From 0f98e75b69d16edce9ca60d7961b8440856a3f72 Mon Sep 17 00:00:00 2001 From: Aaron Turon Date: Thu, 9 Oct 2014 16:27:28 -0700 Subject: [PATCH] Runtime removal: refactor process This patch continues the runtime removal by moving and refactoring the process implementation into the new `sys` module. Because this eliminates APIs in `libnative` and `librustrt`, it is a: [breaking-change] This functionality is likely to be available publicly, in some form, from `std` in the future. --- src/libnative/io/mod.rs | 20 - src/librustrt/rtio.rs | 66 -- src/libstd/io/process.rs | 228 ++++--- src/libstd/sys/common/helper_thread.rs | 11 - src/libstd/{platform_imp => sys}/unix/fs.rs | 0 src/libstd/sys/unix/mod.rs | 2 +- src/libstd/sys/unix/process.rs | 587 ++++++++++++++++++ .../{platform_imp => sys}/windows/fs.rs | 0 src/libstd/sys/windows/mod.rs | 1 + src/libstd/sys/windows/process.rs | 511 +++++++++++++++ 10 files changed, 1250 insertions(+), 176 deletions(-) rename src/libstd/{platform_imp => sys}/unix/fs.rs (100%) create mode 100644 src/libstd/sys/unix/process.rs rename src/libstd/{platform_imp => sys}/windows/fs.rs (100%) create mode 100644 src/libstd/sys/windows/process.rs diff --git a/src/libnative/io/mod.rs b/src/libnative/io/mod.rs index 1d0b9f40d07..29370dee88b 100644 --- a/src/libnative/io/mod.rs +++ b/src/libnative/io/mod.rs @@ -29,13 +29,6 @@ use std::os; use std::rt::rtio::{mod, IoResult, IoError}; use std::num; -// Local re-exports -pub use self::process::Process; - -// Native I/O implementations -pub mod process; -mod util; - #[cfg(any(target_os = "macos", target_os = "ios", target_os = "freebsd", @@ -123,19 +116,6 @@ impl rtio::IoFactory for IoFactory { fn timer_init(&mut self) -> IoResult> { timer::Timer::new().map(|t| box t as Box) } - fn spawn(&mut self, cfg: rtio::ProcessConfig) - -> IoResult<(Box, - Vec>>)> { - process::Process::spawn(cfg).map(|(p, io)| { - (box p as Box, - io.into_iter().map(|p| p.map(|p| { - box p as Box - })).collect()) - }) - } - fn kill(&mut self, pid: libc::pid_t, signum: int) -> IoResult<()> { - process::Process::kill(pid, signum) - } #[cfg(unix)] fn tty_open(&mut self, fd: c_int, _readable: bool) -> IoResult> { diff --git a/src/librustrt/rtio.rs b/src/librustrt/rtio.rs index 3ebfcaea687..cdcefc2088e 100644 --- a/src/librustrt/rtio.rs +++ b/src/librustrt/rtio.rs @@ -46,61 +46,6 @@ pub trait RemoteCallback { fn fire(&mut self); } -/// Data needed to spawn a process. Serializes the `std::io::process::Command` -/// builder. -pub struct ProcessConfig<'a> { - /// Path to the program to run. - pub program: &'a CString, - - /// Arguments to pass to the program (doesn't include the program itself). - pub args: &'a [CString], - - /// Optional environment to specify for the program. If this is None, then - /// it will inherit the current process's environment. - pub env: Option<&'a [(&'a CString, &'a CString)]>, - - /// Optional working directory for the new process. If this is None, then - /// the current directory of the running process is inherited. - pub cwd: Option<&'a CString>, - - /// Configuration for the child process's stdin handle (file descriptor 0). - /// This field defaults to `CreatePipe(true, false)` so the input can be - /// written to. - pub stdin: StdioContainer, - - /// Configuration for the child process's stdout handle (file descriptor 1). - /// This field defaults to `CreatePipe(false, true)` so the output can be - /// collected. - pub stdout: StdioContainer, - - /// Configuration for the child process's stdout handle (file descriptor 2). - /// This field defaults to `CreatePipe(false, true)` so the output can be - /// collected. - pub stderr: StdioContainer, - - /// Any number of streams/file descriptors/pipes may be attached to this - /// process. This list enumerates the file descriptors and such for the - /// process to be spawned, and the file descriptors inherited will start at - /// 3 and go to the length of this array. The first three file descriptors - /// (stdin/stdout/stderr) are configured with the `stdin`, `stdout`, and - /// `stderr` fields. - pub extra_io: &'a [StdioContainer], - - /// Sets the child process's user id. This translates to a `setuid` call in - /// the child process. Setting this value on windows will cause the spawn to - /// fail. Failure in the `setuid` call on unix will also cause the spawn to - /// fail. - pub uid: Option, - - /// Similar to `uid`, but sets the group id of the child process. This has - /// the same semantics as the `uid` field. - pub gid: Option, - - /// If true, the child process is spawned in a detached state. On unix, this - /// means that the child is the leader of a new process group. - pub detach: bool, -} - pub struct LocalIo<'a> { factory: &'a mut IoFactory+'a, } @@ -170,10 +115,6 @@ impl<'a> LocalIo<'a> { pub trait IoFactory { fn timer_init(&mut self) -> IoResult>; - fn spawn(&mut self, cfg: ProcessConfig) - -> IoResult<(Box, - Vec>>)>; - fn kill(&mut self, pid: libc::pid_t, signal: int) -> IoResult<()>; fn tty_open(&mut self, fd: c_int, readable: bool) -> IoResult>; } @@ -184,13 +125,6 @@ pub trait RtioTimer { fn period(&mut self, msecs: u64, cb: Box); } -pub trait RtioProcess { - fn id(&self) -> libc::pid_t; - fn kill(&mut self, signal: int) -> IoResult<()>; - fn wait(&mut self) -> IoResult; - fn set_timeout(&mut self, timeout: Option); -} - pub trait RtioPipe { fn read(&mut self, buf: &mut [u8]) -> IoResult; fn write(&mut self, buf: &[u8]) -> IoResult<()>; diff --git a/src/libstd/io/process.rs b/src/libstd/io/process.rs index 698e0a3460f..d71bab0b48f 100644 --- a/src/libstd/io/process.rs +++ b/src/libstd/io/process.rs @@ -20,14 +20,17 @@ use os; use io::{IoResult, IoError}; use io; use libc; -use mem; -use rt::rtio::{RtioProcess, ProcessConfig, IoFactory, LocalIo}; -use rt::rtio; use c_str::CString; use collections::HashMap; use hash::Hash; #[cfg(windows)] use std::hash::sip::SipState; +use io::pipe::{PipeStream, PipePair}; +use path::BytesContainer; + +use sys; +use sys::fs::FileDesc; +use sys::process::Process as ProcessImp; /// Signal a process to exit, without forcibly killing it. Corresponds to /// SIGTERM on unix platforms. @@ -62,24 +65,29 @@ use std::hash::sip::SipState; /// assert!