Properly initialize file_per_thread_logger for rayon thread pool (#211)

* Properly initialize file_per_thread_logger for rayon thread pool

Cargo.toml

@@ -43,6 +43,7 @@ file-per-thread-logger = "0.1.1"
 wabt = "0.8"
 libc = "0.2.50"
 errno = "0.2.4"
+rayon = "1.1"
 
 [workspace]
 

src/utils.rs

@@ -0,0 +1,27 @@
+pub fn init_file_per_thread_logger() {
+    use super::LOG_FILENAME_PREFIX;
+
+    file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
+
+    // Extending behavior of default spawner:
+    // https://docs.rs/rayon/1.1.0/rayon/struct.ThreadPoolBuilder.html#method.spawn_handler
+    // Source code says DefaultSpawner is implementation detail and
+    // shouldn't be used directly.
+    rayon::ThreadPoolBuilder::new()
+        .spawn_handler(|thread| {
+            let mut b = std::thread::Builder::new();
+            if let Some(name) = thread.name() {
+                b = b.name(name.to_owned());
+            }
+            if let Some(stack_size) = thread.stack_size() {
+                b = b.stack_size(stack_size);
+            }
+            b.spawn(|| {
+                file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
+                thread.run()
+            })?;
+            Ok(())
+        })
+        .build_global()
+        .unwrap();
+}

src/wasm2obj.rs

@@ -52,6 +52,10 @@ use wasmtime_debug::{emit_debugsections, read_debuginfo};
 use wasmtime_environ::{Compiler, Cranelift, ModuleEnvironment, Tunables};
 use wasmtime_obj::emit_module;
 
+mod utils;
+
+static LOG_FILENAME_PREFIX: &str = "wasm2obj.dbg.";
+
 const USAGE: &str = "
 Wasm to native object translation utility.
 Takes a binary WebAssembly module into a native object file.
@@ -68,6 +72,7 @@ Options:
     --target <TARGET>   build for the target triple; default is the host machine
     -g                  generate debug information
     --version           print the Cranelift version
+    -d, --debug         enable debug output on stderr/stdout
 ";
 
 #[derive(Deserialize, Debug, Clone)]
@@ -76,6 +81,7 @@ struct Args {
     arg_output: String,
     arg_target: Option<String>,
     flag_g: bool,
+    flag_debug: bool,
 }
 
 fn read_wasm_file(path: PathBuf) -> Result<Vec<u8>, io::Error> {
@@ -95,6 +101,12 @@ fn main() {
         })
         .unwrap_or_else(|e| e.exit());
 
+    if args.flag_debug {
+        pretty_env_logger::init();
+    } else {
+        utils::init_file_per_thread_logger();
+    }
+
     let path = Path::new(&args.arg_file);
     match handle_module(
         path.to_path_buf(),

src/wasmtime.rs

@@ -37,7 +37,6 @@ use cranelift_codegen::settings;
 use cranelift_codegen::settings::Configurable;
 use cranelift_native;
 use docopt::Docopt;
-use file_per_thread_logger;
 use pretty_env_logger;
 use std::error::Error;
 use std::ffi::OsStr;
@@ -56,6 +55,8 @@ use wasmtime_wast::instantiate_spectest;
 #[cfg(feature = "wasi-c")]
 use wasmtime_wasi_c::instantiate_wasi_c;
 
+mod utils;
+
 static LOG_FILENAME_PREFIX: &str = "wasmtime.dbg.";
 
 const USAGE: &str = "
@@ -203,7 +204,7 @@ fn main() {
     if args.flag_debug {
         pretty_env_logger::init();
     } else {
-        file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
+        utils::init_file_per_thread_logger();
     }
 
     let isa_builder = cranelift_native::builder().unwrap_or_else(|_| {

src/wast.rs

@@ -32,13 +32,14 @@ use cranelift_codegen::settings;
 use cranelift_codegen::settings::Configurable;
 use cranelift_native;
 use docopt::Docopt;
-use file_per_thread_logger;
 use pretty_env_logger;
 use std::path::Path;
 use std::process;
 use wasmtime_jit::Compiler;
 use wasmtime_wast::WastContext;
 
+mod utils;
+
 static LOG_FILENAME_PREFIX: &str = "cranelift.dbg.";
 
 const USAGE: &str = "
@@ -76,7 +77,7 @@ fn main() {
     if args.flag_debug {
         pretty_env_logger::init();
     } else {
-        file_per_thread_logger::initialize(LOG_FILENAME_PREFIX);
+        utils::init_file_per_thread_logger();
     }
 
     let isa_builder = cranelift_native::builder().unwrap_or_else(|_| {

wasmtime-environ/Cargo.toml

@@ -19,7 +19,7 @@ lightbeam = { path = "../lightbeam", optional = true }
 failure = { version = "0.1.3", default-features = false }
 failure_derive = { version = "0.1.3", default-features = false }
 indexmap = "1.0.2"
-rayon = "1.0"
+rayon = "1.1"
 
 [features]
 default = ["std"]