core: Rename Behavior to Dispatch (#2082)

And rename IsolateState to ThreadSafeState.

Also make ThreadSafeState directly implement Dispatch. This is simpler.

12 files changed, 206 insertions, 214 deletions

diff --git a/cli/cli_behavior.rs b/cli/cli_behavior.rs
deleted file mode 100644
index 510b2608c..000000000
--- a/cli/cli_behavior.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-use crate::isolate_state::*;
-use crate::ops;
-use deno::deno_buf;
-use deno::Behavior;
-use deno::Op;
-use std::sync::Arc;
-
-/// Implements deno::Behavior for the main Deno command-line.
-pub struct CliBehavior {
-  pub state: Arc<IsolateState>,
-}
-
-impl CliBehavior {
-  pub fn new(state: Arc<IsolateState>) -> Self {
-    Self { state }
-  }
-}
-
-impl Behavior for CliBehavior {
-  fn dispatch(
-    &mut self,
-    control: &[u8],
-    zero_copy: deno_buf,
-  ) -> (bool, Box<Op>) {
-    ops::dispatch_all(&self.state, control, zero_copy, ops::op_selector_std)
-  }
-}
diff --git a/cli/compiler.rs b/cli/compiler.rs
index d01e9fc0b..bd9cc4c64 100644
--- a/cli/compiler.rs
+++ b/cli/compiler.rs
@@ -1,12 +1,11 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-use crate::cli_behavior::CliBehavior;
-use crate::isolate_state::*;
 use crate::js_errors;
 use crate::js_errors::JSErrorColor;
 use crate::msg;
 use crate::resources;
 use crate::resources::ResourceId;
 use crate::startup_data;
+use crate::state::*;
 use crate::tokio_util;
 use crate::worker::Worker;
 use deno::js_check;
@@ -21,7 +20,6 @@ use std::collections::HashMap;
 use std::str;
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::sync::Mutex;
 use tokio::runtime::Runtime;
 
@@ -88,22 +86,21 @@ fn parse_cmd_id(res_json: &str) -> CmdId {
   }
 }
 
-fn lazy_start(parent_state: Arc<IsolateState>) -> ResourceId {
+fn lazy_start(parent_state: ThreadSafeState) -> ResourceId {
   let mut cell = C_RID.lock().unwrap();
   cell
     .get_or_insert_with(|| {
-      let child_state = Arc::new(IsolateState::new(
+      let child_state = ThreadSafeState::new(
         parent_state.flags.clone(),
         parent_state.argv.clone(),
-      ));
+      );
       let rid = child_state.resource.rid;
       let resource = child_state.resource.clone();
-      let behavior = CliBehavior::new(child_state);
 
       let mut worker = Worker::new(
         "TS".to_string(),
         startup_data::compiler_isolate_init(),
-        behavior,
+        child_state,
       );
 
       js_check(worker.execute("denoMain()"));
@@ -160,7 +157,7 @@ fn req(specifier: &str, referrer: &str, cmd_id: u32) -> Buf {
 }
 
 pub fn compile_async(
-  parent_state: Arc<IsolateState>,
+  parent_state: ThreadSafeState,
   specifier: &str,
   referrer: &str,
   module_meta_data: &ModuleMetaData,
@@ -248,7 +245,7 @@ pub fn compile_async(
 }
 
 pub fn compile_sync(
-  parent_state: Arc<IsolateState>,
+  parent_state: ThreadSafeState,
   specifier: &str,
   referrer: &str,
   module_meta_data: &ModuleMetaData,
@@ -286,12 +283,8 @@ mod tests {
         maybe_source_map: None,
       };
 
-      out = compile_sync(
-        Arc::new(IsolateState::mock()),
-        specifier,
-        &referrer,
-        &out,
-      ).unwrap();
+      out = compile_sync(ThreadSafeState::mock(), specifier, &referrer, &out)
+        .unwrap();
       assert!(
         out
           .maybe_output_code
diff --git a/cli/main.rs b/cli/main.rs
index 346bbbd89..6178dafee 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -11,7 +11,6 @@ extern crate clap;
 extern crate deno;
 
 mod ansi;
-pub mod cli_behavior;
 pub mod compiler;
 pub mod deno_dir;
 pub mod errors;
@@ -20,7 +19,6 @@ mod fs;
 mod global_timer;
 mod http_body;
 mod http_util;
-pub mod isolate_state;
 pub mod js_errors;
 pub mod modules;
 pub mod msg;
@@ -31,20 +29,19 @@ mod repl;
 pub mod resolve_addr;
 pub mod resources;
 mod startup_data;
+pub mod state;
 mod tokio_util;
 mod tokio_write;
 pub mod version;
 pub mod worker;
 
-use crate::cli_behavior::CliBehavior;
 use crate::errors::RustOrJsError;
-use crate::isolate_state::IsolateState;
+use crate::state::ThreadSafeState;
 use crate::worker::Worker;
 use futures::lazy;
 use futures::Future;
 use log::{LevelFilter, Metadata, Record};
 use std::env;
-use std::sync::Arc;
 
 static LOGGER: Logger = Logger;
 
@@ -104,11 +101,12 @@ fn main() {
   let should_prefetch = flags.prefetch || flags.info;
   let should_display_info = flags.info;
 
-  let state = Arc::new(IsolateState::new(flags, rest_argv));
-  let state_ = state.clone();
-  let cli = CliBehavior::new(state_);
-  let mut main_worker =
-    Worker::new("main".to_string(), startup_data::deno_isolate_init(), cli);
+  let state = ThreadSafeState::new(flags, rest_argv);
+  let mut main_worker = Worker::new(
+    "main".to_string(),
+    startup_data::deno_isolate_init(),
+    state.clone(),
+  );
 
   let main_future = lazy(move || {
     // Setup runtime.
diff --git a/cli/msg.rs b/cli/msg.rs
index d4f62604c..d97940a34 100644
--- a/cli/msg.rs
+++ b/cli/msg.rs
@@ -5,7 +5,7 @@
   feature = "cargo-clippy",
   allow(clippy::all, clippy::pedantic)
 )]
-use crate::isolate_state;
+use crate::state;
 use flatbuffers;
 use std::sync::atomic::Ordering;
 
@@ -13,8 +13,8 @@ use std::sync::atomic::Ordering;
 // build_extra/rust/run.py (for the GN+Ninja build).
 include!(concat!(env!("GN_OUT_DIR"), "/gen/cli/msg_generated.rs"));
 
-impl<'a> From<&'a isolate_state::Metrics> for MetricsResArgs {
-  fn from(m: &'a isolate_state::Metrics) -> Self {
+impl<'a> From<&'a state::Metrics> for MetricsResArgs {
+  fn from(m: &'a state::Metrics) -> Self {
     MetricsResArgs {
       ops_dispatched: m.ops_dispatched.load(Ordering::SeqCst) as u64,
       ops_completed: m.ops_completed.load(Ordering::SeqCst) as u64,
diff --git a/cli/ops.rs b/cli/ops.rs
index 3d43b2401..baa159a68 100644
--- a/cli/ops.rs
+++ b/cli/ops.rs
@@ -1,12 +1,10 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 use atty;
 use crate::ansi;
-use crate::cli_behavior::CliBehavior;
 use crate::errors;
 use crate::errors::{DenoError, DenoResult, ErrorKind};
 use crate::fs as deno_fs;
 use crate::http_util;
-use crate::isolate_state::IsolateState;
 use crate::js_errors::apply_source_map;
 use crate::js_errors::JSErrorColor;
 use crate::msg;
@@ -17,6 +15,7 @@ use crate::resources;
 use crate::resources::table_entries;
 use crate::resources::Resource;
 use crate::startup_data;
+use crate::state::ThreadSafeState;
 use crate::tokio_util;
 use crate::tokio_write;
 use crate::version;
@@ -42,7 +41,6 @@ use std::net::Shutdown;
 use std::path::Path;
 use std::path::PathBuf;
 use std::process::Command;
-use std::sync::Arc;
 use std::time::{Duration, Instant, UNIX_EPOCH};
 use tokio;
 use tokio::net::TcpListener;
@@ -62,7 +60,7 @@ pub type OpWithError = dyn Future<Item = Buf, Error = DenoError> + Send;
 // TODO Ideally we wouldn't have to box the OpWithError being returned.
 // The box is just to make it easier to get a prototype refactor working.
 type OpCreator =
-  fn(state: &Arc<IsolateState>, base: &msg::Base<'_>, data: deno_buf)
+  fn(state: &ThreadSafeState, base: &msg::Base<'_>, data: deno_buf)
     -> Box<OpWithError>;
 
 type OpSelector = fn(inner_type: msg::Any) -> Option<OpCreator>;
@@ -77,7 +75,7 @@ fn empty_buf() -> Buf {
 /// control corresponds to the first argument of Deno.core.dispatch().
 /// data corresponds to the second argument of Deno.core.dispatch().
 pub fn dispatch_all(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   control: &[u8],
   zero_copy: deno_buf,
   op_selector: OpSelector,
@@ -209,7 +207,7 @@ pub fn op_selector_std(inner_type: msg::Any) -> Option<OpCreator> {
 // If the High precision flag is not set, the
 // nanoseconds are rounded on 2ms.
 fn op_now(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -245,7 +243,7 @@ fn op_now(
 }
 
 fn op_is_tty(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   _data: deno_buf,
 ) -> Box<OpWithError> {
@@ -270,7 +268,7 @@ fn op_is_tty(
 }
 
 fn op_exit(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   _data: deno_buf,
 ) -> Box<OpWithError> {
@@ -279,7 +277,7 @@ fn op_exit(
 }
 
 fn op_start(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -335,7 +333,7 @@ fn op_start(
 }
 
 fn op_format_error(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -394,7 +392,7 @@ pub fn odd_future(err: DenoError) -> Box<OpWithError> {
 
