rust/src/libcore/run.rs
2012-08-01 19:16:06 -07:00

450 lines
12 KiB
Rust

//! Process spawning
import option::{some, none};
import libc::{pid_t, c_void, c_int};
import io::reader_util;
export program;
export run_program;
export start_program;
export program_output;
export spawn_process;
export waitpid;
#[abi = "cdecl"]
extern mod rustrt {
fn rust_run_program(argv: **libc::c_char, envp: *c_void,
dir: *libc::c_char,
in_fd: c_int, out_fd: c_int, err_fd: c_int)
-> pid_t;
}
/// A value representing a child process
trait program {
/// Returns the process id of the program
fn get_id() -> pid_t;
/// Returns an io::writer that can be used to write to stdin
fn input() -> io::writer;
/// Returns an io::reader that can be used to read from stdout
fn output() -> io::reader;
/// Returns an io::reader that can be used to read from stderr
fn err() -> io::reader;
/// Closes the handle to the child processes standard input
fn close_input();
/**
* Waits for the child process to terminate. Closes the handle
* to stdin if necessary.
*/
fn finish() -> int;
/// Closes open handles
fn destroy();
}
/**
* Run a program, providing stdin, stdout and stderr handles
*
* # Arguments
*
* * prog - The path to an executable
* * args - Vector of arguments to pass to the child process
* * env - optional env-modification for child
* * dir - optional dir to run child in (default current dir)
* * in_fd - A file descriptor for the child to use as std input
* * out_fd - A file descriptor for the child to use as std output
* * err_fd - A file descriptor for the child to use as std error
*
* # Return value
*
* The process id of the spawned process
*/
fn spawn_process(prog: ~str, args: ~[~str],
env: option<~[(~str,~str)]>,
dir: option<~str>,
in_fd: c_int, out_fd: c_int, err_fd: c_int)
-> pid_t {
do with_argv(prog, args) |argv| {
do with_envp(env) |envp| {
do with_dirp(dir) |dirp| {
rustrt::rust_run_program(argv, envp, dirp,
in_fd, out_fd, err_fd)
}
}
}
}
fn with_argv<T>(prog: ~str, args: ~[~str],
cb: fn(**libc::c_char) -> T) -> T {
let mut argptrs = str::as_c_str(prog, |b| ~[b]);
let mut tmps = ~[];
for vec::each(args) |arg| {
let t = @arg;
vec::push(tmps, t);
vec::push_all(argptrs, str::as_c_str(*t, |b| ~[b]));
}
vec::push(argptrs, ptr::null());
vec::as_buf(argptrs, |buf, _len| cb(buf))
}
#[cfg(unix)]
fn with_envp<T>(env: option<~[(~str,~str)]>,
cb: fn(*c_void) -> T) -> T {
// On posixy systems we can pass a char** for envp, which is
// a null-terminated array of "k=v\n" strings.
alt env {
some(es) if !vec::is_empty(es) {
let mut tmps = ~[];
let mut ptrs = ~[];
for vec::each(es) |e| {
let (k,v) = e;
let t = @(fmt!{"%s=%s", k, v});
vec::push(tmps, t);
vec::push_all(ptrs, str::as_c_str(*t, |b| ~[b]));
}
vec::push(ptrs, ptr::null());
vec::as_buf(ptrs, |p, _len|
unsafe { cb(::unsafe::reinterpret_cast(p)) }
)
}
_ {
cb(ptr::null())
}
}
}
#[cfg(windows)]
fn with_envp<T>(env: option<~[(~str,~str)]>,
cb: fn(*c_void) -> T) -> T {
// On win32 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.
unsafe {
alt env {
some(es) if !vec::is_empty(es) {
let mut blk : ~[u8] = ~[];
for vec::each(es) |e| {
let (k,v) = e;
let t = fmt!{"%s=%s", k, v};
let mut v : ~[u8] = ::unsafe::reinterpret_cast(t);
blk += v;
::unsafe::forget(v);
}
blk += ~[0_u8];
vec::as_buf(blk, |p, _len| cb(::unsafe::reinterpret_cast(p)))
}
_ {
cb(ptr::null())
}
}
}
}
fn with_dirp<T>(d: option<~str>,
cb: fn(*libc::c_char) -> T) -> T {
alt d {
some(dir) { str::as_c_str(dir, cb) }
none { cb(ptr::null()) }
}
}
/**
* Spawns a process and waits for it to terminate
*
* # Arguments
*
* * prog - The path to an executable
* * args - Vector of arguments to pass to the child process
*
* # Return value
*
* The process id
*/
fn run_program(prog: ~str, args: ~[~str]) -> int {
let pid = spawn_process(prog, args, none, none,
0i32, 0i32, 0i32);
if pid == -1 as pid_t { fail; }
return waitpid(pid);
}
/**
* Spawns a process and returns a program
*
* The returned value is a boxed class containing a <program> object that can
* be used for sending and receiving data over the standard file descriptors.
* The class will ensure that file descriptors are closed properly.
*
* # Arguments
*
* * prog - The path to an executable
* * args - Vector of arguments to pass to the child process
*
* # Return value
*
* A class with a <program> field
*/
fn start_program(prog: ~str, args: ~[~str]) -> program {
let pipe_input = os::pipe();
let pipe_output = os::pipe();
let pipe_err = os::pipe();
let pid =
spawn_process(prog, args, none, none,
pipe_input.in, pipe_output.out,
pipe_err.out);
if pid == -1 as pid_t { fail; }
libc::close(pipe_input.in);
libc::close(pipe_output.out);
libc::close(pipe_err.out);
type prog_repr = {pid: pid_t,
mut in_fd: c_int,
out_file: *libc::FILE,
err_file: *libc::FILE,
mut finished: bool};
fn close_repr_input(r: prog_repr) {
let invalid_fd = -1i32;
if r.in_fd != invalid_fd {
libc::close(r.in_fd);
r.in_fd = invalid_fd;
}
}
fn finish_repr(r: prog_repr) -> int {
if r.finished { return 0; }
r.finished = true;
close_repr_input(r);
return waitpid(r.pid);
}
fn destroy_repr(r: prog_repr) {
finish_repr(r);
libc::fclose(r.out_file);
libc::fclose(r.err_file);
}
class prog_res {
let r: prog_repr;
new(-r: prog_repr) { self.r = r; }
drop { destroy_repr(self.r); }
}
impl of program for prog_res {
fn get_id() -> pid_t { return self.r.pid; }
fn input() -> io::writer { io::fd_writer(self.r.in_fd, false) }
fn output() -> io::reader { io::FILE_reader(self.r.out_file, false) }
fn err() -> io::reader { io::FILE_reader(self.r.err_file, false) }
fn close_input() { close_repr_input(self.r); }
fn finish() -> int { finish_repr(self.r) }
fn destroy() { destroy_repr(self.r); }
}
let repr = {pid: pid,
mut in_fd: pipe_input.out,
out_file: os::fdopen(pipe_output.in),
err_file: os::fdopen(pipe_err.in),
mut finished: false};
return prog_res(repr) as program;
}
fn read_all(rd: io::reader) -> ~str {
let mut buf = ~"";
while !rd.eof() {
let bytes = rd.read_bytes(4096u);
buf += str::from_bytes(bytes);
}
return buf;
}
/**
* Spawns a process, waits for it to exit, and returns the exit code, and
* contents of stdout and stderr.
*
* # Arguments
*
* * prog - The path to an executable
* * args - Vector of arguments to pass to the child process
*
* # Return value
*
* A record, {status: int, out: str, err: str} containing the exit code,
* the contents of stdout and the contents of stderr.
