fix(solc): add RuntimeOrHandle & fix solc blocking installation

ethers-solc/Cargo.toml

@@ -19,7 +19,7 @@ serde_json = "1.0.68"
 serde = { version = "1.0.130", features = ["derive"] }
 semver = { version = "1.0.9", features = ["serde"] }
 walkdir = "2.3.2"
-tokio = { version = "1.15.0", default-features = false, features = ["process", "io-util", "fs", "time"], optional = true }
+tokio = { version = "1.15.0", default-features = false, features = ["process", "io-util", "fs", "time"] }
 futures-util = { version = "^0.3", optional = true }
 once_cell = "1.10.0"
 regex = "1.5.5"
@@ -80,7 +80,7 @@ required-features = ["full", "project-util"]
 
 [features]
 default = ["rustls"]
-async = ["tokio", "futures-util"]
+async = ["futures-util"]
 full = ["async", "svm-solc"]
 svm-solc = ["svm/blocking", "svm-builds", "sha2"]
 # Utilities for creating and testing project workspaces

ethers-solc/src/compile/mod.rs

@@ -371,9 +371,11 @@ impl Solc {
     /// Blocking version of `Self::install`
     #[cfg(all(feature = "svm-solc"))]
     pub fn blocking_install(version: &Version) -> std::result::Result<Self, svm::SolcVmError> {
+        use crate::utils::RuntimeOrHandle;
+
         tracing::trace!("blocking installing solc version \"{}\"", version);
         crate::report::solc_installation_start(version);
-        match svm::blocking_install(version) {
+        match RuntimeOrHandle::new().block_on(svm::install(version)) {
             Ok(path) => {
                 crate::report::solc_installation_success(version);
                 Ok(Solc::new(path))
@@ -799,6 +801,17 @@ mod tests {
         assert_eq!(res.solc, expected);
     }
 
+    #[test]
+    #[cfg(feature = "svm-solc")]
+    fn can_install_solc_in_tokio_rt() {
+        let ver = "0.8.6";
+        let version = Version::from_str(ver).unwrap();
+        let result = tokio::runtime::Runtime::new()
+            .unwrap()
+            .block_on(async { Solc::blocking_install(&version) });
+        assert!(result.is_ok());
+    }
+
     #[test]
     fn does_not_find_not_installed_version() {
         let ver = "1.1.1";

ethers-solc/src/utils.rs

@@ -12,6 +12,7 @@ use regex::{Match, Regex};
 use semver::Version;
 use serde::de::DeserializeOwned;
 use tiny_keccak::{Hasher, Keccak};
+use tokio::runtime::{Handle, Runtime};
 use walkdir::WalkDir;
 
 /// A regex that matches the import path and identifier of a solidity import
@@ -330,6 +331,35 @@ pub(crate) fn find_fave_or_alt_path(root: impl AsRef<Path>, fave: &str, alt: &st
     p
 }
 
+#[allow(clippy::large_enum_variant)]
+#[derive(Debug)]
+pub enum RuntimeOrHandle {
+    Runtime(Runtime),
+    Handle(Handle),
+}
+
+impl Default for RuntimeOrHandle {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl RuntimeOrHandle {
+    pub fn new() -> RuntimeOrHandle {
+        match Handle::try_current() {
+            Ok(handle) => RuntimeOrHandle::Handle(handle),
+            Err(_) => RuntimeOrHandle::Runtime(Runtime::new().expect("Failed to start runtime")),
+        }
+    }
+
+    pub fn block_on<F: std::future::Future>(&self, f: F) -> F::Output {
+        match &self {
+            RuntimeOrHandle::Runtime(runtime) => runtime.block_on(f),
+            RuntimeOrHandle::Handle(handle) => tokio::task::block_in_place(|| handle.block_on(f)),
+        }
+    }
+}
+
 /// Creates a new named tempdir
 #[cfg(any(test, feature = "project-util"))]
 pub(crate) fn tempdir(name: &str) -> Result<tempfile::TempDir, SolcIoError> {