Address some PR comments

82 files changed, 375 insertions, 494 deletions

diff --git a/src/core/ext/filters/client_channel/backup_poller.cc b/src/core/ext/filters/client_channel/backup_poller.cc
index 1b42f5d6a0..dbdcd53ef5 100644
--- a/src/core/ext/filters/client_channel/backup_poller.cc
+++ b/src/core/ext/filters/client_channel/backup_poller.cc
@@ -112,10 +112,10 @@ static void run_poller(void* arg, grpc_error* error) {
     backup_poller_shutdown_unref(p);
     return;
   }
-  grpc_error* err = grpc_pollset_work(p->pollset, NULL, grpc_exec_ctx_now());
+  grpc_error* err = grpc_pollset_work(p->pollset, NULL, ExecCtx::Get()->Now());
   gpr_mu_unlock(p->pollset_mu);
   GRPC_LOG_IF_ERROR("Run client channel backup poller", err);
-  grpc_timer_init(&p->polling_timer, grpc_exec_ctx_now() + g_poll_interval_ms,
+  grpc_timer_init(&p->polling_timer, ExecCtx::Get()->Now() + g_poll_interval_ms,
                   &p->run_poller_closure);
 }
 
@@ -137,7 +137,7 @@ void grpc_client_channel_start_backup_polling(
     GRPC_CLOSURE_INIT(&g_poller->run_poller_closure, run_poller, g_poller,
                       grpc_schedule_on_exec_ctx);
     grpc_timer_init(&g_poller->polling_timer,
-                    grpc_exec_ctx_now() + g_poll_interval_ms,
+                    ExecCtx::Get()->Now() + g_poll_interval_ms,
                     &g_poller->run_poller_closure);
   }
 
diff --git a/src/core/ext/filters/client_channel/channel_connectivity.cc b/src/core/ext/filters/client_channel/channel_connectivity.cc
index 3069e66775..0ceedb9f86 100644
--- a/src/core/ext/filters/client_channel/channel_connectivity.cc
+++ b/src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -41,14 +41,14 @@ grpc_connectivity_state grpc_channel_check_connectivity_state(
   if (client_channel_elem->filter == &grpc_client_channel_filter) {
     state = grpc_client_channel_check_connectivity_state(client_channel_elem,
                                                          try_to_connect);
-    grpc_exec_ctx_finish();
+
     return state;
   }
   gpr_log(GPR_ERROR,
           "grpc_channel_check_connectivity_state called on something that is "
           "not a client channel, but '%s'",
           client_channel_elem->filter->name);
-  grpc_exec_ctx_finish();
+
   return GRPC_CHANNEL_SHUTDOWN;
 }
 
@@ -241,6 +241,4 @@ void grpc_channel_watch_connectivity_state(
   } else {
     abort();
   }
-
-  grpc_exec_ctx_finish();
 }
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index d4c58fb1e0..63cf417c4e 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -1122,7 +1122,7 @@ static void start_picking_locked(glb_lb_policy* glb_policy) {
   if (glb_policy->lb_fallback_timeout_ms > 0 &&
       glb_policy->serverlist == NULL && !glb_policy->fallback_timer_active) {
     grpc_millis deadline =
-        grpc_exec_ctx_now() + glb_policy->lb_fallback_timeout_ms;
+        ExecCtx::Get()->Now() + glb_policy->lb_fallback_timeout_ms;
     GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_fallback_timer");
     GRPC_CLOSURE_INIT(&glb_policy->lb_on_fallback, lb_on_fallback_timer_locked,
                       glb_policy,
@@ -1271,7 +1271,7 @@ static void maybe_restart_lb_call(glb_lb_policy* glb_policy) {
     if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
       gpr_log(GPR_DEBUG, "[grpclb %p] Connection to LB server lost...",
               glb_policy);
-      grpc_millis timeout = next_try - grpc_exec_ctx_now();
+      grpc_millis timeout = next_try - ExecCtx::Get()->Now();
       if (timeout > 0) {
         gpr_log(GPR_DEBUG,
                 "[grpclb %p] ... retry_timer_active in %" PRIuPTR "ms.",
@@ -1297,7 +1297,7 @@ static void send_client_load_report_locked(void* arg, grpc_error* error);
 
 static void schedule_next_client_load_report(glb_lb_policy* glb_policy) {
   const grpc_millis next_client_load_report_time =
-      grpc_exec_ctx_now() + glb_policy->client_stats_report_interval;
+      ExecCtx::Get()->Now() + glb_policy->client_stats_report_interval;
   GRPC_CLOSURE_INIT(&glb_policy->client_load_report_closure,
                     send_client_load_report_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
@@ -1392,7 +1392,7 @@ static void lb_call_init_locked(glb_lb_policy* glb_policy) {
   grpc_millis deadline =
       glb_policy->lb_call_timeout_ms == 0
           ? GRPC_MILLIS_INF_FUTURE
-          : grpc_exec_ctx_now() + glb_policy->lb_call_timeout_ms;
+          : ExecCtx::Get()->Now() + glb_policy->lb_call_timeout_ms;
   glb_policy->lb_call = grpc_channel_create_pollset_set_call(
       glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
       glb_policy->base.interested_parties,
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index 77d790aa38..f0543964ae 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -265,7 +265,7 @@ static void dns_ares_on_resolved_locked(void* arg, grpc_error* error) {
     gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg);
     grpc_millis next_try =
         grpc_backoff_step(&r->backoff_state).next_attempt_start_time;
-    grpc_millis timeout = next_try - grpc_exec_ctx_now();
+    grpc_millis timeout = next_try - ExecCtx::Get()->Now();
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
index c57fac61a4..925223d189 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
@@ -101,18 +101,7 @@ static void grpc_ares_request_unref(grpc_ares_request* r) {
      request */
   if (gpr_unref(&r->pending_queries)) {
     /* TODO(zyc): Sort results with RFC6724 before invoking on_done. */
-    if (exec_ctx == NULL) {
-      /* A new exec_ctx is created here, as the c-ares interface does not
-         provide one in ares_host_callback. It's safe to schedule on_done with
-         the newly created exec_ctx, since the caller has been warned not to
-         acquire locks in on_done. ares_dns_resolver is using combiner to
-         protect resources needed by on_done. */
-      ExecCtx _local_exec_ctx;
-      GRPC_CLOSURE_SCHED(r->on_done, r->error);
-      grpc_exec_ctx_finish();
-    } else {
-      GRPC_CLOSURE_SCHED(r->on_done, r->error);
-    }
+    GRPC_CLOSURE_SCHED(r->on_done, r->error);
     gpr_mu_destroy(&r->mu);
     grpc_ares_ev_driver_destroy(r->ev_driver);
     gpr_free(r);
@@ -263,7 +252,6 @@ static void on_srv_query_done_cb(void* arg, int status, int timeouts,
     }
   }
   grpc_ares_request_unref(r);
-  grpc_exec_ctx_finish();
 }
 
 static const char g_service_config_attribute_prefix[] = "grpc_config=";
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 4463673e1f..10404ec4ef 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -163,7 +163,7 @@ static void dns_on_resolved_locked(void* arg, grpc_error* error) {
   } else {
     grpc_millis next_try =
         grpc_backoff_step(&r->backoff_state).next_attempt_start_time;
-    grpc_millis timeout = next_try - grpc_exec_ctx_now();
+    grpc_millis timeout = next_try - ExecCtx::Get()->Now();
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
diff --git a/src/core/ext/filters/client_channel/subchannel.cc b/src/core/ext/filters/client_channel/subchannel.cc
index c8583687d5..98f96b5750 100644
--- a/src/core/ext/filters/client_channel/subchannel.cc
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -458,7 +458,7 @@ static void maybe_start_connecting_locked(grpc_subchannel* c) {
     GPR_ASSERT(!c->have_alarm);
     c->have_alarm = true;
     const grpc_millis time_til_next =
-        c->backoff_result.next_attempt_start_time - grpc_exec_ctx_now();
+        c->backoff_result.next_attempt_start_time - ExecCtx::Get()->Now();
     if (time_til_next <= 0) {
       gpr_log(GPR_INFO, "Retry immediately");
     } else {
diff --git a/src/core/ext/filters/client_channel/subchannel_index.cc b/src/core/ext/filters/client_channel/subchannel_index.cc
index cb8e480734..fbab57769c 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.cc
+++ b/src/core/ext/filters/client_channel/subchannel_index.cc
@@ -132,10 +132,8 @@ void grpc_subchannel_index_shutdown(void) {
 
 void grpc_subchannel_index_unref(void) {
   if (gpr_unref(&g_refcount)) {
-    ExecCtx _local_exec_ctx;
     gpr_mu_destroy(&g_mu);
-    gpr_avl_unref(g_subchannel_index, exec_ctx);
-    grpc_exec_ctx_finish();
+    gpr_avl_unref(g_subchannel_index, ExecCtx::Get());
   }
 }
 
@@ -145,12 +143,12 @@ grpc_subchannel* grpc_subchannel_index_find(grpc_subchannel_key* key) {
   // Lock, and take a reference to the subchannel index.
   // We don't need to do the search under a lock as avl's are immutable.
   gpr_mu_lock(&g_mu);
-  gpr_avl index = gpr_avl_ref(g_subchannel_index, exec_ctx);
+  gpr_avl index = gpr_avl_ref(g_subchannel_index, ExecCtx::Get());
   gpr_mu_unlock(&g_mu);
 
   grpc_subchannel* c = GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(
-      (grpc_subchannel*)gpr_avl_get(index, key, exec_ctx), "index_find");
-  gpr_avl_unref(index, exec_ctx);
+      (grpc_subchannel*)gpr_avl_get(index, key, ExecCtx::Get()), "index_find");
+  gpr_avl_unref(index, ExecCtx::Get());
 
   return c;
 }
@@ -166,11 +164,11 @@ grpc_subchannel* grpc_subchannel_index_register(grpc_subchannel_key* key,
     // Compare and swap loop:
     // - take a reference to the current index
     gpr_mu_lock(&g_mu);
-    gpr_avl index = gpr_avl_ref(g_subchannel_index, exec_ctx);
+    gpr_avl index = gpr_avl_ref(g_subchannel_index, ExecCtx::Get());
     gpr_mu_unlock(&g_mu);
 
     // - Check to see if a subchannel already exists
-    c = (grpc_subchannel*)gpr_avl_get(index, key, exec_ctx);
+    c = (grpc_subchannel*)gpr_avl_get(index, key, ExecCtx::Get());
     if (c != NULL) {
       c = GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(c, "index_register");
     }
@@ -180,8 +178,9 @@ grpc_subchannel* grpc_subchannel_index_register(grpc_subchannel_key* key,
     } else {
       // no -> update the avl and compare/swap
       gpr_avl updated = gpr_avl_add(
-          gpr_avl_ref(index, exec_ctx), subchannel_key_copy(key),
-          GRPC_SUBCHANNEL_WEAK_REF(constructed, "index_register"), exec_ctx);
+          gpr_avl_ref(index, ExecCtx::Get()), subchannel_key_copy(key),
+          GRPC_SUBCHANNEL_WEAK_REF(constructed, "index_register"),
+          ExecCtx::Get());
 
       // it may happen (but it's expected to be unlikely)
       // that some other thread has changed the index:
@@ -193,9 +192,9 @@ grpc_subchannel* grpc_subchannel_index_register(grpc_subchannel_key* key,
       }
       gpr_mu_unlock(&g_mu);
 
-      gpr_avl_unref(updated, exec_ctx);
+      gpr_avl_unref(updated, ExecCtx::Get());
     }
-    gpr_avl_unref(index, exec_ctx);
+    gpr_avl_unref(index, ExecCtx::Get());
   }
 
   if (need_to_unref_constructed) {
@@ -212,21 +211,22 @@ void grpc_subchannel_index_unregister(grpc_subchannel_key* key,
     // Compare and swap loop:
     // - take a reference to the current index
     gpr_mu_lock(&g_mu);
-    gpr_avl index = gpr_avl_ref(g_subchannel_index, exec_ctx);
+    gpr_avl index = gpr_avl_ref(g_subchannel_index, ExecCtx::Get());
     gpr_mu_unlock(&g_mu);
 
     // Check to see if this key still refers to the previously
     // registered subchannel
-    grpc_subchannel* c = (grpc_subchannel*)gpr_avl_get(index, key, exec_ctx);
+    grpc_subchannel* c =
+        (grpc_subchannel*)gpr_avl_get(index, key, ExecCtx::Get());
     if (c != constructed) {
-      gpr_avl_unref(index, exec_ctx);
+      gpr_avl_unref(index, ExecCtx::Get());
       break;
     }
 
     // compare and swap the update (some other thread may have
     // mutated the index behind us)
     gpr_avl updated =
-        gpr_avl_remove(gpr_avl_ref(index, exec_ctx), key, exec_ctx);
+        gpr_avl_remove(gpr_avl_ref(index, ExecCtx::Get()), key, ExecCtx::Get());
 
     gpr_mu_lock(&g_mu);
     if (index.root == g_subchannel_index.root) {
@@ -235,8 +235,8 @@ void grpc_subchannel_index_unregister(grpc_subchannel_key* key,
     }
     gpr_mu_unlock(&g_mu);
 
-    gpr_avl_unref(updated, exec_ctx);
-    gpr_avl_unref(index, exec_ctx);
+    gpr_avl_unref(updated, ExecCtx::Get());
+    gpr_avl_unref(index, ExecCtx::Get());
   }
 }
 
diff --git a/src/core/ext/filters/max_age/max_age_filter.cc b/src/core/ext/filters/max_age/max_age_filter.cc
index 1b9ce3b996..015a3ce124 100644
--- a/src/core/ext/filters/max_age/max_age_filter.cc
+++ b/src/core/ext/filters/max_age/max_age_filter.cc
@@ -100,7 +100,7 @@ static void decrease_call_count(channel_data* chand) {
   if (gpr_atm_full_fetch_add(&chand->call_count, -1) == 1) {
     GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_idle_timer");
     grpc_timer_init(&chand->max_idle_timer,
-                    grpc_exec_ctx_now() + chand->max_connection_idle,
+                    ExecCtx::Get()->Now() + chand->max_connection_idle,
                     &chand->close_max_idle_channel);
   }
 }
@@ -121,7 +121,7 @@ static void start_max_age_timer_after_init(void* arg, grpc_error* error) {
   chand->max_age_timer_pending = true;
   GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_timer");
   grpc_timer_init(&chand->max_age_timer,
-                  grpc_exec_ctx_now() + chand->max_connection_age,
+                  ExecCtx::Get()->Now() + chand->max_connection_age,
                   &chand->close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   grpc_transport_op* op = grpc_make_transport_op(NULL);
@@ -141,7 +141,7 @@ static void start_max_age_grace_timer_after_goaway_op(void* arg,
   grpc_timer_init(&chand->max_age_grace_timer,
                   chand->max_connection_age_grace == GRPC_MILLIS_INF_FUTURE
                       ? GRPC_MILLIS_INF_FUTURE
-                      : grpc_exec_ctx_now() + chand->max_connection_age_grace,
+                      : ExecCtx::Get()->Now() + chand->max_connection_age_grace,
                   &chand->force_close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   GRPC_CHANNEL_STACK_UNREF(chand->channel_stack,
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.cc b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
index e7741f97d4..3afca884ca 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
@@ -95,7 +95,7 @@ grpc_channel* grpc_insecure_channel_create(const char* target,
       new_args);
   // Clean up.
   grpc_channel_args_destroy(new_args);
-  grpc_exec_ctx_finish();
+
   return channel != NULL ? channel
                          : grpc_lame_client_channel_create(
                                target, GRPC_STATUS_INTERNAL,
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc
index 37e6f1f30d..b0eff1c992 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc
@@ -60,8 +60,6 @@ grpc_channel* grpc_insecure_channel_create_from_fd(
   grpc_channel_args_destroy(final_args);
   grpc_chttp2_transport_start_reading(transport, NULL);
 