(child.wait().unwrap().success()); /// ``` pub struct Process { - handle: Box, + handle: ProcessImp, forget: bool, + /// None until wait() is called. + exit_code: Option, + + /// Manually delivered signal + exit_signal: Option, + + /// Deadline after which wait() will return + deadline: u64, + /// Handle to the child's stdin, if the `stdin` field of this process's /// `ProcessConfig` was `CreatePipe`. By default, this handle is `Some`. - pub stdin: Option, + pub stdin: Option, /// Handle to the child's stdout, if the `stdout` field of this process's /// `ProcessConfig` was `CreatePipe`. By default, this handle is `Some`. - pub stdout: Option, + pub stdout: Option, /// Handle to the child's stderr, if the `stderr` field of this process's /// `ProcessConfig` was `CreatePipe`. By default, this handle is `Some`. - pub stderr: Option, - - /// Extra I/O handles as configured by the original `ProcessConfig` when - /// this process was created. This is by default empty. - pub extra_io: Vec>, + pub stderr: Option, } /// A representation of environment variable name @@ -130,6 +138,13 @@ impl PartialEq for EnvKey { } } +impl BytesContainer for EnvKey { + fn container_as_bytes<'a>(&'a self) -> &'a [u8] { + let &EnvKey(ref k) = self; + k.container_as_bytes() + } +} + /// A HashMap representation of environment variables. pub type EnvMap = HashMap; @@ -160,7 +175,6 @@ pub struct Command { stdin: StdioContainer, stdout: StdioContainer, stderr: StdioContainer, - extra_io: Vec, uid: Option, gid: Option, detach: bool, @@ -194,7 +208,6 @@ impl Command { stdin: CreatePipe(true, false), stdout: CreatePipe(false, true), stderr: CreatePipe(false, true), - extra_io: Vec::new(), uid: None, gid: None, detach: false, @@ -281,14 +294,6 @@ impl Command { self.stderr = cfg; self } - /// Attaches a stream/file descriptor/pipe to the child process. Inherited - /// file descriptors are numbered consecutively, starting at 3; the first - /// three file descriptors (stdin/stdout/stderr) are configured with the - /// `stdin`, `stdout`, and `stderr` methods. - pub fn extra_io<'a>(&'a mut self, cfg: StdioContainer) -> &'a mut Command { - self.extra_io.push(cfg); - self - } /// Sets the child process's user id. This translates to a `setuid` call in /// the child process. Setting this value on windows will cause the spawn to @@ -315,50 +320,23 @@ impl Command { /// Executes the command as a child process, which is returned. pub fn spawn(&self) -> IoResult { - fn to_rtio(p: StdioContainer) -> rtio::StdioContainer { - match p { - Ignored => rtio::Ignored, - InheritFd(fd) => rtio::InheritFd(fd), - CreatePipe(a, b) => rtio::CreatePipe(a, b), - } - } - let extra_io: Vec = - self.extra_io.iter().map(|x| to_rtio(*x)).collect(); - LocalIo::maybe_raise(|io| { - let env = match self.env { - None => None, - Some(ref env_map) => - Some(env_map.iter() - .map(|(&EnvKey(ref key), val)| (key, val)) - .collect::>()) - }; - let cfg = ProcessConfig { - program: &self.program, - args: self.args.as_slice(), - env: env.as_ref().map(|e| e.as_slice()), - cwd: self.cwd.as_ref(), - stdin: to_rtio(self.stdin), - stdout: to_rtio(self.stdout), - stderr: to_rtio(self.stderr), - extra_io: extra_io.as_slice(), - uid: self.uid, - gid: self.gid, - detach: self.detach, - }; - io.spawn(cfg).map(|(p, io)| { - let mut io = io.into_iter().map(|p| { - p.map(|p| io::PipeStream::new(p)) - }); - Process { - handle: p, - forget: false, - stdin: io.next().unwrap(), - stdout: io.next().unwrap(), - stderr: io.next().unwrap(), - extra_io: io.collect(), - } + let (their_stdin, our_stdin) = try!(setup_io(self.stdin)); + let (their_stdout, our_stdout) = try!(setup_io(self.stdout)); + let (their_stderr, our_stderr) = try!(setup_io(self.stderr)); + + match ProcessImp::spawn(self, their_stdin, their_stdout, their_stderr) { + Err(e) => Err(e), + Ok(handle) => Ok(Process { + handle: handle, + forget: false, + exit_code: None, + exit_signal: None, + deadline: 0, + stdin: our_stdin, + stdout: our_stdout, + stderr: our_stderr, }) - }).map_err(IoError::from_rtio_error) + } } /// Executes the command as a child process, waiting for it to finish and @@ -415,6 +393,58 @@ impl fmt::Show for Command { } } +fn setup_io(io: StdioContainer) -> IoResult<(Option, Option)> { + let ours; + let theirs; + match io { + Ignored => { + theirs = None; + ours = None; + } + InheritFd(fd) => { + theirs = Some(PipeStream::from_filedesc(FileDesc::new(fd, false))); + ours = None; + } + CreatePipe(readable, _writable) => { + let PipePair { reader, writer } = try!(PipeStream::pair()); + if readable { + theirs = Some(reader); + ours = Some(writer); + } else { + theirs = Some(writer); + ours = Some(reader); + } + } + } + Ok((theirs, ours)) +} + +// Allow the sys module to get access to the Command state +impl sys::process::ProcessConfig for Command { + fn program(&self) -> &CString { + &self.program + } + fn args(&self) -> &[CString] { + self.args.as_slice() + } + fn env(&self) -> Option<&EnvMap> { + self.env.as_ref() + } + fn cwd(&self) -> Option<&CString> { + self.cwd.as_ref() + } + fn uid(&self) -> Option { + self.uid.clone() + } + fn gid(&self) -> Option { + self.gid.clone() + } + fn detach(&self) -> bool { + self.detach + } + +} + /// The output of a finished process. #[deriving(PartialEq, Eq, Clone)] pub struct ProcessOutput { @@ -494,9 +524,7 @@ impl Process { /// be successfully delivered if the child has exited, but not yet been /// reaped. pub fn kill(id: libc::pid_t, signal: int) -> IoResult<()> { - LocalIo::maybe_raise(|io| { - io.kill(id, signal) - }).map_err(IoError::from_rtio_error) + unsafe { ProcessImp::killpid(id, signal) } } /// Returns the process id of this child process @@ -518,7 +546,42 @@ impl Process { /// /// If the signal delivery fails, the corresponding error is returned. pub fn signal(&mut self, signal: int) -> IoResult<()> { - self.handle.kill(signal).map_err(IoError::from_rtio_error) + #[cfg(unix)] fn collect_status(p: &mut Process) { + // On Linux (and possibly other unices), a process that has exited will + // continue to accept signals because it is "defunct". The delivery of + // signals will only fail once