// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license. use std::env::current_dir; use std::fs::OpenOptions; use std::io::Error; use std::io::ErrorKind; use std::io::Write; use std::path::Path; use std::path::PathBuf; use std::sync::Arc; use std::time::Duration; use deno_config::glob::FileCollector; use deno_config::glob::FilePatterns; use deno_config::glob::PathOrPattern; use deno_config::glob::PathOrPatternSet; use deno_config::glob::WalkEntry; use deno_core::anyhow::anyhow; use deno_core::anyhow::Context; use deno_core::error::AnyError; pub use deno_core::normalize_path; use deno_core::unsync::spawn_blocking; use deno_core::ModuleSpecifier; use deno_runtime::deno_fs::FileSystem; use deno_runtime::deno_node::PathClean; use crate::util::path::get_atomic_file_path; use crate::util::progress_bar::ProgressBar; use crate::util::progress_bar::ProgressBarStyle; use crate::util::progress_bar::ProgressMessagePrompt; /// Writes the file to the file system at a temporary path, then /// renames it to the destination in a single sys call in order /// to never leave the file system in a corrupted state. /// /// This also handles creating the directory if a NotFound error /// occurs. pub fn atomic_write_file_with_retries>( file_path: &Path, data: T, mode: u32, ) -> std::io::Result<()> { let mut count = 0; loop { match atomic_write_file(file_path, data.as_ref(), mode) { Ok(()) => return Ok(()), Err(err) => { if count >= 5 { // too many retries, return the error return Err(err); } count += 1; let sleep_ms = std::cmp::min(50, 10 * count); std::thread::sleep(std::time::Duration::from_millis(sleep_ms)); } } } } /// Writes the file to the file system at a temporary path, then /// renames it to the destination in a single sys call in order /// to never leave the file system in a corrupted state. /// /// This also handles creating the directory if a NotFound error /// occurs. fn atomic_write_file>( file_path: &Path, data: T, mode: u32, ) -> std::io::Result<()> { fn atomic_write_file_raw( temp_file_path: &Path, file_path: &Path, data: &[u8], mode: u32, ) -> std::io::Result<()> { write_file(temp_file_path, data, mode)?; std::fs::rename(temp_file_path, file_path).map_err(|err| { // clean up the created temp file on error let _ = std::fs::remove_file(temp_file_path); err }) } fn inner(file_path: &Path, data: &[u8], mode: u32) -> std::io::Result<()> { let temp_file_path = get_atomic_file_path(file_path); if let Err(write_err) = atomic_write_file_raw(&temp_file_path, file_path, data, mode) { if write_err.kind() == ErrorKind::NotFound { let parent_dir_path = file_path.parent().unwrap(); match std::fs::create_dir_all(parent_dir_path) { Ok(()) => { return atomic_write_file_raw( &temp_file_path, file_path, data, mode, ) .map_err(|err| add_file_context_to_err(file_path, err)); } Err(create_err) => { if !parent_dir_path.exists() { return Err(Error::new( create_err.kind(), format!( "{:#} (for '{}')\nCheck the permission of the directory.", create_err, parent_dir_path.display() ), )); } } } } return Err(add_file_context_to_err(file_path, write_err)); } Ok(()) } inner(file_path, data.as_ref(), mode) } /// Creates a std::fs::File handling if the parent does not exist. pub fn create_file(file_path: &Path) -> std::io::Result { match std::fs::File::create(file_path) { Ok(file) => Ok(file), Err(err) => { if err.kind() == ErrorKind::NotFound { let parent_dir_path = file_path.parent().unwrap(); match std::fs::create_dir_all(parent_dir_path) { Ok(()) => { return std::fs::File::create(file_path) .map_err(|err| add_file_context_to_err(file_path, err)); } Err(create_err) => { if !parent_dir_path.exists() { return Err(Error::new( create_err.kind(), format!( "{:#} (for '{}')\nCheck the permission of the directory.", create_err, parent_dir_path.display() ), )); } } } } Err(add_file_context_to_err(file_path, err)) } } } fn add_file_context_to_err(file_path: &Path, err: Error) -> Error { Error::new( err.kind(), format!("{:#} (for '{}')", err, file_path.display()), ) } pub fn write_file>( filename: &Path, data: T, mode: u32, ) -> std::io::Result<()> { write_file_2(filename, data, true, mode, true, false) } pub fn write_file_2>( filename: &Path, data: T, update_mode: bool, mode: u32, is_create: bool, is_append: bool, ) -> std::io::Result<()> { let mut file = OpenOptions::new() .read(false) .write(true) .append(is_append) .truncate(!is_append) .create(is_create) .open(filename)?; if update_mode { #[cfg(unix)] { use std::os::unix::fs::PermissionsExt; let mode = mode & 0o777; let permissions = PermissionsExt::from_mode(mode); file.set_permissions(permissions)?; } #[cfg(not(unix))] let _ = mode; } file.write_all(data.as_ref()) } /// Similar to `std::fs::canonicalize()` but strips UNC prefixes on Windows. pub fn canonicalize_path(path: &Path) -> Result { Ok(deno_core::strip_unc_prefix(path.canonicalize()?)) } /// Canonicalizes a path which might be non-existent by going up the /// ancestors until it finds a directory that exists, canonicalizes /// that path, then adds back the remaining path components. /// /// Note: When using this, you should be aware that a symlink may /// subsequently be created along this path by some other code. pub fn canonicalize_path_maybe_not_exists( path: &Path, ) -> Result { canonicalize_path_maybe_not_exists_with_custom_fn(path, canonicalize_path) } pub fn canonicalize_path_maybe_not_exists_with_fs( path: &Path, fs: &dyn FileSystem, ) -> Result { canonicalize_path_maybe_not_exists_with_custom_fn(path, |path| { fs.realpath_sync(path).map_err(|err| err.into_io_error()) }) } fn canonicalize_path_maybe_not_exists_with_custom_fn( path: &Path, canonicalize: impl Fn(&Path) -> Result, ) -> Result { let path = path.to_path_buf().clean(); let mut path = path.as_path(); let mut names_stack = Vec::new(); loop { match canonicalize(path) { Ok(mut canonicalized_path) => { for name in names_stack.into_iter().rev() { canonicalized_path = canonicalized_path.join(name); } return Ok(canonicalized_path); } Err(err) if err.kind() == ErrorKind::NotFound => { names_stack.push(match path.file_name() { Some(name) => name.to_owned(), None => return Err(err), }); path = match path.parent() { Some(parent) => parent, None => return Err(err), }; } Err(err) => return Err(err), } } } pub fn resolve_from_cwd(path: &Path) -> Result { let resolved_path = if path.is_absolute() { path.to_owned() } else { let cwd = current_dir().context("Failed to get current working directory")?; cwd.join(path) }; Ok(normalize_path(resolved_path)) } /// Collects module specifiers that satisfy the given predicate as a file path, by recursively walking `include`. /// Specifiers that start with http and https are left intact. /// Note: This ignores all .git and node_modules folders. pub fn collect_specifiers( mut files: FilePatterns, vendor_folder: Option, predicate: impl Fn(WalkEntry) -> bool, ) -> Result, AnyError> { let mut prepared = vec![]; // break out the remote specifiers if let Some(include_mut) = &mut files.include { let includes = std::mem::take(include_mut); let path_or_patterns = includes.into_path_or_patterns(); let mut result = Vec::with_capacity(path_or_patterns.len()); for path_or_pattern in path_or_patterns { match path_or_pattern { PathOrPattern::Path(path) => { if path.is_dir() { result.push(PathOrPattern::Path(path)); } else if !files.exclude.matches_path(&path) { let url = specifier_from_file_path(&path)?; prepared.push(url); } } PathOrPattern::NegatedPath(path) => { // add it back result.push(PathOrPattern::NegatedPath(path)); } PathOrPattern::RemoteUrl(remote_url) => { prepared.push(remote_url); } PathOrPattern::Pattern(pattern) => { // add it back result.push(PathOrPattern::Pattern(pattern)); } } } *include_mut = PathOrPatternSet::new(result); } let collected_files = FileCollector::new(predicate) .ignore_git_folder() .ignore_node_modules() .set_vendor_folder(vendor_folder) .collect_file_patterns(&deno_config::fs::RealDenoConfigFs, files)?; let mut collected_files_as_urls = collected_files .iter() .map(|f| specifier_from_file_path(f).unwrap()) .collect::>(); collected_files_as_urls.sort(); prepared.extend(collected_files_as_urls); Ok(prepared) } /// Asynchronously removes a directory and all its