-  grpc_exec_ctx_finish();
-
   return channel != NULL ? channel
                          : grpc_lame_client_channel_create(
                                target, GRPC_STATUS_INTERNAL,
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
index a5da71a67c..bebc38c248 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
@@ -211,7 +211,6 @@ grpc_channel* grpc_secure_channel_create(grpc_channel_credentials* creds,
         new_args);
     // Clean up.
     grpc_channel_args_destroy(new_args);
-    grpc_exec_ctx_finish();
   }
   return channel != NULL ? channel
                          : grpc_lame_client_channel_create(
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.cc b/src/core/ext/transport/chttp2/server/chttp2_server.cc
index 6eb1e3491c..bbcfb1b195 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.cc
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.cc
@@ -132,7 +132,7 @@ static void on_accept(void* arg, grpc_endpoint* tcp,
                        connection_state->handshake_mgr);
   // TODO(roth): We should really get this timeout value from channel
   // args instead of hard-coding it.
-  const grpc_millis deadline = grpc_exec_ctx_now() + 120 * GPR_MS_PER_SEC;
+  const grpc_millis deadline = ExecCtx::Get()->Now() + 120 * GPR_MS_PER_SEC;
   grpc_handshake_manager_do_handshake(connection_state->handshake_mgr, tcp,
                                       state->args, deadline, acceptor,
                                       on_handshake_done, connection_state);
@@ -161,10 +161,10 @@ static void tcp_server_shutdown_complete(void* arg, grpc_error* error) {
   gpr_mu_unlock(&state->mu);
   // Flush queued work before destroying handshaker factory, since that
   // may do a synchronous unref.
-  grpc_exec_ctx_flush();
+  ExecCtx::Get()->Flush();
   if (destroy_done != NULL) {
     destroy_done->cb(destroy_done->cb_arg, GRPC_ERROR_REF(error));
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
   }
   grpc_channel_args_destroy(state->args);
   gpr_mu_destroy(&state->mu);
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
index d7aad110b9..6cbb26a349 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
@@ -39,6 +39,6 @@ int grpc_server_add_insecure_http2_port(grpc_server* server, const char* addr) {
 
     GRPC_ERROR_UNREF(err);
   }
-  grpc_exec_ctx_finish();
+
   return port_num;
 }
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc
index 57a8316a58..e5419e5e6e 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc
@@ -61,7 +61,6 @@ void grpc_server_add_insecure_channel_from_fd(grpc_server* server,
 
   grpc_server_setup_transport(server, transport, NULL, server_args);
   grpc_chttp2_transport_start_reading(transport, NULL);
-  grpc_exec_ctx_finish();
 }
 
 #else  // !GPR_SUPPORT_CHANNELS_FROM_FD
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc
index dc7da96210..aeae8f42e3 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc
@@ -76,7 +76,7 @@ done:
   if (sc != NULL) {
     GRPC_SECURITY_CONNECTOR_UNREF(&sc->base, "server");
   }
-  grpc_exec_ctx_finish();
+
   if (err != GRPC_ERROR_NONE) {
     const char* msg = grpc_error_string(err);
     gpr_log(GPR_ERROR, "%s", msg);
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index ecf3cf69ef..e49e26fc35 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -530,7 +530,7 @@ static void init_transport(grpc_chttp2_transport* t,
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
     grpc_timer_init(&t->keepalive_ping_timer,
-                    grpc_exec_ctx_now() + t->keepalive_time,
+                    ExecCtx::Get()->Now() + t->keepalive_time,
                     &t->init_keepalive_ping_locked);
   } else {
     /* Use GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED to indicate there are no
@@ -2585,14 +2585,14 @@ static void init_keepalive_ping_locked(void* arg, grpc_error* error) {
     } else {
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
       grpc_timer_init(&t->keepalive_ping_timer,
-                      grpc_exec_ctx_now() + t->keepalive_time,
+                      ExecCtx::Get()->Now() + t->keepalive_time,
                       &t->init_keepalive_ping_locked);
     }
   } else if (error == GRPC_ERROR_CANCELLED) {
     /* The keepalive ping timer may be cancelled by bdp */
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
     grpc_timer_init(&t->keepalive_ping_timer,
-                    grpc_exec_ctx_now() + t->keepalive_time,
+                    ExecCtx::Get()->Now() + t->keepalive_time,
                     &t->init_keepalive_ping_locked);
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(t, "init keepalive ping");
@@ -2602,7 +2602,7 @@ static void start_keepalive_ping_locked(void* arg, grpc_error* error) {
   grpc_chttp2_transport* t = (grpc_chttp2_transport*)arg;
   GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive watchdog");
   grpc_timer_init(&t->keepalive_watchdog_timer,
-                  grpc_exec_ctx_now() + t->keepalive_time,
+                  ExecCtx::Get()->Now() + t->keepalive_time,
                   &t->keepalive_watchdog_fired_locked);
 }
 
@@ -2614,7 +2614,7 @@ static void finish_keepalive_ping_locked(void* arg, grpc_error* error) {
       grpc_timer_cancel(&t->keepalive_watchdog_timer);
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
       grpc_timer_init(&t->keepalive_ping_timer,
-                      grpc_exec_ctx_now() + t->keepalive_time,
+                      ExecCtx::Get()->Now() + t->keepalive_time,
                       &t->init_keepalive_ping_locked);
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.cc b/src/core/ext/transport/chttp2/transport/flow_control.cc
index 1609fa0532..e54d59b5fa 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.cc
+++ b/src/core/ext/transport/chttp2/transport/flow_control.cc
@@ -160,7 +160,7 @@ TransportFlowControl::TransportFlowControl(const grpc_chttp2_transport* t,
                           .set_min_control_value(-1)
                           .set_max_control_value(25)
                           .set_integral_range(10)),
-      last_pid_update_(grpc_exec_ctx_now()) {}
+      last_pid_update_(ExecCtx::Get()->Now()) {}
 
 uint32_t TransportFlowControl::MaybeSendUpdate(bool writing_anyway) {
   FlowControlTrace trace("t updt sent", this, nullptr);
@@ -306,7 +306,7 @@ double TransportFlowControl::TargetLogBdp() {
 }
 
 double TransportFlowControl::SmoothLogBdp(double value) {
-  grpc_millis now = grpc_exec_ctx_now();
+  grpc_millis now = ExecCtx::Get()->Now();
   double bdp_error = value - pid_controller_.last_control_value();
   const double dt = (double)(now - last_pid_update_) * 1e-3;
   last_pid_update_ = now;
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.cc b/src/core/ext/transport/chttp2/transport/frame_ping.cc
index 1b0dc0dfaa..60172be9cb 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.cc
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.cc
@@ -89,7 +89,7 @@ grpc_error* grpc_chttp2_ping_parser_parse(void* parser,
       grpc_chttp2_ack_ping(t, p->opaque_8bytes);
     } else {
       if (!t->is_client) {
-        grpc_millis now = grpc_exec_ctx_now();
+        grpc_millis now = ExecCtx::Get()->Now();
         grpc_millis next_allowed_ping =
             t->ping_recv_state.last_ping_recv_time +
             t->ping_policy.min_recv_ping_interval_without_data;
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
index e225a0244a..efb6e54ce7 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
@@ -570,7 +570,7 @@ static void deadline_enc(grpc_chttp2_hpack_compressor* c, grpc_millis deadline,
                          framer_state* st) {
   char timeout_str[GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
   grpc_mdelem mdelem;
-  grpc_http2_encode_timeout(deadline - grpc_exec_ctx_now(), timeout_str);
+  grpc_http2_encode_timeout(deadline - ExecCtx::Get()->Now(), timeout_str);
   mdelem = grpc_mdelem_from_slices(GRPC_MDSTR_GRPC_TIMEOUT,
                                    grpc_slice_from_copied_string(timeout_str));
   hpack_enc(c, mdelem, st);
diff --git a/src/core/ext/transport/chttp2/transport/parsing.cc b/src/core/ext/transport/chttp2/transport/parsing.cc
index 5731e9ff78..f7f83c9aee 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.cc
+++ b/src/core/ext/transport/chttp2/transport/parsing.cc
@@ -436,7 +436,7 @@ static void on_initial_header(void* tp, grpc_mdelem md) {
     }
     if (timeout != GRPC_MILLIS_INF_FUTURE) {
       grpc_chttp2_incoming_metadata_buffer_set_deadline(
-          &s->metadata_buffer[0], grpc_exec_ctx_now() + timeout);
+          &s->metadata_buffer[0], ExecCtx::Get()->Now() + timeout);
     }
     GRPC_MDELEM_UNREF(md);
   } else {
diff --git a/src/core/ext/transport/chttp2/transport/writing.cc b/src/core/ext/transport/chttp2/transport/writing.cc
index ec83633472..4f76c2eb23 100644
--- a/src/core/ext/transport/chttp2/transport/writing.cc
+++ b/src/core/ext/transport/chttp2/transport/writing.cc
@@ -68,7 +68,7 @@ static void maybe_initiate_ping(grpc_chttp2_transport* t) {
     }
     return;
   }
-  grpc_millis now = grpc_exec_ctx_now();
+  grpc_millis now = ExecCtx::Get()->Now();
   grpc_millis next_allowed_ping =
       t->ping_state.last_ping_sent_time +
       t->ping_policy.min_sent_ping_interval_without_data;
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.cc b/src/core/ext/transport/cronet/transport/cronet_transport.cc
index bff0fb36ad..3411acc563 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.cc
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.cc
@@ -417,7 +417,6 @@ static void on_failed(bidirectional_stream* stream, int net_error) {
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
   GRPC_CRONET_STREAM_UNREF(s, "cronet transport");
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -444,7 +443,6 @@ static void on_canceled(bidirectional_stream* stream) {
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
   GRPC_CRONET_STREAM_UNREF(s, "cronet transport");
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -463,7 +461,6 @@ static void on_succeeded(bidirectional_stream* stream) {
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
   GRPC_CRONET_STREAM_UNREF(s, "cronet transport");
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -492,7 +489,6 @@ static void on_stream_ready(bidirectional_stream* stream) {
   }
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -548,7 +544,6 @@ static void on_response_headers_received(
   }
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -566,7 +561,6 @@ static void on_write_completed(bidirectional_stream* stream, const char* data) {
   s->state.state_callback_received[OP_SEND_MESSAGE] = true;
   gpr_mu_unlock(&s->mu);
   execute_from_storage(s);
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -608,7 +602,6 @@ static void on_read_completed(bidirectional_stream* stream, char* data,
     gpr_mu_unlock(&s->mu);
     execute_from_storage(s);
   }
-  grpc_exec_ctx_finish();
 }
 
 /*
@@ -666,7 +659,6 @@ static void on_response_trailers_received(
     gpr_mu_unlock(&s->mu);
     execute_from_storage(s);
   }
-  grpc_exec_ctx_finish();
 }
 
 /*
diff --git a/src/core/ext/transport/inproc/inproc_transport.cc b/src/core/ext/transport/inproc/inproc_transport.cc
index 1c7f2873d1..a79b2b26b0 100644
--- a/src/core/ext/transport/inproc/inproc_transport.cc
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -1107,7 +1107,6 @@ void grpc_inproc_transport_init(void) {
   grpc_slice_unref_internal(auth_tmp);
 
   g_fake_auth_value = grpc_slice_from_static_string("inproc-fail");
-  grpc_exec_ctx_finish();
 }
 
 static const grpc_transport_vtable inproc_vtable = {
@@ -1182,7 +1181,6 @@ grpc_channel* grpc_inproc_channel_create(grpc_server* server,
   grpc_channel_args_destroy(client_args);
 
   // Now finish scheduled operations
-  grpc_exec_ctx_finish();
 
   return channel;
 }
@@ -1194,5 +1192,4 @@ void grpc_inproc_transport_shutdown(void) {
   grpc_slice_unref_internal(g_fake_path_value);
   grpc_slice_unref_internal(g_fake_auth_key);
   grpc_slice_unref_internal(g_fake_auth_value);
-  grpc_exec_ctx_finish();
 }
diff --git a/src/core/lib/backoff/backoff.cc b/src/core/lib/backoff/backoff.cc
index e6c55f420d..b75ce79d46 100644
--- a/src/core/lib/backoff/backoff.cc
+++ b/src/core/lib/backoff/backoff.cc
@@ -36,7 +36,7 @@ grpc_backoff_result grpc_backoff_begin(grpc_backoff* backoff) {
   backoff->current_backoff = backoff->initial_backoff;
   const grpc_millis initial_timeout =
       GPR_MAX(backoff->initial_backoff, backoff->min_connect_timeout);
-  const grpc_millis now = grpc_exec_ctx_now();
+  const grpc_millis now = ExecCtx::Get()->Now();
   const grpc_backoff_result result = {now + initial_timeout,
                                       now + backoff->current_backoff};
   return result;
@@ -67,7 +67,7 @@ grpc_backoff_result grpc_backoff_step(grpc_backoff* backoff) {
               backoff->min_connect_timeout);
   const grpc_millis next_timeout = GPR_MIN(
       (grpc_millis)(backoff->current_backoff + jitter), backoff->max_backoff);
-  const grpc_millis now = grpc_exec_ctx_now();
+  const grpc_millis now = ExecCtx::Get()->Now();
   const grpc_backoff_result result = {now + current_timeout,
                                       now + next_timeout};
   return result;
diff --git a/src/core/lib/compression/stream_compression_gzip.cc b/src/core/lib/compression/stream_compression_gzip.cc
index 4d5d0955ce..3fae3490ce 100644
--- a/src/core/lib/compression/stream_compression_gzip.cc
+++ b/src/core/lib/compression/stream_compression_gzip.cc
@@ -58,7 +58,7 @@ static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
       if (r < 0 && r != Z_BUF_ERROR) {
         gpr_log(GPR_ERROR, "zlib error (%d)", r);
         grpc_slice_unref_internal(slice_out);
-        grpc_exec_ctx_finish();
+
         return false;
       } else if (r == Z_STREAM_END && ctx->flate == inflate) {
         eoc = true;
@@ -89,7 +89,7 @@ static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
           default:
             gpr_log(GPR_ERROR, "zlib error (%d)", r);
             grpc_slice_unref_internal(slice_out);
-            grpc_exec_ctx_finish();
+
             return false;
         }
       } else if (flush == Z_FINISH) {
@@ -105,7 +105,7 @@ static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
           default:
             gpr_log(GPR_ERROR, "zlib error (%d)", r);
             grpc_slice_unref_internal(slice_out);
-            grpc_exec_ctx_finish();
+
             return false;
         }
       }
@@ -121,7 +121,7 @@ static bool gzip_flate(grpc_stream_compression_context_gzip* ctx,
     }
     max_output_size -= (slice_size - ctx->zs.avail_out);
   }
-  grpc_exec_ctx_finish();
+
   if (end_of_context) {
     *end_of_context = eoc;
   }
diff --git a/src/core/lib/debug/stats.h b/src/core/lib/debug/stats.h
index 1c2826506c..24b0084130 100644
--- a/src/core/lib/debug/stats.h
+++ b/src/core/lib/debug/stats.h
@@ -35,7 +35,7 @@ typedef struct grpc_stats_data {
 extern grpc_stats_data* grpc_stats_per_cpu_storage;
 
 #define GRPC_THREAD_STATS_DATA() \
-  (&grpc_stats_per_cpu_storage[(exec_ctx)->starting_cpu])
+  (&grpc_stats_per_cpu_storage[ExecCtx::Get()->starting_cpu()])
 
 #define GRPC_STATS_INC_COUNTER(ctr) \
   (gpr_atm_no_barrier_fetch_add(&GRPC_THREAD_STATS_DATA()->counters[(ctr)], 1))
diff --git a/src/core/lib/iomgr/block_annotate.h b/src/core/lib/iomgr/block_annotate.h
index 9db3cf0199..7783da0c14 100644
--- a/src/core/lib/iomgr/block_annotate.h
+++ b/src/core/lib/iomgr/block_annotate.h
@@ -19,6 +19,8 @@
 #ifndef GRPC_CORE_LIB_IOMGR_BLOCK_ANNOTATE_H
 #define GRPC_CORE_LIB_IOMGR_BLOCK_ANNOTATE_H
 
+#include "src/core/lib/iomgr/exec_ctx.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -39,25 +41,18 @@ void gpr_thd_end_blocking_region();
   do {                                        \
     gpr_thd_start_blocking_region();          \
   } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX \
-  do {                                                  \
-    gpr_thd_end_blocking_region();                      \
-  } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX() \
-  do {                                                      \
-    gpr_thd_end_blocking_region();                          \
-    grpc_exec_ctx_invalidate_now();                         \
+#define GRPC_SCHEDULING_END_BLOCKING_REGION \
+  do {                                      \
+    gpr_thd_end_blocking_region();          \
+    ExecCtx::Get()->InvalidateNow();        \
   } while (0)
 #else
 #define GRPC_SCHEDULING_START_BLOCKING_REGION \
   do {                                        \
   } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX \
-  do {                                                  \
-  } while (0)
-#define GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX() \
-  do {                                                      \
-    grpc_exec_ctx_invalidate_now();                         \
+#define GRPC_SCHEDULING_END_BLOCKING_REGION \
+  do {                                      \
+    ExecCtx::Get()->InvalidateNow();        \
   } while (0)
 #endif
 
diff --git a/src/core/lib/iomgr/combiner.cc b/src/core/lib/iomgr/combiner.cc
index b1b8fffdca..c9f5448630 100644
--- a/src/core/lib/iomgr/combiner.cc
+++ b/src/core/lib/iomgr/combiner.cc
@@ -128,20 +128,24 @@ grpc_combiner* grpc_combiner_ref(grpc_combiner* lock GRPC_COMBINER_DEBUG_ARGS) {
 }
 
 static void push_last_on_exec_ctx(grpc_combiner* lock) {
-  lock->next_combiner_on_this_exec_ctx = NULL;
-  if (exec_ctx->active_combiner == NULL) {
-    exec_ctx->active_combiner = exec_ctx->last_combiner = lock;
+  lock->next_combiner_on_this_exec_ctx = nullptr;
+  if (ExecCtx::Get()->combiner_data()->active_combiner == nullptr) {
+    ExecCtx::Get()->combiner_data()->active_combiner =
+        ExecCtx::Get()->combiner_data()->last_combiner = lock;
   } else {
-    exec_ctx->last_combiner->next_combiner_on_this_exec_ctx = lock;
-    exec_ctx->last_combiner = lock;
+    ExecCtx::Get()
+        ->combiner_data()
+        ->last_combiner->next_combiner_on_this_exec_ctx = lock;
+    ExecCtx::Get()->combiner_data()->last_combiner = lock;
   }
 }
 
 static void push_first_on_exec_ctx(grpc_combiner* lock) {
-  lock->next_combiner_on_this_exec_ctx = exec_ctx->active_combiner;
-  exec_ctx->active_combiner = lock;
+  lock->next_combiner_on_this_exec_ctx =
+      ExecCtx::Get()->combiner_data()->active_combiner;
+  ExecCtx::Get()->combiner_data()->active_combiner = lock;
   if (lock->next_combiner_on_this_exec_ctx == NULL) {
-    exec_ctx->last_combiner = lock;
+    ExecCtx::Get()->combiner_data()->last_combiner = lock;
   }
 }
 
@@ -161,7 +165,7 @@ static void combiner_exec(grpc_closure* cl, grpc_error* error) {
     GRPC_STATS_INC_COMBINER_LOCKS_INITIATED();
     GPR_TIMER_MARK("combiner.initiated", 0);
     gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null,
-                             (gpr_atm)exec_ctx);
+                             (gpr_atm)ExecCtx::Get());
     // first element on this list: add it to the list of combiner locks
     // executing within this exec_ctx
     push_last_on_exec_ctx(lock);
@@ -170,7 +174,7 @@ static void combiner_exec(grpc_closure* cl, grpc_error* error) {
     // offload for one or two actions, and that's fine
     gpr_atm initiator =
         gpr_atm_no_barrier_load(&lock->initiating_exec_ctx_or_null);
-    if (initiator != 0 && initiator != (gpr_atm)exec_ctx) {
+    if (initiator != 0 && initiator != (gpr_atm)ExecCtx::Get()) {
       gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null, 0);
     }
   }
@@ -182,10 +186,12 @@ static void combiner_exec(grpc_closure* cl, grpc_error* error) {
 }
 
 static void move_next() {
-  exec_ctx->active_combiner =
-      exec_ctx->active_combiner->next_combiner_on_this_exec_ctx;
-  if (exec_ctx->active_combiner == NULL) {
-    exec_ctx->last_combiner = NULL;
+  ExecCtx::Get()->combiner_data()->active_combiner =
+      ExecCtx::Get()
+          ->combiner_data()
+          ->active_combiner->next_combiner_on_this_exec_ctx;
+  if (ExecCtx::Get()->combiner_data()->active_combiner == NULL) {
+    ExecCtx::Get()->combiner_data()->last_combiner = NULL;
   }
 }
 
@@ -203,7 +209,7 @@ static void queue_offload(grpc_combiner* lock) {
 
 bool grpc_combiner_continue_exec_ctx() {
   GPR_TIMER_BEGIN("combiner.continue_exec_ctx", 0);
-  grpc_combiner* lock = exec_ctx->active_combiner;
+  grpc_combiner* lock = ExecCtx::Get()->combiner_data()->active_combiner;
   if (lock == NULL) {
     GPR_TIMER_END("combiner.continue_exec_ctx", 0);
     return false;
@@ -217,10 +223,11 @@ bool grpc_combiner_continue_exec_ctx() {
                               "contended=%d "
                               "exec_ctx_ready_to_finish=%d "
                               "time_to_execute_final_list=%d",
-                              lock, contended, grpc_exec_ctx_ready_to_finish(),
+                              lock, contended,
+                              ExecCtx::Get()->IsReadyToFinish(),
                               lock->time_to_execute_final_list));
 
-  if (contended && grpc_exec_ctx_ready_to_finish() &&
+  if (contended && ExecCtx::Get()->IsReadyToFinish() &&
       grpc_executor_is_threaded()) {
     GPR_TIMER_MARK("offload_from_finished_exec_ctx", 0);
     // this execution context wants to move on: schedule remaining work to be
@@ -326,11 +333,11 @@ static void combiner_finally_exec(grpc_closure* closure, grpc_error* error) {
   GRPC_STATS_INC_COMBINER_LOCKS_SCHEDULED_FINAL_ITEMS();
   grpc_combiner* lock =
       COMBINER_FROM_CLOSURE_SCHEDULER(closure, finally_scheduler);
-  GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
-                              "C:%p grpc_combiner_execute_finally c=%p; ac=%p",
-                              lock, closure, exec_ctx->active_combiner));
+  GRPC_COMBINER_TRACE(
+      gpr_log(GPR_DEBUG, "C:%p grpc_combiner_execute_finally c=%p; ac=%p", lock,
+              closure, ExecCtx::Get()->combiner_data()->active_combiner));
   GPR_TIMER_BEGIN("combiner.execute_finally", 0);
-  if (exec_ctx->active_combiner != lock) {
+  if (ExecCtx::Get()->combiner_data()->active_combiner != lock) {
     GPR_TIMER_MARK("slowpath", 0);
     GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(enqueue_finally, closure,
                                            grpc_combiner_scheduler(lock)),
diff --git a/src/core/lib/iomgr/endpoint_pair_posix.cc b/src/core/lib/iomgr/endpoint_pair_posix.cc
index 696ac6942f..1a281322a8 100644
--- a/src/core/lib/iomgr/endpoint_pair_posix.cc
+++ b/src/core/lib/iomgr/endpoint_pair_posix.cc
@@ -65,7 +65,6 @@ grpc_endpoint_pair grpc_iomgr_create_endpoint_pair(const char* name,
                              "socketpair-client");
   gpr_free(final_name);
 
-  grpc_exec_ctx_finish();
   return p;
 }
 
diff --git a/src/core/lib/iomgr/endpoint_pair_windows.cc b/src/core/lib/iomgr/endpoint_pair_windows.cc
index d464617097..e0f211cdf9 100644
--- a/src/core/lib/iomgr/endpoint_pair_windows.cc
+++ b/src/core/lib/iomgr/endpoint_pair_windows.cc
@@ -77,7 +77,7 @@ grpc_endpoint_pair grpc_iomgr_create_endpoint_pair(
                              channel_args, "endpoint:server");
   p.server = grpc_tcp_create(grpc_winsocket_create(sv[0], "endpoint:server"),
                              channel_args, "endpoint:client");
-  grpc_exec_ctx_finish();
+
   return p;
 }
 
diff --git a/src/core/lib/iomgr/error.cc b/src/core/lib/iomgr/error.cc
index ce8b538773..157f12a36d 100644
--- a/src/core/lib/iomgr/error.cc
+++ b/src/core/lib/iomgr/error.cc
@@ -157,11 +157,7 @@ static void unref_errs(grpc_error* err) {
   }
 }
 
-static void unref_slice(grpc_slice slice) {
-  ExecCtx _local_exec_ctx;
-  grpc_slice_unref_internal(slice);
-  grpc_exec_ctx_finish();
-}
+static void unref_slice(grpc_slice slice) { grpc_slice_unref_internal(slice); }
 
 static void unref_strs(grpc_error* err) {
   for (size_t which = 0; which < GRPC_ERROR_STR_MAX; ++which) {
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index 31f51df15d..2b486887b8 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -554,7 +554,7 @@ static void pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
 
 static int poll_deadline_to_millis_timeout(grpc_millis millis) {
   if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
-  grpc_millis delta = millis - grpc_exec_ctx_now();
+  grpc_millis delta = millis - ExecCtx::Get()->Now();
   if (delta > INT_MAX) {
     return INT_MAX;
   } else if (delta < 0) {
@@ -630,7 +630,7 @@ static grpc_error* do_epoll_wait(grpc_pollset* ps, grpc_millis deadline) {
                    timeout);
   } while (r < 0 && errno == EINTR);
   if (timeout != 0) {
-    GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX();
+    GRPC_SCHEDULING_END_BLOCKING_REGION;
   }
 
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
@@ -743,7 +743,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
         SET_KICK_STATE(worker, KICKED);
       }
     }
-    grpc_exec_ctx_invalidate_now();
+    ExecCtx::Get()->InvalidateNow();
   }
 
   if (GRPC_TRACER_ON(grpc_polling_trace)) {
@@ -848,7 +848,7 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
   /* Make sure we appear kicked */
   SET_KICK_STATE(worker, KICKED);
   grpc_closure_list_move(&worker->schedule_on_end_work,
-                         &exec_ctx->closure_list);
+                         ExecCtx::Get()->closure_list());
   if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) {
     if (worker->next != worker && worker->next->state == UNKICKED) {
       if (GRPC_TRACER_ON(grpc_polling_trace)) {
@@ -859,9 +859,9 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
       SET_KICK_STATE(worker->next, DESIGNATED_POLLER);
       GRPC_STATS_INC_POLLSET_KICK_WAKEUP_CV();
       gpr_cv_signal(&worker->next->cv);
-      if (grpc_exec_ctx_has_work()) {
+      if (ExecCtx::Get()->HasWork()) {
         gpr_mu_unlock(&pollset->mu);
-        grpc_exec_ctx_flush();
+        ExecCtx::Get()->Flush();
         gpr_mu_lock(&pollset->mu);
       }
     } else {
@@ -892,12 +892,12 @@ static void end_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
         found_worker = check_neighborhood_for_available_poller(neighborhood);
         gpr_mu_unlock(&neighborhood->mu);
       }
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       gpr_mu_lock(&pollset->mu);
     }
-  } else if (grpc_exec_ctx_has_work()) {
+  } else if (ExecCtx::Get()->HasWork()) {
     gpr_mu_unlock(&pollset->mu);
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
     gpr_mu_lock(&pollset->mu);
   }
   if (worker->initialized_cv) {
@@ -948,9 +948,9 @@ static grpc_error* pollset_work(grpc_pollset* ps,
 
        process_epoll_events() returns very quickly: It just queues the work on
        exec_ctx but does not execute it (the actual exectution or more
-       accurately grpc_exec_ctx_flush() happens in end_worker() AFTER selecting
-       a designated poller). So we are not waiting long periods without a
-       designated poller */
+       accurately ExecCtx::Get()->Flush() happens in end_worker() AFTER
+       selecting a designated poller). So we are not waiting long periods
+       without a designated poller */
     if (gpr_atm_acq_load(&g_epoll_set.cursor) ==
         gpr_atm_acq_load(&g_epoll_set.num_events)) {
       append_error(&error, do_epoll_wait(ps, deadline), err_desc);
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index 0979a45270..385b5f68d0 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -682,7 +682,7 @@ static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) {
 
 static int poll_deadline_to_millis_timeout(grpc_millis millis) {
   if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
-  grpc_millis delta = millis - grpc_exec_ctx_now();
+  grpc_millis delta = millis - ExecCtx::Get()->Now();
   if (delta > INT_MAX)
     return INT_MAX;
   else if (delta < 0)
@@ -804,7 +804,7 @@ static grpc_error* pollable_epoll(pollable* p, grpc_millis deadline) {
     r = epoll_wait(p->epfd, p->events, MAX_EPOLL_EVENTS, timeout);
   } while (r < 0 && errno == EINTR);
   if (timeout != 0) {
-    GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX();
+    GRPC_SCHEDULING_END_BLOCKING_REGION;
   }
 
   if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait");
@@ -902,7 +902,7 @@ static bool begin_worker(grpc_pollset* pollset, grpc_pollset_worker* worker,
                 worker->pollable_obj, worker);
       }
     }
-    grpc_exec_ctx_invalidate_now();
+    ExecCtx::Get()->InvalidateNow();
   } else {
     gpr_mu_unlock(&pollset->mu);
   }
@@ -970,7 +970,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
     gpr_log(GPR_DEBUG,
             "PS:%p work hdl=%p worker=%p now=%" PRIdPTR " deadline=%" PRIdPTR
             " kwp=%d pollable=%p",
-            pollset, worker_hdl, WORKER_PTR, grpc_exec_ctx_now(), deadline,
+            pollset, worker_hdl, WORKER_PTR, ExecCtx::Get()->Now(), deadline,
             pollset->kicked_without_poller, pollset->active_pollable);
   }
   static const char* err_desc = "pollset_work";
@@ -990,7 +990,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
           &error,
           pollable_process_events(pollset, WORKER_PTR->pollable_obj, false),
           err_desc);
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       gpr_tls_set(&g_current_thread_pollset, 0);
       gpr_tls_set(&g_current_thread_worker, 0);
     }
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index c42a609fee..a9b094a2fa 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -1090,7 +1090,7 @@ static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) {
 
 static int poll_deadline_to_millis_timeout(grpc_millis millis) {
   if (millis == GRPC_MILLIS_INF_FUTURE) return -1;
-  grpc_millis delta = millis - grpc_exec_ctx_now();
+  grpc_millis delta = millis - ExecCtx::Get()->Now();
   if (delta > INT_MAX)
     return INT_MAX;
   else if (delta < 0)
@@ -1220,7 +1220,7 @@ static void pollset_work_and_unlock(grpc_pollset* pollset,
   GRPC_STATS_INC_SYSCALL_POLL();
   ep_rv =
       epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms, sig_mask);
-  GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX();
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   if (ep_rv < 0) {
     if (errno != EINTR) {
       gpr_asprintf(&err_msg,
@@ -1350,7 +1350,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
 
     pollset_work_and_unlock(pollset, &worker, timeout_ms, &g_orig_sigmask,
                             &error);
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
 
     gpr_mu_lock(&pollset->po.mu);
 
@@ -1373,7 +1373,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
     finish_shutdown_locked(pollset);
 
     gpr_mu_unlock(&pollset->po.mu);
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
     gpr_mu_lock(&pollset->po.mu);
   }
 
diff --git a/src/core/lib/iomgr/ev_poll_posix.cc b/src/core/lib/iomgr/ev_poll_posix.cc
index c7189950f0..cab4f7547c 100644
--- a/src/core/lib/iomgr/ev_poll_posix.cc
+++ b/src/core/lib/iomgr/ev_poll_posix.cc
@@ -976,7 +976,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
       GRPC_SCHEDULING_START_BLOCKING_REGION;
       GRPC_STATS_INC_SYSCALL_POLL();
       r = grpc_poll_function(pfds, pfd_count, timeout);
-      GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX();
+      GRPC_SCHEDULING_END_BLOCKING_REGION;
 
       if (GRPC_TRACER_ON(grpc_polling_trace)) {
         gpr_log(GPR_DEBUG, "%p poll=%d", pollset, r);
@@ -1040,7 +1040,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
      worker list, which means nobody could ask us to re-evaluate polling). */
   done:
     if (!locked) {
-      queued_work |= grpc_exec_ctx_flush();
+      queued_work |= ExecCtx::Get()->Flush();
       gpr_mu_lock(&pollset->mu);
       locked = 1;
     }
@@ -1074,7 +1074,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
       pollset->called_shutdown = 1;
       gpr_mu_unlock(&pollset->mu);
       finish_shutdown(pollset);
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       /* Continuing to access pollset here is safe -- it is the caller's
        * responsibility to not destroy when it has outstanding calls to
        * pollset_work.
@@ -1083,7 +1083,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
     } else if (!grpc_closure_list_empty(pollset->idle_jobs)) {
       GRPC_CLOSURE_LIST_SCHED(&pollset->idle_jobs);
       gpr_mu_unlock(&pollset->mu);
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       gpr_mu_lock(&pollset->mu);
     }
   }
@@ -1110,7 +1110,7 @@ static void pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
 static int poll_deadline_to_millis_timeout(grpc_millis deadline) {
   if (deadline == GRPC_MILLIS_INF_FUTURE) return -1;
   if (deadline == 0) return 0;
-  grpc_millis n = deadline - grpc_exec_ctx_now();
+  grpc_millis n = deadline - ExecCtx::Get()->Now();
   if (n < 0) return 0;
   if (n > INT_MAX) return -1;
   return (int)n;
diff --git a/src/core/lib/iomgr/exec_ctx.cc b/src/core/lib/iomgr/exec_ctx.cc
index c10d1e60f0..fe5a0e7e2d 100644
--- a/src/core/lib/iomgr/exec_ctx.cc
+++ b/src/core/lib/iomgr/exec_ctx.cc
@@ -27,45 +27,19 @@
 
 thread_local ExecCtx* exec_ctx = nullptr;
 
-ExecCtx::ExecCtx()
-    : closure_list(GRPC_CLOSURE_LIST_INIT),
-      active_combiner(nullptr),
-      last_combiner(nullptr),
-      flags(GRPC_EXEC_CTX_FLAG_IS_FINISHED),
-      starting_cpu(gpr_cpu_current_cpu()),
-      check_ready_to_finish_arg(nullptr),
-      check_ready_to_finish(nullptr),
-      now_is_valid(false),
-      now(0),
-      last_exec_ctx(exec_ctx) {
-  exec_ctx = this;
-}
-
-ExecCtx::ExecCtx(uintptr_t fl, bool (*finish_check)(void* arg),
-                 void* finish_check_arg)
-    : closure_list(GRPC_CLOSURE_LIST_INIT),
-      active_combiner(nullptr),
-      last_combiner(nullptr),
-      flags(fl),
-      starting_cpu(gpr_cpu_current_cpu()),
-      check_ready_to_finish_arg(finish_check_arg),
-      check_ready_to_finish(finish_check),
-      now_is_valid(false),
-      now(0),
-      last_exec_ctx(exec_ctx) {
-  exec_ctx = this;
-}
-
+ExecCtx::ExecCtx() : flags_(GRPC_EXEC_CTX_FLAG_IS_FINISHED) { exec_ctx = this; }
+ExecCtx::ExecCtx(uintptr_t fl) : flags_(fl) { exec_ctx = this; }
 ExecCtx::~ExecCtx() {
   GPR_ASSERT(exec_ctx == this);
-  grpc_exec_ctx_finish();
-  exec_ctx = last_exec_ctx;
+  flags_ |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
+  Flush();
+  exec_ctx = last_exec_ctx_;
 }
 
-bool grpc_exec_ctx_ready_to_finish() {
-  if ((exec_ctx->flags & GRPC_EXEC_CTX_FLAG_IS_FINISHED) == 0) {
-    if (exec_ctx->check_ready_to_finish(exec_ctx->check_ready_to_finish_arg)) {
-      exec_ctx->flags |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
+bool ExecCtx::IsReadyToFinish() {
+  if ((flags_ & GRPC_EXEC_CTX_FLAG_IS_FINISHED) == 0) {
+    if (CheckReadyToFinish()) {
+      flags_ |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
       return true;
     }
     return false;
@@ -74,21 +48,7 @@ bool grpc_exec_ctx_ready_to_finish() {
   }
 }
 
-bool grpc_never_ready_to_finish(void* arg_ignored) { return false; }
-
-bool grpc_always_ready_to_finish(void* arg_ignored) { return true; }
-
-bool grpc_exec_ctx_has_work() {
-  return exec_ctx->active_combiner != NULL ||
-         !grpc_closure_list_empty(exec_ctx->closure_list);
-}
-
-void grpc_exec_ctx_finish() {
-  exec_ctx->flags |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
-  grpc_exec_ctx_flush();
-}
-
-static void exec_ctx_run(grpc_closure* closure, grpc_error* error) {
+void exec_ctx_run(grpc_closure* closure, grpc_error* error) {
 #ifndef NDEBUG
   closure->scheduled = false;
   if (GRPC_TRACER_ON(grpc_trace_closure)) {
@@ -107,13 +67,13 @@ static void exec_ctx_run(grpc_closure* closure, grpc_error* error) {
   GRPC_ERROR_UNREF(error);
 }
 
-bool grpc_exec_ctx_flush() {
+bool ExecCtx::Flush() {
   bool did_something = 0;
   GPR_TIMER_BEGIN("grpc_exec_ctx_flush", 0);
   for (;;) {
-    if (!grpc_closure_list_empty(exec_ctx->closure_list)) {
-      grpc_closure* c = exec_ctx->closure_list.head;
-      exec_ctx->closure_list.head = exec_ctx->closure_list.tail = NULL;
+    if (!grpc_closure_list_empty(closure_list_)) {
+      grpc_closure* c = closure_list_.head;
+      closure_list_.head = closure_list_.tail = NULL;
       while (c != NULL) {
         grpc_closure* next = c->next_data.next;
         grpc_error* error = c->error_data.error;
@@ -125,13 +85,13 @@ bool grpc_exec_ctx_flush() {
       break;
     }
   }
-  GPR_ASSERT(exec_ctx->active_combiner == NULL);
+  GPR_ASSERT(combiner_data_.active_combiner == nullptr);
   GPR_TIMER_END("grpc_exec_ctx_flush", 0);
   return did_something;
 }
 
-static void exec_ctx_sched(grpc_closure* closure, grpc_error* error) {
-  grpc_closure_list_append(&exec_ctx->closure_list, closure, error);
+void exec_ctx_sched(grpc_closure* closure, grpc_error* error) {
+  grpc_closure_list_append(exec_ctx->closure_list(), closure, error);
 }
 
 static gpr_timespec
@@ -139,7 +99,7 @@ static gpr_timespec
                                      // last enum value in
                                      // gpr_clock_type
 
-void grpc_exec_ctx_global_init(void) {
+void ExecCtx::GlobalInit(void) {
   for (int i = 0; i < GPR_TIMESPAN; i++) {
     g_start_time[i] = gpr_now((gpr_clock_type)i);
   }
@@ -147,7 +107,7 @@ void grpc_exec_ctx_global_init(void) {
   g_start_time[GPR_TIMESPAN] = gpr_time_0(GPR_TIMESPAN);
 }
 
-void grpc_exec_ctx_global_shutdown(void) {}
+void ExecCtx::GlobalShutdown(void) {}
 
 static gpr_atm timespec_to_atm_round_down(gpr_timespec ts) {
   ts = gpr_time_sub(ts, g_start_time[ts.clock_type]);
@@ -168,16 +128,6 @@ static gpr_atm timespec_to_atm_round_up(gpr_timespec ts) {
   return (gpr_atm)x;
 }
 
-grpc_millis grpc_exec_ctx_now() {
-  if (!exec_ctx->now_is_valid) {
-    exec_ctx->now = timespec_to_atm_round_down(gpr_now(GPR_CLOCK_MONOTONIC));
-    exec_ctx->now_is_valid = true;
-  }
-  return exec_ctx->now;
-}
-
-void grpc_exec_ctx_invalidate_now() { exec_ctx->now_is_valid = false; }
-
 gpr_timespec grpc_millis_to_timespec(grpc_millis millis,
                                      gpr_clock_type clock_type) {
   // special-case infinities as grpc_millis can be 32bit on some platforms
@@ -204,6 +154,16 @@ grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec ts) {
   return timespec_to_atm_round_up(ts);
 }
 
+grpc_millis ExecCtx::Now() {
+  if (!now_is_valid_) {
+    now_ = timespec_to_atm_round_down(gpr_now(GPR_CLOCK_MONOTONIC));
+    now_is_valid_ = true;
+  }
+  return now_;
+}
+
+ExecCtx* ExecCtx::Get() { return exec_ctx; }
+
 static const grpc_closure_scheduler_vtable exec_ctx_scheduler_vtable = {
     exec_ctx_run, exec_ctx_sched, "exec_ctx"};
 static grpc_closure_scheduler exec_ctx_scheduler = {&exec_ctx_scheduler_vtable};
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index a80bcbbc0d..a71e43e178 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -66,95 +66,81 @@ typedef struct grpc_combiner grpc_combiner;
  *  - Instances are always passed as the first argument to a function that
  *    takes it, and always as a pointer (grpc_exec_ctx is never copied).
  */
-struct grpc_exec_ctx {
-  grpc_closure_list closure_list;
-  /** currently active combiner: updated only via combiner.c */
-  grpc_combiner* active_combiner;
-  /** last active combiner in the active combiner list */
-  grpc_combiner* last_combiner;
-  uintptr_t flags;
-  unsigned starting_cpu;
-  void* check_ready_to_finish_arg;
-  bool (*check_ready_to_finish)(void* arg);
-
-  bool now_is_valid;
-  grpc_millis now;
-  const char* creator;
-};
-
-extern grpc_closure_scheduler* grpc_schedule_on_exec_ctx;
-
-bool grpc_exec_ctx_has_work();
-
-/** Flush any work that has been enqueued onto this grpc_exec_ctx.
- *  Caller must guarantee that no interfering locks are held.
- *  Returns true if work was performed, false otherwise. */
-bool grpc_exec_ctx_flush();
-/** Finish any pending work for a grpc_exec_ctx. Must be called before
- *  the instance is destroyed, or work may be lost. */
-void grpc_exec_ctx_finish();
-/** Returns true if we'd like to leave this execution context as soon as
-    possible: useful for deciding whether to do something more or not depending
-    on outside context */
-bool grpc_exec_ctx_ready_to_finish();
-/** A finish check that is never ready to finish */
-bool grpc_never_ready_to_finish(void* arg_ignored);
-/** A finish check that is always ready to finish */
-bool grpc_always_ready_to_finish(void* arg_ignored);
-
-void grpc_exec_ctx_global_init(void);
-
-void grpc_exec_ctx_global_init(void);
-void grpc_exec_ctx_global_shutdown(void);
-
-grpc_millis grpc_exec_ctx_now();
-void grpc_exec_ctx_invalidate_now();
-gpr_timespec grpc_millis_to_timespec(grpc_millis millis, gpr_clock_type clock);
-grpc_millis grpc_timespec_to_millis_round_down(gpr_timespec timespec);
-grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec timespec);
-
-inline grpc_exec_ctx make_exec_ctx(grpc_exec_ctx r) {
-  grpc_exec_ctx_flush();
-  return r;
-}
-
 class ExecCtx {
  public:
   ExecCtx();
-  ExecCtx(uintptr_t fl, bool (*finish_check)(void* arg),
-          void* finish_check_arg);
+  ExecCtx(uintptr_t fl);
   ~ExecCtx();
 
-  grpc_closure_list closure_list;
-  /** currently active combiner: updated only via combiner.c */
-  grpc_combiner* active_combiner;
-  /** last active combiner in the active combiner list */
-  grpc_combiner* last_combiner;
-  uintptr_t flags;
-  unsigned starting_cpu;
-  void* check_ready_to_finish_arg;
-  bool (*check_ready_to_finish)(void* arg);
-
-  bool now_is_valid;
-  grpc_millis now;
-
- private:
-  ExecCtx* last_exec_ctx;
-};
+  unsigned starting_cpu() const { return starting_cpu_; }
+
+  struct CombinerData {
+    /* currently active combiner: updated only via combiner.c */
+    grpc_combiner* active_combiner;
+    /* last active combiner in the active combiner list */
+    grpc_combiner* last_combiner;
+  };
+
+  /** Only to be used by grpc-combiner code */
+  CombinerData* combiner_data() { return &combiner_data_; }
+
+  grpc_closure_list* closure_list() { return &closure_list_; }
+
+  bool HasWork() {
+    return combiner_data_.active_combiner != NULL ||
+           !grpc_closure_list_empty(closure_list_);
+  }
+
+  /** Flush any work that has been enqueued onto this grpc_exec_ctx.
+   *  Caller must guarantee that no interfering locks are held.
+   *  Returns true if work was performed, false otherwise. */
+  bool Flush();
+
+  /** Returns true if we'd like to leave this execution context as soon as
+possible: useful for deciding whether to do something more or not depending
+on outside context */
+  bool IsReadyToFinish();
 
-extern thread_local ExecCtx* exec_ctx;
+  grpc_millis Now();
 
-/* initializer for grpc_exec_ctx:
- *    prefer to use GRPC_EXEC_CTX_INIT whenever possible */
-#define GRPC_EXEC_CTX_INITIALIZER(flags, finish_check, finish_check_arg) \
-  make_exec_ctx(grpc_exec_ctx{GRPC_CLOSURE_LIST_INIT, NULL, NULL, flags, \
-                              gpr_cpu_current_cpu(), finish_check_arg,   \
-                              finish_check, false, 0, __PRETTY_FUNCTION__})
+  void InvalidateNow() { now_is_valid_ = false; }
 
-/* initialize an execution context at the top level of an API call into grpc
-   (this is safe to use elsewhere, though possibly not as efficient) */
-#define GRPC_EXEC_CTX_INIT \
-  GRPC_EXEC_CTX_INITIALIZER(GRPC_EXEC_CTX_FLAG_IS_FINISHED, NULL, NULL)
+  void SetNow(grpc_millis new_val) {
+    now_ = new_val;
+    now_is_valid_ = true;
+  }
+
+  uintptr_t flags() { return flags_; }
+
+  /** Finish any pending work for a grpc_exec_ctx. Must be called before
+   *  the instance is destroyed, or work may be lost. */
+  void Finish();
+
+  static void GlobalInit(void);
+
+  static void GlobalShutdown(void);
+
+  static ExecCtx* Get();
+
+ protected:
+  virtual bool CheckReadyToFinish() { return false; }
+
+  grpc_closure_list closure_list_ = GRPC_CLOSURE_LIST_INIT;
+  CombinerData combiner_data_ = {nullptr, nullptr};
+  uintptr_t flags_;
+  unsigned starting_cpu_ = gpr_cpu_current_cpu();
+
+  bool now_is_valid_ = false;
+  grpc_millis now_ = 0;
+
+  ExecCtx* last_exec_ctx_ = Get();
+};
+
+extern grpc_closure_scheduler* grpc_schedule_on_exec_ctx;
+
+gpr_timespec grpc_millis_to_timespec(grpc_millis millis, gpr_clock_type clock);
+grpc_millis grpc_timespec_to_millis_round_down(gpr_timespec timespec);
+grpc_millis grpc_timespec_to_millis_round_up(gpr_timespec timespec);
 
 #ifdef __cplusplus
 }
diff --git a/src/core/lib/iomgr/executor.cc b/src/core/lib/iomgr/executor.cc
index f764d915ff..bf8805a2cd 100644
--- a/src/core/lib/iomgr/executor.cc
+++ b/src/core/lib/iomgr/executor.cc
@@ -78,7 +78,7 @@ static size_t run_closures(grpc_closure_list list) {
     GRPC_ERROR_UNREF(error);
     c = next;
     n++;
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
   }
 
   return n;
@@ -145,7 +145,7 @@ static void executor_thread(void* arg) {
   thread_state* ts = (thread_state*)arg;
   gpr_tls_set(&g_this_thread_state, (intptr_t)ts);
 
-  ExecCtx _local_exec_ctx(0, grpc_never_ready_to_finish, NULL);
+  ExecCtx _local_exec_ctx;
 
   size_t subtract_depth = 0;
   for (;;) {
@@ -175,10 +175,9 @@ static void executor_thread(void* arg) {
       gpr_log(GPR_DEBUG, "EXECUTOR[%d]: execute", (int)(ts - g_thread_state));
     }
 
-    grpc_exec_ctx_invalidate_now();
+    ExecCtx::Get()->InvalidateNow();
     subtract_depth = run_closures(exec);
   }
-  grpc_exec_ctx_finish();
 }
 
 static void executor_push(grpc_closure* closure, grpc_error* error,
@@ -201,12 +200,12 @@ static void executor_push(grpc_closure* closure, grpc_error* error,
         gpr_log(GPR_DEBUG, "EXECUTOR: schedule %p inline", closure);
 #endif
       }
-      grpc_closure_list_append(&exec_ctx->closure_list, closure, error);
+      grpc_closure_list_append(ExecCtx::Get()->closure_list(), closure, error);
       return;
     }
     thread_state* ts = (thread_state*)gpr_tls_get(&g_this_thread_state);
     if (ts == NULL) {
-      ts = &g_thread_state[GPR_HASH_POINTER(exec_ctx, cur_thread_count)];
+      ts = &g_thread_state[GPR_HASH_POINTER(ExecCtx::Get(), cur_thread_count)];
     } else {
       GRPC_STATS_INC_EXECUTOR_SCHEDULED_TO_SELF();
     }
diff --git a/src/core/lib/iomgr/iocp_windows.cc b/src/core/lib/iomgr/iocp_windows.cc
index 8f15f5e6cc..1686bf2872 100644
--- a/src/core/lib/iomgr/iocp_windows.cc
+++ b/src/core/lib/iomgr/iocp_windows.cc
@@ -46,7 +46,7 @@ static DWORD deadline_to_millis_timeout(grpc_millis deadline) {
   if (deadline == GRPC_MILLIS_INF_FUTURE) {
     return INFINITE;
   }
-  grpc_millis now = grpc_exec_ctx_now();
+  grpc_millis now = ExecCtx::Get()->Now();
   if (deadline < now) return 0;
   grpc_millis timeout = deadline - now;
   if (timeout > std::numeric_limits<DWORD>::max()) return INFINITE;
@@ -65,7 +65,7 @@ grpc_iocp_work_status grpc_iocp_work(grpc_millis deadline) {
   success =
       GetQueuedCompletionStatus(g_iocp, &bytes, &completion_key, &overlapped,
                                 deadline_to_millis_timeout(deadline));
-  grpc_exec_ctx_invalidate_now();
+  ExecCtx::Get()->InvalidateNow();
   if (success == 0 && overlapped == NULL) {
     return GRPC_IOCP_WORK_TIMEOUT;
   }
@@ -118,16 +118,16 @@ void grpc_iocp_flush(void) {
 
   do {
     work_status = grpc_iocp_work(GRPC_MILLIS_INF_PAST);
-  } while (work_status == GRPC_IOCP_WORK_KICK || grpc_exec_ctx_flush());
+  } while (work_status == GRPC_IOCP_WORK_KICK || ExecCtx::Get()->Flush());
 }
 
 void grpc_iocp_shutdown(void) {
   ExecCtx _local_exec_ctx;
   while (gpr_atm_acq_load(&g_custom_events)) {
     grpc_iocp_work(GRPC_MILLIS_INF_FUTURE);
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
   }
-  grpc_exec_ctx_finish();
+
   GPR_ASSERT(CloseHandle(g_iocp));
 }
 
diff --git a/src/core/lib/iomgr/iomgr.cc b/src/core/lib/iomgr/iomgr.cc
index 01d9964cc8..a1add4a303 100644
--- a/src/core/lib/iomgr/iomgr.cc
+++ b/src/core/lib/iomgr/iomgr.cc
@@ -49,7 +49,7 @@ void grpc_iomgr_init() {
   g_shutdown = 0;
   gpr_mu_init(&g_mu);
   gpr_cv_init(&g_rcv);
-  grpc_exec_ctx_global_init();
+  ExecCtx::GlobalInit();
   grpc_executor_init();
   grpc_timer_list_init();
   g_root_object.next = g_root_object.prev = &g_root_object;
@@ -98,11 +98,10 @@ void grpc_iomgr_shutdown() {
       }
       last_warning_time = gpr_now(GPR_CLOCK_REALTIME);
     }
-    exec_ctx->now_is_valid = true;
-    exec_ctx->now = GRPC_MILLIS_INF_FUTURE;
+    ExecCtx::Get()->SetNow(GRPC_MILLIS_INF_FUTURE);
     if (grpc_timer_check(NULL) == GRPC_TIMERS_FIRED) {
       gpr_mu_unlock(&g_mu);
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       grpc_iomgr_platform_flush();
       gpr_mu_lock(&g_mu);
       continue;
@@ -137,14 +136,14 @@ void grpc_iomgr_shutdown() {
   gpr_mu_unlock(&g_mu);
 
   grpc_timer_list_shutdown();
-  grpc_exec_ctx_flush();
+  ExecCtx::Get()->Flush();
 
   /* ensure all threads have left g_mu */
   gpr_mu_lock(&g_mu);
   gpr_mu_unlock(&g_mu);
 
   grpc_iomgr_platform_shutdown();
-  grpc_exec_ctx_global_shutdown();
+  ExecCtx::GlobalShutdown();
   grpc_network_status_shutdown();
   gpr_mu_destroy(&g_mu);
   gpr_cv_destroy(&g_rcv);
diff --git a/src/core/lib/iomgr/iomgr_uv.cc b/src/core/lib/iomgr/iomgr_uv.cc
index 4dda970286..2ab414252a 100644
--- a/src/core/lib/iomgr/iomgr_uv.cc
+++ b/src/core/lib/iomgr/iomgr_uv.cc
@@ -34,7 +34,6 @@ void grpc_iomgr_platform_init(void) {
   grpc_register_tracer(&grpc_tcp_trace);
   grpc_executor_set_threading(false);
   g_init_thread = gpr_thd_currentid();
-  grpc_exec_ctx_finish();
 }
 void grpc_iomgr_platform_flush(void) {}
 void grpc_iomgr_platform_shutdown(void) { grpc_pollset_global_shutdown(); }
diff --git a/src/core/lib/iomgr/load_file.cc b/src/core/lib/iomgr/load_file.cc
index 97e448fb32..feef65cc34 100644
--- a/src/core/lib/iomgr/load_file.cc
+++ b/src/core/lib/iomgr/load_file.cc
@@ -73,6 +73,6 @@ end:
     GRPC_ERROR_UNREF(error);
     error = error_out;
   }
-  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   return error;
 }
diff --git a/src/core/lib/iomgr/pollset_uv.cc b/src/core/lib/iomgr/pollset_uv.cc
index 7028876297..a68ad4a6e3 100644
--- a/src/core/lib/iomgr/pollset_uv.cc
+++ b/src/core/lib/iomgr/pollset_uv.cc
@@ -124,7 +124,7 @@ grpc_error* grpc_pollset_work(grpc_pollset* pollset,
   GRPC_UV_ASSERT_SAME_THREAD();
   gpr_mu_unlock(&grpc_polling_mu);
   if (grpc_pollset_work_run_loop) {
-    grpc_millis now = grpc_exec_ctx_now();
+    grpc_millis now = ExecCtx::Get()->Now();
     if (deadline >= now) {
       timeout = deadline - now;
     } else {
@@ -143,7 +143,7 @@ grpc_error* grpc_pollset_work(grpc_pollset* pollset,
     }
   }
   if (!grpc_closure_list_empty(exec_ctx->closure_list)) {
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
   }
   gpr_mu_lock(&grpc_polling_mu);
   return GRPC_ERROR_NONE;
diff --git a/src/core/lib/iomgr/pollset_windows.cc b/src/core/lib/iomgr/pollset_windows.cc
index dd019b1ec3..5ff3e7cb3a 100644
--- a/src/core/lib/iomgr/pollset_windows.cc
+++ b/src/core/lib/iomgr/pollset_windows.cc
@@ -129,7 +129,7 @@ grpc_error* grpc_pollset_work(grpc_pollset* pollset,
       g_active_poller = &worker;
       gpr_mu_unlock(&grpc_polling_mu);
       grpc_iocp_work(deadline);
-      grpc_exec_ctx_flush();
+      ExecCtx::Get()->Flush();
       gpr_mu_lock(&grpc_polling_mu);
       pollset->is_iocp_worker = 0;
       g_active_poller = NULL;
@@ -160,10 +160,10 @@ grpc_error* grpc_pollset_work(grpc_pollset* pollset,
     while (!worker.kicked) {
       if (gpr_cv_wait(&worker.cv, &grpc_polling_mu,
                       grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME))) {
-        grpc_exec_ctx_invalidate_now();
+        ExecCtx::Get()->InvalidateNow();
         break;
       }
-      grpc_exec_ctx_invalidate_now();
+      ExecCtx::Get()->InvalidateNow();
     }
   } else {
     pollset->kicked_without_pollers = 0;
@@ -171,7 +171,7 @@ grpc_error* grpc_pollset_work(grpc_pollset* pollset,
 done:
   if (!grpc_closure_list_empty(exec_ctx->closure_list)) {
     gpr_mu_unlock(&grpc_polling_mu);
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
     gpr_mu_lock(&grpc_polling_mu);
   }
   if (added_worker) {
diff --git a/src/core/lib/iomgr/resolve_address_posix.cc b/src/core/lib/iomgr/resolve_address_posix.cc
index 3795c3f75e..80a1a45cc0 100644
--- a/src/core/lib/iomgr/resolve_address_posix.cc
+++ b/src/core/lib/iomgr/resolve_address_posix.cc
@@ -81,7 +81,7 @@ static grpc_error* blocking_resolve_address_impl(
 
   GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
 
   if (s != 0) {
     /* Retry if well-known service name is recognized */
@@ -90,7 +90,7 @@ static grpc_error* blocking_resolve_address_impl(
       if (strcmp(port, svc[i][0]) == 0) {
         GRPC_SCHEDULING_START_BLOCKING_REGION;
         s = getaddrinfo(host, svc[i][1], &hints, &result);
-        GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
+        GRPC_SCHEDULING_END_BLOCKING_REGION;
         break;
       }
     }
diff --git a/src/core/lib/iomgr/resolve_address_uv.cc b/src/core/lib/iomgr/resolve_address_uv.cc
index 038926af07..ffd70c4f35 100644
--- a/src/core/lib/iomgr/resolve_address_uv.cc
+++ b/src/core/lib/iomgr/resolve_address_uv.cc
@@ -131,7 +131,7 @@ static void getaddrinfo_callback(uv_getaddrinfo_t* req, int status,
      original error probably has more interesting information */
   error = handle_addrinfo_result(status, res, r->addresses);
   GRPC_CLOSURE_SCHED(r->on_done, error);
-  grpc_exec_ctx_finish();
+
   gpr_free(r->hints);
   gpr_free(r->host);
   gpr_free(r->port);
diff --git a/src/core/lib/iomgr/resolve_address_windows.cc b/src/core/lib/iomgr/resolve_address_windows.cc
index 15f3fd9f1a..4e2bc7b5ca 100644
--- a/src/core/lib/iomgr/resolve_address_windows.cc
+++ b/src/core/lib/iomgr/resolve_address_windows.cc
@@ -87,7 +87,7 @@ static grpc_error* blocking_resolve_address_impl(
 
   GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_SCHEDULING_END_BLOCKING_REGION_NO_EXEC_CTX;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   if (s != 0) {
     error = GRPC_WSA_ERROR(WSAGetLastError(), "getaddrinfo");
     goto done;
diff --git a/src/core/lib/iomgr/resource_quota.cc b/src/core/lib/iomgr/resource_quota.cc
index b58ae1cb21..8fee585f4b 100644
--- a/src/core/lib/iomgr/resource_quota.cc
+++ b/src/core/lib/iomgr/resource_quota.cc
@@ -624,7 +624,6 @@ void grpc_resource_quota_unref_internal(grpc_resource_quota* resource_quota) {
 void grpc_resource_quota_unref(grpc_resource_quota* resource_quota) {
   ExecCtx _local_exec_ctx;
   grpc_resource_quota_unref_internal(resource_quota);
-  grpc_exec_ctx_finish();
 }
 
 grpc_resource_quota* grpc_resource_quota_ref_internal(
@@ -656,7 +655,6 @@ void grpc_resource_quota_resize(grpc_resource_quota* resource_quota,
                            (gpr_atm)GPR_MIN((size_t)GPR_ATM_MAX, size));
   GRPC_CLOSURE_INIT(&a->closure, rq_resize, a, grpc_schedule_on_exec_ctx);
   GRPC_CLOSURE_SCHED(&a->closure, GRPC_ERROR_NONE);
-  grpc_exec_ctx_finish();
 }
 
 size_t grpc_resource_quota_peek_size(grpc_resource_quota* resource_quota) {
diff --git a/src/core/lib/iomgr/tcp_client_uv.cc b/src/core/lib/iomgr/tcp_client_uv.cc
index 2a127993a2..7454b01445 100644
--- a/src/core/lib/iomgr/tcp_client_uv.cc
+++ b/src/core/lib/iomgr/tcp_client_uv.cc
@@ -105,11 +105,10 @@ static void uv_tc_on_connect(uv_connect_t* req, int status) {
   }
   done = (--connect->refs == 0);
   if (done) {
-    grpc_exec_ctx_flush();
+    ExecCtx::Get()->Flush();
     uv_tcp_connect_cleanup(connect);
   }
   GRPC_CLOSURE_SCHED(closure, error);
-  grpc_exec_ctx_finish();
 }
 
 static void tcp_client_connect_impl(grpc_closure* closure, grpc_endpoint** ep,
diff --git a/src/core/lib/iomgr/tcp_posix.cc b/src/core/lib/iomgr/tcp_posix.cc
index 697281d8b1..de3dabd7fc 100644
--- a/src/core/lib/iomgr/tcp_posix.cc
+++ b/src/core/lib/iomgr/tcp_posix.cc
@@ -130,7 +130,7 @@ static void run_poller(void* bp, grpc_error* error_ignored) {
     gpr_log(GPR_DEBUG, "BACKUP_POLLER:%p run", p);
   }
   gpr_mu_lock(p->pollset_mu);
-  grpc_millis deadline = grpc_exec_ctx_now() + 13 * GPR_MS_PER_SEC;
+  grpc_millis deadline = ExecCtx::Get()->Now() + 13 * GPR_MS_PER_SEC;
   GRPC_STATS_INC_TCP_BACKUP_POLLER_POLLS();
   GRPC_LOG_IF_ERROR(
       "backup_poller:pollset_work",
diff --git a/src/core/lib/iomgr/tcp_server_uv.cc b/src/core/lib/iomgr/tcp_server_uv.cc
index 8d5387fe6e..9db2cbe58d 100644
--- a/src/core/lib/iomgr/tcp_server_uv.cc
+++ b/src/core/lib/iomgr/tcp_server_uv.cc
@@ -142,7 +142,6 @@ static void handle_close_callback(uv_handle_t* handle) {
   if (sp->server->open_ports == 0 && sp->server->shutdown) {
     finish_shutdown(sp->server);
   }
-  grpc_exec_ctx_finish();
 }
 
 static void close_listener(grpc_tcp_listener* sp) {
@@ -177,14 +176,8 @@ void grpc_tcp_server_unref(grpc_tcp_server* s) {
     /* Complete shutdown_starting work before destroying. */
     ExecCtx _local_exec_ctx;
     GRPC_CLOSURE_LIST_SCHED(&s->shutdown_starting);
-    if (exec_ctx == NULL) {
-      grpc_exec_ctx_flush();
-      tcp_server_destroy(s);
-      grpc_exec_ctx_finish();
-    } else {
-      grpc_exec_ctx_finish();
-      tcp_server_destroy(s);
-    }
+    ExecCtx::Get()->Flush();
+    tcp_server_destroy(s);
   }
 }
 