the child has been reaped. For this + // reason, if the process hasn't exited yet, then we attempt to collect + // their status with WNOHANG. + if p.exit_code.is_none() { + match p.handle.try_wait() { + Some(code) => { p.exit_code = Some(code); } + None => {} + } + } + } + #[cfg(windows)] fn collect_status(_p: &mut Process) {} + + collect_status(self); + + // if the process has finished, and therefore had waitpid called, + // and we kill it, then on unix we might ending up killing a + // newer process that happens to have the same (re-used) id + if self.exit_code.is_some() { + return Err(IoError { + kind: io::InvalidInput, + desc: "invalid argument: can't kill an exited process", + detail: None, + }) + } + + // A successfully delivered signal that isn't 0 (just a poll for being + // alive) is recorded for windows (see wait()) + match unsafe { self.handle.kill(signal) } { + Ok(()) if signal == 0 => Ok(()), + Ok(()) => { self.exit_signal = Some(signal); Ok(()) } + Err(e) => Err(e), + } + } /// Sends a signal to this child requesting that it exits. This is @@ -545,10 +608,21 @@ impl Process { /// `set_timeout` and the timeout expires before the child exits. pub fn wait(&mut self) -> IoResult { drop(self.stdin.take()); - match self.handle.wait() { - Ok(rtio::ExitSignal(s)) => Ok(ExitSignal(s)), - Ok(rtio::ExitStatus(s)) => Ok(ExitStatus(s)), - Err(e) => Err(IoError::from_rtio_error(e)), + match self.exit_code { + Some(code) => Ok(code), + None => { + let code = try!(self.handle.wait(self.deadline)); + // On windows, waitpid will never return a signal. If a signal + // was successfully delivered to the process, however, we can + // consider it as having died via a signal. + let code = match self.exit_signal { + None => code, + Some(signal) if cfg!(windows) => ExitSignal(signal), + Some(..) => code, + }; + self.exit_code = Some(code); + Ok(code) + } } } @@ -594,7 +668,7 @@ impl Process { /// ``` #[experimental = "the type of the timeout is likely to change"] pub fn set_timeout(&mut self, timeout_ms: Option) { - self.handle.set_timeout(timeout_ms) + self.deadline = timeout_ms.map(|i| i + sys::timer::now()).unwrap_or(0); } /// Simultaneously wait for the child to exit and collect all remaining @@ -653,7 +727,6 @@ impl Drop for Process { drop(self.stdin.take()); drop(self.stdout.take()); drop(self.stderr.take()); - drop(mem::replace(&mut self.extra_io, Vec::new())); self.set_timeout(None); let _ = self.wait().unwrap(); @@ -1109,8 +1182,7 @@ mod tests { #[test] fn dont_close_fd_on_command_spawn() { - use std::rt::rtio::{Truncate, Write}; - use self::native::io::file; + use sys::fs; let path = if cfg!(windows) { Path::new("NUL") @@ -1118,7 +1190,7 @@ mod tests { Path::new("/dev/null") }; - let mut fdes = match file::open(&path.to_c_str(), Truncate, Write) { + let mut fdes = match fs::open(&path, Truncate, Write) { Ok(f) => f, Err(_) => panic!("failed to open file descriptor"), }; @@ -1126,7 +1198,7 @@ mod tests { let mut cmd = pwd_cmd(); let _ = cmd.stdout(InheritFd(fdes.fd())); assert!(cmd.status().unwrap().success()); - assert!(fdes.inner_write("extra write\n".as_bytes()).is_ok()); + assert!(fdes.write("extra write\n".as_bytes()).is_ok()); } #[test] diff --git a/src/libstd/sys/common/helper_thread.rs b/src/libstd/sys/common/helper_thread.rs index 8c8ec4466a7..87907fde277 100644 --- a/src/libstd/sys/common/helper_thread.rs +++ b/src/libstd/sys/common/helper_thread.rs @@ -20,8 +20,6 @@ //! can be created in the future and there must be no active timers at that //! time. -#![macro_escape] - use mem; use rt::bookkeeping; use rt::mutex::StaticNativeMutex; @@ -57,15 +55,6 @@ pub struct Helper { pub initialized: UnsafeCell, } -macro_rules! helper_init( (static $name:ident: Helper<$m:ty>) => ( - static $name: Helper<$m> = Helper { - lock: ::std::rt::mutex::NATIVE_MUTEX_INIT, - chan: ::std::cell::UnsafeCell { value: 0 as *mut Sender<$m> }, - signal: ::std::cell::UnsafeCell { value: 0 }, - initialized: ::std::cell::UnsafeCell { value: false }, - }; -) ) - impl Helper { /// Lazily boots a helper thread, becoming a no-op if the helper has already /// been spawned. diff --git a/src/libstd/platform_imp/unix/fs.rs b/src/libstd/sys/unix/fs.rs similarity index 100% rename from src/libstd/platform_imp/unix/fs.rs rename to src/libstd/sys/unix/fs.rs diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs index 6295864e0e1..b404dc7fdbd 100644 --- a/src/libstd/sys/unix/mod.rs +++ b/src/libstd/sys/unix/mod.rs @@ -17,7 +17,6 @@ use prelude::*; use io::{mod, IoResult, IoError}; use sys_common::mkerr_libc; - macro_rules! helper_init( (static $name:ident: Helper<$m:ty>) => ( static $name: Helper<$m> = Helper { lock: ::rt::mutex::NATIVE_MUTEX_INIT, @@ -34,6 +33,7 @@ pub mod tcp; pub mod udp; pub mod pipe; pub mod helper_signal; +pub mod process; pub mod addrinfo { pub use sys_common::net::get_host_addresses; diff --git a/src/libstd/sys/unix/process.rs b/src/libstd/sys/unix/process.rs new file mode 100644 index 00000000000..0965d98d9b0 --- /dev/null +++ b/src/libstd/sys/unix/process.rs @@ -0,0 +1,587 @@ +// Copyright 2014 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use libc::{mod, pid_t, c_void, c_int}; +use c_str::CString; +use io::{mod, IoResult, IoError}; +use mem; +use os; +use ptr; +use prelude::*; +use io::process::{ProcessExit, ExitStatus, ExitSignal}; +use collections; +use path::BytesContainer; +use hash::Hash; + +use sys::{mod, retry, c, wouldblock, set_nonblocking, ms_to_timeval}; +use sys::fs::FileDesc; +use sys_common::helper_thread::Helper; +use sys_common::{AsFileDesc, mkerr_libc, timeout}; + +pub use sys_common::ProcessConfig; + +helper_init!(static HELPER: Helper) + +/// The unique id of the process (this should never be negative). +pub struct Process { + pub pid: pid_t +} + +enum Req { + NewChild(libc::pid_t, Sender, u64), +} + +impl Process { + pub fn id(&self) -> pid_t { + self.pid + } + + pub unsafe fn kill(&self, signal: int) -> IoResult<()> { + Process::killpid(self.pid, signal) + } + + pub unsafe fn killpid(pid: pid_t, signal: int) -> IoResult<()> { + let r = libc::funcs::posix88::signal::kill(pid, signal as c_int); + mkerr_libc(r) + } + + pub fn spawn(cfg: &C, in_fd: Option