descendants, but does not error /// when the directory does not exist. pub async fn remove_dir_all_if_exists(path: &Path) -> std::io::Result<()> { let result = tokio::fs::remove_dir_all(path).await; match result { Err(err) if err.kind() == std::io::ErrorKind::NotFound => Ok(()), _ => result, } } mod clone_dir_imp { #[cfg(target_vendor = "apple")] mod apple { use super::super::copy_dir_recursive; use deno_core::error::AnyError; use std::os::unix::ffi::OsStrExt; use std::path::Path; fn clonefile(from: &Path, to: &Path) -> std::io::Result<()> { let from = std::ffi::CString::new(from.as_os_str().as_bytes())?; let to = std::ffi::CString::new(to.as_os_str().as_bytes())?; // SAFETY: `from` and `to` are valid C strings. let ret = unsafe { libc::clonefile(from.as_ptr(), to.as_ptr(), 0) }; if ret != 0 { return Err(std::io::Error::last_os_error()); } Ok(()) } pub fn clone_dir_recursive(from: &Path, to: &Path) -> Result<(), AnyError> { if let Some(parent) = to.parent() { std::fs::create_dir_all(parent)?; } // Try to clone the whole directory if let Err(err) = clonefile(from, to) { if err.kind() != std::io::ErrorKind::AlreadyExists { log::warn!( "Failed to clone dir {:?} to {:?} via clonefile: {}", from, to, err ); } // clonefile won't overwrite existing files, so if the dir exists // we need to handle it recursively. copy_dir_recursive(from, to)?; } Ok(()) } } #[cfg(target_vendor = "apple")] pub(super) use apple::clone_dir_recursive; #[cfg(not(target_vendor = "apple"))] pub(super) fn clone_dir_recursive( from: &std::path::Path, to: &std::path::Path, ) -> Result<(), deno_core::error::AnyError> { if let Err(e) = super::hard_link_dir_recursive(from, to) { log::debug!("Failed to hard link dir {:?} to {:?}: {}", from, to, e); super::copy_dir_recursive(from, to)?; } Ok(()) } } /// Clones a directory to another directory. The exact method /// is not guaranteed - it may be a hardlink, copy, or other platform-specific /// operation. /// /// Note: Does not handle symlinks. pub fn clone_dir_recursive(from: &Path, to: &Path) -> Result<(), AnyError> { clone_dir_imp::clone_dir_recursive(from, to) } /// Copies a directory to another directory. /// /// Note: Does not handle symlinks. pub fn copy_dir_recursive(from: &Path, to: &Path) -> Result<(), AnyError> { std::fs::create_dir_all(to) .with_context(|| format!("Creating {}", to.display()))?; let read_dir = std::fs::read_dir(from) .with_context(|| format!("Reading {}", from.display()))?; for entry in read_dir { let entry = entry?; let file_type = entry.file_type()?; let new_from = from.join(entry.file_name()); let new_to = to.join(entry.file_name()); if file_type.is_dir() { copy_dir_recursive(&new_from, &new_to).with_context(|| { format!("Dir {} to {}", new_from.display(), new_to.display()) })?; } else if file_type.is_file() { std::fs::copy(&new_from, &new_to).with_context(|| { format!("Copying {} to {}", new_from.display(), new_to.display()) })?; } } Ok(()) } /// Hardlinks the files in one directory to another directory. /// /// Note: Does not handle symlinks. pub fn hard_link_dir_recursive(from: &Path, to: &Path) -> Result<(), AnyError> { std::fs::create_dir_all(to) .with_context(|| format!("Creating {}", to.display()))?; let read_dir = std::fs::read_dir(from) .with_context(|| format!("Reading {}", from.display()))?; for entry in read_dir { let entry = entry?; let file_type = entry.file_type()?; let new_from = from.join(entry.file_name()); let new_to = to.join(entry.file_name()); if file_type.is_dir() { hard_link_dir_recursive(&new_from, &new_to).with_context(|| { format!("Dir {} to {}", new_from.display(), new_to.display()) })?; } else if file_type.is_file() { // note: chance for race conditions here between attempting to create, // then removing, then attempting to create. There doesn't seem to be // a way to hard link with overwriting in Rust, but maybe there is some // way with platform specific code. The workaround here is to handle // scenarios where something else might create or remove files. if let Err(err) = std::fs::hard_link(&new_from, &new_to) { if err.kind() == ErrorKind::AlreadyExists { if let Err(err) = std::fs::remove_file(&new_to) { if err.kind() == ErrorKind::NotFound { // Assume another process/thread created this hard link to the file we are wanting // to remove then sleep a little bit to let the other process/thread move ahead // faster to reduce contention. std::thread::sleep(Duration::from_millis(10)); } else { return Err(err).with_context(|| { format!