 // https://github.com/denoland/deno/blob/golang/os.go#L100-L154
 fn op_fetch_module_meta_data(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -435,7 +433,7 @@ fn op_fetch_module_meta_data(
 }
 
 fn op_chdir(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -449,7 +447,7 @@ fn op_chdir(
 }
 
 fn op_global_timer_stop(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -462,7 +460,7 @@ fn op_global_timer_stop(
 }
 
 fn op_global_timer(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -495,7 +493,7 @@ fn op_global_timer(
 }
 
 fn op_set_env(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -511,7 +509,7 @@ fn op_set_env(
 }
 
 fn op_env(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -543,7 +541,7 @@ fn op_env(
 }
 
 fn op_permissions(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -573,7 +571,7 @@ fn op_permissions(
 }
 
 fn op_revoke_permission(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -596,7 +594,7 @@ fn op_revoke_permission(
 }
 
 fn op_fetch(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -683,7 +681,7 @@ where
 }
 
 fn op_make_temp_dir(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -732,7 +730,7 @@ fn op_make_temp_dir(
 }
 
 fn op_mkdir(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -754,7 +752,7 @@ fn op_mkdir(
 }
 
 fn op_chmod(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -793,7 +791,7 @@ fn op_chmod(
 }
 
 fn op_open(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -883,7 +881,7 @@ fn op_open(
 }
 
 fn op_close(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -900,7 +898,7 @@ fn op_close(
 }
 
 fn op_shutdown(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -926,7 +924,7 @@ fn op_shutdown(
 }
 
 fn op_read(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -964,7 +962,7 @@ fn op_read(
 }
 
 fn op_write(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1001,7 +999,7 @@ fn op_write(
 }
 
 fn op_seek(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1023,7 +1021,7 @@ fn op_seek(
 }
 
 fn op_remove(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1052,7 +1050,7 @@ fn op_remove(
 }
 
 fn op_copy_file(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1108,7 +1106,7 @@ fn get_mode(_perm: &fs::Permissions) -> u32 {
 }
 
 fn op_cwd(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1134,7 +1132,7 @@ fn op_cwd(
 }
 
 fn op_stat(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1186,7 +1184,7 @@ fn op_stat(
 }
 
 fn op_read_dir(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1247,7 +1245,7 @@ fn op_read_dir(
 }
 
 fn op_rename(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1267,7 +1265,7 @@ fn op_rename(
 }
 
 fn op_link(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1289,7 +1287,7 @@ fn op_link(
 }
 
 fn op_symlink(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1318,7 +1316,7 @@ fn op_symlink(
 }
 
 fn op_read_link(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1356,7 +1354,7 @@ fn op_read_link(
 }
 
 fn op_repl_start(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1387,7 +1385,7 @@ fn op_repl_start(
 }
 
 fn op_repl_readline(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1423,7 +1421,7 @@ fn op_repl_readline(
 }
 
 fn op_truncate(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1446,7 +1444,7 @@ fn op_truncate(
 }
 
 fn op_listen(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1508,7 +1506,7 @@ fn new_conn(cmd_id: u32, tcp_stream: TcpStream) -> OpResult {
 }
 
 fn op_accept(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1534,7 +1532,7 @@ fn op_accept(
 }
 
 fn op_dial(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1560,7 +1558,7 @@ fn op_dial(
 }
 
 fn op_metrics(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1584,7 +1582,7 @@ fn op_metrics(
 }
 
 fn op_resources(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1636,7 +1634,7 @@ fn subprocess_stdio_map(v: msg::ProcessStdio) -> std::process::Stdio {
 }
 
 fn op_run(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1709,7 +1707,7 @@ fn op_run(
 }
 
 fn op_run_status(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1765,7 +1763,7 @@ fn op_run_status(
 }
 
 struct GetMessageFuture {
-  pub state: Arc<IsolateState>,
+  pub state: ThreadSafeState,
 }
 
 impl Future for GetMessageFuture {
@@ -1782,7 +1780,7 @@ impl Future for GetMessageFuture {
 
 /// Get message from host as guest worker
 fn op_worker_get_message(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1817,7 +1815,7 @@ fn op_worker_get_message(
 
 /// Post message to host as guest worker
 fn op_worker_post_message(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1847,7 +1845,7 @@ fn op_worker_post_message(
 
 /// Create worker as the host
 fn op_create_worker(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1859,16 +1857,15 @@ fn op_create_worker(
   Box::new(futures::future::result(move || -> OpResult {
     let parent_state = state.clone();
 
-    let child_state = Arc::new(IsolateState::new(
+    let child_state = ThreadSafeState::new(
       parent_state.flags.clone(),
       parent_state.argv.clone(),
-    ));
+    );
     let rid = child_state.resource.rid;
-    let behavior = CliBehavior::new(child_state);
     let name = format!("USER-WORKER-{}", specifier);
 
     let mut worker =
-      Worker::new(name, startup_data::deno_isolate_init(), behavior);
+      Worker::new(name, startup_data::deno_isolate_init(), child_state);
     js_check(worker.execute("denoMain()"));
     js_check(worker.execute("workerMain()"));
     let result = worker.execute_mod(specifier, false);
@@ -1899,7 +1896,7 @@ fn op_create_worker(
 
 /// Return when the worker closes
 fn op_host_get_worker_closed(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1930,7 +1927,7 @@ fn op_host_get_worker_closed(
 
 /// Get message from guest worker as host
 fn op_host_get_message(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
@@ -1964,7 +1961,7 @@ fn op_host_get_message(
 
 /// Post message to guest worker as host
 fn op_host_post_message(
-  _state: &Arc<IsolateState>,
+  _state: &ThreadSafeState,
   base: &msg::Base<'_>,
   data: deno_buf,
 ) -> Box<OpWithError> {
diff --git a/cli/resources.rs b/cli/resources.rs
index b1689c890..3a7121d4c 100644
--- a/cli/resources.rs
+++ b/cli/resources.rs
@@ -13,8 +13,8 @@ use crate::errors::bad_resource;
 use crate::errors::DenoError;
 use crate::errors::DenoResult;
 use crate::http_body::HttpBody;
-use crate::isolate_state::WorkerChannels;
 use crate::repl::Repl;
+use crate::state::WorkerChannels;
 
 use deno::Buf;
 
diff --git a/cli/isolate_state.rs b/cli/state.rs
index a672f5ee2..09a57d985 100644
--- a/cli/isolate_state.rs
+++ b/cli/state.rs
@@ -4,16 +4,22 @@ use crate::errors::DenoResult;
 use crate::flags;
 use crate::global_timer::GlobalTimer;
 use crate::modules::Modules;
+use crate::ops;
 use crate::permissions::DenoPermissions;
 use crate::resources;
 use crate::resources::ResourceId;
 use crate::worker::Worker;
+use deno::deno_buf;
 use deno::Buf;
+use deno::Dispatch;
+use deno::Op;
 use futures::future::Shared;
 use std;
 use std::collections::HashMap;
 use std::env;
+use std::ops::Deref;
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
 use std::sync::Mutex;
 use std::time::Instant;
 use tokio::sync::mpsc as async_mpsc;
@@ -34,12 +40,15 @@ pub struct Metrics {
   pub resolve_count: AtomicUsize,
 }
 
-// Isolate cannot be passed between threads but IsolateState can.
-// IsolateState satisfies Send and Sync.
+// Wrap State so that it can implement Dispatch.
+pub struct ThreadSafeState(Arc<State>);
+
+// Isolate cannot be passed between threads but ThreadSafeState can.
+// ThreadSafeState satisfies Send and Sync.
 // So any state that needs to be accessed outside the main V8 thread should be
-// inside IsolateState.
+// inside ThreadSafeState.
 #[cfg_attr(feature = "cargo-clippy", allow(stutter))]
-pub struct IsolateState {
+pub struct State {
   pub dir: deno_dir::DenoDir,
   pub argv: Vec<String>,
   pub permissions: DenoPermissions,
@@ -53,7 +62,30 @@ pub struct IsolateState {
   pub resource: resources::Resource,
 }
 
-impl IsolateState {
+impl Clone for ThreadSafeState {
+  fn clone(&self) -> Self {
+    ThreadSafeState(self.0.clone())
+  }
+}
+
+impl Deref for ThreadSafeState {
+  type Target = Arc<State>;
+  fn deref(&self) -> &Self::Target {
+    &self.0
+  }
+}
+
+impl Dispatch for ThreadSafeState {
+  fn dispatch(
+    &mut self,
+    control: &[u8],
+    zero_copy: deno_buf,
+  ) -> (bool, Box<Op>) {
+    ops::dispatch_all(self, control, zero_copy, ops::op_selector_std)
+  }
+}
+
+impl ThreadSafeState {
   pub fn new(flags: flags::DenoFlags, argv_rest: Vec<String>) -> Self {
     let custom_root = env::var("DENO_DIR").map(|s| s.into()).ok();
 
@@ -63,7 +95,7 @@ impl IsolateState {
     let external_channels = (worker_in_tx, worker_out_rx);
     let resource = resources::add_worker(external_channels);
 
-    Self {
+    ThreadSafeState(Arc::new(State {
       dir: deno_dir::DenoDir::new(custom_root).unwrap(),
       argv: argv_rest,
       permissions: DenoPermissions::from_flags(&flags),
@@ -75,7 +107,7 @@ impl IsolateState {
       workers: Mutex::new(UserWorkerTable::new()),
       start_time: Instant::now(),
       resource,
-    }
+    }))
   }
 
   /// Read main module from argv
@@ -121,11 +153,11 @@ impl IsolateState {
   }
 
   #[cfg(test)]
-  pub fn mock() -> IsolateState {
+  pub fn mock() -> ThreadSafeState {
     let argv = vec![String::from("./deno"), String::from("hello.js")];
     // For debugging: argv.push_back(String::from("-D"));
     let (flags, rest_argv) = flags::set_flags(argv).unwrap();
-    IsolateState::new(flags, rest_argv)
+    ThreadSafeState::new(flags, rest_argv)
   }
 
   pub fn metrics_op_dispatched(
@@ -152,3 +184,9 @@ impl IsolateState {
       .fetch_add(bytes_received, Ordering::SeqCst);
   }
 }
+
+#[test]
+fn thread_safe() {
+  fn f<S: Send + Sync>(_: S) {}
+  f(ThreadSafeState::mock());
+}
diff --git a/cli/worker.rs b/cli/worker.rs
index 6609c5005..325ec46eb 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -1,13 +1,12 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
-use crate::cli_behavior::CliBehavior;
 use crate::compiler::compile_async;
 use crate::compiler::ModuleMetaData;
 use crate::errors::DenoError;
 use crate::errors::RustOrJsError;
-use crate::isolate_state::IsolateState;
 use crate::js_errors;
 use crate::js_errors::JSErrorColor;
 use crate::msg;
+use crate::state::ThreadSafeState;
 use crate::tokio_util;
 use deno;
 use deno::deno_mod;
@@ -17,24 +16,23 @@ use futures::future::Either;
 use futures::Async;
 use futures::Future;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 
 /// Wraps deno::Isolate to provide source maps, ops for the CLI, and
 /// high-level module loading
 pub struct Worker {
-  inner: deno::Isolate<CliBehavior>,
-  state: Arc<IsolateState>,
+  inner: deno::Isolate<ThreadSafeState>,
+  state: ThreadSafeState,
 }
 
 impl Worker {
   pub fn new(
     _name: String,
     startup_data: StartupData,
-    behavior: CliBehavior,
+    state: ThreadSafeState,
   ) -> Worker {
-    let state = behavior.state.clone();
+    let state_ = state.clone();
     Self {
-      inner: deno::Isolate::new(startup_data, behavior),
+      inner: deno::Isolate::new(startup_data, state_),
       state,
     }
   }
@@ -107,7 +105,7 @@ impl Worker {
     js_filename: &str,
     is_prefetch: bool,
   ) -> Result<(), RustOrJsError> {
-    // TODO move isolate_state::execute_mod impl here.
+    // TODO move state::execute_mod impl here.
     self
       .execute_mod_inner(js_filename, is_prefetch)
       .map_err(|err| match err {
@@ -204,7 +202,7 @@ impl Future for Worker {
 }
 
 fn fetch_module_meta_data_and_maybe_compile_async(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   specifier: &str,
   referrer: &str,
 ) -> impl Future<Item = ModuleMetaData, Error = DenoError> {
@@ -239,7 +237,7 @@ fn fetch_module_meta_data_and_maybe_compile_async(
 }
 
 fn fetch_module_meta_data_and_maybe_compile(
-  state: &Arc<IsolateState>,
+  state: &ThreadSafeState,
   specifier: &str,
   referrer: &str,
 ) -> Result<ModuleMetaData, DenoError> {
@@ -251,11 +249,10 @@ fn fetch_module_meta_data_and_maybe_compile(
 #[cfg(test)]
 mod tests {
   use super::*;
-  use crate::cli_behavior::CliBehavior;
   use crate::flags;
-  use crate::isolate_state::IsolateState;
   use crate::resources;
   use crate::startup_data;
+  use crate::state::ThreadSafeState;
   use crate::tokio_util;
   use deno::js_check;
   use futures::future::lazy;
@@ -272,11 +269,11 @@ mod tests {
     let argv = vec![String::from("./deno"), filename.clone()];
     let (flags, rest_argv) = flags::set_flags(argv).unwrap();
 
-    let state = Arc::new(IsolateState::new(flags, rest_argv));
+    let state = ThreadSafeState::new(flags, rest_argv);
     let state_ = state.clone();
     tokio_util::run(lazy(move || {
-      let cli = CliBehavior::new(state.clone());
-      let mut worker = Worker::new("TEST".to_string(), StartupData::None, cli);
+      let mut worker =
+        Worker::new("TEST".to_string(), StartupData::None, state);
       if let Err(err) = worker.execute_mod(&filename, false) {
         eprintln!("execute_mod err {:?}", err);
       }
@@ -295,11 +292,11 @@ mod tests {
     let argv = vec![String::from("./deno"), filename.clone()];
     let (flags, rest_argv) = flags::set_flags(argv).unwrap();
 
-    let state = Arc::new(IsolateState::new(flags, rest_argv));
+    let state = ThreadSafeState::new(flags, rest_argv);
     let state_ = state.clone();
     tokio_util::run(lazy(move || {
-      let cli = CliBehavior::new(state.clone());
-      let mut worker = Worker::new("TEST".to_string(), StartupData::None, cli);
+      let mut worker =
+        Worker::new("TEST".to_string(), StartupData::None, state);
       if let Err(err) = worker.execute_mod(&filename, false) {
         eprintln!("execute_mod err {:?}", err);
       }
@@ -311,10 +308,9 @@ mod tests {
   }
 
   fn create_test_worker() -> Worker {
-    let state = Arc::new(IsolateState::mock());
-    let cli = CliBehavior::new(state.clone());
+    let state = ThreadSafeState::mock();
     let mut worker =
-      Worker::new("TEST".to_string(), startup_data::deno_isolate_init(), cli);
+      Worker::new("TEST".to_string(), startup_data::deno_isolate_init(), state);
     js_check(worker.execute("denoMain()"));
     js_check(worker.execute("workerMain()"));
     worker
diff --git a/core/README.md b/core/README.md
index de7bfc3e3..516606961 100644
--- a/core/README.md
+++ b/core/README.md
@@ -4,7 +4,7 @@ This Rust crate contains the essential V8 bindings for Deno's command-line
 interface (Deno CLI). The main abstraction here is the Isolate which proivdes a
 way to execute JavaScript. The Isolate is modeled as a
 `Future<Item=(), Error=JSError>` which completes once all of its ops have
-completed. The user must define what an Op is by implementing the `Behavior`
+completed. The user must define what an Op is by implementing the `Dispatch`
 trait, and by doing so define any "built-in" functionality that would be
 provided by the VM. Ops are triggered by `Deno.core.dispatch()`.
 
diff --git a/core/http_bench.rs b/core/http_bench.rs
index fced92bf8..977432465 100644
--- a/core/http_bench.rs
+++ b/core/http_bench.rs
@@ -98,7 +98,7 @@ pub type HttpBenchOp = dyn Future<Item = i32, Error = std::io::Error> + Send;
 
 struct HttpBench();
 
-impl Behavior for HttpBench {
+impl Dispatch for HttpBench {
   fn dispatch(
     &mut self,
     control: &[u8],
diff --git a/core/isolate.rs b/core/isolate.rs
index 72121889d..0710f94da 100644
--- a/core/isolate.rs
+++ b/core/isolate.rs
@@ -66,10 +66,8 @@ pub enum StartupData<'a> {
   None,
 }
 
-/// Defines the behavior of an Isolate.
-// TODO(ry) Now that Behavior only has the dispatch method, it should be renamed
-// to Dispatcher.
-pub trait Behavior {
+/// Defines the how Deno.core.dispatch() acts.
+pub trait Dispatch {
   /// Called whenever Deno.core.dispatch() is called in JavaScript. zero_copy_buf
   /// corresponds to the second argument of Deno.core.dispatch().
   fn dispatch(
@@ -85,21 +83,21 @@ pub trait Behavior {
 /// pending ops have completed.
 ///
 /// Ops are created in JavaScript by calling Deno.core.dispatch(), and in Rust
-/// by implementing deno::Behavior::dispatch. An Op corresponds exactly to a
+/// by implementing deno::Dispatch::dispatch. An Op corresponds exactly to a
 /// Promise in JavaScript.
-pub struct Isolate<B: Behavior> {
+pub struct Isolate<B: Dispatch> {
   libdeno_isolate: *const libdeno::isolate,
   shared_libdeno_isolate: Arc<Mutex<Option<*const libdeno::isolate>>>,
-  behavior: B,
+  dispatcher: B,
   needs_init: bool,
   shared: SharedQueue,
   pending_ops: VecDeque<PendingOp>,
   polled_recently: bool,
 }
 
-unsafe impl<B: Behavior> Send for Isolate<B> {}
+unsafe impl<B: Dispatch> Send for Isolate<B> {}
 
-impl<B: Behavior> Drop for Isolate<B> {
+impl<B: Dispatch> Drop for Isolate<B> {
   fn drop(&mut self) {
     // remove shared_libdeno_isolate reference
     *self.shared_libdeno_isolate.lock().unwrap() = None;
@@ -110,10 +108,10 @@ impl<B: Behavior> Drop for Isolate<B> {
 
 static DENO_INIT: Once = ONCE_INIT;
 
-impl<B: Behavior> Isolate<B> {
+impl<B: Dispatch> Isolate<B> {
   /// startup_data defines the snapshot or script used at startup to initalize
   /// the isolate.
-  pub fn new(startup_data: StartupData, behavior: B) -> Self {
+  pub fn new(startup_data: StartupData, dispatcher: B) -> Self {
     DENO_INIT.call_once(|| {
       unsafe { libdeno::deno_init() };
     });
@@ -141,7 +139,7 @@ impl<B: Behavior> Isolate<B> {
     let mut core_isolate = Self {
       libdeno_isolate,
       shared_libdeno_isolate: Arc::new(Mutex::new(Some(libdeno_isolate))),
-      behavior,
+      dispatcher,
       shared,
       needs_init,
       pending_ops: VecDeque::new(),
@@ -186,11 +184,11 @@ impl<B: Behavior> Isolate<B> {
     let (is_sync, op) = if control_argv0.len() > 0 {
       // The user called Deno.core.send(control)
       isolate
-        .behavior
+        .dispatcher
         .dispatch(control_argv0.as_ref(), zero_copy_buf)
     } else if let Some(c) = control_shared {
       // The user called Deno.sharedQueue.push(control)
-      isolate.behavior.dispatch(&c, zero_copy_buf)
+      isolate.dispatcher.dispatch(&c, zero_copy_buf)
     } else {
       // The sharedQueue is empty. The shouldn't happen usually, but it's also
       // not technically a failure.
@@ -366,7 +364,7 @@ impl<'a> ResolveContext<'a> {
   }
 }
 
-impl<B: Behavior> Isolate<B> {
+impl<B: Dispatch> Isolate<B> {
   pub fn mod_instantiate(
     &mut self,
     id: deno_mod,
@@ -432,7 +430,7 @@ impl Drop for LockerScope {
   }
 }
 
-impl<B: Behavior> Future for Isolate<B> {
+impl<B: Dispatch> Future for Isolate<B> {
   type Item = ();
   type Error = JSError;
 
@@ -540,7 +538,7 @@ pub mod tests {
   use super::*;
   use std::sync::atomic::{AtomicUsize, Ordering};
 
-  pub enum TestBehaviorMode {
+  pub enum TestDispatchMode {
     AsyncImmediate,
     OverflowReqSync,
     OverflowResSync,
@@ -548,16 +546,16 @@ pub mod tests {
     OverflowResAsync,
   }
 
-  pub struct TestBehavior {
+  pub struct TestDispatch {
     pub dispatch_count: usize,
-    mode: TestBehaviorMode,
+    mode: TestDispatchMode,
   }
 
-  impl TestBehavior {
-    pub fn setup(mode: TestBehaviorMode) -> Isolate<Self> {
+  impl TestDispatch {
+    pub fn setup(mode: TestDispatchMode) -> Isolate<Self> {
       let mut isolate = Isolate::new(
         StartupData::None,
-        TestBehavior {
+        TestDispatch {
           dispatch_count: 0,
           mode,
         },
@@ -572,12 +570,12 @@ pub mod tests {
           }
           "#,
       ));
-      assert_eq!(isolate.behavior.dispatch_count, 0);
+      assert_eq!(isolate.dispatcher.dispatch_count, 0);
       isolate
     }
   }
 
-  impl Behavior for TestBehavior {
+  impl Dispatch for TestDispatch {
     fn dispatch(
       &mut self,
       control: &[u8],
@@ -585,18 +583,18 @@ pub mod tests {
     ) -> (bool, Box<Op>) {
       self.dispatch_count += 1;
       match self.mode {
-        TestBehaviorMode::AsyncImmediate => {
+        TestDispatchMode::AsyncImmediate => {
           assert_eq!(control.len(), 1);
           assert_eq!(control[0], 42);
           let buf = vec![43u8].into_boxed_slice();
           (false, Box::new(futures::future::ok(buf)))
         }
-        TestBehaviorMode::OverflowReqSync => {
+        TestDispatchMode::OverflowReqSync => {
           assert_eq!(control.len(), 100 * 1024 * 1024);
           let buf = vec![43u8].into_boxed_slice();
           (true, Box::new(futures::future::ok(buf)))
         }
-        TestBehaviorMode::OverflowResSync => {
+        TestDispatchMode::OverflowResSync => {
           assert_eq!(control.len(), 1);
           assert_eq!(control[0], 42);
           let mut vec = Vec::<u8>::new();
@@ -605,12 +603,12 @@ pub mod tests {
           let buf = vec.into_boxed_slice();
           (true, Box::new(futures::future::ok(buf)))
         }
-        TestBehaviorMode::OverflowReqAsync => {
+        TestDispatchMode::OverflowReqAsync => {
           assert_eq!(control.len(), 100 * 1024 * 1024);
           let buf = vec![43u8].into_boxed_slice();
           (false, Box::new(futures::future::ok(buf)))
         }
-        TestBehaviorMode::OverflowResAsync => {
+        TestDispatchMode::OverflowResAsync => {
           assert_eq!(control.len(), 1);
           assert_eq!(control[0], 42);
           let mut vec = Vec::<u8>::new();
@@ -625,7 +623,7 @@ pub mod tests {
 
   #[test]
   fn test_dispatch() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
     js_check(isolate.execute(
       "filename.js",
       r#"
@@ -637,12 +635,12 @@ pub mod tests {
         main();
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 2);
+    assert_eq!(isolate.dispatcher.dispatch_count, 2);
   }
 
   #[test]
   fn test_mods() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
     let mod_a = isolate
       .mod_new(
         true,
@@ -654,7 +652,7 @@ pub mod tests {
         Deno.core.send(control);
       "#,
       ).unwrap();
-    assert_eq!(isolate.behavior.dispatch_count, 0);
+    assert_eq!(isolate.dispatcher.dispatch_count, 0);
 
     let imports = isolate.mod_get_imports(mod_a);
     assert_eq!(imports, vec!["b.js".to_string()]);
@@ -675,21 +673,21 @@ pub mod tests {
     };
 
     js_check(isolate.mod_instantiate(mod_b, &mut resolve));
-    assert_eq!(isolate.behavior.dispatch_count, 0);
+    assert_eq!(isolate.dispatcher.dispatch_count, 0);
     assert_eq!(resolve_count.load(Ordering::SeqCst), 0);
 
     js_check(isolate.mod_instantiate(mod_a, &mut resolve));
-    assert_eq!(isolate.behavior.dispatch_count, 0);
+    assert_eq!(isolate.dispatcher.dispatch_count, 0);
     assert_eq!(resolve_count.load(Ordering::SeqCst), 1);
 
     js_check(isolate.mod_evaluate(mod_a));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
     assert_eq!(resolve_count.load(Ordering::SeqCst), 1);
   }
 
   #[test]
   fn test_poll_async_immediate_ops() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
 
     js_check(isolate.execute(
       "setup2.js",
@@ -700,7 +698,7 @@ pub mod tests {
         });
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 0);
+    assert_eq!(isolate.dispatcher.dispatch_count, 0);
     js_check(isolate.execute(
       "check1.js",
       r#"
@@ -710,9 +708,9 @@ pub mod tests {
         assert(nrecv == 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
     js_check(isolate.execute(
       "check2.js",
       r#"
@@ -721,17 +719,17 @@ pub mod tests {
         assert(nrecv == 1);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 2);
+    assert_eq!(isolate.dispatcher.dispatch_count, 2);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
     js_check(isolate.execute("check3.js", "assert(nrecv == 2)"));
-    assert_eq!(isolate.behavior.dispatch_count, 2);
+    assert_eq!(isolate.dispatcher.dispatch_count, 2);
     // We are idle, so the next poll should be the last.
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
   }
 
   #[test]
   fn test_shared() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
 
     js_check(isolate.execute(
       "setup2.js",
@@ -744,7 +742,7 @@ pub mod tests {
         });
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 0);
+    assert_eq!(isolate.dispatcher.dispatch_count, 0);
 
     js_check(isolate.execute(
       "send1.js",
@@ -759,7 +757,7 @@ pub mod tests {
         assert(nrecv === 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 2);
+    assert_eq!(isolate.dispatcher.dispatch_count, 2);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
 
     js_check(isolate.execute("send1.js", "assert(nrecv === 2);"));
@@ -770,7 +768,7 @@ pub mod tests {
     let (tx, rx) = std::sync::mpsc::channel::<bool>();
     let tx_clone = tx.clone();
 
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
     let shared = isolate.shared_isolate_handle();
 
     let t1 = std::thread::spawn(move || {
@@ -827,7 +825,7 @@ pub mod tests {
   fn dangling_shared_isolate() {
     let shared = {
       // isolate is dropped at the end of this block
-      let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+      let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
       isolate.shared_isolate_handle()
     };
 
@@ -837,7 +835,7 @@ pub mod tests {
 
   #[test]
   fn overflow_req_sync() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::OverflowReqSync);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::OverflowReqSync);
     js_check(isolate.execute(
       "overflow_req_sync.js",
       r#"
@@ -852,14 +850,14 @@ pub mod tests {
         assert(asyncRecv == 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
   }
 
   #[test]
   fn overflow_res_sync() {
     // TODO(ry) This test is quite slow due to memcpy-ing 100MB into JS. We
     // should optimize this.
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::OverflowResSync);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::OverflowResSync);
     js_check(isolate.execute(
       "overflow_res_sync.js",
       r#"
@@ -874,12 +872,12 @@ pub mod tests {
         assert(asyncRecv == 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
   }
 
   #[test]
   fn overflow_req_async() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::OverflowReqAsync);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::OverflowReqAsync);
     js_check(isolate.execute(
       "overflow_req_async.js",
       r#"
@@ -897,7 +895,7 @@ pub mod tests {
         assert(asyncRecv == 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
     js_check(isolate.execute("check.js", "assert(asyncRecv == 1);"));
   }
@@ -906,7 +904,7 @@ pub mod tests {
   fn overflow_res_async() {
     // TODO(ry) This test is quite slow due to memcpy-ing 100MB into JS. We
     // should optimize this.
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::OverflowResAsync);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::OverflowResAsync);
     js_check(isolate.execute(
       "overflow_res_async.js",
       r#"
@@ -923,7 +921,7 @@ pub mod tests {
         assert(asyncRecv == 0);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 1);
+    assert_eq!(isolate.dispatcher.dispatch_count, 1);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
     js_check(isolate.execute("check.js", "assert(asyncRecv == 1);"));
   }
@@ -932,7 +930,7 @@ pub mod tests {
   fn overflow_res_multiple_dispatch_async() {
     // TODO(ry) This test is quite slow due to memcpy-ing 100MB into JS. We
     // should optimize this.
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::OverflowResAsync);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::OverflowResAsync);
     js_check(isolate.execute(
       "overflow_res_multiple_dispatch_async.js",
       r#"
@@ -952,14 +950,14 @@ pub mod tests {
         Deno.core.dispatch(control);
         "#,
     ));
-    assert_eq!(isolate.behavior.dispatch_count, 2);
+    assert_eq!(isolate.dispatcher.dispatch_count, 2);
     assert_eq!(Ok(Async::Ready(())), isolate.poll());
     js_check(isolate.execute("check.js", "assert(asyncRecv == 2);"));
   }
 
   #[test]
   fn test_js() {
-    let mut isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+    let mut isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
     js_check(
       isolate
         .execute("shared_queue_test.js", include_str!("shared_queue_test.js")),
diff --git a/core/modules.rs b/core/modules.rs
index b013b8655..7a9b0a3b2 100644
--- a/core/modules.rs
+++ b/core/modules.rs
@@ -18,7 +18,7 @@ use std::collections::HashMap;
 pub type SourceCodeFuture<E> = dyn Future<Item = String, Error = E> + Send;
 
 pub trait Loader {
-  type Behavior: crate::isolate::Behavior;
+  type Dispatch: crate::isolate::Dispatch;
   type Error: std::error::Error + 'static;
 
   /// Returns an absolute URL.
@@ -32,9 +32,9 @@ pub trait Loader {
 
   fn isolate_and_modules<'a: 'b + 'c, 'b, 'c>(
     &'a mut self,
-  ) -> (&'b mut Isolate<Self::Behavior>, &'c mut Modules);
+  ) -> (&'b mut Isolate<Self::Dispatch>, &'c mut Modules);
 
-  fn isolate<'a: 'b, 'b>(&'a mut self) -> &'b mut Isolate<Self::Behavior> {
+  fn isolate<'a: 'b, 'b>(&'a mut self) -> &'b mut Isolate<Self::Dispatch> {
     let (isolate, _) = self.isolate_and_modules();
     isolate
   }
@@ -262,14 +262,14 @@ mod tests {
 
   struct MockLoader {
     pub loads: Vec<String>,
-    pub isolate: Isolate<TestBehavior>,
+    pub isolate: Isolate<TestDispatch>,
     pub modules: Modules,
   }
 
   impl MockLoader {
     fn new() -> Self {
       let modules = Modules::new();
-      let isolate = TestBehavior::setup(TestBehaviorMode::AsyncImmediate);
+      let isolate = TestDispatch::setup(TestDispatchMode::AsyncImmediate);
       Self {
         loads: Vec::new(),
         isolate,
@@ -279,7 +279,7 @@ mod tests {
   }
 
   impl Loader for MockLoader {
-    type Behavior = TestBehavior;
+    type Dispatch = TestDispatch;
     type Error = std::io::Error;
 
     fn resolve(specifier: &str, _referrer: &str) -> String {
@@ -304,7 +304,7 @@ mod tests {
 
     fn isolate_and_modules<'a: 'b + 'c, 'b, 'c>(
       &'a mut self,
-    ) -> (&'b mut Isolate<Self::Behavior>, &'c mut Modules) {
+    ) -> (&'b mut Isolate<Self::Dispatch>, &'c mut Modules) {
       (&mut self.isolate, &mut self.modules)
     }
   }