, + out_fd: Option

, err_fd: Option

) + -> IoResult + where C: ProcessConfig, P: AsFileDesc, + K: BytesContainer + Eq + Hash, V: BytesContainer + { + use libc::funcs::posix88::unistd::{fork, dup2, close, chdir, execvp}; + use libc::funcs::bsd44::getdtablesize; + + mod rustrt { + extern { + pub fn rust_unset_sigprocmask(); + } + } + + #[cfg(target_os = "macos")] + unsafe fn set_environ(envp: *const c_void) { + extern { fn _NSGetEnviron() -> *mut *const c_void; } + + *_NSGetEnviron() = envp; + } + #[cfg(not(target_os = "macos"))] + unsafe fn set_environ(envp: *const c_void) { + extern { static mut environ: *const c_void; } + environ = envp; + } + + unsafe fn set_cloexec(fd: c_int) { + let ret = c::ioctl(fd, c::FIOCLEX); + assert_eq!(ret, 0); + } + + let dirp = cfg.cwd().map(|c| c.as_ptr()).unwrap_or(ptr::null()); + + // temporary until unboxed closures land + let cfg = unsafe { + mem::transmute::<&ProcessConfig,&'static ProcessConfig>(cfg) + }; + + with_envp(cfg.env(), proc(envp) { + with_argv(cfg.program(), cfg.args(), proc(argv) unsafe { + let (input, mut output) = try!(sys::os::pipe()); + + // We may use this in the child, so perform allocations before the + // fork + let devnull = "/dev/null".to_c_str(); + + set_cloexec(output.fd()); + + let pid = fork(); + if pid < 0 { + return Err(super::last_error()) + } else if pid > 0 { + drop(output); + let mut bytes = [0, ..4]; + return match input.read(bytes) { + Ok(4) => { + let errno = (bytes[0] as i32 << 24) | + (bytes[1] as i32 << 16) | + (bytes[2] as i32 << 8) | + (bytes[3] as i32 << 0); + Err(super::decode_error(errno)) + } + Err(..) => Ok(Process { pid: pid }), + Ok(..) => panic!("short read on the cloexec pipe"), + }; + } + + // And at this point we've reached a special time in the life of the + // child. The child must now be considered hamstrung and unable to + // do anything other than syscalls really. Consider the following + // scenario: + // + // 1. Thread A of process 1 grabs the malloc() mutex + // 2. Thread B of process 1 forks(), creating thread C + // 3. Thread C of process 2 then attempts to malloc() + // 4. The memory of process 2 is the same as the memory of + // process 1, so the mutex is locked. + // + // This situation looks a lot like deadlock, right? It turns out + // that this is what pthread_atfork() takes care of, which is + // presumably implemented across platforms. The first thing that + // threads to *before* forking is to do things like grab the malloc + // mutex, and then after the fork they unlock it. + // + // Despite this information, libnative's spawn has been witnessed to + // deadlock on both OSX and FreeBSD. I'm not entirely sure why, but + // all collected backtraces point at malloc/free traffic in the + // child spawned process. + // + // For this reason, the block of code below should contain 0 + // invocations of either malloc of free (or their related friends). + // + // As an example of not having malloc/free traffic, we don't close + // this file descriptor by dropping the FileDesc (which contains an + // allocation). Instead we just close it manually. This will never + // have the drop glue anyway because this code never returns (the + // child will either exec() or invoke libc::exit) + let _ = libc::close(input.fd()); + + fn fail(output: &mut FileDesc) -> ! { + let errno = sys::os::errno(); + let bytes = [ + (errno >> 24) as u8, + (errno >> 16) as u8, + (errno >> 8) as u8, + (errno >> 0) as u8, + ]; + assert!(output.write(bytes).is_ok()); + unsafe { libc::_exit(1) } + } + + rustrt::rust_unset_sigprocmask(); + + // If a stdio file descriptor is set to be ignored (via a -1 file + // descriptor), then we don't actually close it, but rather open + // up /dev/null into that file descriptor. Otherwise, the first file + // descriptor opened up in the child would be numbered as one of the + // stdio file descriptors, which is likely to wreak havoc. + let setup = |src: Option

, dst: c_int| { + let src = match src { + None => { + let flags = if dst == libc::STDIN_FILENO { + libc::O_RDONLY + } else { + libc::O_RDWR + }; + libc::open(devnull.as_ptr(), flags, 0) + } + Some(obj) => { + let fd = obj.as_fd().fd(); + // Leak the memory and the file descriptor. We're in the + // child now an all our resources are going to be + // cleaned up very soon + mem::forget(obj); + fd + } + }; + src != -1 && retry(|| dup2(src, dst)) != -1 + }; + + if !setup(in_fd, libc::STDIN_FILENO) { fail(&mut output) } + if !setup(out_fd, libc::STDOUT_FILENO) { fail(&mut output) } + if !setup(err_fd, libc::STDERR_FILENO) { fail(&mut output) } + + // close all other fds + for fd in range(3, getdtablesize()).rev() { + if fd != output.fd() { + let _ = close(fd as c_int); + } + } + + match cfg.gid() { + Some(u) => { + if libc::setgid(u as libc::gid_t) != 0 { + fail(&mut output); + } + } + None => {} + } + match cfg.uid() { + Some(u) => { + // When dropping privileges from root, the `setgroups` call + // will remove any extraneous groups. If we don't call this, + // then even though our uid has dropped, we may still have + // groups that enable us to do super-user things. This will + // fail if we aren't root, so don't bother checking the + // return value, this is just done as an optimistic + // privilege dropping function. + extern { + fn setgroups(ngroups: libc::c_int, + ptr: *const libc::c_void) -> libc::c_int; + } + let _ = setgroups(0, 0 as *const libc::c_void); + + if libc::setuid(u as libc::uid_t) != 0 { + fail(&mut output); + } + } + None => {} + } + if cfg.detach() { + // Don't check the error of setsid because it fails if we're the + // process leader already. We just forked so it shouldn't return + // error, but ignore it anyway. + let _ = libc::setsid(); + } + if !dirp.is_null() && chdir(dirp) == -1 { + fail(&mut output); + } + if !envp.is_null() { + set_environ(envp); + } + let _ = execvp(*argv, argv as *mut _); + fail(&mut output); + }) + }) + } + + pub fn wait(&self, deadline: u64) -> IoResult { + use std::cmp; + use std::comm; + + static mut WRITE_FD: libc::c_int = 0; + + let mut status = 0 as c_int; + if deadline == 0 { + return match retry(|| unsafe { c::waitpid(self.pid, &mut status, 0) }) { + -1 => panic!