Replace futures::executor::block_on with tokio::block_in_place

src/machine/system_calls.rs

@@ -91,6 +91,8 @@ use roxmltree;
 use futures::future;
 #[cfg(feature = "http")]
 use reqwest::Url;
+use tokio::runtime::Handle;
+use tokio::task;
 #[cfg(feature = "http")]
 use warp::hyper::header::{HeaderName, HeaderValue};
 #[cfg(feature = "http")]
@@ -4378,7 +4380,8 @@ impl Machine {
             }
 
             // do it!
-            match futures::executor::block_on(req.send()) {
+            task::block_in_place(move || {
+                match Handle::current().block_on(req.send()) {
                     Ok(resp) => {
                         // status code
                         let status = resp.status().as_u16();
@@ -4409,11 +4412,13 @@ impl Machine {
 
                         let headers_list =
                             iter_to_heap_list(&mut self.machine_st.heap, headers.into_iter());
+
                         unify!(
                             self.machine_st,
                             heap_loc_as_cell!(headers_list),
                             self.machine_st.registers[6]
                         );
+
                         // body
                         let reader = futures::executor::block_on(resp.bytes()).unwrap().reader();
 
@@ -4426,7 +4431,8 @@ impl Machine {
 
                         self.indices
                             .add_stream(stream, atom!("http_open"), 3)
-                        .map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
+                            .map_err(|stub_gen| stub_gen(&mut self.machine_st))
+                            .unwrap();
 
                         let stream = stream_as_cell!(stream);
 
@@ -4437,6 +4443,7 @@ impl Machine {
                         self.machine_st.fail = true;
                     }
                 }
+            });
         } else {
             let err = self
                 .machine_st

tests-pl/issue-http_open-hanging.pl

@@ -0,0 +1,23 @@
+:- module(http_open_hanging, [submit_request/0]).
+
+:- use_module(library(charsio)).
+:- use_module(library(http/http_open)).
+
+send_request :-
+    Options = [
+        method('get'),
+        status_code(StatusCode),
+        request_headers([]),
+        headers(_)
+    ],
+    http_open("https://scryer.pl", _Stream, Options),
+    write_term('received response with status code':StatusCode, []), nl.
+
+main :-
+    send_request,
+    send_request,
+    send_request,
+    send_request,
+    send_request.
+
+:- initialization(main).

tests/scryer/helper.rs

@@ -1,3 +1,5 @@
+use scryer_prolog::MachineBuilder;
+
 pub(crate) trait Expectable {
     #[track_caller]
     fn assert_eq(self, other: &[u8]);
@@ -31,3 +33,17 @@ pub(crate) fn load_module_test<T: Expectable>(file: &str, expected: T) {
     let mut wam = MachineBuilder::default().build();
     expected.assert_eq(wam.test_load_file(file).as_slice());
 }
+
+/// Same as `load_module_test` with tokio runtime
+#[cfg(not(target_arch = "wasm32"))]
+pub(crate) fn load_module_test_with_tokio_runtime<T: Expectable>(file: &str, expected: T) {
+    let runtime = tokio::runtime::Builder::new_multi_thread()
+        .enable_all()
+        .build()
+        .unwrap();
+
+    runtime.block_on(async move {
+        let mut wam = MachineBuilder::default().build();
+        expected.assert_eq(wam.test_load_file(file).as_slice())
+    });
+}

tests/scryer/issues.rs

@@ -1,4 +1,6 @@
 use crate::helper::load_module_test;
+#[cfg(not(target_arch = "wasm32"))]
+use crate::helper::load_module_test_with_tokio_runtime;
 use serial_test::serial;
 
 // issue #831
@@ -43,3 +45,14 @@ fn load_context_unreachable() {
 fn issue2725_dcg_without_module() {
     load_module_test("tests-pl/issue2725.pl", "");
 }
+
+#[test]
+#[cfg(feature = "http")]
+#[cfg(not(target_arch = "wasm32"))]
+#[cfg_attr(miri, ignore = "it takes too long to run")]
+fn http_open_hanging() {
+    load_module_test_with_tokio_runtime(
+        "tests-pl/issue-http_open-hanging.pl",
+            "received response with status code:200\nreceived response with status code:200\nreceived response with status code:200\nreceived response with status code:200\nreceived response with status code:200\n"
+    );
+}