( "Removing file to hard link {} to {}", new_from.display(), new_to.display() ) }); } } // Always attempt to recreate the hardlink. In contention scenarios, the other process // might have been killed or exited after removing the file, but before creating the hardlink if let Err(err) = std::fs::hard_link(&new_from, &new_to) { // Assume another process/thread created this hard link to the file we are wanting // to now create then sleep a little bit to let the other process/thread move ahead // faster to reduce contention. if err.kind() == ErrorKind::AlreadyExists { std::thread::sleep(Duration::from_millis(10)); } else { return Err(err).with_context(|| { format!( "Hard linking {} to {}", new_from.display(), new_to.display() ) }); } } } else { return Err(err).with_context(|| { format!( "Hard linking {} to {}", new_from.display(), new_to.display() ) }); } } } } Ok(()) } pub fn symlink_dir(oldpath: &Path, newpath: &Path) -> Result<(), AnyError> { let err_mapper = |err: Error| { Error::new( err.kind(), format!( "{}, symlink '{}' -> '{}'", err, oldpath.display(), newpath.display() ), ) }; #[cfg(unix)] { use std::os::unix::fs::symlink; symlink(oldpath, newpath).map_err(err_mapper)?; } #[cfg(not(unix))] { use std::os::windows::fs::symlink_dir; symlink_dir(oldpath, newpath).map_err(err_mapper)?; } Ok(()) } /// Gets the total size (in bytes) of a directory. pub fn dir_size(path: &Path) -> std::io::Result { let entries = std::fs::read_dir(path)?; let mut total = 0; for entry in entries { let entry = entry?; total += match entry.metadata()? { data if data.is_dir() => dir_size(&entry.path())?, data => data.len(), }; } Ok(total) } struct LaxSingleProcessFsFlagInner { file_path: PathBuf, fs_file: std::fs::File, finished_token: Arc, } impl Drop for LaxSingleProcessFsFlagInner { fn drop(&mut self) { use fs3::FileExt; // kill the poll thread self.finished_token.cancel(); // release the file lock if let Err(err) = self.fs_file.unlock() { log::debug!( "Failed releasing lock for {}. {:#}", self.file_path.display(), err ); } } } /// A file system based flag that will attempt to synchronize multiple /// processes so they go one after the other. In scenarios where /// synchronization cannot be achieved, it will allow the current process /// to proceed. /// /// This should only be used in places where it's ideal for multiple /// processes to not update something on the file system at the same time, /// but it's not that big of a deal. pub struct LaxSingleProcessFsFlag( #[allow(dead_code)] Option, ); impl LaxSingleProcessFsFlag { pub async fn lock(file_path: PathBuf, long_wait_message: &str) -> Self { log::debug!("Acquiring file lock at {}", file_path.display()); use fs3::FileExt; let last_updated_path = file_path.with_extension("lock.poll"); let start_instant = std::time::Instant::now(); let open_result = std::fs::OpenOptions::new() .read(true) .write(true) .create(true) .truncate(false) .open(&file_path); match open_result { Ok(fs_file) => { let mut pb_update_guard = None; let mut error_count = 0; while error_count < 10 { let lock_result = fs_file.try_lock_exclusive(); let poll_file_update_ms = 100; match lock_result { Ok(_) => { log::debug!