malloc(sizeof(ContextList)));
     elem->context = context;
     elem->next = nullptr;
-    if(head_ == nullptr) {
-      head = elem;
+    if(*head_ == nullptr) {
+      *head = elem;
       return;
     }
-    ContextListElement *ptr = head_;
+    ptr = *head;
     while(ptr->next != nullptr) {
       ptr = ptr->next;
     }
@@ -50,17 +50,13 @@ class ContextList {
 
   /* Executes a function \a fn with each context in the list and \a arg. It also
    * frees up the entire list after this operation. */
-  void Execute(void (*fn)(void *context, void *arg)) {
-    ContextListElement *ptr;
-    while(head_ != nullptr){
-      fn(head->context, arg);
-      ptr = head_;
-      head_ = head_->next;
-      gpr_free(ptr);
-    }
-  }
+  void Execute(ContextList *head, grpc_core::Timestamps *ts, grpc_error* error);
+
  private:
-  ContextListElement *head_;
+    void *context;
+    ContextListElement *next;
 };
 
+grpc_http2_set_write_timestamps_callback(void (*fn)(void *, grpc_core::Timestamps*));
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CONTEXT_LIST_H */

src/core/ext/transport/chttp2/transport/internal.h

@@ -469,6 +469,7 @@ struct grpc_chttp2_transport {
   bool keepalive_permit_without_calls;
   /** keep-alive state machine state */
   grpc_chttp2_keepalive_state keepalive_state;
+  ContextList *cl;
 };
 
 typedef enum {
@@ -479,6 +480,7 @@ typedef enum {
 } grpc_published_metadata_method;
 
 struct grpc_chttp2_stream {
+  void *context;
   grpc_chttp2_transport* t;
   grpc_stream_refcount* refcount;
 

src/core/ext/transport/chttp2/transport/writing.cc

@@ -487,6 +487,7 @@ class StreamWriteContext {
       return;  // early out: nothing to do
     }
 
+    ContextList::Append(&t_->cl, s_->context);
     while ((s_->flow_controlled_buffer.length > 0 ||
             s_->compressed_data_buffer.length > 0) &&
            data_send_context.max_outgoing() > 0) {