Add await into worker.ts

[samuelteixeiras]

I am running this code on Mac, if I did not add that await in the front of the console.log I have the error:

deno run --allow-read main.ts 
hello world
thread 'deno-worker-0' panicked at 'Failed to post message to host: TrySendError { kind: Disconnected }', cli/ops/worker_host.rs:142:7
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'Worker thread panicked: Any', cli/ops/worker_host.rs:329:11

If that await before the console.log is not be needed this is possible bug.

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[pgasiorowski]

Ubuntu 18 also panicks but with slightly different stacktrace pointing at src/libcore/result.rs:1188:5:

$ RUST_BACKTRACE=1 deno run --allow-read main.ts 
hello world
thread 'deno-worker-0' panicked at 'Failed to post message to host: TrySendError { kind: Disconnected }', src/libcore/result.rs:1188:5
stack backtrace:
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: std::io::Write::write_fmt
   3: std::panicking::default_hook::{{closure}}
   4: std::panicking::default_hook
   5: std::panicking::rust_panic_with_hook
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
   9: core::result::Result<T,E>::expect
             at /usr/src/rustc-1.41.0/src/libcore/result.rs:983
  10: deno::ops::worker_host::run_worker_thread::{{closure}}
             at cli/ops/worker_host.rs:142
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread 'main' panicked at 'Worker thread panicked: Any', src/libcore/result.rs:1188:5
stack backtrace:
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: std::io::Write::write_fmt
   3: std::panicking::default_hook::{{closure}}
   4: std::panicking::default_hook
   5: std::panicking::rust_panic_with_hook
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
   9: core::result::Result<T,E>::expect
             at /usr/src/rustc-1.41.0/src/libcore/result.rs:983
  10: deno::ops::worker_host::op_host_get_message::{{closure}}
             at cli/ops/worker_host.rs:332
  11: <std::future::GenFuture<T> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libstd/future.rs:43
  12: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:119
  13: futures_util::future::future::chain::Chain<Fut1,Fut2,Data>::poll
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/chain.rs:44
  14: <futures_util::future::future::then::Then<Fut1,Fut2,F> as core::future::future::Future>::poll
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/then.rs:44
  15: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:119
  16: <futures_util::future::future::map::Map<Fut,F> as core::future::future::Future>::poll
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/map.rs:40
  17: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:119
  18: <futures_util::future::future::map::Map<Fut,F> as core::future::future::Future>::poll
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/map.rs:40
  19: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:119
  20: <futures_util::stream::futures_unordered::FuturesUnordered<Fut> as futures_core::stream::Stream>::poll_next
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/stream/futures_unordered/mod.rs:544
  21: <&mut S as futures_core::stream::Stream>::poll_next
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.4/src/stream.rs:102
  22: <futures_util::stream::stream::fuse::Fuse<S> as futures_core::stream::Stream>::poll_next
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/stream/stream/fuse.rs:85
  23: futures_util::stream::select::poll_inner
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/stream/select.rs:115
  24: <futures_util::stream::select::Select<St1,St2> as futures_core::stream::Stream>::poll_next
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/stream/select.rs:100
  25: futures_util::stream::stream::StreamExt::poll_next_unpin
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/stream/stream/mod.rs:1184
  26: <deno_core::isolate::CoreIsolate as core::future::future::Future>::poll
             at core/isolate.rs:507
  27: <alloc::boxed::Box<F> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/liballoc/boxed.rs:1182
  28: futures_util::future::future::FutureExt::poll_unpin
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/mod.rs:507
  29: <deno_core::es_isolate::EsIsolate as core::future::future::Future>::poll
             at core/es_isolate.rs:582
  30: <alloc::boxed::Box<F> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/liballoc/boxed.rs:1182
  31: futures_util::future::future::FutureExt::poll_unpin
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.4/src/future/future/mod.rs:507
  32: <deno::worker::Worker as core::future::future::Future>::poll
             at cli/worker.rs:220
  33: <&mut F as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:107
  34: std::future::poll_with_tls_context
             at /usr/src/rustc-1.41.0/src/libstd/future.rs:99
  35: deno::run_command::{{closure}}
             at cli/main.rs:518
  36: <std::future::GenFuture<T> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libstd/future.rs:43
  37: <core::pin::Pin<P> as core::future::future::Future>::poll
             at /usr/src/rustc-1.41.0/src/libcore/future/future.rs:119
  38: tokio::runtime::basic_scheduler::BasicScheduler<P>::block_on::{{closure}}::{{closure}}
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/basic_scheduler.rs:131
  39: tokio::coop::budget::{{closure}}
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/coop.rs:97
  40: std::thread::local::LocalKey<T>::try_with
             at /usr/src/rustc-1.41.0/src/libstd/thread/local.rs:262
  41: std::thread::local::LocalKey<T>::with
             at /usr/src/rustc-1.41.0/src/libstd/thread/local.rs:239
  42: tokio::coop::budget
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/coop.rs:79
  43: tokio::runtime::basic_scheduler::BasicScheduler<P>::block_on::{{closure}}
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/basic_scheduler.rs:131
  44: tokio::runtime::basic_scheduler::enter::{{closure}}
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/basic_scheduler.rs:213
  45: tokio::macros::scoped_tls::ScopedKey<T>::set
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/macros/scoped_tls.rs:64
  46: tokio::runtime::basic_scheduler::enter
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/basic_scheduler.rs:213
  47: tokio::runtime::basic_scheduler::BasicScheduler<P>::block_on
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/basic_scheduler.rs:123
  48: tokio::runtime::Runtime::block_on::{{closure}}
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/mod.rs:444
  49: tokio::runtime::context::enter
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/context.rs:72
  50: tokio::runtime::handle::Handle::enter
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/handle.rs:71
  51: tokio::runtime::Runtime::block_on
             at /home/woodzu/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-0.2.20/src/runtime/mod.rs:441
  52: deno::tokio_util::run_basic
             at cli/tokio_util.rs:18
  53: deno::main
             at cli/main.rs:669
  54: std::rt::lang_start::{{closure}}
             at /usr/src/rustc-1.41.0/src/libstd/rt.rs:67
  55: std::panicking::try::do_call
  56: __rust_maybe_catch_panic
  57: std::rt::lang_start_internal
  58: std::rt::lang_start
             at /usr/src/rustc-1.41.0/src/libstd/rt.rs:67
  59: main
  60: __libc_start_main
  61: _start
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[pgasiorowski]

Duplicate of #5334

[bartlomieju]

@samuelteixeiras thanks for the patch, but it's not really a valid solution. The problem you're seeing is described in #5334 and requires fixing Rust ops. As a temporary workaround you can add short delay before closing the worker. Closing without merge

[samuelteixeiras]

thank you for the response @bartlomieju and @WooDzu