("Acquired file lock at {}", file_path.display()); let _ignore = std::fs::write(&last_updated_path, ""); let token = Arc::new(tokio_util::sync::CancellationToken::new()); // Spawn a blocking task that will continually update a file // signalling the lock is alive. This is a fail safe for when // a file lock is never released. For example, on some operating // systems, if a process does not release the lock (say it's // killed), then the OS may release it at an indeterminate time // // This uses a blocking task because we use a single threaded // runtime and this is time sensitive so we don't want it to update // at the whims of of whatever is occurring on the runtime thread. spawn_blocking({ let token = token.clone(); let last_updated_path = last_updated_path.clone(); move || { let mut i = 0; while !token.is_cancelled() { i += 1; let _ignore = std::fs::write(&last_updated_path, i.to_string()); std::thread::sleep(Duration::from_millis( poll_file_update_ms, )); } } }); return Self(Some(LaxSingleProcessFsFlagInner { file_path, fs_file, finished_token: token, })); } Err(_) => { // show a message if it's been a while if pb_update_guard.is_none() && start_instant.elapsed().as_millis() > 1_000 { let pb = ProgressBar::new(ProgressBarStyle::TextOnly); let guard = pb.update_with_prompt( ProgressMessagePrompt::Blocking, long_wait_message, ); pb_update_guard = Some((guard, pb)); } // sleep for a little bit tokio::time::sleep(Duration::from_millis(20)).await; // Poll the last updated path to check if it's stopped updating, // which is an indication that the file lock is claimed, but // was never properly released. match std::fs::metadata(&last_updated_path) .and_then(|p| p.modified()) { Ok(last_updated_time) => { let current_time = std::time::SystemTime::now(); match current_time.duration_since(last_updated_time) { Ok(duration) => { if duration.as_millis() > (poll_file_update_ms * 2) as u128 { // the other process hasn't updated this file in a long time // so maybe it was killed and the operating system hasn't // released the file lock yet return Self(None); } else { error_count = 0; // reset } } Err(_) => { error_count += 1; } } } Err(_) => { error_count += 1; } } } } } drop(pb_update_guard); // explicit for clarity Self(None) } Err(err) => { log::debug!( "Failed to open file lock at {}. {:#}", file_path.display(), err ); Self(None) // let the process through } } } } pub fn specifier_from_file_path( path: &Path, ) -> Result { ModuleSpecifier::from_file_path(path) .map_err(|_| anyhow!("Invalid file path '{}'", path.display())) } #[cfg(test)] mod tests { use super::*; use deno_core::futures; use deno_core::parking_lot::Mutex; use pretty_assertions::assert_eq; use test_util::PathRef; use test_util::TempDir; use tokio::sync::Notify; #[test] fn resolve_from_cwd_child() { let cwd = current_dir().unwrap(); assert_eq!(resolve_from_cwd(Path::new("a")).unwrap(), cwd.join("a")); } #[test] fn resolve_from_cwd_dot() { let cwd = current_dir().unwrap(); assert_eq!(resolve_from_cwd(Path::new(".")).unwrap(), cwd); } #[test] fn resolve_from_cwd_parent() { let cwd = current_dir().unwrap(); assert_eq!(resolve_from_cwd(Path::new("a/..")).unwrap(), cwd); } #[test] fn test_normalize_path() { assert_eq!(normalize_path(Path::new("a/../b")), PathBuf::from("b")); assert_eq!(normalize_path(Path::new("a/./b/")), PathBuf::from("a/b/")); assert_eq!( normalize_path(Path::new("a/./b/../c")), PathBuf::from("a/c") ); if cfg!(windows) { assert_eq!( normalize_path(Path::new("C:\\a\\.\\b\\..\\c")), PathBuf::from("C:\\a\\c") ); } } #[test] fn resolve_from_cwd_absolute() { let expected = Path::new("a"); let cwd = current_dir().unwrap(); let absolute_expected = cwd.join(expected); assert_eq!(resolve_from_cwd(expected).unwrap(), absolute_expected); } #[test] fn test_collect_specifiers() { fn create_files(dir_path: &PathRef, files: &[&str]) { dir_path.create_dir_all(); for f in files { dir_path.join(f).write(""); } } // dir.ts // ├── a.ts // ├── b.js // ├── child // │ ├── e.mjs // │ ├── f.mjsx // │ ├── .foo.TS // │ └── README.md // ├── c.tsx // ├── d.jsx // └── ignore // ├── g.d.ts // └── .gitignore let t = TempDir::new(); let root_dir_path = t.path().join("dir.ts"); let root_dir_files = ["a.ts", "b.js", "c.tsx", "d.jsx"]; create_files(&root_dir_path, &root_dir_files); let child_dir_path = root_dir_path.join("child"); let child_dir_files = ["e.mjs", "f.mjsx", ".foo.TS", "README.md"]; create_files(&child_dir_path, &child_dir_files); let ignore_dir_path = root_dir_path.join("ignore"); let ignore_dir_files = ["g.d.ts", ".gitignore"]; create_files(&ignore_dir_path, &ignore_dir_files); let predicate = |e: WalkEntry| { // exclude