refactor: rename ThreadSafeState, use RefCell for mutable state (#3931)

* rename ThreadSafeState to State
* State stores InnerState wrapped in Rc and RefCell

30 files changed, 452 insertions, 462 deletions

diff --git a/cli/compilers/compiler_worker.rs b/cli/compilers/compiler_worker.rs
index f76395e75..3252aae02 100644
--- a/cli/compilers/compiler_worker.rs
+++ b/cli/compilers/compiler_worker.rs
@@ -1,6 +1,6 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use crate::ops;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use crate::worker::Worker;
 use deno_core;
 use deno_core::StartupData;
@@ -23,11 +23,7 @@ use std::ops::DerefMut;
 pub struct CompilerWorker(Worker);
 
 impl CompilerWorker {
-  pub fn new(
-    name: String,
-    startup_data: StartupData,
-    state: ThreadSafeState,
-  ) -> Self {
+  pub fn new(name: String, startup_data: StartupData, state: State) -> Self {
     let state_ = state.clone();
     let mut worker = Worker::new(name, startup_data, state_);
     {
diff --git a/cli/compilers/ts.rs b/cli/compilers/ts.rs
index 303c24b6a..91c264345 100644
--- a/cli/compilers/ts.rs
+++ b/cli/compilers/ts.rs
@@ -249,9 +249,8 @@ impl TsCompiler {
   fn setup_worker(global_state: GlobalState) -> CompilerWorker {
     let entry_point =
       ModuleSpecifier::resolve_url_or_path("./__$deno$ts_compiler.ts").unwrap();
-    let worker_state =
-      ThreadSafeState::new(global_state.clone(), None, entry_point)
-        .expect("Unable to create worker state");
+    let worker_state = State::new(global_state.clone(), None, entry_point)
+      .expect("Unable to create worker state");
 
     // Count how many times we start the compiler worker.
     global_state
diff --git a/cli/compilers/wasm.rs b/cli/compilers/wasm.rs
index 6b8da100a..c1c179f62 100644
--- a/cli/compilers/wasm.rs
+++ b/cli/compilers/wasm.rs
@@ -52,9 +52,8 @@ impl WasmCompiler {
     let entry_point =
       ModuleSpecifier::resolve_url_or_path("./__$deno$wasm_compiler.ts")
         .unwrap();
-    let worker_state =
-      ThreadSafeState::new(global_state.clone(), None, entry_point)
-        .expect("Unable to create worker state");
+    let worker_state = State::new(global_state.clone(), None, entry_point)
+      .expect("Unable to create worker state");
 
     // Count how many times we start the compiler worker.
     global_state
diff --git a/cli/import_map.rs b/cli/import_map.rs
index 1a9207288..f9c50345d 100644
--- a/cli/import_map.rs
+++ b/cli/import_map.rs
@@ -38,7 +38,7 @@ const SUPPORTED_FETCH_SCHEMES: [&str; 3] = ["http", "https", "file"];
 type SpecifierMap = IndexMap<String, Vec<ModuleSpecifier>>;
 type ScopesMap = IndexMap<String, SpecifierMap>;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct ImportMap {
   base_url: String,
   imports: SpecifierMap,
diff --git a/cli/lib.rs b/cli/lib.rs
index e752d6f2a..945554434 100644
--- a/cli/lib.rs
+++ b/cli/lib.rs
@@ -61,7 +61,7 @@ use crate::deno_error::js_check;
 use crate::deno_error::{print_err_and_exit, print_msg_and_exit};
 use crate::global_state::GlobalState;
 use crate::ops::io::get_stdio;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use crate::worker::MainWorker;
 use deno_core::v8_set_flags;
 use deno_core::ErrBox;
@@ -107,17 +107,17 @@ fn create_main_worker(
   global_state: GlobalState,
   main_module: ModuleSpecifier,
 ) -> MainWorker {
-  let state = ThreadSafeState::new(global_state, None, main_module)
+  let state = State::new(global_state, None, main_module)
     .map_err(deno_error::print_err_and_exit)
     .unwrap();
 
   let state_ = state.clone();
   {
-    let mut resource_table = state_.lock_resource_table();
+    let mut state = state_.borrow_mut();
     let (stdin, stdout, stderr) = get_stdio();
-    resource_table.add("stdin", Box::new(stdin));
-    resource_table.add("stdout", Box::new(stdout));
-    resource_table.add("stderr", Box::new(stderr));
+    state.resource_table.add("stdin", Box::new(stdin));
+    state.resource_table.add("stdout", Box::new(stdout));
+    state.resource_table.add("stderr", Box::new(stderr));
   }
 
   MainWorker::new("main".to_string(), startup_data::deno_isolate_init(), state)
@@ -157,7 +157,7 @@ async fn print_file_info(
   worker: &MainWorker,
   module_specifier: ModuleSpecifier,
 ) {
-  let global_state = worker.state.global_state.clone();
+  let global_state = worker.state.borrow().global_state.clone();
 
   let maybe_source_file = global_state
     .file_fetcher
diff --git a/cli/ops/compiler.rs b/cli/ops/compiler.rs
index 2934c79ee..cce2f4980 100644
--- a/cli/ops/compiler.rs
+++ b/cli/ops/compiler.rs
@@ -3,11 +3,11 @@ use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::futures::future::try_join_all;
 use crate::msg;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::Loader;
 use deno_core::*;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("cache", s.core_op(json_op(s.stateful_op(op_cache))));
   i.register_op(
     "resolve_modules",
@@ -28,7 +28,7 @@ struct CacheArgs {
 }
 
 fn op_cache(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -37,11 +37,15 @@ fn op_cache(
   let module_specifier = ModuleSpecifier::resolve_url(&args.module_id)
     .expect("Should be valid module specifier");
 
-  state.global_state.ts_compiler.cache_compiler_output(
-    &module_specifier,
-    &args.extension,
-    &args.contents,
-  )?;
+  state
+    .borrow()
+    .global_state
+    .ts_compiler
+    .cache_compiler_output(
+      &module_specifier,
+      &args.extension,
+      &args.contents,
+    )?;
 
   Ok(JsonOp::Sync(json!({})))
 }
@@ -53,7 +57,7 @@ struct SpecifiersReferrerArgs {
 }
 
 fn op_resolve_modules(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -78,7 +82,7 @@ fn op_resolve_modules(
 }
 
 fn op_fetch_source_files(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -93,18 +97,17 @@ fn op_fetch_source_files(
   };
 
   let mut futures = vec![];
+  let global_state = state.borrow().global_state.clone();
+
   for specifier in &args.specifiers {
     let resolved_specifier =
       ModuleSpecifier::resolve_url(&specifier).expect("Invalid specifier");
-    let fut = state
-      .global_state
+    let fut = global_state
       .file_fetcher
       .fetch_source_file_async(&resolved_specifier, ref_specifier.clone());
     futures.push(fut);
   }
 
-  let global_state = state.global_state.clone();
-
   let future = Box::pin(async move {
     let files = try_join_all(futures).await?;
 
diff --git a/cli/ops/errors.rs b/cli/ops/errors.rs
index 14edf9cee..af0d7c93d 100644
--- a/cli/ops/errors.rs
+++ b/cli/ops/errors.rs
@@ -4,11 +4,11 @@ use crate::fmt_errors::JSError;
 use crate::ops::json_op;
 use crate::source_maps::get_orig_position;
 use crate::source_maps::CachedMaps;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use std::collections::HashMap;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "apply_source_map",
     s.core_op(json_op(s.stateful_op(op_apply_source_map))),
@@ -25,12 +25,13 @@ struct FormatErrorArgs {
 }
 
 fn op_format_error(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: FormatErrorArgs = serde_json::from_value(args)?;
-  let error = JSError::from_json(&args.error, &state.global_state.ts_compiler);
+  let error =
+    JSError::from_json(&args.error, &state.borrow().global_state.ts_compiler);
 
   Ok(JsonOp::Sync(json!({
     "error": error.to_string(),
@@ -45,7 +46,7 @@ struct ApplySourceMap {
 }
 
 fn op_apply_source_map(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -57,7 +58,7 @@ fn op_apply_source_map(
     args.line.into(),
     args.column.into(),
     &mut mappings_map,
-    &state.global_state.ts_compiler,
+    &state.borrow().global_state.ts_compiler,
   );
 
   Ok(JsonOp::Sync(json!({
diff --git a/cli/ops/fetch.rs b/cli/ops/fetch.rs
index 7ce3f1a40..f43133d7f 100644
--- a/cli/ops/fetch.rs
+++ b/cli/ops/fetch.rs
@@ -3,7 +3,7 @@ use super::dispatch_json::{Deserialize, JsonOp, Value};
 use super::io::StreamResource;
 use crate::http_util::{create_http_client, HttpBody};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures::future::FutureExt;
 use http::header::HeaderName;
@@ -12,7 +12,7 @@ use http::Method;
 use std;
 use std::convert::From;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("fetch", s.core_op(json_op(s.stateful_op(op_fetch))));
 }
 
@@ -24,7 +24,7 @@ struct FetchArgs {
 }
 
 pub fn op_fetch(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -65,8 +65,8 @@ pub fn op_fetch(
     }
 
     let body = HttpBody::from(res);
-    let mut table = state_.lock_resource_table();
-    let rid = table.add(
+    let mut state = state_.borrow_mut();
+    let rid = state.resource_table.add(
       "httpBody",
       Box::new(StreamResource::HttpBody(Box::new(body))),
     );
diff --git a/cli/ops/files.rs b/cli/ops/files.rs
index f32de90b9..d625d4590 100644
--- a/cli/ops/files.rs
+++ b/cli/ops/files.rs
@@ -6,7 +6,7 @@ use crate::deno_error::DenoError;
 use crate::deno_error::ErrorKind;
 use crate::fs as deno_fs;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures::future::FutureExt;
 use std;
@@ -15,7 +15,7 @@ use std::io::SeekFrom;
 use std::path::Path;
 use tokio;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("open", s.core_op(json_op(s.stateful_op(op_open))));
   i.register_op("close", s.core_op(json_op(s.stateful_op(op_close))));
   i.register_op("seek", s.core_op(json_op(s.stateful_op(op_seek))));
@@ -43,7 +43,7 @@ struct OpenOptions {
 }
 
 fn op_open(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -130,8 +130,10 @@ fn op_open(
 
   let fut = async move {
     let fs_file = open_options.open(filename).await?;
-    let mut table = state_.lock_resource_table();
-    let rid = table.add("fsFile", Box::new(StreamResource::FsFile(fs_file)));
+    let mut state = state_.borrow_mut();
+    let rid = state
+      .resource_table
+      .add("fsFile", Box::new(StreamResource::FsFile(fs_file)));
     Ok(json!(rid))
   };
 
@@ -149,14 +151,17 @@ struct CloseArgs {
 }
 
 fn op_close(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: CloseArgs = serde_json::from_value(args)?;
 
-  let mut table = state.lock_resource_table();
-  table.close(args.rid as u32).ok_or_else(bad_resource)?;
+  let mut state = state.borrow_mut();
+  state
+    .resource_table
+    .close(args.rid as u32)
+    .ok_or_else(bad_resource)?;
   Ok(JsonOp::Sync(json!({})))
 }
 
@@ -170,7 +175,7 @@ struct SeekArgs {
 }
 
 fn op_seek(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -191,13 +196,14 @@ fn op_seek(
     }
   };
 
-  let mut table = state.lock_resource_table();
-  let resource = table
-    .get_mut::<StreamResource>(rid)
+  let state = state.borrow();
+  let resource = state
+    .resource_table
+    .get::<StreamResource>(rid)
     .ok_or_else(bad_resource)?;
 
   let tokio_file = match resource {
-    StreamResource::FsFile(ref mut file) => file,
+    StreamResource::FsFile(ref file) => file,
     _ => return Err(bad_resource()),
   };
   let mut file = futures::executor::block_on(tokio_file.try_clone())?;
diff --git a/cli/ops/fs.rs b/cli/ops/fs.rs
index 1112db495..c9b9f0e31 100644
--- a/cli/ops/fs.rs
+++ b/cli/ops/fs.rs
@@ -6,7 +6,7 @@ use crate::deno_error::ErrorKind;
 use crate::fs as deno_fs;
 use crate::ops::dispatch_json::JsonResult;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use remove_dir_all::remove_dir_all;
 use std::convert::From;
@@ -19,7 +19,7 @@ use std::os::unix::fs::MetadataExt;
 #[cfg(unix)]
 use std::os::unix::fs::PermissionsExt;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("chdir", s.core_op(json_op(s.stateful_op(op_chdir))));
   i.register_op("mkdir", s.core_op(json_op(s.stateful_op(op_mkdir))));
   i.register_op("chmod", s.core_op(json_op(s.stateful_op(op_chmod))));
@@ -48,7 +48,7 @@ struct ChdirArgs {
 }
 
 fn op_chdir(
-  _state: &ThreadSafeState,
+  _state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -67,7 +67,7 @@ struct MkdirArgs {
 }
 
 fn op_mkdir(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -94,7 +94,7 @@ struct ChmodArgs {
 }
 
 fn op_chmod(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -128,7 +128,7 @@ struct ChownArgs {
 }
 
 fn op_chown(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -156,7 +156,7 @@ struct RemoveArgs {
 }
 
 fn op_remove(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -191,7 +191,7 @@ struct CopyFileArgs {
 }
 
 fn op_copy_file(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -290,7 +290,7 @@ struct StatArgs {
 }
 
 fn op_stat(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -320,7 +320,7 @@ struct RealpathArgs {
 }
 
 fn op_realpath(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -352,7 +352,7 @@ struct ReadDirArgs {
 }
 
 fn op_read_dir(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -389,7 +389,7 @@ struct RenameArgs {
 }
 
 fn op_rename(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -418,7 +418,7 @@ struct LinkArgs {
 }
 
 fn op_link(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -446,7 +446,7 @@ struct SymlinkArgs {
 }
 
 fn op_symlink(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -478,7 +478,7 @@ struct ReadLinkArgs {
 }
 
 fn op_read_link(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -506,7 +506,7 @@ struct TruncateArgs {
 }
 
 fn op_truncate(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -535,7 +535,7 @@ struct MakeTempDirArgs {
 }
 
 fn op_make_temp_dir(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -575,7 +575,7 @@ struct Utime {
 }
 
 fn op_utime(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -590,7 +590,7 @@ fn op_utime(
 }
 
 fn op_cwd(
-  _state: &ThreadSafeState,
+  _state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
diff --git a/cli/ops/io.rs b/cli/ops/io.rs
index 9c074b8ba..4128060f1 100644
--- a/cli/ops/io.rs
+++ b/cli/ops/io.rs
@@ -3,7 +3,7 @@ use crate::deno_error;
 use crate::deno_error::bad_resource;
 use crate::http_util::HttpBody;
 use crate::ops::minimal_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::ErrBox;
 use deno_core::*;
 use futures::future::FutureExt;
@@ -47,7 +47,7 @@ lazy_static! {
   };
 }
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "read",
     s.core_op(minimal_op(s.stateful_minimal_op(op_read))),
@@ -131,7 +131,7 @@ enum IoState {
 ///
 /// The returned future will resolve to both the I/O stream and the buffer
 /// as well as the number of bytes read once the read operation is completed.
-pub fn read<T>(state: &ThreadSafeState, rid: ResourceId, buf: T) -> Read<T>
+pub fn read<T>(state: &State, rid: ResourceId, buf: T) -> Read<T>
 where
   T: AsMut<[u8]>,
 {
@@ -151,7 +151,7 @@ pub struct Read<T> {
   rid: ResourceId,
   buf: T,
   io_state: IoState,
-  state: ThreadSafeState,
+  state: State,
 }
 
 impl<T> Future for Read<T>
@@ -166,8 +166,9 @@ where
       panic!("poll a Read after it's done");
     }
 
-    let mut table = inner.state.lock_resource_table();
-    let resource = table
+    let mut state = inner.state.borrow_mut();
+    let resource = state
+      .resource_table
       .get_mut::<StreamResource>(inner.rid)
       .ok_or_else(bad_resource)?;
     let nread = ready!(resource.poll_read(cx, &mut inner.buf.as_mut()[..]))?;
@@ -177,7 +178,7 @@ where
 }
 
 pub fn op_read(
-  state: &ThreadSafeState,
+  state: &State,
   rid: i32,
   zero_copy: Option<ZeroCopyBuf>,
 ) -> Pin<Box<MinimalOp>> {
@@ -257,7 +258,7 @@ pub struct Write<T> {
   rid: ResourceId,
   buf: T,
   io_state: IoState,
-  state: ThreadSafeState,
+  state: State,
   nwritten: i32,
 }
 
@@ -266,7 +267,7 @@ pub struct Write<T> {
 ///
 /// Any error which happens during writing will cause both the stream and the
 /// buffer to get destroyed.
-pub fn write<T>(state: &ThreadSafeState, rid: ResourceId, buf: T) -> Write<T>
+pub fn write<T>(state: &State, rid: ResourceId, buf: T) -> Write<T>
 where
   T: AsRef<[u8]>,
 {
@@ -294,8 +295,9 @@ where
     }
 
     if inner.io_state == IoState::Pending {
-      let mut table = inner.state.lock_resource_table();
-      let resource = table
+      let mut state = inner.state.borrow_mut();
+      let resource = state
+        .resource_table
         .get_mut::<StreamResource>(inner.rid)
         .ok_or_else(bad_resource)?;
 
@@ -309,8 +311,9 @@ where
     // Figure out why it's needed and preferably remove it.
     // https://github.com/denoland/deno/issues/3565
     if inner.io_state == IoState::Flush {
-      let mut table = inner.state.lock_resource_table();
-      let resource = table
+      let mut state = inner.state.borrow_mut();
+      let resource = state
+        .resource_table
         .get_mut::<StreamResource>(inner.rid)
         .ok_or_else(bad_resource)?;
       ready!(resource.poll_flush(cx))?;
@@ -322,7 +325,7 @@ where
 }
 
 pub fn op_write(
-  state: &ThreadSafeState,
+  state: &State,
   rid: i32,
   zero_copy: Option<ZeroCopyBuf>,
 ) -> Pin<Box<MinimalOp>> {
diff --git a/cli/ops/net.rs b/cli/ops/net.rs
index 5b35d9287..569aebca0 100644
--- a/cli/ops/net.rs
+++ b/cli/ops/net.rs
@@ -4,7 +4,7 @@ use super::io::StreamResource;
 use crate::deno_error::bad_resource;
 use crate::ops::json_op;
 use crate::resolve_addr::resolve_addr;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures::future::FutureExt;
 use std;
@@ -19,7 +19,7 @@ use tokio;
 use tokio::net::TcpListener;
 use tokio::net::TcpStream;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("accept", s.core_op(json_op(s.stateful_op(op_accept))));
   i.register_op("connect", s.core_op(json_op(s.stateful_op(op_connect))));
   i.register_op("shutdown", s.core_op(json_op(s.stateful_op(op_shutdown))));
@@ -33,7 +33,7 @@ enum AcceptState {
 }
 
 /// Simply accepts a connection.
-pub fn accept(state: &ThreadSafeState, rid: ResourceId) -> Accept {
+pub fn accept(state: &State, rid: ResourceId) -> Accept {
   Accept {
     accept_state: AcceptState::Pending,
     rid,
@@ -45,7 +45,7 @@ pub fn accept(state: &ThreadSafeState, rid: ResourceId) -> Accept {
 pub struct Accept<'a> {
   accept_state: AcceptState,
   rid: ResourceId,
-  state: &'a ThreadSafeState,
+  state: &'a State,
 }
 
 impl Future for Accept<'_> {
@@ -57,8 +57,9 @@ impl Future for Accept<'_> {
       panic!("poll Accept after it's done");
     }
 
-    let mut table = inner.state.lock_resource_table();
-    let listener_resource = table
+    let mut state = inner.state.borrow_mut();
+    let listener_resource = state
+      .resource_table
       .get_mut::<TcpListenerResource>(inner.rid)
       .ok_or_else(|| {
         let e = std::io::Error::new(
@@ -95,25 +96,29 @@ struct AcceptArgs {
 }
 
 fn op_accept(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: AcceptArgs = serde_json::from_value(args)?;
   let rid = args.rid as u32;
   let state_ = state.clone();
-  let table = state.lock_resource_table();
-  table
-    .get::<TcpListenerResource>(rid)
-    .ok_or_else(bad_resource)?;
+  {
+    let state = state.borrow();
+    state
+      .resource_table
+      .get::<TcpListenerResource>(rid)
+      .ok_or_else(bad_resource)?;
+  }
 
   let op = async move {
     let (tcp_stream, _socket_addr) = accept(&state_, rid).await?;
     let local_addr = tcp_stream.local_addr()?;
     let remote_addr = tcp_stream.peer_addr()?;
-    let mut table = state_.lock_resource_table();
-    let rid =
-      table.add("tcpStream", Box::new(StreamResource::TcpStream(tcp_stream)));
+    let mut state = state_.borrow_mut();
+    let rid = state
+      .resource_table
+      .add("tcpStream", Box::new(StreamResource::TcpStream(tcp_stream)));
     Ok(json!({
       "rid": rid,
       "localAddr": {
@@ -140,7 +145,7 @@ struct ConnectArgs {
 }
 
 fn op_connect(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -154,9 +159,10 @@ fn op_connect(
     let tcp_stream = TcpStream::connect(&addr).await?;
     let local_addr = tcp_stream.local_addr()?;
     let remote_addr = tcp_stream.peer_addr()?;
-    let mut table = state_.lock_resource_table();
-    let rid =
-      table.add("tcpStream", Box::new(StreamResource::TcpStream(tcp_stream)));
+    let mut state = state_.borrow_mut();
+    let rid = state
+      .resource_table
+      .add("tcpStream", Box::new(StreamResource::TcpStream(tcp_stream)));
     Ok(json!({
       "rid": rid,
       "localAddr": {
@@ -182,7 +188,7 @@ struct ShutdownArgs {
 }
 
 fn op_shutdown(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -197,8 +203,9 @@ fn op_shutdown(
     _ => unimplemented!(),
   };
 
-  let mut table = state.lock_resource_table();
-  let resource = table
+  let mut state = state.borrow_mut();
+  let resource = state
+    .resource_table
     .get_mut::<StreamResource>(rid)
     .ok_or_else(bad_resource)?;
   match resource {
@@ -272,7 +279,7 @@ impl TcpListenerResource {
 }
 
 fn op_listen(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -290,8 +297,10 @@ fn op_listen(
     waker: None,
     local_addr,
   };
-  let mut table = state.lock_resource_table();
-  let rid = table.add("tcpListener", Box::new(listener_resource));
+  let mut state = state.borrow_mut();
+  let rid = state
+    .resource_table
+    .add("tcpListener", Box::new(listener_resource));
   debug!(
     "New listener {} {}:{}",
     rid,
diff --git a/cli/ops/os.rs b/cli/ops/os.rs
index ce2320d92..8def5ac1e 100644
--- a/cli/ops/os.rs
+++ b/cli/ops/os.rs
@@ -1,7 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use atty;
 use deno_core::*;
 use std::collections::HashMap;
@@ -10,7 +10,7 @@ use std::io::{Error, ErrorKind};
 use sys_info;
 use url::Url;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("exit", s.core_op(json_op(s.stateful_op(op_exit))));
   i.register_op("is_tty", s.core_op(json_op(s.stateful_op(op_is_tty))));
   i.register_op("env", s.core_op(json_op(s.stateful_op(op_env))));
@@ -27,7 +27,7 @@ struct GetDirArgs {
 }
 
 fn op_get_dir(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -73,7 +73,7 @@ fn op_get_dir(
 }
 
 fn op_exec_path(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -93,7 +93,7 @@ struct SetEnv {
 }
 
 fn op_set_env(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -104,7 +104,7 @@ fn op_set_env(
 }
 
 fn op_env(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -119,7 +119,7 @@ struct GetEnv {
 }
 
 fn op_get_env(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -138,7 +138,7 @@ struct Exit {
 }
 
 fn op_exit(
-  _s: &ThreadSafeState,
+  _s: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -147,7 +147,7 @@ fn op_exit(
 }
 
 fn op_is_tty(
-  _s: &ThreadSafeState,
+  _s: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -159,7 +159,7 @@ fn op_is_tty(
 }
 
 fn op_hostname(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
diff --git a/cli/ops/permissions.rs b/cli/ops/permissions.rs
index 39d49c32f..7c7cb682c 100644
--- a/cli/ops/permissions.rs
+++ b/cli/ops/permissions.rs
@@ -3,11 +3,11 @@ use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::deno_error::other_error;
 use crate::fs as deno_fs;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use std::path::Path;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "query_permission",
     s.core_op(json_op(s.stateful_op(op_query_permission))),
@@ -38,14 +38,14 @@ fn resolve_path(path: &str) -> String {
 }
 
 pub fn op_query_permission(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: PermissionArgs = serde_json::from_value(args)?;
-  let permissions = state.permissions.lock().unwrap();
+  let state = state.borrow();
   let resolved_path = args.path.as_ref().map(String::as_str).map(resolve_path);
-  let perm = permissions.get_permission_state(
+  let perm = state.permissions.get_permission_state(
     &args.name,
     &args.url.as_ref().map(String::as_str),
     &resolved_path.as_ref().map(String::as_str).map(Path::new),
@@ -54,12 +54,13 @@ pub fn op_query_permission(
 }
 
 pub fn op_revoke_permission(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: PermissionArgs = serde_json::from_value(args)?;
-  let mut permissions = state.permissions.lock().unwrap();
+  let mut state = state.borrow_mut();
+  let permissions = &mut state.permissions;
   match args.name.as_ref() {
     "run" => permissions.allow_run.revoke(),
     "read" => permissions.allow_read.revoke(),
@@ -80,12 +81,13 @@ pub fn op_revoke_permission(
 }
 
 pub fn op_request_permission(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: PermissionArgs = serde_json::from_value(args)?;
-  let mut permissions = state.permissions.lock().unwrap();
+  let mut state = state.borrow_mut();
+  let permissions = &mut state.permissions;
   let resolved_path = args.path.as_ref().map(String::as_str).map(resolve_path);
   let perm = match args.name.as_ref() {
     "run" => Ok(permissions.request_run()),
diff --git a/cli/ops/plugins.rs b/cli/ops/plugins.rs
index 24a59917e..ecaa66b53 100644
--- a/cli/ops/plugins.rs
+++ b/cli/ops/plugins.rs
@@ -1,7 +1,7 @@
 use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::fs as deno_fs;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use dlopen::symbor::Library;
 use std::collections::HashMap;
@@ -9,11 +9,7 @@ use std::ffi::OsStr;
 use std::path::Path;
 use std::sync::Arc;
 
-pub fn init(
-  i: &mut Isolate,
-  s: &ThreadSafeState,
-  r: Arc<deno_core::OpRegistry>,
-) {
+pub fn init(i: &mut Isolate, s: &State, r: Arc<deno_core::OpRegistry>) {
   let r_ = r;
   i.register_op(
     "open_plugin",
@@ -56,7 +52,7 @@ struct OpenPluginArgs {
 
 pub fn op_open_plugin(
   registry: &Arc<deno_core::OpRegistry>,
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -70,9 +66,14 @@ pub fn op_open_plugin(
     lib,
     ops: HashMap::new(),
   };
-  let mut table = state.lock_resource_table();
-  let rid = table.add("plugin", Box::new(plugin_resource));
-  let plugin_resource = table.get_mut::<PluginResource>(rid).unwrap();
+  let mut state_ = state.borrow_mut();
+  let rid = state_
+    .resource_table
+    .add("plugin", Box::new(plugin_resource));
+  let plugin_resource = state_
+    .resource_table
+    .get_mut::<PluginResource>(rid)
+    .unwrap();
 
   let init_fn = *unsafe {
     plugin_resource
diff --git a/cli/ops/process.rs b/cli/ops/process.rs
index 1ffd6b78e..e93bcbc0f 100644
--- a/cli/ops/process.rs
+++ b/cli/ops/process.rs
@@ -4,12 +4,11 @@ use super::io::StreamResource;
 use crate::deno_error::bad_resource;
 use crate::ops::json_op;
 use crate::signal::kill;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures;
 use futures::future::FutureExt;
 use futures::future::TryFutureExt;
-use futures::task::SpawnExt;
 use std;
 use std::convert::From;
 use std::future::Future;
@@ -22,7 +21,7 @@ use tokio::process::Command;
 #[cfg(unix)]
 use std::os::unix::process::ExitStatusExt;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("run", s.core_op(json_op(s.stateful_op(op_run))));
   i.register_op(
     "run_status",
@@ -31,12 +30,10 @@ pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
   i.register_op("kill", s.core_op(json_op(s.stateful_op(op_kill))));
 }
 
-fn clone_file(
-  rid: u32,
-  state: &ThreadSafeState,
-) -> Result<std::fs::File, ErrBox> {
-  let mut table = state.lock_resource_table();
-  let repr = table
+fn clone_file(rid: u32, state: &State) -> Result<std::fs::File, ErrBox> {
+  let mut state = state.borrow_mut();
+  let repr = state
+    .resource_table
     .get_mut::<StreamResource>(rid)
     .ok_or_else(bad_resource)?;
   let file = match repr {
@@ -76,7 +73,7 @@ struct ChildResource {
 }
 
 fn op_run(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -131,7 +128,8 @@ fn op_run(
   let mut child = c.spawn()?;
   let pid = child.id();
 
-  let mut table = state_.lock_resource_table();
+  let mut state = state_.borrow_mut();
+  let table = &mut state.resource_table;
 
   let stdin_rid = match child.stdin.take() {
     Some(child_stdin) => {
@@ -180,7 +178,7 @@ fn op_run(
 
 pub struct ChildStatus {
   rid: ResourceId,
-  state: ThreadSafeState,
+  state: State,
 }
 
 impl Future for ChildStatus {
@@ -188,8 +186,9 @@ impl Future for ChildStatus {
 
   fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
     let inner = self.get_mut();
-    let mut table = inner.state.lock_resource_table();
-    let child_resource = table
+    let mut state = inner.state.borrow_mut();
+    let child_resource = state
+      .resource_table
       .get_mut::<ChildResource>(inner.rid)
       .ok_or_else(bad_resource)?;
     let child = &mut child_resource.child;
@@ -204,7 +203,7 @@ struct RunStatusArgs {
 }
 
 fn op_run_status(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -239,10 +238,7 @@ fn op_run_status(
     }))
   };
 
-  let pool = futures::executor::ThreadPool::new().unwrap();
-  let handle = pool.spawn_with_handle(future).unwrap();
-
-  Ok(JsonOp::Async(handle.boxed()))
+  Ok(JsonOp::Async(future.boxed_local()))
 }
 
 #[derive(Deserialize)]
@@ -252,7 +248,7 @@ struct KillArgs {
 }
 
 fn op_kill(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
diff --git a/cli/ops/random.rs b/cli/ops/random.rs
index 950e9c7f0..3c570090b 100644
--- a/cli/ops/random.rs
+++ b/cli/ops/random.rs
@@ -1,12 +1,12 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use super::dispatch_json::{JsonOp, Value};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use rand::thread_rng;
 use rand::Rng;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "get_random_values",
     s.core_op(json_op(s.stateful_op(op_get_random_values))),
@@ -14,15 +14,14 @@ pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
 }
 
 fn op_get_random_values(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   assert!(zero_copy.is_some());
 
-  if let Some(ref seeded_rng) = state.seeded_rng {
-    let mut rng = seeded_rng.lock().unwrap();
-    rng.fill(&mut zero_copy.unwrap()[..]);
+  if let Some(ref mut seeded_rng) = state.borrow_mut().seeded_rng {
+    seeded_rng.fill(&mut zero_copy.unwrap()[..]);
   } else {
     let mut rng = thread_rng();
     rng.fill(&mut zero_copy.unwrap()[..]);
diff --git a/cli/ops/repl.rs b/cli/ops/repl.rs
index 9b47f262a..d7c94a56e 100644
--- a/cli/ops/repl.rs
+++ b/cli/ops/repl.rs
@@ -4,12 +4,12 @@ use crate::deno_error::bad_resource;
 use crate::ops::json_op;
 use crate::repl;
 use crate::repl::Repl;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use std::sync::Arc;
 use std::sync::Mutex;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "repl_start",
     s.core_op(json_op(s.stateful_op(op_repl_start))),
@@ -29,7 +29,7 @@ struct ReplStartArgs {
 }
 
 fn op_repl_start(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -37,11 +37,11 @@ fn op_repl_start(
 
   debug!("op_repl_start {}", args.history_file);
   let history_path =
-    repl::history_path(&state.global_state.dir, &args.history_file);
+    repl::history_path(&state.borrow().global_state.dir, &args.history_file);
   let repl = repl::Repl::new(history_path);
+  let mut state = state.borrow_mut();
   let resource = ReplResource(Arc::new(Mutex::new(repl)));
-  let mut table = state.lock_resource_table();
-  let rid = table.add("repl", Box::new(resource));
+  let rid = state.resource_table.add("repl", Box::new(resource));
   Ok(JsonOp::Sync(json!(rid)))
 }
 
@@ -52,7 +52,7 @@ struct ReplReadlineArgs {
 }
 
 fn op_repl_readline(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -60,12 +60,14 @@ fn op_repl_readline(
   let rid = args.rid as u32;
   let prompt = args.prompt;
   debug!("op_repl_readline {} {}", rid, prompt);
-  let state = state.clone();
+  let state = state.borrow();
+  let resource = state
+    .resource_table
+    .get::<ReplResource>(rid)
+    .ok_or_else(bad_resource)?;
+  let repl = resource.0.clone();
 
   blocking_json(false, move || {
-    let table = state.lock_resource_table();
-    let resource = table.get::<ReplResource>(rid).ok_or_else(bad_resource)?;
-    let repl = resource.0.clone();
     let line = repl.lock().unwrap().readline(&prompt)?;
     Ok(json!(line))
   })
diff --git a/cli/ops/resources.rs b/cli/ops/resources.rs
index 447082f80..1fef4a530 100644
--- a/cli/ops/resources.rs
+++ b/cli/ops/resources.rs
@@ -1,19 +1,19 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use super::dispatch_json::{JsonOp, Value};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("resources", s.core_op(json_op(s.stateful_op(op_resources))));
 }
 
 fn op_resources(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
-  let resource_table = state.lock_resource_table();
-  let serialized_resources = resource_table.entries();
+  let state = state.borrow();
+  let serialized_resources = state.resource_table.entries();
   Ok(JsonOp::Sync(json!(serialized_resources)))
 }
diff --git a/cli/ops/runtime.rs b/cli/ops/runtime.rs
index 210bbfcf6..a962f4e83 100644
--- a/cli/ops/runtime.rs
+++ b/cli/ops/runtime.rs
@@ -3,7 +3,7 @@ use super::dispatch_json::{JsonOp, Value};
 use crate::colors;
 use crate::fs as deno_fs;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use crate::version;
 use crate::DenoSubcommand;
 use deno_core::*;
@@ -19,15 +19,16 @@ static BUILD_OS: &str = "win";
 #[cfg(target_arch = "x86_64")]
 static BUILD_ARCH: &str = "x64";
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("start", s.core_op(json_op(s.stateful_op(op_start))));
 }
 
 fn op_start(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
+  let state = state.borrow();
   let gs = &state.global_state;
 
   Ok(JsonOp::Sync(json!({
diff --git a/cli/ops/runtime_compiler.rs b/cli/ops/runtime_compiler.rs
index 0cdc1094e..9cfda013b 100644
--- a/cli/ops/runtime_compiler.rs
+++ b/cli/ops/runtime_compiler.rs
@@ -3,11 +3,11 @@ use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::compilers::runtime_compile_async;
 use crate::compilers::runtime_transpile_async;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use std::collections::HashMap;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("compile", s.core_op(json_op(s.stateful_op(op_compile))));
   i.register_op("transpile", s.core_op(json_op(s.stateful_op(op_transpile))));
 }
@@ -22,13 +22,13 @@ struct CompileArgs {
 }
 
 fn op_compile(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: CompileArgs = serde_json::from_value(args)?;
   Ok(JsonOp::Async(runtime_compile_async(
-    state.global_state.clone(),
+    state.borrow().global_state.clone(),
     &args.root_name,
     &args.sources,
     args.bundle,
@@ -43,13 +43,13 @@ struct TranspileArgs {
 }
 
 fn op_transpile(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: TranspileArgs = serde_json::from_value(args)?;
   Ok(JsonOp::Async(runtime_transpile_async(
-    state.global_state.clone(),
+    state.borrow().global_state.clone(),
     &args.sources,
     &args.options,
   )))
diff --git a/cli/ops/signal.rs b/cli/ops/signal.rs
index f815cb57c..8d70f9fe8 100644
--- a/cli/ops/signal.rs
+++ b/cli/ops/signal.rs
@@ -1,7 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use super::dispatch_json::{JsonOp, Value};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 
 #[cfg(unix)]
@@ -17,7 +17,7 @@ use std::task::Waker;
 #[cfg(unix)]
 use tokio::signal::unix::{signal, Signal, SignalKind};
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "signal_bind",
     s.core_op(json_op(s.stateful_op(op_signal_bind))),
@@ -51,13 +51,13 @@ struct SignalArgs {
 
 #[cfg(unix)]
 fn op_signal_bind(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: BindSignalArgs = serde_json::from_value(args)?;
-  let mut table = state.lock_resource_table();
-  let rid = table.add(
+  let mut state = state.borrow_mut();
+  let rid = state.resource_table.add(
     "signal",
     Box::new(SignalStreamResource(
       signal(SignalKind::from_raw(args.signo)).expect(""),
@@ -71,7 +71,7 @@ fn op_signal_bind(
 
 #[cfg(unix)]
 fn op_signal_poll(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -80,8 +80,10 @@ fn op_signal_poll(
   let state_ = state.clone();
 
   let future = poll_fn(move |cx| {
-    let mut table = state_.lock_resource_table();
-    if let Some(mut signal) = table.get_mut::<SignalStreamResource>(rid) {
+    let mut state = state_.borrow_mut();
+    if let Some(mut signal) =
+      state.resource_table.get_mut::<SignalStreamResource>(rid)
+    {
       signal.1 = Some(cx.waker().clone());
       return signal.0.poll_recv(cx);
     }
@@ -94,14 +96,14 @@ fn op_signal_poll(
 
 #[cfg(unix)]
 pub fn op_signal_unbind(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: SignalArgs = serde_json::from_value(args)?;
   let rid = args.rid as u32;
-  let mut table = state.lock_resource_table();
-  let resource = table.get::<SignalStreamResource>(rid);
+  let mut state = state.borrow_mut();
+  let resource = state.resource_table.get::<SignalStreamResource>(rid);
   if let Some(signal) = resource {
     if let Some(waker) = &signal.1 {
       // Wakes up the pending poll if exists.
@@ -109,13 +111,13 @@ pub fn op_signal_unbind(
       waker.clone().wake();
     }
   }
-  table.close(rid).ok_or_else(bad_resource)?;
+  state.resource_table.close(rid).ok_or_else(bad_resource)?;
   Ok(JsonOp::Sync(json!({})))
 }
 
 #[cfg(not(unix))]
 pub fn op_signal_bind(
-  _state: &ThreadSafeState,
+  _state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -124,7 +126,7 @@ pub fn op_signal_bind(
 
 #[cfg(not(unix))]
 fn op_signal_unbind(
-  _state: &ThreadSafeState,
+  _state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -133,7 +135,7 @@ fn op_signal_unbind(
 
 #[cfg(not(unix))]
 fn op_signal_poll(
-  _state: &ThreadSafeState,
+  _state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
diff --git a/cli/ops/timers.rs b/cli/ops/timers.rs
index 75b53518c..ebcbcd706 100644
--- a/cli/ops/timers.rs
+++ b/cli/ops/timers.rs
@@ -1,14 +1,14 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use super::dispatch_json::{Deserialize, JsonOp, Value};
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures::future::FutureExt;
 use std;
 use std::time::Duration;
 use std::time::Instant;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "global_timer_stop",
     s.core_op(json_op(s.stateful_op(op_global_timer_stop))),
@@ -21,13 +21,12 @@ pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
 }
 
 fn op_global_timer_stop(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
-  let state = state;
-  let mut t = state.global_timer.lock().unwrap();
-  t.cancel();
+  let mut state = state.borrow_mut();
+  state.global_timer.cancel();
   Ok(JsonOp::Sync(json!({})))
 }
 
@@ -37,17 +36,17 @@ struct GlobalTimerArgs {
 }
 
 fn op_global_timer(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: GlobalTimerArgs = serde_json::from_value(args)?;
   let val = args.timeout;
 
-  let state = state;
-  let mut t = state.global_timer.lock().unwrap();
+  let mut state = state.borrow_mut();
   let deadline = Instant::now() + Duration::from_millis(val);
-  let f = t
+  let f = state
+    .global_timer
     .new_timeout(deadline)
     .then(move |_| futures::future::ok(json!({})));
 
@@ -59,19 +58,19 @@ fn op_global_timer(
 // If the High precision flag is not set, the
 // nanoseconds are rounded on 2ms.
 fn op_now(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
+  let state = state.borrow();
   let seconds = state.start_time.elapsed().as_secs();
   let mut subsec_nanos = state.start_time.elapsed().subsec_nanos();
   let reduced_time_precision = 2_000_000; // 2ms in nanoseconds
-  let permissions = state.permissions.lock().unwrap();
 
   // If the permission is not enabled
   // Round the nano result on 2 milliseconds
   // see: https://developer.mozilla.org/en-US/docs/Web/API/DOMHighResTimeStamp#Reduced_time_precision
-  if !permissions.allow_hrtime.is_allow() {
+  if !state.permissions.allow_hrtime.is_allow() {
     subsec_nanos -= subsec_nanos % reduced_time_precision
   }
 
diff --git a/cli/ops/tls.rs b/cli/ops/tls.rs
index 45b2f2d38..6dbe99c85 100644
--- a/cli/ops/tls.rs
+++ b/cli/ops/tls.rs
@@ -6,7 +6,7 @@ use crate::deno_error::DenoError;
 use crate::deno_error::ErrorKind;
 use crate::ops::json_op;
 use crate::resolve_addr::resolve_addr;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures::future::FutureExt;
 use std;
@@ -35,7 +35,7 @@ use webpki;
 use webpki::DNSNameRef;
 use webpki_roots;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "connect_tls",
     s.core_op(json_op(s.stateful_op(op_connect_tls))),
@@ -60,7 +60,7 @@ struct ConnectTLSArgs {
 }
 
 pub fn op_connect_tls(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -95,8 +95,8 @@ pub fn op_connect_tls(
     let dnsname =
       DNSNameRef::try_from_ascii_str(&domain).expect("Invalid DNS lookup");
     let tls_stream = tls_connector.connect(dnsname, tcp_stream).await?;
-    let mut table = state_.lock_resource_table();
-    let rid = table.add(
+    let mut state = state_.borrow_mut();
+    let rid = state.resource_table.add(
       "clientTlsStream",
       Box::new(StreamResource::ClientTlsStream(Box::new(tls_stream))),
     );
@@ -241,7 +241,7 @@ struct ListenTlsArgs {
 }
 
 fn op_listen_tls(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -270,8 +270,10 @@ fn op_listen_tls(
     waker: None,
     local_addr,
   };
-  let mut table = state.lock_resource_table();
-  let rid = table.add("tlsListener", Box::new(tls_listener_resource));
+  let mut state = state.borrow_mut();
+  let rid = state
+    .resource_table
+    .add("tlsListener", Box::new(tls_listener_resource));
 
   Ok(JsonOp::Sync(json!({
     "rid": rid,
@@ -290,7 +292,7 @@ enum AcceptTlsState {
 }
 
 /// Simply accepts a TLS connection.
-pub fn accept_tls(state: &ThreadSafeState, rid: ResourceId) -> AcceptTls {
+pub fn accept_tls(state: &State, rid: ResourceId) -> AcceptTls {
   AcceptTls {
     accept_state: AcceptTlsState::Pending,
     rid,
@@ -302,7 +304,7 @@ pub fn accept_tls(state: &ThreadSafeState, rid: ResourceId) -> AcceptTls {
 pub struct AcceptTls {
   accept_state: AcceptTlsState,
   rid: ResourceId,
-  state: ThreadSafeState,
+  state: State,
 }
 
 impl Future for AcceptTls {
@@ -314,8 +316,9 @@ impl Future for AcceptTls {
       panic!("poll AcceptTls after it's done");
     }
 
-    let mut table = inner.state.lock_resource_table();
-    let listener_resource = table
+    let mut state = inner.state.borrow_mut();
+    let listener_resource = state
+      .resource_table
       .get_mut::<TlsListenerResource>(inner.rid)
       .ok_or_else(|| {
         let e = std::io::Error::new(
@@ -352,7 +355,7 @@ struct AcceptTlsArgs {
 }
 
 fn op_accept_tls(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -364,8 +367,9 @@ fn op_accept_tls(
     let local_addr = tcp_stream.local_addr()?;
     let remote_addr = tcp_stream.peer_addr()?;
     let tls_acceptor = {
-      let table = state.lock_resource_table();
-      let resource = table
+      let state = state.borrow();
+      let resource = state
+        .resource_table
         .get::<TlsListenerResource>(rid)
         .ok_or_else(bad_resource)
         .expect("Can't find tls listener");
@@ -373,8 +377,8 @@ fn op_accept_tls(
     };
     let tls_stream = tls_acceptor.accept(tcp_stream).await?;
     let rid = {
-      let mut table = state.lock_resource_table();
-      table.add(
+      let mut state = state.borrow_mut();
+      state.resource_table.add(
         "serverTlsStream",
         Box::new(StreamResource::ServerTlsStream(Box::new(tls_stream))),
       )
diff --git a/cli/ops/web_worker.rs b/cli/ops/web_worker.rs
index 7bfc70a84..ae6b10abc 100644
--- a/cli/ops/web_worker.rs
+++ b/cli/ops/web_worker.rs
@@ -3,14 +3,14 @@ use super::dispatch_json::{JsonOp, Value};
 use crate::deno_error::DenoError;
 use crate::deno_error::ErrorKind;
 use crate::ops::json_op;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core::*;
 use futures;
 use futures::future::FutureExt;
 use std;
 use std::convert::From;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "worker_post_message",
     s.core_op(json_op(s.stateful_op(op_worker_post_message))),
@@ -23,14 +23,21 @@ pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
 
 /// Get message from host as guest worker
 fn op_worker_get_message(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let state_ = state.clone();
   let op = async move {
-    let c = state_.worker_channels_internal.lock().unwrap();
-    let maybe_buf = c.as_ref().unwrap().get_message().await;
+    let fut = {
+      let state = state_.borrow();
+      state
+        .worker_channels_internal
+        .as_ref()
+        .unwrap()
+        .get_message()
+    };
+    let maybe_buf = fut.await;
     debug!("op_worker_get_message");
     Ok(json!({ "data": maybe_buf }))
   };
@@ -40,13 +47,17 @@ fn op_worker_get_message(
 
 /// Post message to host as guest worker
 fn op_worker_post_message(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let d = Vec::from(data.unwrap().as_ref()).into_boxed_slice();
-  let c = state.worker_channels_internal.lock().unwrap();
-  let fut = c.as_ref().unwrap().post_message(d);
+  let state = state.borrow();
+  let fut = state
+    .worker_channels_internal
+    .as_ref()
+    .unwrap()
+    .post_message(d);
   futures::executor::block_on(fut)
     .map_err(|e| DenoError::new(ErrorKind::Other, e.to_string()))?;
 
diff --git a/cli/ops/worker_host.rs b/cli/ops/worker_host.rs
index f8b3edfce..fabe0b5e8 100644
--- a/cli/ops/worker_host.rs
+++ b/cli/ops/worker_host.rs
@@ -4,11 +4,11 @@ use crate::deno_error::bad_resource;
 use crate::deno_error::js_check;
 use crate::deno_error::DenoError;
 use crate::deno_error::ErrorKind;
-use crate::ops::dispatch_json::JsonResult;
 use crate::ops::json_op;
 use crate::startup_data;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use crate::web_worker::WebWorker;
+use crate::worker::WorkerChannelsExternal;
 use deno_core::*;
 use futures;
 use futures::future::FutureExt;
@@ -17,7 +17,7 @@ use std;
 use std::convert::From;
 use std::sync::atomic::Ordering;
 
-pub fn init(i: &mut Isolate, s: &ThreadSafeState) {
+pub fn init(i: &mut Isolate, s: &State) {
   i.register_op(
     "create_worker",
     s.core_op(json_op(s.stateful_op(op_create_worker))),
@@ -48,7 +48,7 @@ struct CreateWorkerArgs {
 
 /// Create worker as the host
 fn op_create_worker(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -59,37 +59,31 @@ fn op_create_worker(
   let source_code = args.source_code.clone();
   let args_name = args.name;
   let parent_state = state.clone();
-
-  let (load_sender, load_receiver) =
-    std::sync::mpsc::sync_channel::<JsonResult>(1);
+  let state = state.borrow();
+  let global_state = state.global_state.clone();
+  let child_permissions = state.permissions.clone();
+  let referrer = state.main_module.to_string();
+  drop(state);
+
+  let (handle_sender, handle_receiver) =
+    std::sync::mpsc::sync_channel::<Result<WorkerChannelsExternal, ErrBox>>(1);
+
+  // TODO(bartlomieju): Isn't this wrong?
+  let result = ModuleSpecifier::resolve_url_or_path(&specifier)?;
+  let module_specifier = if !has_source_code {
+    ModuleSpecifier::resolve_import(&specifier, &referrer)?
+  } else {
+    result
+  };
 
   std::thread::spawn(move || {
-    // TODO(bartlomieju): Isn't this wrong?
-    let result = ModuleSpecifier::resolve_url_or_path(&specifier);
-    if let Err(err) = result {
-      load_sender.send(Err(err.into())).unwrap();
-      return;
-    }
-
-    let module_specifier = if !has_source_code {
-      let referrer = parent_state.main_module.to_string();
-      let result = ModuleSpecifier::resolve_import(&specifier, &referrer);
-      if let Err(err) = result {
-        load_sender.send(Err(err.into())).unwrap();
-        return;
-      }
-      result.unwrap()
-    } else {
-      result.unwrap()
-    };
-
-    let result = ThreadSafeState::new_for_worker(
-      parent_state.global_state.clone(),
-      Some(parent_state.permissions.clone()), // by default share with parent
+    let result = State::new_for_worker(
+      global_state,
+      Some(child_permissions), // by default share with parent
       module_specifier.clone(),
     );
     if let Err(err) = result {
-      load_sender.send(Err(err)).unwrap();
+      handle_sender.send(Err(err)).unwrap();
       return;
     }
     let child_state = result.unwrap();
@@ -109,12 +103,12 @@ fn op_create_worker(
     js_check(worker.execute(&script));
     js_check(worker.execute("runWorkerMessageLoop()"));
 
-    let worker_id = parent_state.add_child_worker(&worker);
+    handle_sender.send(Ok(worker.thread_safe_handle())).unwrap();
 
     // Has provided source code, execute immediately.
     if has_source_code {
       js_check(worker.execute(&source_code));
-      load_sender.send(Ok(json!({ "id": worker_id }))).unwrap();
+      // FIXME(bartlomieju): runtime is not run in this case
       return;
     }
 
@@ -128,14 +122,13 @@ fn op_create_worker(
     }
     .boxed_local();
 
-    load_sender.send(Ok(json!({ "id": worker_id }))).unwrap();
-
     crate::tokio_util::run_basic(fut);
   });
 
-  let r = load_receiver.recv().unwrap();
+  let handle = handle_receiver.recv().unwrap()?;
+  let worker_id = parent_state.add_child_worker(handle);
 
-  Ok(JsonOp::Sync(r.unwrap()))
+  Ok(JsonOp::Sync(json!({ "id": worker_id })))
 }
 
 #[derive(Deserialize)]
@@ -144,16 +137,15 @@ struct WorkerArgs {
 }
 
 fn op_host_close_worker(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: WorkerArgs = serde_json::from_value(args)?;
   let id = args.id as u32;
-  let state_ = state.clone();
+  let mut state = state.borrow_mut();
 
-  let mut workers_table = state_.workers.lock().unwrap();
-  let maybe_worker_handle = workers_table.remove(&id);
+  let maybe_worker_handle = state.workers.remove(&id);
   if let Some(worker_handle) = maybe_worker_handle {
     let mut sender = worker_handle.sender.clone();
     sender.close_channel();
@@ -173,16 +165,16 @@ struct HostGetMessageArgs {
 
 /// Get message from guest worker as host
 fn op_host_get_message(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   _data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
   let args: HostGetMessageArgs = serde_json::from_value(args)?;
-  let state_ = state.clone();
   let id = args.id as u32;
-  let mut table = state_.workers.lock().unwrap();
+
+  let state = state.borrow();
   // TODO: don't return bad resource anymore
-  let worker_handle = table.get_mut(&id).ok_or_else(bad_resource)?;
+  let worker_handle = state.workers.get(&id).ok_or_else(bad_resource)?;
   let fut = worker_handle.get_message();
   let op = async move {
     let maybe_buf = fut.await;
@@ -198,7 +190,7 @@ struct HostPostMessageArgs {
 
 /// Post message to guest worker as host
 fn op_host_post_message(
-  state: &ThreadSafeState,
+  state: &State,
   args: Value,
   data: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
@@ -207,9 +199,9 @@ fn op_host_post_message(
   let msg = Vec::from(data.unwrap().as_ref()).into_boxed_slice();
 
   debug!("post message to worker {}", id);
-  let mut table = state.workers.lock().unwrap();
+  let state = state.borrow();
   // TODO: don't return bad resource anymore
-  let worker_handle = table.get_mut(&id).ok_or_else(bad_resource)?;
+  let worker_handle = state.workers.get(&id).ok_or_else(bad_resource)?;
   let fut = worker_handle
     .post_message(msg)
     .map_err(|e| DenoError::new(ErrorKind::Other, e.to_string()));
@@ -218,10 +210,11 @@ fn op_host_post_message(
 }
 
 fn op_metrics(
-  state: &ThreadSafeState,
+  state: &State,
   _args: Value,
   _zero_copy: Option<ZeroCopyBuf>,
 ) -> Result<JsonOp, ErrBox> {
+  let state = state.borrow();
   let m = &state.metrics;
 
   Ok(JsonOp::Sync(json!({
diff --git a/cli/shell.rs b/cli/shell.rs
index 268ec3b76..8e52f51fd 100644
--- a/cli/shell.rs
+++ b/cli/shell.rs
@@ -55,7 +55,7 @@ impl fmt::Debug for Shell {
 enum ShellOut {
   /// A plain write object without color support
   // TODO(ry) Disabling this type of output because it makes Shell
-  // not thread safe and thus not includable in ThreadSafeState.
+  // not thread safe and thus not includable in State.
   // But I think we will want this in the future.
   //Write(Box<dyn Write>),
   /// Color-enabled stdio, with information on whether color should be used
diff --git a/cli/state.rs b/cli/state.rs
index 86479d707..4e2f47e62 100644
--- a/cli/state.rs
+++ b/cli/state.rs
@@ -8,7 +8,6 @@ use crate::metrics::Metrics;
 use crate::ops::JsonOp;
 use crate::ops::MinimalOp;
 use crate::permissions::DenoPermissions;
-use crate::web_worker::WebWorker;
 use crate::worker::WorkerChannelsExternal;
 use crate::worker::WorkerChannelsInternal;
 use deno_core::Buf;
@@ -19,68 +18,53 @@ use deno_core::ModuleSpecifier;
 use deno_core::Op;
 use deno_core::ResourceTable;
 use deno_core::ZeroCopyBuf;
-use futures::channel::mpsc;
 use futures::future::FutureExt;
 use futures::future::TryFutureExt;
 use rand::rngs::StdRng;
 use rand::SeedableRng;
 use serde_json::Value;
 use std;
+use std::cell::RefCell;
 use std::collections::HashMap;
 use std::ops::Deref;
 use std::path::Path;
 use std::pin::Pin;
+use std::rc::Rc;
 use std::str;
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
-use std::sync::Mutex;
-use std::sync::MutexGuard;
 use std::time::Instant;
 
-/// 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 ThreadSafeState.
-pub struct ThreadSafeState(Arc<State>);
+#[derive(Clone)]
+pub struct State(Rc<RefCell<StateInner>>);
+
+impl Deref for State {
+  type Target = Rc<RefCell<StateInner>>;
+  fn deref(&self) -> &Self::Target {
+    &self.0
+  }
+}
 
 #[cfg_attr(feature = "cargo-clippy", allow(stutter))]
-pub struct State {
+pub struct StateInner {
   pub global_state: GlobalState,
-  pub permissions: Arc<Mutex<DenoPermissions>>,
+  pub permissions: DenoPermissions,
   pub main_module: ModuleSpecifier,
   /// When flags contains a `.import_map_path` option, the content of the
   /// import map file will be resolved and set.
   pub import_map: Option<ImportMap>,
   pub metrics: Metrics,
-  pub global_timer: Mutex<GlobalTimer>,
-  pub workers: Mutex<HashMap<u32, WorkerChannelsExternal>>,
-  pub worker_channels_internal: Mutex<Option<WorkerChannelsInternal>>,
-  pub loading_workers: Mutex<HashMap<u32, mpsc::Receiver<Result<(), ErrBox>>>>,
+  pub global_timer: GlobalTimer,
+  pub workers: HashMap<u32, WorkerChannelsExternal>,
+  pub worker_channels_internal: Option<WorkerChannelsInternal>,
   pub next_worker_id: AtomicUsize,
   pub start_time: Instant,
-  pub seeded_rng: Option<Mutex<StdRng>>,
-  pub resource_table: Mutex<ResourceTable>,
+  pub seeded_rng: Option<StdRng>,
+  pub resource_table: ResourceTable,
   pub target_lib: TargetLib,
 }
 
-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 ThreadSafeState {
-  pub fn lock_resource_table(&self) -> MutexGuard<ResourceTable> {
-    self.resource_table.lock().unwrap()
-  }
-
+impl State {
   /// Wrap core `OpDispatcher` to collect metrics.
   pub fn core_op<D>(
     &self,
@@ -130,7 +114,7 @@ impl ThreadSafeState {
     dispatcher: D,
   ) -> impl Fn(i32, Option<ZeroCopyBuf>) -> Pin<Box<MinimalOp>>
   where
-    D: Fn(&ThreadSafeState, i32, Option<ZeroCopyBuf>) -> Pin<Box<MinimalOp>>,
+    D: Fn(&State, i32, Option<ZeroCopyBuf>) -> Pin<Box<MinimalOp>>,
   {
     let state = self.clone();
 
@@ -149,11 +133,7 @@ impl ThreadSafeState {
     dispatcher: D,
   ) -> impl Fn(Value, Option<ZeroCopyBuf>) -> Result<JsonOp, ErrBox>
   where
-    D: Fn(
-      &ThreadSafeState,
-      Value,
-      Option<ZeroCopyBuf>,
-    ) -> Result<JsonOp, ErrBox>,
+    D: Fn(&State, Value, Option<ZeroCopyBuf>) -> Result<JsonOp, ErrBox>,
   {
     let state = self.clone();
 
@@ -163,7 +143,7 @@ impl ThreadSafeState {
   }
 }
 
-impl Loader for ThreadSafeState {
+impl Loader for State {
   fn resolve(
     &self,
     specifier: &str,
@@ -171,7 +151,7 @@ impl Loader for ThreadSafeState {
     is_main: bool,
   ) -> Result<ModuleSpecifier, ErrBox> {
     if !is_main {
-      if let Some(import_map) = &self.import_map {
+      if let Some(import_map) = &self.borrow().import_map {
         let result = import_map.resolve(specifier, referrer)?;
         if let Some(r) = result {
           return Ok(r);
@@ -198,11 +178,12 @@ impl Loader for ThreadSafeState {
       }
     }
 
+    let state = self.borrow();
     // TODO(bartlomieju): incrementing resolve_count here has no sense...
-    self.metrics.resolve_count.fetch_add(1, Ordering::SeqCst);
+    state.metrics.resolve_count.fetch_add(1, Ordering::SeqCst);
     let module_url_specified = module_specifier.to_string();
-    let global_state = self.global_state.clone();
-    let target_lib = self.target_lib.clone();
+    let global_state = state.global_state.clone();
+    let target_lib = state.target_lib.clone();
     let fut = async move {
       let compiled_module = global_state
         .fetch_compiled_module(module_specifier, maybe_referrer, target_lib)
@@ -220,11 +201,11 @@ impl Loader for ThreadSafeState {
   }
 }
 
-impl ThreadSafeState {
+impl State {
   /// If `shared_permission` is None then permissions from globa state are used.
   pub fn new(
     global_state: GlobalState,
-    shared_permissions: Option<Arc<Mutex<DenoPermissions>>>,
+    shared_permissions: Option<DenoPermissions>,
     main_module: ModuleSpecifier,
   ) -> Result<Self, ErrBox> {
     let import_map: Option<ImportMap> =
@@ -234,116 +215,114 @@ impl ThreadSafeState {
       };
 
     let seeded_rng = match global_state.flags.seed {
-      Some(seed) => Some(Mutex::new(StdRng::seed_from_u64(seed))),
+      Some(seed) => Some(StdRng::seed_from_u64(seed)),
       None => None,
     };
 
     let permissions = if let Some(perm) = shared_permissions {
       perm
     } else {
-      Arc::new(Mutex::new(global_state.permissions.clone()))
+      global_state.permissions.clone()
     };
 
-    let state = State {
+    let state = Rc::new(RefCell::new(StateInner {
       global_state,
       main_module,
       permissions,
       import_map,
       metrics: Metrics::default(),
-      global_timer: Mutex::new(GlobalTimer::new()),
-      worker_channels_internal: Mutex::new(None),
-      workers: Mutex::new(HashMap::new()),
-      loading_workers: Mutex::new(HashMap::new()),
+      global_timer: GlobalTimer::new(),
+      worker_channels_internal: None,
+      workers: HashMap::new(),
       next_worker_id: AtomicUsize::new(0),
       start_time: Instant::now(),
       seeded_rng,
 
-      resource_table: Mutex::new(ResourceTable::default()),
+      resource_table: ResourceTable::default(),
       target_lib: TargetLib::Main,
-    };
+    }));
 
-    Ok(ThreadSafeState(Arc::new(state)))
+    Ok(Self(state))
   }
 
   /// If `shared_permission` is None then permissions from globa state are used.
   pub fn new_for_worker(
     global_state: GlobalState,
-    shared_permissions: Option<Arc<Mutex<DenoPermissions>>>,
+    shared_permissions: Option<DenoPermissions>,
     main_module: ModuleSpecifier,
   ) -> Result<Self, ErrBox> {
     let seeded_rng = match global_state.flags.seed {
-      Some(seed) => Some(Mutex::new(StdRng::seed_from_u64(seed))),
+      Some(seed) => Some(StdRng::seed_from_u64(seed)),
       None => None,
     };
 
     let permissions = if let Some(perm) = shared_permissions {
       perm
     } else {
-      Arc::new(Mutex::new(global_state.permissions.clone()))
+      global_state.permissions.clone()
     };
 
-    let state = State {
+    let state = Rc::new(RefCell::new(StateInner {
       global_state,
       main_module,
       permissions,
       import_map: None,
       metrics: Metrics::default(),
-      global_timer: Mutex::new(GlobalTimer::new()),
-      worker_channels_internal: Mutex::new(None),
-      workers: Mutex::new(HashMap::new()),
-      loading_workers: Mutex::new(HashMap::new()),
+      global_timer: GlobalTimer::new(),
+      worker_channels_internal: None,
+      workers: HashMap::new(),
       next_worker_id: AtomicUsize::new(0),
       start_time: Instant::now(),
       seeded_rng,
 
-      resource_table: Mutex::new(ResourceTable::default()),
+      resource_table: ResourceTable::default(),
       target_lib: TargetLib::Worker,
-    };
+    }));
 
-    Ok(ThreadSafeState(Arc::new(state)))
+    Ok(Self(state))
   }
 
-  pub fn add_child_worker(&self, worker: &WebWorker) -> u32 {
-    let worker_id = self.next_worker_id.fetch_add(1, Ordering::Relaxed) as u32;
-    let handle = worker.thread_safe_handle();
-    let mut workers_tl = self.workers.lock().unwrap();
-    workers_tl.insert(worker_id, handle);
+  pub fn add_child_worker(&self, handle: WorkerChannelsExternal) -> u32 {
+    let mut inner_state = self.borrow_mut();
+    let worker_id =
+      inner_state.next_worker_id.fetch_add(1, Ordering::Relaxed) as u32;
+    inner_state.workers.insert(worker_id, handle);
     worker_id
   }
 
   #[inline]
   pub fn check_read(&self, path: &Path) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_read(path)
+    self.borrow().permissions.check_read(path)
   }
 
   #[inline]
   pub fn check_write(&self, path: &Path) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_write(path)
+    self.borrow().permissions.check_write(path)
   }
 
   #[inline]
   pub fn check_env(&self) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_env()
+    self.borrow().permissions.check_env()
   }
 
   #[inline]
   pub fn check_net(&self, hostname: &str, port: u16) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_net(hostname, port)
+    self.borrow().permissions.check_net(hostname, port)
   }
 
   #[inline]
   pub fn check_net_url(&self, url: &url::Url) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_net_url(url)
+    self.borrow().permissions.check_net_url(url)
   }
 
   #[inline]
   pub fn check_run(&self) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_run()
+    self.borrow().permissions.check_run()
   }
 
   #[inline]
   pub fn check_plugin(&self, filename: &Path) -> Result<(), ErrBox> {
-    self.permissions.lock().unwrap().check_plugin(filename)
+    self.borrow().permissions.check_plugin(filename)
   }
 
   pub fn check_dyn_import(
@@ -371,10 +350,10 @@ impl ThreadSafeState {
   }
 
   #[cfg(test)]
-  pub fn mock(main_module: &str) -> ThreadSafeState {
+  pub fn mock(main_module: &str) -> State {
     let module_specifier = ModuleSpecifier::resolve_url_or_path(main_module)
       .expect("Invalid entry module");
-    ThreadSafeState::new(
+    State::new(
       GlobalState::mock(vec!["deno".to_string()]),
       None,
       module_specifier,
@@ -387,28 +366,24 @@ impl ThreadSafeState {
     bytes_sent_control: usize,
     bytes_sent_data: usize,
   ) {
-    self.metrics.ops_dispatched.fetch_add(1, Ordering::SeqCst);
-    self
+    let state = self.borrow();
+    state.metrics.ops_dispatched.fetch_add(1, Ordering::SeqCst);
+    state
       .metrics
       .bytes_sent_control
       .fetch_add(bytes_sent_control, Ordering::SeqCst);
-    self
+    state
       .metrics
       .bytes_sent_data
       .fetch_add(bytes_sent_data, Ordering::SeqCst);
   }
 
   pub fn metrics_op_completed(&self, bytes_received: usize) {
-    self.metrics.ops_completed.fetch_add(1, Ordering::SeqCst);
-    self
+    let state = self.borrow();
+    state.metrics.ops_completed.fetch_add(1, Ordering::SeqCst);
+    state
       .metrics
       .bytes_received
       .fetch_add(bytes_received, Ordering::SeqCst);
   }
 }
-
-#[test]
-fn thread_safe() {
-  fn f<S: Send + Sync>(_: S) {}
-  f(ThreadSafeState::mock("./hello.js"));
-}
diff --git a/cli/web_worker.rs b/cli/web_worker.rs
index 7115b9027..05e3184d9 100644
--- a/cli/web_worker.rs
+++ b/cli/web_worker.rs
@@ -1,6 +1,6 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use crate::ops;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use crate::worker::Worker;
 use deno_core;
 use deno_core::ErrBox;
@@ -23,11 +23,7 @@ use std::task::Poll;
 pub struct WebWorker(Worker);
 
 impl WebWorker {
-  pub fn new(
-    name: String,
-    startup_data: StartupData,
-    state: ThreadSafeState,
-  ) -> Self {
+  pub fn new(name: String, startup_data: StartupData, state: State) -> Self {
     let state_ = state.clone();
     let mut worker = Worker::new(name, startup_data, state_);
     {
@@ -70,11 +66,11 @@ impl Future for WebWorker {
 mod tests {
   use super::*;
   use crate::startup_data;
-  use crate::state::ThreadSafeState;
+  use crate::state::State;
   use crate::tokio_util;
 
   fn create_test_worker() -> WebWorker {
-    let state = ThreadSafeState::mock("./hello.js");
+    let state = State::mock("./hello.js");
     let mut worker = WebWorker::new(
       "TEST".to_string(),
       startup_data::deno_isolate_init(),
@@ -104,48 +100,53 @@ mod tests {
     worker.execute(source).unwrap();
 
     let handle = worker.thread_safe_handle();
-    let _ = tokio_util::spawn_thread(move || tokio_util::run_basic(worker));
-
-    tokio_util::run_basic(async move {
-      let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
-      let r = handle.post_message(msg.clone()).await;
-      assert!(r.is_ok());
-
-      let maybe_msg = handle.get_message().await;
-      assert!(maybe_msg.is_some());
-
-      let r = handle.post_message(msg.clone()).await;
-      assert!(r.is_ok());
-
-      let maybe_msg = handle.get_message().await;
-      assert!(maybe_msg.is_some());
-      assert_eq!(*maybe_msg.unwrap(), *b"[1,2,3]");
-
-      let msg = json!("exit")
-        .to_string()
-        .into_boxed_str()
-        .into_boxed_bytes();
-      let r = handle.post_message(msg).await;
-      assert!(r.is_ok());
+    let _ = tokio_util::spawn_thread(move || {
+      tokio_util::run_basic(async move {
+        let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
+        let r = handle.post_message(msg.clone()).await;
+        assert!(r.is_ok());
+
+        let maybe_msg = handle.get_message().await;
+        assert!(maybe_msg.is_some());
+
+        let r = handle.post_message(msg.clone()).await;
+        assert!(r.is_ok());
+
+        let maybe_msg = handle.get_message().await;
+        assert!(maybe_msg.is_some());
+        assert_eq!(*maybe_msg.unwrap(), *b"[1,2,3]");
+
+        let msg = json!("exit")
+          .to_string()
+          .into_boxed_str()
+          .into_boxed_bytes();
+        let r = handle.post_message(msg).await;
+        assert!(r.is_ok());
+      })
     });
+
+    let r = tokio_util::run_basic(worker);
+    assert!(r.is_ok())
   }
 
   #[test]
   fn removed_from_resource_table_on_close() {
     let mut worker = create_test_worker();
     let handle = worker.thread_safe_handle();
-    let worker_complete_fut = tokio_util::spawn_thread(move || {
-      worker
-        .execute("onmessage = () => { delete self.onmessage; }")
-        .unwrap();
-      tokio_util::run_basic(worker)
+
+    worker
+      .execute("onmessage = () => { delete self.onmessage; }")
+      .unwrap();
+
+    let worker_post_message_fut = tokio_util::spawn_thread(move || {
+      let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
+      let r = futures::executor::block_on(handle.post_message(msg));
+      assert!(r.is_ok());
     });
 
-    let msg = json!("hi").to_string().into_boxed_str().into_boxed_bytes();
     tokio_util::run_basic(async move {
-      let r = handle.post_message(msg).await;
-      assert!(r.is_ok());
-      let r = worker_complete_fut.await;
+      worker_post_message_fut.await;
+      let r = worker.await;
       assert!(r.is_ok());
     });
   }
diff --git a/cli/worker.rs b/cli/worker.rs
index c7efa95fa..20b8b8021 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -1,7 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 use crate::fmt_errors::JSError;
 use crate::ops;
-use crate::state::ThreadSafeState;
+use crate::state::State;
 use deno_core;
 use deno_core::Buf;
 use deno_core::ErrBox;
@@ -112,28 +112,24 @@ fn create_channels() -> (WorkerChannelsInternal, WorkerChannelsExternal) {
 pub struct Worker {
   pub name: String,
   pub isolate: Box<deno_core::EsIsolate>,
-  pub state: ThreadSafeState,
+  pub state: State,
   external_channels: WorkerChannelsExternal,
 }
 
 impl Worker {
-  pub fn new(
-    name: String,
-    startup_data: StartupData,
-    state: ThreadSafeState,
-  ) -> Self {
+  pub fn new(name: String, startup_data: StartupData, state: State) -> Self {
     let mut isolate =
       deno_core::EsIsolate::new(Box::new(state.clone()), startup_data, false);
 
-    let global_state_ = state.global_state.clone();
+    let global_state_ = state.borrow().global_state.clone();
     isolate.set_js_error_create(move |v8_exception| {
       JSError::from_v8_exception(v8_exception, &global_state_.ts_compiler)
     });
 
     let (internal_channels, external_channels) = create_channels();
     {
-      let mut c = state.worker_channels_internal.lock().unwrap();
-      *c = Some(internal_channels);
+      let mut state = state.borrow_mut();
+      state.worker_channels_internal = Some(internal_channels);
     }
 
     Self {
@@ -170,7 +166,7 @@ impl Worker {
   ) -> Result<(), ErrBox> {
     let specifier = module_specifier.to_string();
     let id = self.isolate.load_module(&specifier, maybe_code).await?;
-    self.state.global_state.progress.done();
+    self.state.borrow().global_state.progress.done();
     if !is_prefetch {
       return self.isolate.mod_evaluate(id);
     }
@@ -203,11 +199,7 @@ impl Future for Worker {
 pub struct MainWorker(Worker);
 
 impl MainWorker {
-  pub fn new(
-    name: String,
-    startup_data: StartupData,
-    state: ThreadSafeState,
-  ) -> Self {
+  pub fn new(name: String, startup_data: StartupData, state: State) -> Self {
     let state_ = state.clone();
     let mut worker = Worker::new(name, startup_data, state_);
     {
@@ -257,7 +249,7 @@ mod tests {
   use crate::flags;
   use crate::global_state::GlobalState;
   use crate::startup_data;
-  use crate::state::ThreadSafeState;
+  use crate::state::State;
   use crate::tokio_util;
   use futures::executor::block_on;
   use std::sync::atomic::Ordering;
@@ -280,8 +272,7 @@ mod tests {
       ModuleSpecifier::resolve_url_or_path(&p.to_string_lossy()).unwrap();
     let global_state = GlobalState::new(flags::DenoFlags::default()).unwrap();
     let state =
-      ThreadSafeState::new(global_state, None, module_specifier.clone())
-        .unwrap();
+      State::new(global_state, None, module_specifier.clone()).unwrap();
     let state_ = state.clone();
     tokio_util::run_basic(async move {
       let mut worker =
@@ -296,8 +287,8 @@ mod tests {
         panic!("Future got unexpected error: {:?}", e);
       }
     });
-
-    let metrics = &state_.metrics;
+    let mut state = state_.borrow_mut();
+    let metrics = &mut state.metrics;
     assert_eq!(metrics.resolve_count.load(Ordering::SeqCst), 2);
     // Check that we didn't start the compiler.
     assert_eq!(metrics.compiler_starts.load(Ordering::SeqCst), 0);
@@ -313,8 +304,7 @@ mod tests {
       ModuleSpecifier::resolve_url_or_path(&p.to_string_lossy()).unwrap();
     let global_state = GlobalState::new(flags::DenoFlags::default()).unwrap();
     let state =
-      ThreadSafeState::new(global_state, None, module_specifier.clone())
-        .unwrap();
+      State::new(global_state, None, module_specifier.clone()).unwrap();
     let state_ = state.clone();
     tokio_util::run_basic(async move {
       let mut worker =
@@ -330,7 +320,8 @@ mod tests {
       }
     });
 
-    let metrics = &state_.metrics;
+    let mut state = state_.borrow_mut();
+    let metrics = &mut state.metrics;
     // TODO  assert_eq!(metrics.resolve_count.load(Ordering::SeqCst), 2);
     // Check that we didn't start the compiler.
     assert_eq!(metrics.compiler_starts.load(Ordering::SeqCst), 0);
@@ -353,12 +344,8 @@ mod tests {
       ..flags::DenoFlags::default()
     };
     let global_state = GlobalState::new(flags).unwrap();
-    let state = ThreadSafeState::new(
-      global_state.clone(),
-      None,
-      module_specifier.clone(),
-    )
-    .unwrap();
+    let state =
+      State::new(global_state.clone(), None, module_specifier.clone()).unwrap();
     let mut worker = MainWorker::new(
       "TEST".to_string(),
       startup_data::deno_isolate_init(),
@@ -374,6 +361,7 @@ mod tests {
     if let Err(e) = (&mut *worker).await {
       panic!("Future got unexpected error: {:?}", e);
     }
+    let state = state.borrow_mut();
     assert_eq!(state.metrics.resolve_count.load(Ordering::SeqCst), 3);
     // Check that we've only invoked the compiler once.
     assert_eq!(
@@ -384,7 +372,7 @@ mod tests {
   }
 
   fn create_test_worker() -> MainWorker {
-    let state = ThreadSafeState::mock("./hello.js");
+    let state = State::mock("./hello.js");
     let mut worker = MainWorker::new(
       "TEST".to_string(),
       startup_data::deno_isolate_init(),