@@ -255,7 +248,6 @@ static void on_connect(uv_stream_t* server, int status) {
   } else {
     sp->has_pending_connection = true;
   }
-  grpc_exec_ctx_finish();
 }
 
 static grpc_error* add_socket_to_server(grpc_tcp_server* s, uv_tcp_t* handle,
diff --git a/src/core/lib/iomgr/tcp_uv.cc b/src/core/lib/iomgr/tcp_uv.cc
index 571c1d6f9a..3ea9674840 100644
--- a/src/core/lib/iomgr/tcp_uv.cc
+++ b/src/core/lib/iomgr/tcp_uv.cc
@@ -115,7 +115,6 @@ static void uv_close_callback(uv_handle_t* handle) {
   ExecCtx _local_exec_ctx;
   grpc_tcp* tcp = (grpc_tcp*)handle->data;
   TCP_UNREF(tcp, "destroy");
-  grpc_exec_ctx_finish();
 }
 
 static grpc_slice alloc_read_slice(grpc_resource_user* resource_user) {
@@ -130,7 +129,6 @@ static void alloc_uv_buf(uv_handle_t* handle, size_t suggested_size,
   (void)suggested_size;
   buf->base = (char*)GRPC_SLICE_START_PTR(tcp->read_slice);
   buf->len = GRPC_SLICE_LENGTH(tcp->read_slice);
-  grpc_exec_ctx_finish();
 }
 
 static void read_callback(uv_stream_t* stream, ssize_t nread,
@@ -174,7 +172,6 @@ static void read_callback(uv_stream_t* stream, ssize_t nread,
     error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("TCP Read failed");
   }
   GRPC_CLOSURE_SCHED(cb, error);
-  grpc_exec_ctx_finish();
 }
 
 static void uv_endpoint_read(grpc_endpoint* ep, grpc_slice_buffer* read_slices,
@@ -224,7 +221,6 @@ static void write_callback(uv_write_t* req, int status) {
   grpc_resource_user_free(tcp->resource_user,
                           sizeof(uv_buf_t) * tcp->write_slices->count);
   GRPC_CLOSURE_SCHED(cb, error);
-  grpc_exec_ctx_finish();
 }
 
 static void uv_endpoint_write(grpc_endpoint* ep,
@@ -384,7 +380,6 @@ grpc_endpoint* grpc_tcp_create(uv_tcp_t* handle,
   uv_unref((uv_handle_t*)handle);
 #endif
 
-  grpc_exec_ctx_finish();
   return &tcp->base;
 }
 
diff --git a/src/core/lib/iomgr/timer_generic.cc b/src/core/lib/iomgr/timer_generic.cc
index e7fe12b07b..d5e6066f35 100644
--- a/src/core/lib/iomgr/timer_generic.cc
+++ b/src/core/lib/iomgr/timer_generic.cc
@@ -249,7 +249,7 @@ void grpc_timer_list_init() {
   g_shared_mutables.initialized = true;
   g_shared_mutables.checker_mu = GPR_SPINLOCK_INITIALIZER;
   gpr_mu_init(&g_shared_mutables.mu);
-  g_shared_mutables.min_timer = grpc_exec_ctx_now();
+  g_shared_mutables.min_timer = ExecCtx::Get()->Now();
   gpr_tls_init(&g_last_seen_min_timer);
   gpr_tls_set(&g_last_seen_min_timer, 0);
   grpc_register_tracer(&grpc_timer_trace);
@@ -341,7 +341,7 @@ void grpc_timer_init(grpc_timer* timer, grpc_millis deadline,
   if (GRPC_TRACER_ON(grpc_timer_trace)) {
     gpr_log(GPR_DEBUG,
             "TIMER %p: SET %" PRIdPTR " now %" PRIdPTR " call %p[%p]", timer,
-            deadline, grpc_exec_ctx_now(), closure, closure->cb);
+            deadline, ExecCtx::Get()->Now(), closure, closure->cb);
   }
 
   if (!g_shared_mutables.initialized) {
@@ -354,7 +354,7 @@ void grpc_timer_init(grpc_timer* timer, grpc_millis deadline,
 
   gpr_mu_lock(&shard->mu);
   timer->pending = true;
-  grpc_millis now = grpc_exec_ctx_now();
+  grpc_millis now = ExecCtx::Get()->Now();
   if (deadline <= now) {
     timer->pending = false;
     GRPC_CLOSURE_SCHED(timer->closure, GRPC_ERROR_NONE);
@@ -607,7 +607,7 @@ static grpc_timer_check_result run_some_expired_timers(gpr_atm now,
 
 grpc_timer_check_result grpc_timer_check(grpc_millis* next) {
   // prelude
-  grpc_millis now = grpc_exec_ctx_now();
+  grpc_millis now = ExecCtx::Get()->Now();
 
   /* fetch from a thread-local first: this avoids contention on a globally
      mutable cacheline in the common case */
diff --git a/src/core/lib/iomgr/timer_manager.cc b/src/core/lib/iomgr/timer_manager.cc
index 499fc73748..69adb673d8 100644
--- a/src/core/lib/iomgr/timer_manager.cc
+++ b/src/core/lib/iomgr/timer_manager.cc
@@ -101,7 +101,6 @@ void grpc_timer_manager_tick() {
   ExecCtx _local_exec_ctx;
   grpc_millis next = GRPC_MILLIS_INF_FUTURE;
   grpc_timer_check(&next);
-  grpc_exec_ctx_finish();
 }
 
 static void run_some_timers() {
@@ -126,7 +125,7 @@ static void run_some_timers() {
   if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
     gpr_log(GPR_DEBUG, "flush exec_ctx");
   }
-  grpc_exec_ctx_flush();
+  ExecCtx::Get()->Flush();
   gpr_mu_lock(&g_mu);
   // garbage collect any threads hanging out that are dead
   gc_completed_threads();
@@ -179,7 +178,7 @@ static bool wait_until(grpc_millis next) {
         g_timed_waiter_deadline = next;
 
         if (GRPC_TRACER_ON(grpc_timer_check_trace)) {
-          grpc_millis wait_time = next - grpc_exec_ctx_now();
+          grpc_millis wait_time = next - ExecCtx::Get()->Now();
           gpr_log(GPR_DEBUG, "sleep for a %" PRIdPTR " milliseconds",
                   wait_time);
         }
@@ -224,7 +223,7 @@ static bool wait_until(grpc_millis next) {
 static void timer_main_loop() {
   for (;;) {
     grpc_millis next = GRPC_MILLIS_INF_FUTURE;
-    grpc_exec_ctx_invalidate_now();
+    ExecCtx::Get()->InvalidateNow();
     // check timer state, updates next to the next time to run a check
     switch (grpc_timer_check(&next)) {
       case GRPC_TIMERS_FIRED:
@@ -274,9 +273,9 @@ static void timer_thread_cleanup(completed_thread* ct) {
 static void timer_thread(void* completed_thread_ptr) {
   // this threads exec_ctx: we try to run things through to completion here
   // since it's easy to spin up new threads
-  ExecCtx _local_exec_ctx(0, grpc_never_ready_to_finish, NULL);
+  ExecCtx _local_exec_ctx;
   timer_main_loop();
-  grpc_exec_ctx_finish();
+
   timer_thread_cleanup((completed_thread*)completed_thread_ptr);
 }
 
diff --git a/src/core/lib/iomgr/timer_uv.cc b/src/core/lib/iomgr/timer_uv.cc
index 94601d99af..6edd4169f1 100644
--- a/src/core/lib/iomgr/timer_uv.cc
+++ b/src/core/lib/iomgr/timer_uv.cc
@@ -51,7 +51,6 @@ void run_expired_timer(uv_timer_t* handle) {
   timer->pending = 0;
   GRPC_CLOSURE_SCHED(timer->closure, GRPC_ERROR_NONE);
   stop_uv_timer(handle);
-  grpc_exec_ctx_finish();
 }
 
 void grpc_timer_init(grpc_timer* timer, grpc_millis deadline,
@@ -60,13 +59,13 @@ void grpc_timer_init(grpc_timer* timer, grpc_millis deadline,
   uv_timer_t* uv_timer;
   GRPC_UV_ASSERT_SAME_THREAD();
   timer->closure = closure;
-  if (deadline <= grpc_exec_ctx_now()) {
+  if (deadline <= ExecCtx::Get()->Now()) {
     timer->pending = 0;
     GRPC_CLOSURE_SCHED(timer->closure, GRPC_ERROR_NONE);
     return;
   }
   timer->pending = 1;
-  timeout = (uint64_t)(deadline - grpc_exec_ctx_now());
+  timeout = (uint64_t)(deadline - ExecCtx::Get()->Now());
   uv_timer = (uv_timer_t*)gpr_malloc(sizeof(uv_timer_t));
   uv_timer_init(uv_default_loop(), uv_timer);
   uv_timer->data = timer;
diff --git a/src/core/lib/security/context/security_context.cc b/src/core/lib/security/context/security_context.cc
index 1d708c997c..9b58b3657f 100644
--- a/src/core/lib/security/context/security_context.cc
+++ b/src/core/lib/security/context/security_context.cc
@@ -57,7 +57,7 @@ grpc_call_error grpc_call_set_credentials(grpc_call* call,
     grpc_call_credentials_unref(ctx->creds);
     ctx->creds = grpc_call_credentials_ref(creds);
   }
-  grpc_exec_ctx_finish();
+
   return GRPC_CALL_OK;
 }
 
@@ -95,7 +95,6 @@ void grpc_client_security_context_destroy(void* ctx) {
     c->extension.destroy(c->extension.instance);
   }
   gpr_free(ctx);
-  grpc_exec_ctx_finish();
 }
 
 /* --- grpc_server_security_context --- */
diff --git a/src/core/lib/security/credentials/credentials.cc b/src/core/lib/security/credentials/credentials.cc
index 20c4ae70fb..6a272653f8 100644
--- a/src/core/lib/security/credentials/credentials.cc
+++ b/src/core/lib/security/credentials/credentials.cc
@@ -74,7 +74,6 @@ void grpc_channel_credentials_release(grpc_channel_credentials* creds) {
   GRPC_API_TRACE("grpc_channel_credentials_release(creds=%p)", 1, (creds));
   ExecCtx _local_exec_ctx;
   grpc_channel_credentials_unref(creds);
-  grpc_exec_ctx_finish();
 }
 
 grpc_call_credentials* grpc_call_credentials_ref(grpc_call_credentials* creds) {
@@ -97,7 +96,6 @@ void grpc_call_credentials_release(grpc_call_credentials* creds) {
   GRPC_API_TRACE("grpc_call_credentials_release(creds=%p)", 1, (creds));
   ExecCtx _local_exec_ctx;
   grpc_call_credentials_unref(creds);
-  grpc_exec_ctx_finish();
 }
 
 bool grpc_call_credentials_get_request_metadata(
@@ -213,7 +211,6 @@ void grpc_server_credentials_release(grpc_server_credentials* creds) {
   GRPC_API_TRACE("grpc_server_credentials_release(creds=%p)", 1, (creds));
   ExecCtx _local_exec_ctx;
   grpc_server_credentials_unref(creds);
-  grpc_exec_ctx_finish();
 }
 
 grpc_security_status grpc_server_credentials_create_security_connector(
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.cc b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
index 897b9d7520..03ec4bc3b3 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.cc
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
@@ -114,13 +114,13 @@ static int is_stack_running_on_compute_engine() {
       grpc_resource_quota_create("google_default_credentials");
   grpc_httpcli_get(
       &context, &detector.pollent, resource_quota, &request,
-      grpc_exec_ctx_now() + max_detection_delay,
+      ExecCtx::Get()->Now() + max_detection_delay,
       GRPC_CLOSURE_CREATE(on_compute_engine_detection_http_response, &detector,
                           grpc_schedule_on_exec_ctx),
       &detector.response);
   grpc_resource_quota_unref_internal(resource_quota);
 
-  grpc_exec_ctx_flush();
+  ExecCtx::Get()->Flush();
 
   /* Block until we get the response. This is not ideal but this should only be
      called once for the lifetime of the process by the default credentials. */
@@ -144,7 +144,7 @@ static int is_stack_running_on_compute_engine() {
   grpc_pollset_shutdown(grpc_polling_entity_pollset(&detector.pollent),
                         &destroy_closure);
   g_polling_mu = NULL;
-  grpc_exec_ctx_flush();
+  ExecCtx::Get()->Flush();
 
   gpr_free(grpc_polling_entity_pollset(&detector.pollent));
   grpc_http_response_destroy(&detector.response);
@@ -285,7 +285,7 @@ end:
   } else {
     GRPC_ERROR_UNREF(error);
   }
-  grpc_exec_ctx_finish();
+
   return result;
 }
 
@@ -299,7 +299,6 @@ void grpc_flush_cached_google_default_credentials(void) {
   }
   compute_engine_detection_done = 0;
   gpr_mu_unlock(&g_state_mu);
-  grpc_exec_ctx_finish();
 }
 
 /* -- Well known credentials path. -- */
diff --git a/src/core/lib/security/credentials/iam/iam_credentials.cc b/src/core/lib/security/credentials/iam/iam_credentials.cc
index 07938ec67e..4d9da0cbe3 100644
--- a/src/core/lib/security/credentials/iam/iam_credentials.cc
+++ b/src/core/lib/security/credentials/iam/iam_credentials.cc
@@ -77,6 +77,6 @@ grpc_call_credentials* grpc_google_iam_credentials_create(
       grpc_slice_from_copied_string(authority_selector));
   grpc_credentials_mdelem_array_add(&c->md_array, md);
   GRPC_MDELEM_UNREF(md);
-  grpc_exec_ctx_finish();
+
   return &c->base;
 }
diff --git a/src/core/lib/security/credentials/jwt/jwt_credentials.cc b/src/core/lib/security/credentials/jwt/jwt_credentials.cc
index 1d43ee6e03..ccc3f4aeed 100644
--- a/src/core/lib/security/credentials/jwt/jwt_credentials.cc
+++ b/src/core/lib/security/credentials/jwt/jwt_credentials.cc
@@ -185,6 +185,6 @@ grpc_call_credentials* grpc_service_account_jwt_access_credentials_create(
   grpc_call_credentials* creds =
       grpc_service_account_jwt_access_credentials_create_from_auth_json_key(
           grpc_auth_json_key_create_from_string(json_key), token_lifetime);
-  grpc_exec_ctx_finish();
+
   return creds;
 }
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.cc b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
index eaa2078787..5246e1f985 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.cc
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
@@ -358,7 +358,7 @@ static verifier_cb_ctx* verifier_cb_ctx_create(
   ctx->signed_data = grpc_slice_from_copied_buffer(signed_jwt, signed_jwt_len);
   ctx->user_data = user_data;
   ctx->user_cb = cb;
-  grpc_exec_ctx_finish();
+
   return ctx;
 }
 
@@ -702,7 +702,7 @@ static void on_openid_config_retrieved(void* user_data, grpc_error* error) {
   resource_quota = grpc_resource_quota_create("jwt_verifier");
   grpc_httpcli_get(
       &ctx->verifier->http_ctx, &ctx->pollent, resource_quota, &req,
-      grpc_exec_ctx_now() + grpc_jwt_verifier_max_delay,
+      ExecCtx::Get()->Now() + grpc_jwt_verifier_max_delay,
       GRPC_CLOSURE_CREATE(on_keys_retrieved, ctx, grpc_schedule_on_exec_ctx),
       &ctx->responses[HTTP_RESPONSE_KEYS]);
   grpc_resource_quota_unref_internal(resource_quota);
@@ -828,7 +828,7 @@ static void retrieve_key_and_verify(verifier_cb_ctx* ctx) {
      extreme memory pressure. */
   resource_quota = grpc_resource_quota_create("jwt_verifier");
   grpc_httpcli_get(&ctx->verifier->http_ctx, &ctx->pollent, resource_quota,
-                   &req, grpc_exec_ctx_now() + grpc_jwt_verifier_max_delay,
+                   &req, ExecCtx::Get()->Now() + grpc_jwt_verifier_max_delay,
                    http_cb, &ctx->responses[rsp_idx]);
   grpc_resource_quota_unref_internal(resource_quota);
   gpr_free(req.host);
diff --git a/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc b/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
index bae9692938..b653705609 100644
--- a/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
+++ b/src/core/lib/security/credentials/oauth2/oauth2_credentials.cc
@@ -216,8 +216,9 @@ static void on_oauth2_token_fetcher_http_response(void* user_data,
   gpr_mu_lock(&c->mu);
   c->token_fetch_pending = false;
   c->access_token_md = GRPC_MDELEM_REF(access_token_md);
-  c->token_expiration =
-      status == GRPC_CREDENTIALS_OK ? grpc_exec_ctx_now() + token_lifetime : 0;
+  c->token_expiration = status == GRPC_CREDENTIALS_OK
+                            ? ExecCtx::Get()->Now() + token_lifetime
+                            : 0;
   grpc_oauth2_pending_get_request_metadata* pending_request =
       c->pending_requests;
   c->pending_requests = NULL;
@@ -255,7 +256,7 @@ static bool oauth2_token_fetcher_get_request_metadata(
   grpc_mdelem cached_access_token_md = GRPC_MDNULL;
   gpr_mu_lock(&c->mu);
   if (!GRPC_MDISNULL(c->access_token_md) &&
-      (c->token_expiration - grpc_exec_ctx_now() > refresh_threshold)) {
+      (c->token_expiration - ExecCtx::Get()->Now() > refresh_threshold)) {
     cached_access_token_md = GRPC_MDELEM_REF(c->access_token_md);
   }
   if (!GRPC_MDISNULL(cached_access_token_md)) {
@@ -287,7 +288,7 @@ static bool oauth2_token_fetcher_get_request_metadata(
     c->fetch_func(grpc_credentials_metadata_request_create(creds),
                   &c->httpcli_context, &c->pollent,
                   on_oauth2_token_fetcher_http_response,
-                  grpc_exec_ctx_now() + refresh_threshold);
+                  ExecCtx::Get()->Now() + refresh_threshold);
   }
   return false;
 }
@@ -517,7 +518,7 @@ grpc_call_credentials* grpc_access_token_credentials_create(
   c->access_token_md = grpc_mdelem_from_slices(
       grpc_slice_from_static_string(GRPC_AUTHORIZATION_METADATA_KEY),
       grpc_slice_from_copied_string(token_md_value));
-  grpc_exec_ctx_finish();
+
   gpr_free(token_md_value);
   return &c->base;
 }
diff --git a/src/core/lib/security/credentials/plugin/plugin_credentials.cc b/src/core/lib/security/credentials/plugin/plugin_credentials.cc
index 064666a7d0..025d024617 100644
--- a/src/core/lib/security/credentials/plugin/plugin_credentials.cc
+++ b/src/core/lib/security/credentials/plugin/plugin_credentials.cc
@@ -116,9 +116,8 @@ static void plugin_md_request_metadata_ready(void* request,
                                              grpc_status_code status,
                                              const char* error_details) {
   /* called from application code */
-  ExecCtx _local_exec_ctx(
-      GRPC_EXEC_CTX_FLAG_IS_FINISHED | GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP,
-      NULL, NULL);
+  ExecCtx _local_exec_ctx(GRPC_EXEC_CTX_FLAG_IS_FINISHED |
+                          GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP);
   grpc_plugin_credentials_pending_request* r =
       (grpc_plugin_credentials_pending_request*)request;
   if (GRPC_TRACER_ON(grpc_plugin_credentials_trace)) {
@@ -141,7 +140,6 @@ static void plugin_md_request_metadata_ready(void* request,
             r->creds, r);
   }
   gpr_free(r);
-  grpc_exec_ctx_finish();
 }
 
 static bool plugin_get_request_metadata(grpc_call_credentials* creds,
diff --git a/src/core/lib/security/transport/security_handshaker.cc b/src/core/lib/security/transport/security_handshaker.cc
index cb20401409..4ed2ec55bd 100644
--- a/src/core/lib/security/transport/security_handshaker.cc
+++ b/src/core/lib/security/transport/security_handshaker.cc
@@ -266,7 +266,6 @@ static void on_handshake_next_done_grpc_wrapper(
   } else {
     gpr_mu_unlock(&h->mu);
   }
-  grpc_exec_ctx_finish();
 }
 
 static grpc_error* do_handshaker_next_locked(
diff --git a/src/core/lib/security/transport/server_auth_filter.cc b/src/core/lib/security/transport/server_auth_filter.cc
index 5f21a2933b..86817076f8 100644
--- a/src/core/lib/security/transport/server_auth_filter.cc
+++ b/src/core/lib/security/transport/server_auth_filter.cc
@@ -141,7 +141,6 @@ static void on_md_processing_done(
   }
   grpc_metadata_array_destroy(&calld->md);
   GRPC_CALL_STACK_UNREF(calld->owning_call, "server_auth_metadata");
-  grpc_exec_ctx_finish();
 }
 
 static void cancel_call(void* arg, grpc_error* error) {
diff --git a/src/core/lib/slice/slice.cc b/src/core/lib/slice/slice.cc
index 3b3b2e4f05..6e1554d471 100644
--- a/src/core/lib/slice/slice.cc
+++ b/src/core/lib/slice/slice.cc
@@ -69,7 +69,6 @@ grpc_slice grpc_slice_ref(grpc_slice slice) {
 void grpc_slice_unref(grpc_slice slice) {
   ExecCtx _local_exec_ctx;
   grpc_slice_unref_internal(slice);
-  grpc_exec_ctx_finish();
 }
 
 /* grpc_slice_from_static_string support structure - a refcount that does
diff --git a/src/core/lib/slice/slice_buffer.cc b/src/core/lib/slice/slice_buffer.cc
index 6774269972..4bc54c303f 100644
--- a/src/core/lib/slice/slice_buffer.cc
+++ b/src/core/lib/slice/slice_buffer.cc
@@ -75,7 +75,6 @@ void grpc_slice_buffer_destroy_internal(grpc_slice_buffer* sb) {
 void grpc_slice_buffer_destroy(grpc_slice_buffer* sb) {
   ExecCtx _local_exec_ctx;
   grpc_slice_buffer_destroy_internal(sb);
-  grpc_exec_ctx_finish();
 }
 
 uint8_t* grpc_slice_buffer_tiny_add(grpc_slice_buffer* sb, size_t n) {
@@ -175,7 +174,6 @@ void grpc_slice_buffer_reset_and_unref_internal(grpc_slice_buffer* sb) {
 void grpc_slice_buffer_reset_and_unref(grpc_slice_buffer* sb) {
   ExecCtx _local_exec_ctx;
   grpc_slice_buffer_reset_and_unref_internal(sb);
-  grpc_exec_ctx_finish();
 }
 
 void grpc_slice_buffer_swap(grpc_slice_buffer* a, grpc_slice_buffer* b) {
diff --git a/src/core/lib/surface/alarm.cc b/src/core/lib/surface/alarm.cc
index 395ffd393c..7aee100f3f 100644
--- a/src/core/lib/surface/alarm.cc
+++ b/src/core/lib/surface/alarm.cc
@@ -51,7 +51,7 @@ static void alarm_unref(grpc_alarm* alarm) {
     if (alarm->cq != NULL) {
       GRPC_CQ_INTERNAL_UNREF(alarm->cq, "alarm");
     }
-    grpc_exec_ctx_finish();
+
     gpr_free(alarm);
   }
 }
@@ -126,13 +126,11 @@ void grpc_alarm_set(grpc_alarm* alarm, grpc_completion_queue* cq,
   GPR_ASSERT(grpc_cq_begin_op(cq, tag));
   grpc_timer_init(&alarm->alarm, grpc_timespec_to_millis_round_up(deadline),
                   &alarm->on_alarm);
-  grpc_exec_ctx_finish();
 }
 
 void grpc_alarm_cancel(grpc_alarm* alarm, void* reserved) {
   ExecCtx _local_exec_ctx;
   grpc_timer_cancel(&alarm->alarm);
-  grpc_exec_ctx_finish();
 }
 
 void grpc_alarm_destroy(grpc_alarm* alarm, void* reserved) {
diff --git a/src/core/lib/surface/byte_buffer.cc b/src/core/lib/surface/byte_buffer.cc
index f3c10797f3..6a9b13bb41 100644
--- a/src/core/lib/surface/byte_buffer.cc
+++ b/src/core/lib/surface/byte_buffer.cc
@@ -78,7 +78,6 @@ void grpc_byte_buffer_destroy(grpc_byte_buffer* bb) {
       break;
   }
   gpr_free(bb);
-  grpc_exec_ctx_finish();
 }
 
 size_t grpc_byte_buffer_length(grpc_byte_buffer* bb) {
diff --git a/src/core/lib/surface/byte_buffer_reader.cc b/src/core/lib/surface/byte_buffer_reader.cc
index fb66829baa..9a9e26ecdc 100644
--- a/src/core/lib/surface/byte_buffer_reader.cc
+++ b/src/core/lib/surface/byte_buffer_reader.cc
@@ -70,7 +70,7 @@ int grpc_byte_buffer_reader_init(grpc_byte_buffer_reader* reader,
       reader->current.index = 0;
       break;
   }
-  grpc_exec_ctx_finish();
+
   return 1;
 }
 
@@ -118,6 +118,6 @@ grpc_slice grpc_byte_buffer_reader_readall(grpc_byte_buffer_reader* reader) {
     grpc_slice_unref_internal(in_slice);
     GPR_ASSERT(bytes_read <= input_size);
   }
-  grpc_exec_ctx_finish();
+
   return out_slice;
 }
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 5e1c0badd0..bbb7a39e29 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -595,7 +595,7 @@ void grpc_call_unref(grpc_call* c) {
     grpc_call_combiner_set_notify_on_cancel(&c->call_combiner, NULL);
   }
   GRPC_CALL_INTERNAL_UNREF(c, "destroy");
-  grpc_exec_ctx_finish();
+
   GPR_TIMER_END("grpc_call_unref", 0);
 }
 
@@ -604,7 +604,7 @@ grpc_call_error grpc_call_cancel(grpc_call* call, void* reserved) {
   GPR_ASSERT(!reserved);
   ExecCtx _local_exec_ctx;
   cancel_with_error(call, STATUS_FROM_API_OVERRIDE, GRPC_ERROR_CANCELLED);
-  grpc_exec_ctx_finish();
+
   return GRPC_CALL_OK;
 }
 
@@ -659,7 +659,7 @@ grpc_call_error grpc_call_cancel_with_status(grpc_call* c,
       4, (c, (int)status, description, reserved));
   GPR_ASSERT(reserved == NULL);
   cancel_with_status(c, STATUS_FROM_API_OVERRIDE, status, description);
-  grpc_exec_ctx_finish();
+
   return GRPC_CALL_OK;
 }
 
@@ -2048,7 +2048,6 @@ grpc_call_error grpc_call_start_batch(grpc_call* call, const grpc_op* ops,
     err = call_start_batch(call, ops, nops, tag, 0);
   }
 
-  grpc_exec_ctx_finish();
   return err;
 }
 
diff --git a/src/core/lib/surface/call_details.cc b/src/core/lib/surface/call_details.cc
index 01b19abefb..03ce7f88fb 100644
--- a/src/core/lib/surface/call_details.cc
+++ b/src/core/lib/surface/call_details.cc
@@ -37,5 +37,4 @@ void grpc_call_details_destroy(grpc_call_details* cd) {
   ExecCtx _local_exec_ctx;
   grpc_slice_unref_internal(cd->method);
   grpc_slice_unref_internal(cd->host);
-  grpc_exec_ctx_finish();
 }
diff --git a/src/core/lib/surface/channel.cc b/src/core/lib/surface/channel.cc
index dc1fc1632e..7725351f74 100644
--- a/src/core/lib/surface/channel.cc
+++ b/src/core/lib/surface/channel.cc
@@ -252,7 +252,6 @@ void grpc_channel_get_info(grpc_channel* channel,
   grpc_channel_element* elem =
       grpc_channel_stack_element(CHANNEL_STACK_FROM_CHANNEL(channel), 0);
   elem->filter->get_channel_info(elem, channel_info);
-  grpc_exec_ctx_finish();
 }
 
 static grpc_call* grpc_channel_create_call_internal(
@@ -305,7 +304,7 @@ grpc_call* grpc_channel_create_call(grpc_channel* channel,
                                              grpc_slice_ref_internal(*host))
                    : GRPC_MDNULL,
       grpc_timespec_to_millis_round_up(deadline));
-  grpc_exec_ctx_finish();
+
   return call;
 }
 
@@ -344,7 +343,7 @@ void* grpc_channel_register_call(grpc_channel* channel, const char* method,
   rc->next = channel->registered_calls;
   channel->registered_calls = rc;
   gpr_mu_unlock(&channel->registered_call_mu);
-  grpc_exec_ctx_finish();
+
   return rc;
 }
 
@@ -370,7 +369,7 @@ grpc_call* grpc_channel_create_registered_call(
       channel, parent_call, propagation_mask, completion_queue, NULL,
       GRPC_MDELEM_REF(rc->path), GRPC_MDELEM_REF(rc->authority),
       grpc_timespec_to_millis_round_up(deadline));
-  grpc_exec_ctx_finish();
+
   return call;
 }
 
@@ -416,8 +415,6 @@ void grpc_channel_destroy(grpc_channel* channel) {
   elem->filter->start_transport_op(elem, op);
 
   GRPC_CHANNEL_INTERNAL_UNREF(channel, "channel");
-
-  grpc_exec_ctx_finish();
 }
 
 grpc_channel_stack* grpc_channel_get_channel_stack(grpc_channel* channel) {
diff --git a/src/core/lib/surface/channel_ping.cc b/src/core/lib/surface/channel_ping.cc
index 0966a8d967..06cdbf6c73 100644
--- a/src/core/lib/surface/channel_ping.cc
+++ b/src/core/lib/surface/channel_ping.cc
@@ -60,5 +60,4 @@ void grpc_channel_ping(grpc_channel* channel, grpc_completion_queue* cq,
   op->bind_pollset = grpc_cq_pollset(cq);
   GPR_ASSERT(grpc_cq_begin_op(cq, tag));
   top_elem->filter->start_transport_op(top_elem, op);
-  grpc_exec_ctx_finish();
 }
diff --git a/src/core/lib/surface/completion_queue.cc b/src/core/lib/surface/completion_queue.cc
index b69d40534d..0b0a8d070d 100644
--- a/src/core/lib/surface/completion_queue.cc
+++ b/src/core/lib/surface/completion_queue.cc
@@ -124,7 +124,7 @@ static grpc_error* non_polling_poller_work(grpc_pollset* pollset,
   while (!npp->shutdown && !w.kicked &&
          !gpr_cv_wait(&w.cv, &npp->mu, deadline_ts))
     ;
-  grpc_exec_ctx_invalidate_now();
+  ExecCtx::Get()->InvalidateNow();
   if (&w == npp->root) {
     npp->root = w.next;
     if (&w == npp->root) {
@@ -371,7 +371,6 @@ int grpc_completion_queue_thread_local_cache_flush(grpc_completion_queue* cq,
       gpr_mu_unlock(cq->mu);
       GRPC_CQ_INTERNAL_UNREF(cq, "shutting_down");
     }
-    grpc_exec_ctx_finish();
   }
   gpr_tls_set(&g_cached_event, (intptr_t)0);
   gpr_tls_set(&g_cached_cq, (intptr_t)0);
@@ -412,8 +411,6 @@ static grpc_cq_completion* cq_event_queue_pop(grpc_cq_event_queue* q) {
     GRPC_STATS_INC_CQ_EV_QUEUE_TRYLOCK_FAILURES();
   }
 
-  grpc_exec_ctx_finish();
-
   if (c) {
     gpr_atm_no_barrier_fetch_add(&q->num_queue_items, -1);
   }
@@ -445,7 +442,6 @@ grpc_completion_queue* grpc_completion_queue_create_internal(
 
   ExecCtx _local_exec_ctx;
   GRPC_STATS_INC_CQS_CREATED();
-  grpc_exec_ctx_finish();
 
   cq = (grpc_completion_queue*)gpr_zalloc(sizeof(grpc_completion_queue) +
                                           vtable->data_size +
@@ -639,9 +635,9 @@ static void cq_end_op_for_next(grpc_completion_queue* cq, void* tag,
        error != GRPC_ERROR_NONE)) {
     const char* errmsg = grpc_error_string(error);
     GRPC_API_TRACE(
-        "cq_end_op_for_next(=%p, cq=%p, tag=%p, error=%s, "
+        "cq_end_op_for_next(cq=%p, tag=%p, error=%s, "
         "done=%p, done_arg=%p, storage=%p)",
-        7, (exec_ctx, cq, tag, errmsg, done, done_arg, storage));
+        6, (cq, tag, errmsg, done, done_arg, storage));
     if (GRPC_TRACER_ON(grpc_trace_operation_failures) &&
         error != GRPC_ERROR_NONE) {
       gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
@@ -726,9 +722,9 @@ static void cq_end_op_for_pluck(grpc_completion_queue* cq, void* tag,
        error != GRPC_ERROR_NONE)) {
     const char* errmsg = grpc_error_string(error);
     GRPC_API_TRACE(
-        "cq_end_op_for_pluck(=%p, cq=%p, tag=%p, error=%s, "
+        "cq_end_op_for_pluck(cq=%p, tag=%p, error=%s, "
         "done=%p, done_arg=%p, storage=%p)",
-        7, (exec_ctx, cq, tag, errmsg, done, done_arg, storage));
+        6, (cq, tag, errmsg, done, done_arg, storage));
     if (GRPC_TRACER_ON(grpc_trace_operation_failures) &&
         error != GRPC_ERROR_NONE) {
       gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
@@ -794,31 +790,40 @@ typedef struct {
   bool first_loop;
 } cq_is_finished_arg;
 
-static bool cq_is_next_finished(void* arg) {
-  cq_is_finished_arg* a = (cq_is_finished_arg*)arg;
-  grpc_completion_queue* cq = a->cq;
-  cq_next_data* cqd = (cq_next_data*)DATA_FROM_CQ(cq);
-  GPR_ASSERT(a->stolen_completion == NULL);
+class ExecCtxNext : public ExecCtx {
+ public:
+  ExecCtxNext(void* arg) : ExecCtx(0), check_ready_to_finish_arg_(arg) {}
 
-  gpr_atm current_last_seen_things_queued_ever =
-      gpr_atm_no_barrier_load(&cqd->things_queued_ever);
+  bool CheckReadyToFinish() override {
+    cq_is_finished_arg* a = (cq_is_finished_arg*)check_ready_to_finish_arg_;
+    grpc_completion_queue* cq = a->cq;
+    cq_next_data* cqd = (cq_next_data*)DATA_FROM_CQ(cq);
+    GPR_ASSERT(a->stolen_completion == NULL);
 
-  if (current_last_seen_things_queued_ever != a->last_seen_things_queued_ever) {
-    a->last_seen_things_queued_ever =
+    gpr_atm current_last_seen_things_queued_ever =
         gpr_atm_no_barrier_load(&cqd->things_queued_ever);
 
-    /* Pop a cq_completion from the queue. Returns NULL if the queue is empty
-     * might return NULL in some cases even if the queue is not empty; but
-     * that
-     * is ok and doesn't affect correctness. Might effect the tail latencies a
-     * bit) */
-    a->stolen_completion = cq_event_queue_pop(&cqd->queue);
-    if (a->stolen_completion != NULL) {
-      return true;
+    if (current_last_seen_things_queued_ever !=
+        a->last_seen_things_queued_ever) {
+      a->last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cqd->things_queued_ever);
+
+      /* Pop a cq_completion from the queue. Returns NULL if the queue is empty
+       * might return NULL in some cases even if the queue is not empty; but
+       * that
+       * is ok and doesn't affect correctness. Might effect the tail latencies a
+       * bit) */
+      a->stolen_completion = cq_event_queue_pop(&cqd->queue);
+      if (a->stolen_completion != NULL) {
+        return true;
+      }
     }
+    return !a->first_loop && a->deadline < ExecCtx::Get()->Now();
   }
-  return !a->first_loop && a->deadline < grpc_exec_ctx_now();
-}
+
+ private:
+  void* check_ready_to_finish_arg_;
+};
 
 #ifndef NDEBUG
 static void dump_pending_tags(grpc_completion_queue* cq) {
@@ -873,7 +878,7 @@ static grpc_event cq_next(grpc_completion_queue* cq, gpr_timespec deadline,
       NULL,
       NULL,
       true};
-  ExecCtx _local_exec_ctx(0, cq_is_next_finished, &is_finished_arg);
+  ExecCtxNext _local_exec_ctx(&is_finished_arg);
   for (;;) {
     grpc_millis iteration_deadline = deadline_millis;
 
@@ -923,7 +928,8 @@ static grpc_event cq_next(grpc_completion_queue* cq, gpr_timespec deadline,
       break;
     }
 
-    if (!is_finished_arg.first_loop && grpc_exec_ctx_now() >= deadline_millis) {
+    if (!is_finished_arg.first_loop &&
+        ExecCtx::Get()->Now() >= deadline_millis) {
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
       dump_pending_tags(cq);
@@ -959,7 +965,7 @@ static grpc_event cq_next(grpc_completion_queue* cq, gpr_timespec deadline,
 
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, &ret);
   GRPC_CQ_INTERNAL_UNREF(cq, "next");
-  grpc_exec_ctx_finish();
+
   GPR_ASSERT(is_finished_arg.stolen_completion == NULL);
 
   GPR_TIMER_END("grpc_completion_queue_next", 0);
@@ -1039,37 +1045,46 @@ static void del_plucker(grpc_completion_queue* cq, void* tag,
   GPR_UNREACHABLE_CODE(return );
 }
 
-static bool cq_is_pluck_finished(void* arg) {
-  cq_is_finished_arg* a = (cq_is_finished_arg*)arg;
-  grpc_completion_queue* cq = a->cq;
-  cq_pluck_data* cqd = (cq_pluck_data*)DATA_FROM_CQ(cq);
+class ExecCtxPluck : public ExecCtx {
+ public:
+  ExecCtxPluck(void* arg) : ExecCtx(0), check_ready_to_finish_arg_(arg) {}
 
-  GPR_ASSERT(a->stolen_completion == NULL);
-  gpr_atm current_last_seen_things_queued_ever =
-      gpr_atm_no_barrier_load(&cqd->things_queued_ever);
-  if (current_last_seen_things_queued_ever != a->last_seen_things_queued_ever) {
-    gpr_mu_lock(cq->mu);
-    a->last_seen_things_queued_ever =
+  bool CheckReadyToFinish() override {
+    cq_is_finished_arg* a = (cq_is_finished_arg*)check_ready_to_finish_arg_;
+    grpc_completion_queue* cq = a->cq;
+    cq_pluck_data* cqd = (cq_pluck_data*)DATA_FROM_CQ(cq);
+
+    GPR_ASSERT(a->stolen_completion == NULL);
+    gpr_atm current_last_seen_things_queued_ever =
         gpr_atm_no_barrier_load(&cqd->things_queued_ever);
-    grpc_cq_completion* c;
-    grpc_cq_completion* prev = &cqd->completed_head;
-    while ((c = (grpc_cq_completion*)(prev->next & ~(uintptr_t)1)) !=
-           &cqd->completed_head) {
-      if (c->tag == a->tag) {
-        prev->next = (prev->next & (uintptr_t)1) | (c->next & ~(uintptr_t)1);
-        if (c == cqd->completed_tail) {
-          cqd->completed_tail = prev;
+    if (current_last_seen_things_queued_ever !=
+        a->last_seen_things_queued_ever) {
+      gpr_mu_lock(cq->mu);
+      a->last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cqd->things_queued_ever);
+      grpc_cq_completion* c;
+      grpc_cq_completion* prev = &cqd->completed_head;
+      while ((c = (grpc_cq_completion*)(prev->next & ~(uintptr_t)1)) !=
+             &cqd->completed_head) {
+        if (c->tag == a->tag) {
+          prev->next = (prev->next & (uintptr_t)1) | (c->next & ~(uintptr_t)1);
+          if (c == cqd->completed_tail) {
+            cqd->completed_tail = prev;
+          }
+          gpr_mu_unlock(cq->mu);
+          a->stolen_completion = c;
+          return true;
         }
-        gpr_mu_unlock(cq->mu);
-        a->stolen_completion = c;
-        return true;
+        prev = c;
       }
-      prev = c;
+      gpr_mu_unlock(cq->mu);
     }
-    gpr_mu_unlock(cq->mu);
+    return !a->first_loop && a->deadline < ExecCtx::Get()->Now();
   }
-  return !a->first_loop && a->deadline < grpc_exec_ctx_now();
-}
+
+ private:
+  void* check_ready_to_finish_arg_;
+};
 
 static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
                            gpr_timespec deadline, void* reserved) {
@@ -1106,7 +1121,7 @@ static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
       NULL,
       tag,
       true};
-  ExecCtx _local_exec_ctx(0, cq_is_pluck_finished, &is_finished_arg);
+  ExecCtxPluck _local_exec_ctx(&is_finished_arg);
   for (;;) {
     if (is_finished_arg.stolen_completion != NULL) {
       gpr_mu_unlock(cq->mu);
@@ -1153,7 +1168,8 @@ static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
       dump_pending_tags(cq);
       break;
     }
-    if (!is_finished_arg.first_loop && grpc_exec_ctx_now() >= deadline_millis) {
+    if (!is_finished_arg.first_loop &&
+        ExecCtx::Get()->Now() >= deadline_millis) {
       del_plucker(cq, tag, &worker);
       gpr_mu_unlock(cq->mu);
       memset(&ret, 0, sizeof(ret));
@@ -1182,7 +1198,7 @@ static grpc_event cq_pluck(grpc_completion_queue* cq, void* tag,
 done:
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cq, &ret);
   GRPC_CQ_INTERNAL_UNREF(cq, "pluck");
-  grpc_exec_ctx_finish();
+
   GPR_ASSERT(is_finished_arg.stolen_completion == NULL);
 
   GPR_TIMER_END("grpc_completion_queue_pluck", 0);
@@ -1238,7 +1254,7 @@ void grpc_completion_queue_shutdown(grpc_completion_queue* cq) {
   GPR_TIMER_BEGIN("grpc_completion_queue_shutdown", 0);
   GRPC_API_TRACE("grpc_completion_queue_shutdown(cq=%p)", 1, (cq));
   cq->vtable->shutdown(cq);
-  grpc_exec_ctx_finish();
+
   GPR_TIMER_END("grpc_completion_queue_shutdown", 0);
 }
 
@@ -1249,7 +1265,7 @@ void grpc_completion_queue_destroy(grpc_completion_queue* cq) {
 
   ExecCtx _local_exec_ctx;
   GRPC_CQ_INTERNAL_UNREF(cq, "destroy");
-  grpc_exec_ctx_finish();
+
   GPR_TIMER_END("grpc_completion_queue_destroy", 0);
 }
 
diff --git a/src/core/lib/surface/init.cc b/src/core/lib/surface/init.cc
index 66c8c3b6da..20e17a7f60 100644
--- a/src/core/lib/surface/init.cc
+++ b/src/core/lib/surface/init.cc
@@ -168,14 +168,14 @@ void grpc_init(void) {
     grpc_iomgr_start();
   }
   gpr_mu_unlock(&g_init_mu);
-  grpc_exec_ctx_finish();
+
   GRPC_API_TRACE("grpc_init(void)", 0, ());
 }
 
 void grpc_shutdown(void) {
   int i;
   GRPC_API_TRACE("grpc_shutdown(void)", 0, ());
-  ExecCtx _local_exec_ctx(0, grpc_never_ready_to_finish, NULL);
+  ExecCtx _local_exec_ctx;
   gpr_mu_lock(&g_init_mu);
   if (--g_initializations == 0) {
     grpc_executor_shutdown();
@@ -194,7 +194,6 @@ void grpc_shutdown(void) {
     grpc_stats_shutdown();
   }
   gpr_mu_unlock(&g_init_mu);
-  grpc_exec_ctx_finish();
 }
 
 int grpc_is_initialized(void) {
diff --git a/src/core/lib/surface/lame_client.cc b/src/core/lib/surface/lame_client.cc
index 5cd8c1fd89..da081e68cb 100644
--- a/src/core/lib/surface/lame_client.cc
+++ b/src/core/lib/surface/lame_client.cc
@@ -169,6 +169,6 @@ grpc_channel* grpc_lame_client_channel_create(const char* target,
   auto chand = reinterpret_cast<grpc_core::ChannelData*>(elem->channel_data);
   chand->error_code = error_code;
   chand->error_message = error_message;
-  grpc_exec_ctx_finish();
+
   return channel;
 }
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index 6e3ce005a2..0d4435d556 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -1047,8 +1047,6 @@ void grpc_server_start(grpc_server* server) {
       GRPC_CLOSURE_CREATE(start_listeners, server,
                           grpc_executor_scheduler(GRPC_EXECUTOR_SHORT)),
       GRPC_ERROR_NONE);
-
-  grpc_exec_ctx_finish();
 }
 
 void grpc_server_get_pollsets(grpc_server* server, grpc_pollset*** pollsets,
@@ -1188,7 +1186,7 @@ void grpc_server_shutdown_and_notify(grpc_server* server,
     grpc_cq_end_op(cq, tag, GRPC_ERROR_NONE, done_published_shutdown, NULL,
                    (grpc_cq_completion*)gpr_malloc(sizeof(grpc_cq_completion)));
     gpr_mu_unlock(&server->mu_global);
-    goto done;
+    return;
   }
   server->shutdown_tags = (shutdown_tag*)gpr_realloc(
       server->shutdown_tags,
@@ -1198,7 +1196,7 @@ void grpc_server_shutdown_and_notify(grpc_server* server,
   sdt->cq = cq;
   if (gpr_atm_acq_load(&server->shutdown_flag)) {
     gpr_mu_unlock(&server->mu_global);
-    goto done;
+    return;
   }
 
   server->last_shutdown_message_time = gpr_now(GPR_CLOCK_REALTIME);
@@ -1225,9 +1223,6 @@ void grpc_server_shutdown_and_notify(grpc_server* server,
 
   channel_broadcaster_shutdown(&broadcaster, true /* send_goaway */,
                                GRPC_ERROR_NONE);
-
-done:
-  grpc_exec_ctx_finish();
 }
 
 void grpc_server_cancel_all_calls(grpc_server* server) {
@@ -1243,7 +1238,6 @@ void grpc_server_cancel_all_calls(grpc_server* server) {
   channel_broadcaster_shutdown(
       &broadcaster, false /* send_goaway */,
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Cancelling all calls"));
-  grpc_exec_ctx_finish();
 }
 
 void grpc_server_destroy(grpc_server* server) {
@@ -1265,7 +1259,6 @@ void grpc_server_destroy(grpc_server* server) {
   gpr_mu_unlock(&server->mu_global);
 
   server_unref(server);
-  grpc_exec_ctx_finish();
 }
 
 void grpc_server_add_listener(grpc_server* server, void* arg,
@@ -1368,7 +1361,7 @@ grpc_call_error grpc_server_request_call(
   rc->initial_metadata = initial_metadata;
   error = queue_call_request(server, cq_idx, rc);
 done:
-  grpc_exec_ctx_finish();
+
   return error;
 }
 
@@ -1425,7 +1418,7 @@ grpc_call_error grpc_server_request_registered_call(
   rc->data.registered.optional_payload = optional_payload;
   error = queue_call_request(server, cq_idx, rc);
 done:
-  grpc_exec_ctx_finish();
+
   return error;
 }
 
diff --git a/src/core/lib/transport/bdp_estimator.cc b/src/core/lib/transport/bdp_estimator.cc
index 47d65870d1..4e279b4d94 100644
--- a/src/core/lib/transport/bdp_estimator.cc
+++ b/src/core/lib/transport/bdp_estimator.cc
@@ -79,7 +79,7 @@ grpc_millis BdpEstimator::CompletePing() {
   }
   ping_state_ = PingState::UNSCHEDULED;
   accumulator_ = 0;
-  return grpc_exec_ctx_now() + inter_ping_delay_;
+  return ExecCtx::Get()->Now() + inter_ping_delay_;
 }
 
 }  // namespace grpc_core
diff --git a/src/core/lib/transport/status_conversion.cc b/src/core/lib/transport/status_conversion.cc
index fd7764f2db..61470b8c78 100644
--- a/src/core/lib/transport/status_conversion.cc
+++ b/src/core/lib/transport/status_conversion.cc
@@ -46,8 +46,8 @@ grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
     case GRPC_HTTP2_CANCEL:
       /* http2 cancel translates to STATUS_CANCELLED iff deadline hasn't been
        * exceeded */
-      return grpc_exec_ctx_now() > deadline ? GRPC_STATUS_DEADLINE_EXCEEDED
-                                            : GRPC_STATUS_CANCELLED;
+      return ExecCtx::Get()->Now() > deadline ? GRPC_STATUS_DEADLINE_EXCEEDED
+                                              : GRPC_STATUS_CANCELLED;
     case GRPC_HTTP2_ENHANCE_YOUR_CALM:
       return GRPC_STATUS_RESOURCE_EXHAUSTED;
     case GRPC_HTTP2_INADEQUATE_SECURITY:
diff --git a/src/core/lib/transport/transport.cc b/src/core/lib/transport/transport.cc
index 6f31bd07f9..ca80a7404d 100644
--- a/src/core/lib/transport/transport.cc
+++ b/src/core/lib/transport/transport.cc
@@ -62,7 +62,7 @@ void grpc_stream_unref(grpc_stream_refcount* refcount, const char* reason) {
 void grpc_stream_unref(grpc_stream_refcount* refcount) {
 #endif
   if (gpr_unref(&refcount->refs)) {
-    if (exec_ctx->flags & GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP) {
+    if (ExecCtx::Get()->flags() & GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP) {
       /* Ick.
          The thread we're running on MAY be owned (indirectly) by a call-stack.
          If that's the case, destroying the call-stack MAY try to destroy the