dotfiles e.path .file_name() .and_then(|f| f.to_str()) .map(|f| !f.starts_with('.')) .unwrap_or(false) }; let result = collect_specifiers( FilePatterns { base: root_dir_path.to_path_buf(), include: Some( PathOrPatternSet::from_include_relative_path_or_patterns( root_dir_path.as_path(), &[ "http://localhost:8080".to_string(), "./".to_string(), "https://localhost:8080".to_string(), ], ) .unwrap(), ), exclude: PathOrPatternSet::new(vec![PathOrPattern::Path( ignore_dir_path.to_path_buf(), )]), }, None, predicate, ) .unwrap(); let root_dir_url = ModuleSpecifier::from_file_path(&root_dir_path) .unwrap() .to_string(); let expected = vec![ "http://localhost:8080/".to_string(), "https://localhost:8080/".to_string(), format!("{root_dir_url}/a.ts"), format!("{root_dir_url}/b.js"), format!("{root_dir_url}/c.tsx"), format!("{root_dir_url}/child/README.md"), format!("{root_dir_url}/child/e.mjs"), format!("{root_dir_url}/child/f.mjsx"), format!("{root_dir_url}/d.jsx"), ]; assert_eq!( result .into_iter() .map(|s| s.to_string()) .collect::>(), expected ); let scheme = if cfg!(target_os = "windows") { "file:///" } else { "file://" }; let result = collect_specifiers( FilePatterns { base: root_dir_path.to_path_buf(), include: Some(PathOrPatternSet::new(vec![PathOrPattern::new( &format!( "{}{}", scheme, root_dir_path.join("child").to_string().replace('\\', "/") ), ) .unwrap()])), exclude: Default::default(), }, None, predicate, ) .unwrap(); let expected = vec![ format!("{root_dir_url}/child/README.md"), format!("{root_dir_url}/child/e.mjs"), format!("{root_dir_url}/child/f.mjsx"), ]; assert_eq!( result .into_iter() .map(|s| s.to_string()) .collect::>(), expected ); } #[tokio::test] async fn lax_fs_lock() { let temp_dir = TempDir::new(); let lock_path = temp_dir.path().join("file.lock"); let signal1 = Arc::new(Notify::new()); let signal2 = Arc::new(Notify::new()); let signal3 = Arc::new(Notify::new()); let signal4 = Arc::new(Notify::new()); tokio::spawn({ let lock_path = lock_path.clone(); let signal1 = signal1.clone(); let signal2 = signal2.clone(); let signal3 = signal3.clone(); let signal4 = signal4.clone(); let temp_dir = temp_dir.clone(); async move { let flag = LaxSingleProcessFsFlag::lock(lock_path.to_path_buf(), "waiting") .await; signal1.notify_one(); signal2.notified().await; tokio::time::sleep(Duration::from_millis(10)).await; // give the other thread time to acquire the lock temp_dir.write("file.txt", "update1"); signal3.notify_one(); signal4.notified().await; drop(flag); } }); let signal5 = Arc::new(Notify::new()); tokio::spawn({ let temp_dir = temp_dir.clone(); let signal5 = signal5.clone(); async move { signal1.notified().await; signal2.notify_one(); let flag = LaxSingleProcessFsFlag::lock(lock_path.to_path_buf(), "waiting") .await; temp_dir.write("file.txt", "update2"); signal5.notify_one(); drop(flag); } }); signal3.notified().await; assert_eq!(temp_dir.read_to_string("file.txt"), "update1"); signal4.notify_one(); signal5.notified().await; assert_eq!(temp_dir.read_to_string("file.txt"), "update2"); } #[tokio::test] async fn lax_fs_lock_ordered() { let temp_dir = TempDir::new(); let lock_path = temp_dir.path().join("file.lock"); let output_path = temp_dir.path().join("output"); let expected_order = Arc::new(Mutex::new(Vec::new())); let count = 10; let mut tasks = Vec::with_capacity(count); std::fs::write(&output_path, "").unwrap(); for i in 0..count { let lock_path = lock_path.clone(); let output_path = output_path.clone(); let expected_order = expected_order.clone(); tasks.push(tokio::spawn(async move { let flag = LaxSingleProcessFsFlag::lock(lock_path.to_path_buf(), "waiting") .await; expected_order.lock().push(i.to_string()); // be extremely racy let mut output = std::fs::read_to_string(&output_path).unwrap(); if !output.is_empty() { output.push('\n'); } output.push_str(&i.to_string()); std::fs::write(&output_path, output).unwrap(); drop(flag); })); } futures::future::join_all(tasks).await; let expected_output = expected_order.lock().join("\n"); assert_eq!( std::fs::read_to_string(output_path).unwrap(), expected_output ); } }