("unknown waitpid error: {}", super::last_error()), + _ => Ok(translate_status(status)), + } + } + + // On unix, wait() and its friends have no timeout parameters, so there is + // no way to time out a thread in wait(). From some googling and some + // thinking, it appears that there are a few ways to handle timeouts in + // wait(), but the only real reasonable one for a multi-threaded program is + // to listen for SIGCHLD. + // + // With this in mind, the waiting mechanism with a timeout barely uses + // waitpid() at all. There are a few times that waitpid() is invoked with + // WNOHANG, but otherwise all the necessary blocking is done by waiting for + // a SIGCHLD to arrive (and that blocking has a timeout). Note, however, + // that waitpid() is still used to actually reap the child. + // + // Signal handling is super tricky in general, and this is no exception. Due + // to the async nature of SIGCHLD, we use the self-pipe trick to transmit + // data out of the signal handler to the rest of the application. The first + // idea would be to have each thread waiting with a timeout to read this + // output file descriptor, but a write() is akin to a signal(), not a + // broadcast(), so it would only wake up one thread, and possibly the wrong + // thread. Hence a helper thread is used. + // + // The helper thread here is responsible for farming requests for a + // waitpid() with a timeout, and then processing all of the wait requests. + // By guaranteeing that only this helper thread is reading half of the + // self-pipe, we're sure that we'll never lose a SIGCHLD. This helper thread + // is also responsible for select() to wait for incoming messages or + // incoming SIGCHLD messages, along with passing an appropriate timeout to + // select() to wake things up as necessary. + // + // The ordering of the following statements is also very purposeful. First, + // we must be guaranteed that the helper thread is booted and available to + // receive SIGCHLD signals, and then we must also ensure that we do a + // nonblocking waitpid() at least once before we go ask the sigchld helper. + // This prevents the race where the child exits, we boot the helper, and + // then we ask for the child's exit status (never seeing a sigchld). + // + // The actual communication between the helper thread and this thread is + // quite simple, just a channel moving data around. + + unsafe { HELPER.boot(register_sigchld, waitpid_helper) } + + match self.try_wait() { + Some(ret) => return Ok(ret), + None => {} + } + + let (tx, rx) = channel(); + unsafe { HELPER.send(NewChild(self.pid, tx, deadline)); } + return match rx.recv_opt() { + Ok(e) => Ok(e), + Err(()) => Err(timeout("wait timed out")), + }; + + // Register a new SIGCHLD handler, returning the reading half of the + // self-pipe plus the old handler registered (return value of sigaction). + // + // Be sure to set up the self-pipe first because as soon as we register a + // handler we're going to start receiving signals. + fn register_sigchld() -> (libc::c_int, c::sigaction) { + unsafe { + let mut pipes = [0, ..2]; + assert_eq!(libc::pipe(pipes.as_mut_ptr()), 0); + set_nonblocking(pipes[0], true).ok().unwrap(); + set_nonblocking(pipes[1], true).ok().unwrap(); + WRITE_FD = pipes[1]; + + let mut old: c::sigaction = mem::zeroed(); + let mut new: c::sigaction = mem::zeroed(); + new.sa_handler = sigchld_handler; + new.sa_flags = c::SA_NOCLDSTOP; + assert_eq!(c::sigaction(c::SIGCHLD, &new, &mut old), 0); + (pipes[0], old) + } + } + + // Helper thread for processing SIGCHLD messages + fn waitpid_helper(input: libc::c_int, + messages: Receiver, + (read_fd, old): (libc::c_int, c::sigaction)) { + set_nonblocking(input, true).ok().unwrap(); + let mut set: c::fd_set = unsafe { mem::zeroed() }; + let mut tv: libc::timeval; + let mut active = Vec::<(libc::pid_t, Sender, u64)>::new(); + let max = cmp::max(input, read_fd) + 1; + + 'outer: loop { + // Figure out the timeout of our syscall-to-happen. If we're waiting + // for some processes, then they'll have a timeout, otherwise we + // wait indefinitely for a message to arrive. + // + // FIXME: sure would be nice to not have to scan the entire array + let min = active.iter().map(|a| *a.ref2()).enumerate().min_by(|p| { + p.val1() + }); + let (p, idx) = match min { + Some((idx, deadline)) => { + let now = sys::timer::now(); + let ms = if now < deadline {deadline - now} else {0}; + tv = ms_to_timeval(ms); + (&mut tv as *mut _, idx) + } + None => (ptr::null_mut(), -1), + }; + + // Wait for something to happen + c::fd_set(&mut set, input); + c::fd_set(&mut set, read_fd); + match unsafe { c::select(max, &mut set, ptr::null_mut(), + ptr::null_mut(), p) } { + // interrupted, retry + -1 if os::errno() == libc::EINTR as uint => continue, + + // We read something, break out and process + 1 | 2 => {} + + // Timeout, the pending request is removed + 0 => { + drop(active.remove(idx)); + continue + } + + n => panic!("error in select {} ({})", os::errno(), n), + } + + // Process any pending messages + if drain(input) { + loop { + match messages.try_recv() { + Ok(NewChild(pid, tx, deadline)) => { + active.push((pid, tx, deadline)); + } + Err(comm::Disconnected) => { + assert!(active.len() == 0); + break 'outer; + } + Err(comm::Empty) => break, + } + } + } + + // If a child exited (somehow received SIGCHLD), then poll all + // children to see if any of them exited. + // + // We also attempt to be responsible netizens when dealing with + // SIGCHLD by invoking any previous SIGCHLD handler instead of just + // ignoring any previous SIGCHLD handler. Note that we don't provide + // a 1:1 mapping of our handler invocations to the previous handler + // invocations because we drain the `read_fd` entirely. This is + // probably OK because the kernel is already allowed to coalesce + // simultaneous signals, we're just doing some extra coalescing. + // + // Another point of note is that this likely runs the signal handler + // on a different thread than the one that received the signal. I + // *think* this is ok at this time. + // + // The main reason for doing this is to allow stdtest to run native + // tests as well. Both libgreen and libnative are running around + // with process timeouts, but libgreen should get there first + // (currently libuv doesn't handle old signal handlers). + if drain(read_fd) { + let i: uint = unsafe { mem::transmute(old.sa_handler) }; + if i != 0 { + assert!(old.sa_flags & c::SA_SIGINFO == 0); + (old.sa_handler)(c::SIGCHLD); + } + + // FIXME: sure would be nice to not have to scan the entire + // array... + active.retain(|&(pid, ref tx, _)| { + let pr = Process { pid: pid }; + match pr.try_wait() { + Some(msg) => { tx.send(msg); false } + None => true, + } + }); + } + } + + // Once this helper thread is done, we re-register the old sigchld + // handler and close our intermediate file descriptors. + unsafe { + assert_eq!(c::sigaction(c::SIGCHLD, &old, ptr::null_mut()), 0); + let _ = libc::close(read_fd); + let _ = libc::close(WRITE_FD); + WRITE_FD = -1; + } + } + + // Drain all pending data from the file descriptor, returning if any data + // could be drained. This requires that the file descriptor is in + // nonblocking mode. + fn drain(fd: libc::c_int) -> bool { + let mut ret = false; + loop { + let mut buf = [0u8, ..1]; + match unsafe { + libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, + buf.len() as libc::size_t) + } { + n if n > 0 => { ret = true; } + 0 => return true, + -1 if wouldblock() => return ret, + n => panic!("bad read {} ({})", os::last_os_error(), n), + } + } + } + + // Signal handler for SIGCHLD signals, must be async-signal-safe! + // + // This function will write to the writing half of the "self pipe" to wake + // up the helper thread if it's waiting. Note that this write must be + // nonblocking because if it blocks and the reader is the thread we + // interrupted, then we'll deadlock. + // + // When writing, if the write returns EWOULDBLOCK then we choose to ignore + // it. At that point we're guaranteed that there's something in the pipe + // which will wake up the other end at some point, so we just allow this + // signal to be coalesced with the pending signals on the pipe. + extern fn sigchld_handler(_signum: libc::c_int) { + let msg = 1i; + match unsafe { + libc::write(WRITE_FD, &msg as *const _ as *const libc::c_void, 1) + } { + 1 => {} + -1 if wouldblock() => {} // see above comments + n => panic!("bad error on write fd: {} {}", n, os::errno()), + } + } + } + + pub fn try_wait(&self) -> Option { + let mut status = 0 as c_int; + match retry(|| unsafe { + c::waitpid(self.pid, &mut status, c::WNOHANG) + }) { + n if n == self.pid => Some(translate_status(status)), + 0 => None, + n => panic!("unknown waitpid error `{}`: {}", n, + super::last_error()), + } + } +} + +fn with_argv(prog: &CString, args: &[CString], + cb: proc(*const *const libc::c_char) -> T) -> T { + let mut ptrs: Vec<*const libc::c_char> = Vec::with_capacity(args.len()+1); + + // Convert the CStrings into an array of pointers. Note: the + // lifetime of the various CStrings involved is guaranteed to be + // larger than the lifetime of our invocation of cb, but this is + // technically unsafe as the callback could leak these pointers + // out of our scope. + ptrs.push(prog.as_ptr()); + ptrs.extend(args.iter().map(|tmp| tmp.as_ptr())); + + // Add a terminating null pointer (required by libc). + ptrs.push(ptr::null()); + + cb(ptrs.as_ptr()) +} + +fn with_envp(env: Option<&collections::HashMap>, + cb: proc(*const c_void) -> T) -> T + where K: BytesContainer + Eq + Hash, V: BytesContainer +{ + // On posixy systems we can pass a char** for envp, which is a + // null-terminated array of "k=v\0" strings. Since we must create + // these strings locally, yet expose a raw pointer to them, we + // create a temporary vector to own the CStrings that outlives the + // call to cb. + match env { + Some(env) => { + let mut tmps = Vec::with_capacity(env.len()); + + for pair in env.iter() { + let mut kv = Vec::new(); + kv.push_all(pair.ref0().container_as_bytes()); + kv.push('=' as u8); + kv.push_all(pair.ref1().container_as_bytes()); + kv.push(0); // terminating null + tmps.push(kv); + } + + // As with `with_argv`, this is unsafe, since cb could leak the pointers. + let mut ptrs: Vec<*const libc::c_char> = + tmps.iter() + .map(|tmp| tmp.as_ptr() as *const libc::c_char) + .collect(); + ptrs.push(ptr::null()); + + cb(ptrs.as_ptr() as *const c_void) + } + _ => cb(ptr::null()) + } +} + +fn translate_status(status: c_int) -> ProcessExit { + #![allow(non_snake_case)] + #[cfg(any(target_os = "linux", target_os = "android"))] + mod imp { + pub fn WIFEXITED(status: i32) -> bool { (status & 0xff) == 0 } + pub fn WEXITSTATUS(status: i32) -> i32 { (status >> 8) & 0xff } + pub fn WTERMSIG(status: i32) -> i32 { status & 0x7f } + } + + #[cfg(any(target_os = "macos", + target_os = "ios", + target_os = "freebsd", + target_os = "dragonfly"))] + mod imp { + pub fn WIFEXITED(status: i32) -> bool { (status & 0x7f) == 0 } + pub fn WEXITSTATUS(status: i32) -> i32 { status >> 8 } + pub fn WTERMSIG(status: i32) -> i32 { status & 0o177 } + } + + if imp::WIFEXITED(status) { + ExitStatus(imp::WEXITSTATUS(status) as int) + } else { + ExitSignal(imp::WTERMSIG(status) as int) + } +} diff --git a/src/libstd/platform_imp/windows/fs.rs b/src/libstd/sys/windows/fs.rs similarity index 100% rename from src/libstd/platform_imp/windows/fs.rs rename to src/libstd/sys/windows/fs.rs diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs index 6f6ca3f2e62..f50244701e4 100644 --- a/src/libstd/sys/windows/mod.rs +++ b/src/libstd/sys/windows/mod.rs @@ -40,6 +40,7 @@ pub mod tcp; pub mod udp; pub mod pipe; pub mod helper_signal; +pub mod process; pub mod addrinfo { pub use sys_common::net::get_host_addresses; diff --git a/src/libstd/sys/windows/process.rs b/src/libstd/sys/windows/process.rs new file mode 100644 index 00000000000..67e87841ed2 --- /dev/null +++ b/src/libstd/sys/windows/process.rs @@ -0,0 +1,511 @@ +// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use libc::{pid_t, c_void, c_int}; +use libc; +use c_str::CString; +use io; +use mem; +use os; +use ptr; +use prelude::*; +use io::process::{ProcessExit, ExitStatus, ExitSignal}; +use collections; +use path::BytesContainer; +use hash::Hash; +use io::{IoResult, IoError}; + +use sys::fs; +use sys::{mod, retry, c, wouldblock, set_nonblocking, ms_to_timeval, timer}; +use sys::fs::FileDesc; +use sys_common::helper_thread::Helper; +use sys_common::{AsFileDesc, mkerr_libc, timeout}; + +use io::fs::PathExtensions; +use string::String; + +pub use sys_common::ProcessConfig; + +/** + * A value representing a child process. + * + * The lifetime of this value is linked to the lifetime of the actual + * process - the Process destructor calls self.finish() which waits + * for the process to terminate. + */ +pub struct Process { + /// The unique id of the process (this should never be negative). + pid: pid_t, + + /// A HANDLE to the process, which will prevent the pid being + /// re-used until the handle is closed. + handle: *mut (), +} + +impl Drop for Process { + fn drop(&mut self) { + free_handle(self.handle); + } +} + +impl Process { + pub fn id(&self) -> pid_t { + self.pid + } + + pub unsafe fn kill(&self, signal: int) -> IoResult<()> { + Process::killpid(self.pid, signal) + } + + pub unsafe fn killpid(pid: pid_t, signal: int) -> IoResult<()> { + let handle = libc::OpenProcess(libc::PROCESS_TERMINATE | + libc::PROCESS_QUERY_INFORMATION, + libc::FALSE, pid as libc::DWORD); + if handle.is_null() { + return Err(super::last_error()) + } + let ret = match signal { + // test for existence on signal 0 + 0 => { + let mut status = 0; + let ret = libc::GetExitCodeProcess(handle, &mut status); + if ret == 0 { + Err(super::last_error()) + } else if status != libc::STILL_ACTIVE { + Err(IoError { + kind: io::InvalidInput, + desc: "no process to kill", + detail: None, + }) + } else { + Ok(()) + } + } + 15 | 9 => { // sigterm or sigkill + let ret = libc::TerminateProcess(handle, 1); + super::mkerr_winbool(ret) + } + _ => Err(IoError { + kind: io::IoUnavailable, + desc: "unsupported signal on windows", + detail: None, + }) + }; + let _ = libc::CloseHandle(handle); + return ret; + } + + pub fn spawn(cfg: &C, in_fd: Option

, + out_fd: Option

, err_fd: Option

) + -> IoResult + where C: ProcessConfig, P: AsFileDesc, + K: BytesContainer + Eq + Hash, V: BytesContainer + { + use libc::types::os::arch::extra::{DWORD, HANDLE, STARTUPINFO}; + use libc::consts::os::extra::{ + TRUE, FALSE, + STARTF_USESTDHANDLES, + INVALID_HANDLE_VALUE, + DUPLICATE_SAME_ACCESS + }; + use libc::funcs::extra::kernel32::{ + GetCurrentProcess, + DuplicateHandle, + CloseHandle, + CreateProcessW + }; + use libc::funcs::extra::msvcrt::get_osfhandle; + + use mem; + use iter::Iterator; + use str::StrPrelude; + + if cfg.gid().is_some() || cfg.uid().is_some() { + return Err(IoError { + kind: io::IoUnavailable, + desc: "unsupported gid/uid requested on windows", + detail: None, + }) + } + + // To have the spawning semantics of unix/windows stay the same, we need to + // read the *child's* PATH if one is provided. See #15149 for more details. + let program = cfg.env().and_then(|env| { + for (key, v) in env.iter() { + if b"PATH" != key.container_as_bytes() { continue } + + // Split the value and test each path to see if the + // program exists. + for path in os::split_paths(v.container_as_bytes()).into_iter() { + let path = path.join(cfg.program().as_bytes_no_nul()) + .with_extension(os::consts::EXE_EXTENSION); + if path.exists() { + return Some(path.to_c_str()) + } + } + break + } + None + }); + + unsafe { + let mut si = zeroed_startupinfo(); + si.cb = mem::size_of::() as DWORD; + si.dwFlags = STARTF_USESTDHANDLES; + + let cur_proc = GetCurrentProcess(); + + // Similarly to unix, we don't actually leave holes for the stdio file + // descriptors, but rather open up /dev/null equivalents. These + // equivalents are drawn from libuv's windows process spawning. + let set_fd = |fd: &Option

, slot: &mut HANDLE, + is_stdin: bool| { + match *fd { + None => { + let access = if is_stdin { + libc::FILE_GENERIC_READ + } else { + libc::FILE_GENERIC_WRITE | libc::FILE_READ_ATTRIBUTES + }; + let size = mem::size_of::(); + let mut sa = libc::SECURITY_ATTRIBUTES { + nLength: size as libc::DWORD, + lpSecurityDescriptor: ptr::null_mut(), + bInheritHandle: 1, + }; + let mut filename: Vec = "NUL".utf16_units().collect(); + filename.push(0); + *slot = libc::CreateFileW(filename.as_ptr(), + access, + libc::FILE_SHARE_READ | + libc::FILE_SHARE_WRITE, + &mut sa, + libc::OPEN_EXISTING, + 0, + ptr::null_mut()); + if *slot == INVALID_HANDLE_VALUE { + return Err(super::last_error()) + } + } + Some(ref fd) => { + let orig = get_osfhandle(fd.as_fd().fd()) as HANDLE; + if orig == INVALID_HANDLE_VALUE { + return Err(super::last_error()) + } + if DuplicateHandle(cur_proc, orig, cur_proc, slot, + 0, TRUE, DUPLICATE_SAME_ACCESS) == FALSE { + return Err(super::last_error()) + } + } + } + Ok(()) + }; + + try!(set_fd(&in_fd, &mut si.hStdInput, true)); + try!(set_fd(&out_fd, &mut si.hStdOutput, false)); + try!(set_fd(&err_fd, &mut si.hStdError, false)); + + let cmd_str = make_command_line(program.as_ref().unwrap_or(cfg.program()), + cfg.args()); + let mut pi = zeroed_process_information(); + let mut create_err = None; + + // stolen from the libuv code. + let mut flags = libc::CREATE_UNICODE_ENVIRONMENT; + if cfg.detach() { + flags |= libc::DETACHED_PROCESS | libc::CREATE_NEW_PROCESS_GROUP; + } + + with_envp(cfg.env(), |envp| { + with_dirp(cfg.cwd(), |dirp| { + let mut cmd_str: Vec = cmd_str.as_slice().utf16_units().collect(); + cmd_str.push(0); + let created = CreateProcessW(ptr::null(), + cmd_str.as_mut_ptr(), + ptr::null_mut(), + ptr::null_mut(), + TRUE, + flags, envp, dirp, + &mut si, &mut pi); + if created == FALSE { + create_err = Some(super::last_error()); + } + }) + }); + + assert!(CloseHandle(si.hStdInput) != 0); + assert!(CloseHandle(si.hStdOutput) != 0); + assert!(CloseHandle(si.hStdError) != 0); + + match create_err { + Some(err) => return Err(err), + None => {} + } + + // We close the thread handle because we don't care about keeping the + // thread id valid, and we aren't keeping the thread handle around to be + // able to close it later. We don't close the process handle however + // because std::we want the process id to stay valid at least until the + // calling code closes the process handle. + assert!(CloseHandle(pi.hThread) != 0); + + Ok(Process { + pid: pi.dwProcessId as pid_t, + handle: pi.hProcess as *mut () + }) + } + } + + /** + * Waits for a process to exit and returns the exit code, failing + * if there is no process with the specified id. + * + * Note that this is private to avoid race conditions on unix where if + * a user calls waitpid(some_process.get_id()) then some_process.finish() + * and some_process.destroy() and some_process.finalize() will then either + * operate on a none-existent process or, even worse, on a newer process + * with the same id. + */ + pub fn wait(&self, deadline: u64) -> IoResult { + use libc::types::os::arch::extra::DWORD; + use libc::consts::os::extra::{ + SYNCHRONIZE, + PROCESS_QUERY_INFORMATION, + FALSE, + STILL_ACTIVE, + INFINITE, + WAIT_TIMEOUT, + WAIT_OBJECT_0, + }; + use libc::funcs::extra::kernel32::{ + OpenProcess, + GetExitCodeProcess, + CloseHandle, + WaitForSingleObject, + }; + + unsafe { + let process = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION, + FALSE, + self.pid as DWORD); + if process.is_null() { + return Err(super::last_error()) + } + + loop { + let mut status = 0; + if GetExitCodeProcess(process, &mut status) == FALSE { + let err = Err(super::last_error()); + assert!(CloseHandle(process) != 0); + return err; + } + if status != STILL_ACTIVE { + assert!(CloseHandle(process) != 0); + return Ok(ExitStatus(status as int)); + } + let interval = if deadline == 0 { + INFINITE + } else { + let now = timer::now(); + if deadline < now {0} else {(deadline - now) as u32} + }; + match WaitForSingleObject(process, interval) { + WAIT_OBJECT_0 => {} + WAIT_TIMEOUT => { + assert!(CloseHandle(process) != 0); + return Err(timeout("process wait timed out")) + } + _ => { + let err = Err(super::last_error()); + assert!(CloseHandle(process) != 0); + return err + } + } + } + } + } +} + +fn zeroed_startupinfo() -> libc::types::os::arch::extra::STARTUPINFO { + libc::types::os::arch::extra::STARTUPINFO { + cb: 0, + lpReserved: ptr::null_mut(), + lpDesktop: ptr::null_mut(), + lpTitle: ptr::null_mut(), + dwX: 0, + dwY: 0, + dwXSize: 0, + dwYSize: 0, + dwXCountChars: 0, + dwYCountCharts: 0, + dwFillAttribute: 0, + dwFlags: 0, + wShowWindow: 0, + cbReserved2: 0, + lpReserved2: ptr::null_mut(), + hStdInput: libc::INVALID_HANDLE_VALUE, + hStdOutput: libc::INVALID_HANDLE_VALUE, + hStdError: libc::INVALID_HANDLE_VALUE, + } +} + +fn zeroed_process_information() -> libc::types::os::arch::extra::PROCESS_INFORMATION { + libc::types::os::arch::extra::PROCESS_INFORMATION { + hProcess: ptr::null_mut(), + hThread: ptr::null_mut(), + dwProcessId: 0, + dwThreadId: 0 + } +} + +fn make_command_line(prog: &CString, args: &[CString]) -> String { + let mut cmd = String::new(); + append_arg(&mut cmd, prog.as_str() + .expect("expected program name to be utf-8 encoded")); + for arg in args.iter() { + cmd.push(' '); + append_arg(&mut cmd, arg.as_str() + .expect("expected argument to be utf-8 encoded")); + } + return cmd; + + fn append_arg(cmd: &mut String, arg: &str) { + // If an argument has 0 characters then we need to quote it to ensure + // that it actually gets passed through on the command line or otherwise + // it will be dropped entirely when parsed on the other end. + let quote = arg.chars().any(|c| c == ' ' || c == '\t') || arg.len() == 0; + if quote { + cmd.push('"'); + } + let argvec: Vec = arg.chars().collect(); + for i in range(0u, argvec.len()) { + append_char_at(cmd, argvec.as_slice(), i); + } + if quote { + cmd.push('"'); + } + } + + fn append_char_at(cmd: &mut String, arg: &[char], i: uint) { + match arg[i] { + '"' => { + // Escape quotes. + cmd.push_str("\\\""); + } + '\\' => { + if backslash_run_ends_in_quote(arg, i) { + // Double all backslashes that are in runs before quotes. + cmd.push_str("\\\\"); + } else { + // Pass other backslashes through unescaped. + cmd.push('\\'); + } + } + c => { + cmd.push(c); + } + } + } + + fn backslash_run_ends_in_quote(s: &[char], mut i: uint) -> bool { + while i < s.len() && s[i] == '\\' { + i += 1; + } + return i < s.len() && s[i] == '"'; + } +} + +fn with_envp(env: Option<&collections::HashMap>, + cb: |*mut c_void| -> T) -> T + where K: BytesContainer + Eq + Hash, V: BytesContainer +{ + // On Windows we pass an "environment block" which is not a char**, but + // rather a concatenation of null-terminated k=v\0 sequences, with a final + // \0 to terminate. + match env { + Some(env) => { + let mut blk = Vec::new(); + + for pair in env.iter() { + let kv = format!("{}={}", + pair.ref0().container_as_str().unwrap(), + pair.ref1().container_as_str().unwrap()); + blk.extend(kv.as_slice().utf16_units()); + blk.push(0); + } + + blk.push(0); + + cb(blk.as_mut_ptr() as *mut c_void) + } + _ => cb(ptr::null_mut()) + } +} + +fn with_dirp(d: Option<&CString>, cb: |*const u16| -> T) -> T { + match d { + Some(dir) => { + let dir_str = dir.as_str() + .expect("expected workingdirectory to be utf-8 encoded"); + let mut dir_str: Vec = dir_str.utf16_units().collect(); + dir_str.push(0); + cb(dir_str.as_ptr()) + }, + None => cb(ptr::null()) + } +} + +fn free_handle(handle: *mut ()) { + assert!(unsafe { + libc::CloseHandle(mem::transmute(handle)) != 0 + }) +} + +#[cfg(test)] +mod tests { + + #[test] + fn test_make_command_line() { + use prelude::*; + use str; + use c_str::CString; + use super::make_command_line; + + fn test_wrapper(prog: &str, args: &[&str]) -> String { + make_command_line(&prog.to_c_str(), + args.iter() + .map(|a| a.to_c_str()) + .collect::>() + .as_slice()) + } + + assert_eq!( + test_wrapper("prog", ["aaa", "bbb", "ccc"]), + "prog aaa bbb ccc".to_string() + ); + + assert_eq!( + test_wrapper("C:\\Program Files\\blah\\blah.exe", ["aaa"]), + "\"C:\\Program Files\\blah\\blah.exe\" aaa".to_string() + ); + assert_eq!( + test_wrapper("C:\\Program Files\\test", ["aa\"bb"]), + "\"C:\\Program Files\\test\" aa\\\"bb".to_string() + ); + assert_eq!( + test_wrapper("echo", ["a b c"]), + "echo \"a b c\"".to_string() + ); + assert_eq!( + test_wrapper("\u03c0\u042f\u97f3\u00e6\u221e", []), + "\u03c0\u042f\u97f3\u00e6\u221e".to_string() + ); + } +}