*/
fn program_output(prog: ~str, args: ~[~str]) ->
{status: int, out: ~str, err: ~str} {
let pipe_in = os::pipe();
let pipe_out = os::pipe();
let pipe_err = os::pipe();
let pid = spawn_process(prog, args, none, none,
pipe_in.in, pipe_out.out, pipe_err.out);
os::close(pipe_in.in);
os::close(pipe_out.out);
os::close(pipe_err.out);
if pid == -1i32 {
os::close(pipe_in.out);
os::close(pipe_out.in);
os::close(pipe_err.in);
fail;
}
os::close(pipe_in.out);
// Spawn two entire schedulers to read both stdout and sterr
// in parallel so we don't deadlock while blocking on one
// or the other. FIXME (#2625): Surely there's a much more
// clever way to do this.
let p = comm::port();
let ch = comm::chan(p);
do task::spawn_sched(task::single_threaded) {
let errput = readclose(pipe_err.in);
comm::send(ch, (2, errput));
};
do task::spawn_sched(task::single_threaded) {
let output = readclose(pipe_out.in);
comm::send(ch, (1, output));
};
let status = run::waitpid(pid);
let mut errs = ~"";
let mut outs = ~"";
let mut count = 2;
while count > 0 {
let stream = comm::recv(p);
alt check stream {
(1, s) {
outs = s;
}
(2, s) {
errs = s;
}
};
count -= 1;
};
return {status: status, out: outs, err: errs};
}
fn writeclose(fd: c_int, s: ~str) {
import io::writer_util;
error!{"writeclose %d, %s", fd as int, s};
let writer = io::fd_writer(fd, false);
writer.write_str(s);
os::close(fd);
}
fn readclose(fd: c_int) -> ~str {
let file = os::fdopen(fd);
let reader = io::FILE_reader(file, false);
let mut buf = ~"";
while !reader.eof() {
let bytes = reader.read_bytes(4096u);
buf += str::from_bytes(bytes);
}
os::fclose(file);
return buf;
}
/// Waits for a process to exit and returns the exit code
fn waitpid(pid: pid_t) -> int {
return waitpid_os(pid);
#[cfg(windows)]
fn waitpid_os(pid: pid_t) -> int {
os::waitpid(pid) as int
}
#[cfg(unix)]
fn waitpid_os(pid: pid_t) -> int {
#[cfg(target_os = "linux")]
fn WIFEXITED(status: i32) -> bool {
(status & 0xffi32) == 0i32
}
#[cfg(target_os = "macos")]
#[cfg(target_os = "freebsd")]
fn WIFEXITED(status: i32) -> bool {
(status & 0x7fi32) == 0i32
}
#[cfg(target_os = "linux")]
fn WEXITSTATUS(status: i32) -> i32 {
(status >> 8i32) & 0xffi32
}
#[cfg(target_os = "macos")]
#[cfg(target_os = "freebsd")]
fn WEXITSTATUS(status: i32) -> i32 {
status >> 8i32
}
let status = os::waitpid(pid);
return if WIFEXITED(status) {
WEXITSTATUS(status) as int
} else {
1
};
}
}
#[cfg(test)]
mod tests {
import io::writer_util;
// Regression test for memory leaks
#[ignore(cfg(windows))] // FIXME (#2626)
fn test_leaks() {
run::run_program(~"echo", ~[]);
run::start_program(~"echo", ~[]);
run::program_output(~"echo", ~[]);
}
#[test]
fn test_pipes() {
let pipe_in = os::pipe();
let pipe_out = os::pipe();
let pipe_err = os::pipe();
let pid =
run::spawn_process(
~"cat", ~[], none, none,
pipe_in.in, pipe_out.out, pipe_err.out);
os::close(pipe_in.in);
os::close(pipe_out.out);
os::close(pipe_err.out);
if pid == -1i32 { fail; }
let expected = ~"test";
writeclose(pipe_in.out, expected);
let actual = readclose(pipe_out.in);
readclose(pipe_err.in);
os::waitpid(pid);
log(debug, expected);
log(debug, actual);
assert (expected == actual);
}
#[test]
fn waitpid() {
let pid = run::spawn_process(~"false", ~[],
none, none,
0i32, 0i32, 0i32);
let status = run::waitpid(pid);
assert status == 1;
}
}
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End: