Centralize subprocess creation in a single function.
Getting the vfork + execve combination right isn't easy, and the code was partially duplicated between callproc.c and process.c. Centralize the spawn operation in a single function that deals with the nasty details. Going forward, we should be able to use posix_spawn from either libc or Gnulib (or CreateProcessW on Windows) in the non-pty case. * src/callproc.c (emacs_spawn): New function to start an asynchronous subprocess. Merge code from 'call_process' and 'create_process' into this function. (call_process): Use new 'emacs_spawn' function. (child_setup): Make static, since there are no users outside this compilation unit left. (CHILD_SETUP_TYPE): Move from header file, since there are no users outside this compilation unit left. * src/process.c (create_process): Use new 'emacs_spawn' function.
This commit is contained in:
Philipp Stephani
parent
3096437593
commit
bf7041a6f6
3 changed files with 202 additions and 223 deletions
270
src/callproc.c
270
src/callproc.c
|
|
@ -100,6 +100,15 @@ enum
|
|||
};
|
||||
|
||||
static Lisp_Object call_process (ptrdiff_t, Lisp_Object *, int, ptrdiff_t);
|
||||
|
||||
#ifdef DOS_NT
|
||||
# define CHILD_SETUP_TYPE int
|
||||
#else
|
||||
# define CHILD_SETUP_TYPE _Noreturn void
|
||||
#endif
|
||||
|
||||
static CHILD_SETUP_TYPE child_setup (int, int, int, char *const *,
|
||||
char *const *, const char *);
|
||||
|
||||
/* Return the current buffer's working directory, or the home
|
||||
directory if it's unreachable, as a string suitable for a system call.
|
||||
|
|
@ -300,8 +309,7 @@ call_process (ptrdiff_t nargs, Lisp_Object *args, int filefd,
|
|||
#ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */
|
||||
char *tempfile = NULL;
|
||||
#else
|
||||
sigset_t oldset;
|
||||
pid_t pid;
|
||||
pid_t pid = -1;
|
||||
#endif
|
||||
int child_errno;
|
||||
int fd_output, fd_error;
|
||||
|
|
@ -588,77 +596,10 @@ call_process (ptrdiff_t nargs, Lisp_Object *args, int filefd,
|
|||
|
||||
#ifndef MSDOS
|
||||
|
||||
block_input ();
|
||||
block_child_signal (&oldset);
|
||||
|
||||
#ifdef WINDOWSNT
|
||||
pid = child_setup (filefd, fd_output, fd_error, new_argv, env,
|
||||
SSDATA (current_dir));
|
||||
#else /* not WINDOWSNT */
|
||||
|
||||
/* vfork, and prevent local vars from being clobbered by the vfork. */
|
||||
{
|
||||
Lisp_Object volatile buffer_volatile = buffer;
|
||||
Lisp_Object volatile coding_systems_volatile = coding_systems;
|
||||
Lisp_Object volatile current_dir_volatile = current_dir;
|
||||
bool volatile display_p_volatile = display_p;
|
||||
int volatile fd_error_volatile = fd_error;
|
||||
int volatile filefd_volatile = filefd;
|
||||
ptrdiff_t volatile count_volatile = count;
|
||||
ptrdiff_t volatile sa_avail_volatile = sa_avail;
|
||||
ptrdiff_t volatile sa_count_volatile = sa_count;
|
||||
char **volatile new_argv_volatile = new_argv;
|
||||
char *const *volatile env_volatile = env;
|
||||
int volatile callproc_fd_volatile[CALLPROC_FDS];
|
||||
for (i = 0; i < CALLPROC_FDS; i++)
|
||||
callproc_fd_volatile[i] = callproc_fd[i];
|
||||
|
||||
pid = vfork ();
|
||||
|
||||
buffer = buffer_volatile;
|
||||
coding_systems = coding_systems_volatile;
|
||||
current_dir = current_dir_volatile;
|
||||
display_p = display_p_volatile;
|
||||
fd_error = fd_error_volatile;
|
||||
filefd = filefd_volatile;
|
||||
count = count_volatile;
|
||||
sa_avail = sa_avail_volatile;
|
||||
sa_count = sa_count_volatile;
|
||||
new_argv = new_argv_volatile;
|
||||
env = env_volatile;
|
||||
|
||||
for (i = 0; i < CALLPROC_FDS; i++)
|
||||
callproc_fd[i] = callproc_fd_volatile[i];
|
||||
fd_output = callproc_fd[CALLPROC_STDOUT];
|
||||
}
|
||||
|
||||
if (pid == 0)
|
||||
{
|
||||
#ifdef DARWIN_OS
|
||||
/* Work around a macOS bug, where SIGCHLD is apparently
|
||||
delivered to a vforked child instead of to its parent. See:
|
||||
https://lists.gnu.org/r/emacs-devel/2017-05/msg00342.html
|
||||
*/
|
||||
signal (SIGCHLD, SIG_DFL);
|
||||
#endif
|
||||
|
||||
unblock_child_signal (&oldset);
|
||||
dissociate_controlling_tty ();
|
||||
|
||||
/* Emacs ignores SIGPIPE, but the child should not. */
|
||||
signal (SIGPIPE, SIG_DFL);
|
||||
/* Likewise for SIGPROF. */
|
||||
#ifdef SIGPROF
|
||||
signal (SIGPROF, SIG_DFL);
|
||||
#endif
|
||||
|
||||
child_setup (filefd, fd_output, fd_error, new_argv, env,
|
||||
SSDATA (current_dir));
|
||||
}
|
||||
|
||||
#endif /* not WINDOWSNT */
|
||||
|
||||
child_errno = errno;
|
||||
child_errno
|
||||
= emacs_spawn (&pid, filefd, fd_output, fd_error, new_argv, env,
|
||||
SSDATA (current_dir), NULL);
|
||||
eassert ((child_errno == 0) == (0 < pid));
|
||||
|
||||
if (pid > 0)
|
||||
{
|
||||
|
|
@ -678,9 +619,6 @@ call_process (ptrdiff_t nargs, Lisp_Object *args, int filefd,
|
|||
}
|
||||
}
|
||||
|
||||
unblock_child_signal (&oldset);
|
||||
unblock_input ();
|
||||
|
||||
if (pid < 0)
|
||||
report_file_errno (CHILD_SETUP_ERROR_DESC, Qnil, child_errno);
|
||||
|
||||
|
|
@ -1221,7 +1159,7 @@ exec_failed (char const *name, int err)
|
|||
On MS-Windows, either return a pid or return -1 and set errno.
|
||||
On MS-DOS, either return an exit status or signal an error. */
|
||||
|
||||
CHILD_SETUP_TYPE
|
||||
static CHILD_SETUP_TYPE
|
||||
child_setup (int in, int out, int err, char *const *new_argv,
|
||||
char *const *env, const char *current_dir)
|
||||
{
|
||||
|
|
@ -1287,6 +1225,184 @@ child_setup (int in, int out, int err, char *const *new_argv,
|
|||
#endif /* not WINDOWSNT */
|
||||
}
|
||||
|
||||
/* Start a new asynchronous subprocess. If successful, return zero
|
||||
and store the process identifier of the new process in *NEWPID.
|
||||
Use STDIN, STDOUT, and STDERR as standard streams for the new
|
||||
process. Use ARGV as argument vector for the new process; use
|
||||
process image file ARGV[0]. Use ENVP for the environment block for
|
||||
the new process. Use CWD as working directory for the new process.
|
||||
If PTY is not NULL, it must be a pseudoterminal device. If PTY is
|
||||
NULL, don't perform any terminal setup. */
|
||||
|
||||
int
|
||||
emacs_spawn (pid_t *newpid, int stdin, int stdout, int stderr,
|
||||
char *const *argv, char *const *envp, const char *cwd,
|
||||
const char *pty)
|
||||
{
|
||||
sigset_t oldset;
|
||||
int pid;
|
||||
|
||||
block_input ();
|
||||
block_child_signal (&oldset);
|
||||
|
||||
#ifndef WINDOWSNT
|
||||
/* vfork, and prevent local vars from being clobbered by the vfork. */
|
||||
pid_t *volatile newpid_volatile = newpid;
|
||||
const char *volatile cwd_volatile = cwd;
|
||||
const char *volatile pty_volatile = pty;
|
||||
char *const *volatile argv_volatile = argv;
|
||||
int volatile stdin_volatile = stdin;
|
||||
int volatile stdout_volatile = stdout;
|
||||
int volatile stderr_volatile = stderr;
|
||||
char *const *volatile envp_volatile = envp;
|
||||
|
||||
#ifdef DARWIN_OS
|
||||
/* Darwin doesn't let us run setsid after a vfork, so use fork when
|
||||
necessary. Below, we reset SIGCHLD handling after a vfork, as
|
||||
apparently macOS can mistakenly deliver SIGCHLD to the child. */
|
||||
if (pty != NULL)
|
||||
pid = fork ();
|
||||
else
|
||||
pid = vfork ();
|
||||
#else
|
||||
pid = vfork ();
|
||||
#endif
|
||||
|
||||
newpid = newpid_volatile;
|
||||
cwd = cwd_volatile;
|
||||
pty = pty_volatile;
|
||||
argv = argv_volatile;
|
||||
stdin = stdin_volatile;
|
||||
stdout = stdout_volatile;
|
||||
stderr = stderr_volatile;
|
||||
envp = envp_volatile;
|
||||
|
||||
if (pid == 0)
|
||||
#endif /* not WINDOWSNT */
|
||||
{
|
||||
bool pty_flag = pty != NULL;
|
||||
/* Make the pty be the controlling terminal of the process. */
|
||||
#ifdef HAVE_PTYS
|
||||
dissociate_controlling_tty ();
|
||||
|
||||
/* Make the pty's terminal the controlling terminal. */
|
||||
if (pty_flag && stdin >= 0)
|
||||
{
|
||||
#ifdef TIOCSCTTY
|
||||
/* We ignore the return value
|
||||
because faith@cs.unc.edu says that is necessary on Linux. */
|
||||
ioctl (stdin, TIOCSCTTY, 0);
|
||||
#endif
|
||||
}
|
||||
#if defined (LDISC1)
|
||||
if (pty_flag && stdin >= 0)
|
||||
{
|
||||
struct termios t;
|
||||
tcgetattr (stdin, &t);
|
||||
t.c_lflag = LDISC1;
|
||||
if (tcsetattr (stdin, TCSANOW, &t) < 0)
|
||||
emacs_perror ("create_process/tcsetattr LDISC1");
|
||||
}
|
||||
#else
|
||||
#if defined (NTTYDISC) && defined (TIOCSETD)
|
||||
if (pty_flag && stdin >= 0)
|
||||
{
|
||||
/* Use new line discipline. */
|
||||
int ldisc = NTTYDISC;
|
||||
ioctl (stdin, TIOCSETD, &ldisc);
|
||||
}
|
||||
#endif
|
||||
#endif
|
||||
|
||||
#if !defined (DONT_REOPEN_PTY)
|
||||
/*** There is a suggestion that this ought to be a
|
||||
conditional on TIOCSPGRP, or !defined TIOCSCTTY.
|
||||
Trying the latter gave the wrong results on Debian GNU/Linux 1.1;
|
||||
that system does seem to need this code, even though
|
||||
both TIOCSCTTY is defined. */
|
||||
/* Now close the pty (if we had it open) and reopen it.
|
||||
This makes the pty the controlling terminal of the subprocess. */
|
||||
if (pty_flag)
|
||||
{
|
||||
|
||||
/* I wonder if emacs_close (emacs_open (pty, ...))
|
||||
would work? */
|
||||
if (stdin >= 0)
|
||||
emacs_close (stdin);
|
||||
stdout = stdin = emacs_open (pty, O_RDWR, 0);
|
||||
|
||||
if (stdin < 0)
|
||||
{
|
||||
emacs_perror (pty);
|
||||
_exit (EXIT_CANCELED);
|
||||
}
|
||||
|
||||
}
|
||||
#endif /* not DONT_REOPEN_PTY */
|
||||
|
||||
#ifdef SETUP_SLAVE_PTY
|
||||
if (pty_flag)
|
||||
{
|
||||
SETUP_SLAVE_PTY;
|
||||
}
|
||||
#endif /* SETUP_SLAVE_PTY */
|
||||
#endif /* HAVE_PTYS */
|
||||
|
||||
#ifdef DARWIN_OS
|
||||
/* Work around a macOS bug, where SIGCHLD is apparently
|
||||
delivered to a vforked child instead of to its parent. See:
|
||||
https://lists.gnu.org/r/emacs-devel/2017-05/msg00342.html
|
||||
*/
|
||||
signal (SIGCHLD, SIG_DFL);
|
||||
#endif
|
||||
|
||||
signal (SIGINT, SIG_DFL);
|
||||
signal (SIGQUIT, SIG_DFL);
|
||||
#ifdef SIGPROF
|
||||
signal (SIGPROF, SIG_DFL);
|
||||
#endif
|
||||
|
||||
/* Emacs ignores SIGPIPE, but the child should not. */
|
||||
signal (SIGPIPE, SIG_DFL);
|
||||
/* Likewise for SIGPROF. */
|
||||
#ifdef SIGPROF
|
||||
signal (SIGPROF, SIG_DFL);
|
||||
#endif
|
||||
|
||||
/* Stop blocking SIGCHLD in the child. */
|
||||
unblock_child_signal (&oldset);
|
||||
|
||||
if (pty_flag)
|
||||
child_setup_tty (stdout);
|
||||
|
||||
if (stderr < 0)
|
||||
stderr = stdout;
|
||||
#ifdef WINDOWSNT
|
||||
pid = child_setup (stdin, stdout, stderr, argv, envp, cwd);
|
||||
#else /* not WINDOWSNT */
|
||||
child_setup (stdin, stdout, stderr, argv, envp, cwd);
|
||||
#endif /* not WINDOWSNT */
|
||||
}
|
||||
|
||||
/* Back in the parent process. */
|
||||
|
||||
int vfork_error = pid < 0 ? errno : 0;
|
||||
|
||||
/* Stop blocking in the parent. */
|
||||
unblock_child_signal (&oldset);
|
||||
unblock_input ();
|
||||
|
||||
if (pid < 0)
|
||||
{
|
||||
eassert (0 < vfork_error);
|
||||
return vfork_error;
|
||||
}
|
||||
|
||||
eassert (0 < pid);
|
||||
*newpid = pid;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static bool
|
||||
getenv_internal_1 (const char *var, ptrdiff_t varlen, char **value,
|
||||
ptrdiff_t *valuelen, Lisp_Object env)
|
||||
|
|
|
|||
|
|
@ -4493,15 +4493,13 @@ extern void setup_process_coding_systems (Lisp_Object);
|
|||
|
||||
/* Defined in callproc.c. */
|
||||
#ifdef DOS_NT
|
||||
# define CHILD_SETUP_TYPE int
|
||||
# define CHILD_SETUP_ERROR_DESC "Spawning child process"
|
||||
#else
|
||||
# define CHILD_SETUP_TYPE _Noreturn void
|
||||
# define CHILD_SETUP_ERROR_DESC "Doing vfork"
|
||||
#endif
|
||||
|
||||
extern CHILD_SETUP_TYPE child_setup (int, int, int, char *const *,
|
||||
char *const *, const char *);
|
||||
extern int emacs_spawn (pid_t *, int, int, int, char *const *,
|
||||
char *const *, const char *, const char *);
|
||||
extern char *const *make_environment_block (Lisp_Object);
|
||||
extern void init_callproc_1 (void);
|
||||
extern void init_callproc (void);
|
||||
|
|
|
|||
149
src/process.c
149
src/process.c
|
|
@ -2047,13 +2047,12 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
|
|||
{
|
||||
struct Lisp_Process *p = XPROCESS (process);
|
||||
int inchannel, outchannel;
|
||||
pid_t pid;
|
||||
pid_t pid = -1;
|
||||
int vfork_errno;
|
||||
int forkin, forkout, forkerr = -1;
|
||||
bool pty_flag = 0;
|
||||
char pty_name[PTY_NAME_SIZE];
|
||||
Lisp_Object lisp_pty_name = Qnil;
|
||||
sigset_t oldset;
|
||||
|
||||
inchannel = outchannel = -1;
|
||||
|
||||
|
|
@ -2130,154 +2129,20 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
|
|||
setup_process_coding_systems (process);
|
||||
char *const *env = make_environment_block (current_dir);
|
||||
|
||||
block_input ();
|
||||
block_child_signal (&oldset);
|
||||
|
||||
#ifndef WINDOWSNT
|
||||
/* vfork, and prevent local vars from being clobbered by the vfork. */
|
||||
Lisp_Object volatile current_dir_volatile = current_dir;
|
||||
Lisp_Object volatile lisp_pty_name_volatile = lisp_pty_name;
|
||||
char **volatile new_argv_volatile = new_argv;
|
||||
int volatile forkin_volatile = forkin;
|
||||
int volatile forkout_volatile = forkout;
|
||||
int volatile forkerr_volatile = forkerr;
|
||||
struct Lisp_Process *p_volatile = p;
|
||||
char *const *volatile env_volatile = env;
|
||||
|
||||
#ifdef DARWIN_OS
|
||||
/* Darwin doesn't let us run setsid after a vfork, so use fork when
|
||||
necessary. Also, reset SIGCHLD handling after a vfork, as
|
||||
apparently macOS can mistakenly deliver SIGCHLD to the child. */
|
||||
if (pty_flag)
|
||||
pid = fork ();
|
||||
else
|
||||
{
|
||||
pid = vfork ();
|
||||
if (pid == 0)
|
||||
signal (SIGCHLD, SIG_DFL);
|
||||
}
|
||||
#else
|
||||
pid = vfork ();
|
||||
#endif
|
||||
|
||||
current_dir = current_dir_volatile;
|
||||
lisp_pty_name = lisp_pty_name_volatile;
|
||||
new_argv = new_argv_volatile;
|
||||
forkin = forkin_volatile;
|
||||
forkout = forkout_volatile;
|
||||
forkerr = forkerr_volatile;
|
||||
p = p_volatile;
|
||||
env = env_volatile;
|
||||
|
||||
pty_flag = p->pty_flag;
|
||||
eassert (pty_flag == ! NILP (lisp_pty_name));
|
||||
|
||||
if (pid == 0)
|
||||
#endif /* not WINDOWSNT */
|
||||
{
|
||||
/* Make the pty be the controlling terminal of the process. */
|
||||
#ifdef HAVE_PTYS
|
||||
dissociate_controlling_tty ();
|
||||
vfork_errno
|
||||
= emacs_spawn (&pid, forkin, forkout, forkerr, new_argv, env,
|
||||
SSDATA (current_dir),
|
||||
pty_flag ? SSDATA (lisp_pty_name) : NULL);
|
||||
|
||||
/* Make the pty's terminal the controlling terminal. */
|
||||
if (pty_flag && forkin >= 0)
|
||||
{
|
||||
#ifdef TIOCSCTTY
|
||||
/* We ignore the return value
|
||||
because faith@cs.unc.edu says that is necessary on Linux. */
|
||||
ioctl (forkin, TIOCSCTTY, 0);
|
||||
#endif
|
||||
}
|
||||
#if defined (LDISC1)
|
||||
if (pty_flag && forkin >= 0)
|
||||
{
|
||||
struct termios t;
|
||||
tcgetattr (forkin, &t);
|
||||
t.c_lflag = LDISC1;
|
||||
if (tcsetattr (forkin, TCSANOW, &t) < 0)
|
||||
emacs_perror ("create_process/tcsetattr LDISC1");
|
||||
}
|
||||
#else
|
||||
#if defined (NTTYDISC) && defined (TIOCSETD)
|
||||
if (pty_flag && forkin >= 0)
|
||||
{
|
||||
/* Use new line discipline. */
|
||||
int ldisc = NTTYDISC;
|
||||
ioctl (forkin, TIOCSETD, &ldisc);
|
||||
}
|
||||
#endif
|
||||
#endif
|
||||
eassert ((vfork_errno == 0) == (0 < pid));
|
||||
|
||||
#if !defined (DONT_REOPEN_PTY)
|
||||
/*** There is a suggestion that this ought to be a
|
||||
conditional on TIOCSPGRP, or !defined TIOCSCTTY.
|
||||
Trying the latter gave the wrong results on Debian GNU/Linux 1.1;
|
||||
that system does seem to need this code, even though
|
||||
both TIOCSCTTY is defined. */
|
||||
/* Now close the pty (if we had it open) and reopen it.
|
||||
This makes the pty the controlling terminal of the subprocess. */
|
||||
if (pty_flag)
|
||||
{
|
||||
|
||||
/* I wonder if emacs_close (emacs_open (SSDATA (lisp_pty_name), ...))
|
||||
would work? */
|
||||
if (forkin >= 0)
|
||||
emacs_close (forkin);
|
||||
forkout = forkin = emacs_open (SSDATA (lisp_pty_name), O_RDWR, 0);
|
||||
|
||||
if (forkin < 0)
|
||||
{
|
||||
emacs_perror (SSDATA (lisp_pty_name));
|
||||
_exit (EXIT_CANCELED);
|
||||
}
|
||||
|
||||
}
|
||||
#endif /* not DONT_REOPEN_PTY */
|
||||
|
||||
#ifdef SETUP_SLAVE_PTY
|
||||
if (pty_flag)
|
||||
{
|
||||
SETUP_SLAVE_PTY;
|
||||
}
|
||||
#endif /* SETUP_SLAVE_PTY */
|
||||
#endif /* HAVE_PTYS */
|
||||
|
||||
signal (SIGINT, SIG_DFL);
|
||||
signal (SIGQUIT, SIG_DFL);
|
||||
#ifdef SIGPROF
|
||||
signal (SIGPROF, SIG_DFL);
|
||||
#endif
|
||||
|
||||
/* Emacs ignores SIGPIPE, but the child should not. */
|
||||
signal (SIGPIPE, SIG_DFL);
|
||||
|
||||
/* Stop blocking SIGCHLD in the child. */
|
||||
unblock_child_signal (&oldset);
|
||||
|
||||
if (pty_flag)
|
||||
child_setup_tty (forkout);
|
||||
|
||||
if (forkerr < 0)
|
||||
forkerr = forkout;
|
||||
#ifdef WINDOWSNT
|
||||
pid = child_setup (forkin, forkout, forkerr, new_argv, env,
|
||||
SSDATA (current_dir));
|
||||
#else /* not WINDOWSNT */
|
||||
child_setup (forkin, forkout, forkerr, new_argv, env,
|
||||
SSDATA (current_dir));
|
||||
#endif /* not WINDOWSNT */
|
||||
}
|
||||
|
||||
/* Back in the parent process. */
|
||||
|
||||
vfork_errno = errno;
|
||||
p->pid = pid;
|
||||
if (pid >= 0)
|
||||
p->alive = 1;
|
||||
|
||||
/* Stop blocking in the parent. */
|
||||
unblock_child_signal (&oldset);
|
||||
unblock_input ();
|
||||
|
||||
/* Environment block no longer needed. */
|
||||
unbind_to (count, Qnil);
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue