X-Git-Url: http://git.hcoop.net/bpt/emacs.git/blobdiff_plain/c194970e15b6d6efa07697679a25dfab3aa76442..d983a10b9a070fd8f6d4f48ec44e5514b62feaa6:/src/sysdep.c
diff --git a/src/sysdep.c b/src/sysdep.c
index b7141011d0..5291c5d59a 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -54,6 +54,9 @@ along with GNU Emacs. If not, see . */
#ifdef WINDOWSNT
#define read sys_read
#define write sys_write
+#ifndef STDERR_FILENO
+#define STDERR_FILENO fileno(GetStdHandle(STD_ERROR_HANDLE))
+#endif
#include
#endif /* not WINDOWSNT */
@@ -98,7 +101,6 @@ along with GNU Emacs. If not, see . */
#define _P_WAIT 0
int _cdecl _spawnlp (int, const char *, const char *, ...);
int _cdecl _getpid (void);
-extern char *getwd (char *);
#endif
#include "syssignal.h"
@@ -131,12 +133,12 @@ char*
get_current_dir_name (void)
{
char *buf;
- char *pwd;
+ char *pwd = getenv ("PWD");
struct stat dotstat, pwdstat;
- /* If PWD is accurate, use it instead of calling getwd. PWD is
+ /* If PWD is accurate, use it instead of calling getcwd. PWD is
sometimes a nicer name, and using it may avoid a fatal error if a
parent directory is searchable but not readable. */
- if ((pwd = getenv ("PWD")) != 0
+ if (pwd
&& (IS_DIRECTORY_SEP (*pwd) || (*pwd && IS_DEVICE_SEP (pwd[1])))
&& stat (pwd, &pwdstat) == 0
&& stat (".", &dotstat) == 0
@@ -152,7 +154,6 @@ get_current_dir_name (void)
return NULL;
strcpy (buf, pwd);
}
-#ifdef HAVE_GETCWD
else
{
size_t buf_size = 1024;
@@ -176,22 +177,6 @@ get_current_dir_name (void)
return NULL;
}
}
-#else
- else
- {
- /* We need MAXPATHLEN here. */
- buf = malloc (MAXPATHLEN + 1);
- if (!buf)
- return NULL;
- if (getwd (buf) == NULL)
- {
- int tmp_errno = errno;
- free (buf);
- errno = tmp_errno;
- return NULL;
- }
- }
-#endif
return buf;
}
#endif
@@ -281,48 +266,74 @@ init_baud_rate (int fd)
#ifndef MSDOS
-static void
-wait_for_termination_1 (pid_t pid, int interruptible)
+/* Wait for the subprocess with process id CHILD to terminate or change status.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ Use waitpid-style OPTIONS when waiting.
+ If INTERRUPTIBLE, this function is interruptible by a signal.
+
+ Return CHILD if successful, 0 if no status is available;
+ the latter is possible only when options & NOHANG. */
+static pid_t
+get_child_status (pid_t child, int *status, int options, bool interruptible)
{
- while (1)
- {
-#ifdef WINDOWSNT
- wait (0);
- break;
-#else /* not WINDOWSNT */
- int status;
- int wait_result = waitpid (pid, &status, 0);
- if (wait_result < 0)
- {
- if (errno != EINTR)
- break;
- }
- else
- {
- record_child_status_change (wait_result, status);
- break;
- }
+ pid_t pid;
-#endif /* not WINDOWSNT */
+ /* Invoke waitpid only with a known process ID; do not invoke
+ waitpid with a nonpositive argument. Otherwise, Emacs might
+ reap an unwanted process by mistake. For example, invoking
+ waitpid (-1, ...) can mess up glib by reaping glib's subprocesses,
+ so that another thread running glib won't find them. */
+ eassert (0 < child);
+
+ while ((pid = waitpid (child, status, options)) < 0)
+ {
+ /* Check that CHILD is a child process that has not been reaped,
+ and that STATUS and OPTIONS are valid. Otherwise abort,
+ as continuing after this internal error could cause Emacs to
+ become confused and kill innocent-victim processes. */
+ if (errno != EINTR)
+ emacs_abort ();
+
+ /* Note: the MS-Windows emulation of waitpid calls QUIT
+ internally. */
if (interruptible)
QUIT;
}
-}
-/* Wait for subprocess with process id `pid' to terminate and
- make sure it will get eliminated (not remain forever as a zombie) */
+ /* If successful and status is requested, tell wait_reading_process_output
+ that it needs to wake up and look around. */
+ if (pid && status && input_available_clear_time)
+ *input_available_clear_time = make_emacs_time (0, 0);
+ return pid;
+}
+
+/* Wait for the subprocess with process id CHILD to terminate.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ If INTERRUPTIBLE, this function is interruptible by a signal. */
void
-wait_for_termination (pid_t pid)
+wait_for_termination (pid_t child, int *status, bool interruptible)
{
- wait_for_termination_1 (pid, 0);
+ get_child_status (child, status, 0, interruptible);
}
-/* Like the above, but allow keyboard interruption. */
-void
-interruptible_wait_for_termination (pid_t pid)
+/* Report whether the subprocess with process id CHILD has changed status.
+ Termination counts as a change of status.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ Use waitpid-style OPTIONS to check status, but do not wait.
+
+ Return CHILD if successful, 0 if no status is available because
+ the process's state has not changed. */
+pid_t
+child_status_changed (pid_t child, int *status, int options)
{
- wait_for_termination_1 (pid, 1);
+ return get_child_status (child, status, WNOHANG | options, 0);
}
/*
@@ -446,20 +457,15 @@ static void restore_signal_handlers (struct save_signal *);
void
sys_suspend (void)
{
-#if defined (SIGTSTP) && !defined (MSDOS)
-
- {
- int pgrp = EMACS_GETPGRP (0);
- EMACS_KILLPG (pgrp, SIGTSTP);
- }
-
-#else /* No SIGTSTP */
+#ifndef DOS_NT
+ kill (0, SIGTSTP);
+#else
/* On a system where suspending is not implemented,
instead fork a subshell and let it talk directly to the terminal
while we wait. */
sys_subshell ();
-#endif /* no SIGTSTP */
+#endif
}
/* Fork a subshell. */
@@ -471,7 +477,8 @@ sys_subshell (void)
int st;
char oldwd[MAXPATHLEN+1]; /* Fixed length is safe on MSDOS. */
#endif
- int pid;
+ pid_t pid;
+ int status;
struct save_signal saved_handlers[5];
Lisp_Object dir;
unsigned char *volatile str_volatile = 0;
@@ -509,7 +516,6 @@ sys_subshell (void)
#ifdef DOS_NT
pid = 0;
save_signal_handlers (saved_handlers);
- synch_process_alive = 1;
#else
pid = vfork ();
if (pid == -1)
@@ -521,7 +527,7 @@ sys_subshell (void)
const char *sh = 0;
#ifdef DOS_NT /* MW, Aug 1993 */
- getwd (oldwd);
+ getcwd (oldwd, sizeof oldwd);
if (sh == 0)
sh = (char *) egetenv ("SUSPEND"); /* KFS, 1994-12-14 */
#endif
@@ -578,14 +584,12 @@ sys_subshell (void)
/* Do this now if we did not do it before. */
#ifndef MSDOS
save_signal_handlers (saved_handlers);
- synch_process_alive = 1;
#endif
#ifndef DOS_NT
- wait_for_termination (pid);
+ wait_for_termination (pid, &status, 0);
#endif
restore_signal_handlers (saved_handlers);
- synch_process_alive = 0;
}
static void
@@ -680,6 +684,75 @@ ignore_sigio (void)
}
+/* Saving and restoring the process group of Emacs's terminal. */
+
+/* The process group of which Emacs was a member when it initially
+ started.
+
+ If Emacs was in its own process group (i.e. inherited_pgroup ==
+ getpid ()), then we know we're running under a shell with job
+ control (Emacs would never be run as part of a pipeline).
+ Everything is fine.
+
+ If Emacs was not in its own process group, then we know we're
+ running under a shell (or a caller) that doesn't know how to
+ separate itself from Emacs (like sh). Emacs must be in its own
+ process group in order to receive SIGIO correctly. In this
+ situation, we put ourselves in our own pgroup, forcibly set the
+ tty's pgroup to our pgroup, and make sure to restore and reinstate
+ the tty's pgroup just like any other terminal setting. If
+ inherited_group was not the tty's pgroup, then we'll get a
+ SIGTTmumble when we try to change the tty's pgroup, and a CONT if
+ it goes foreground in the future, which is what should happen. */
+
+static pid_t inherited_pgroup;
+
+void
+init_foreground_group (void)
+{
+ pid_t pgrp = getpgrp ();
+ inherited_pgroup = getpid () == pgrp ? 0 : pgrp;
+}
+
+/* Safely set a controlling terminal FD's process group to PGID.
+ If we are not in the foreground already, POSIX requires tcsetpgrp
+ to deliver a SIGTTOU signal, which would stop us. This is an
+ annoyance, so temporarily ignore the signal.
+
+ In practice, platforms lacking SIGTTOU also lack tcsetpgrp, so
+ skip all this unless SIGTTOU is defined. */
+static void
+tcsetpgrp_without_stopping (int fd, pid_t pgid)
+{
+#ifdef SIGTTOU
+ signal_handler_t handler;
+ block_input ();
+ handler = signal (SIGTTOU, SIG_IGN);
+ tcsetpgrp (fd, pgid);
+ signal (SIGTTOU, handler);
+ unblock_input ();
+#endif
+}
+
+/* Split off the foreground process group to Emacs alone. When we are
+ in the foreground, but not started in our own process group,
+ redirect the tty device handle FD to point to our own process
+ group. FD must be the file descriptor of the controlling tty. */
+static void
+narrow_foreground_group (int fd)
+{
+ if (inherited_pgroup && setpgid (0, 0) == 0)
+ tcsetpgrp_without_stopping (fd, getpid ());
+}
+
+/* Set the tty to our original foreground group. */
+static void
+widen_foreground_group (int fd)
+{
+ if (inherited_pgroup && setpgid (0, inherited_pgroup) == 0)
+ tcsetpgrp_without_stopping (fd, inherited_pgroup);
+}
+
/* Getting and setting emacs_tty structures. */
/* Set *TC to the parameters associated with the terminal FD.
@@ -796,6 +869,8 @@ init_sys_modes (struct tty_display_info *tty_out)
if (!tty_out->output)
return; /* The tty is suspended. */
+ narrow_foreground_group (fileno (tty_out->input));
+
if (! tty_out->old_tty)
tty_out->old_tty = xmalloc (sizeof *tty_out->old_tty);
@@ -965,8 +1040,7 @@ init_sys_modes (struct tty_display_info *tty_out)
#endif
#endif
-#ifdef F_SETFL
-#ifdef F_GETOWN /* F_SETFL does not imply existence of F_GETOWN */
+#ifdef F_GETOWN
if (interrupt_input)
{
old_fcntl_owner[fileno (tty_out->input)] =
@@ -984,7 +1058,6 @@ init_sys_modes (struct tty_display_info *tty_out)
#endif /* HAVE_GPM */
}
#endif /* F_GETOWN */
-#endif /* F_SETFL */
#ifdef _IOFBF
/* This symbol is defined on recent USG systems.
@@ -1204,8 +1277,8 @@ reset_sys_modes (struct tty_display_info *tty_out)
fsync (fileno (tty_out->output));
#endif
-#ifdef F_SETFL
-#ifdef F_SETOWN /* F_SETFL does not imply existence of F_SETOWN */
+#ifndef DOS_NT
+#ifdef F_SETOWN
if (interrupt_input)
{
reset_sigio (fileno (tty_out->input));
@@ -1213,11 +1286,9 @@ reset_sys_modes (struct tty_display_info *tty_out)
old_fcntl_owner[fileno (tty_out->input)]);
}
#endif /* F_SETOWN */
-#ifdef O_NDELAY
fcntl (fileno (tty_out->input), F_SETFL,
- fcntl (fileno (tty_out->input), F_GETFL, 0) & ~O_NDELAY);
+ fcntl (fileno (tty_out->input), F_GETFL, 0) & ~O_NONBLOCK);
#endif
-#endif /* F_SETFL */
if (tty_out->old_tty)
while (emacs_set_tty (fileno (tty_out->input),
@@ -1228,6 +1299,7 @@ reset_sys_modes (struct tty_display_info *tty_out)
dos_ttcooked ();
#endif
+ widen_foreground_group (fileno (tty_out->input));
}
#ifdef HAVE_PTYS
@@ -1441,9 +1513,7 @@ emacs_sigaction_init (struct sigaction *action, signal_handler_t handler)
/* When handling a signal, block nonfatal system signals that are caught
by Emacs. This makes race conditions less likely. */
sigaddset (&action->sa_mask, SIGALRM);
-#ifdef SIGCHLD
sigaddset (&action->sa_mask, SIGCHLD);
-#endif
#ifdef SIGDANGER
sigaddset (&action->sa_mask, SIGDANGER);
#endif
@@ -1540,12 +1610,20 @@ deliver_thread_signal (int sig, signal_handler_t handler)
errno = old_errno;
}
-#if !defined HAVE_STRSIGNAL && !HAVE_DECL_SYS_SIGLIST
-static char *my_sys_siglist[NSIG];
-# ifdef sys_siglist
-# undef sys_siglist
+#if !HAVE_DECL_SYS_SIGLIST
+# undef sys_siglist
+# ifdef _sys_siglist
+# define sys_siglist _sys_siglist
+# else
+# define sys_siglist my_sys_siglist
+static char const *sys_siglist[NSIG];
# endif
-# define sys_siglist my_sys_siglist
+#endif
+
+#ifdef _sys_nsig
+# define sys_siglist_entries _sys_nsig
+#else
+# define sys_siglist_entries NSIG
#endif
/* Handle bus errors, invalid instruction, etc. */
@@ -1608,25 +1686,18 @@ init_signals (bool dumping)
main_thread = pthread_self ();
#endif
-#if !defined HAVE_STRSIGNAL && !HAVE_DECL_SYS_SIGLIST
+#if !HAVE_DECL_SYS_SIGLIST && !defined _sys_siglist
if (! initialized)
{
sys_siglist[SIGABRT] = "Aborted";
# ifdef SIGAIO
sys_siglist[SIGAIO] = "LAN I/O interrupt";
# endif
-# ifdef SIGALRM
sys_siglist[SIGALRM] = "Alarm clock";
-# endif
# ifdef SIGBUS
sys_siglist[SIGBUS] = "Bus error";
# endif
-# ifdef SIGCLD
- sys_siglist[SIGCLD] = "Child status changed";
-# endif
-# ifdef SIGCHLD
sys_siglist[SIGCHLD] = "Child status changed";
-# endif
# ifdef SIGCONT
sys_siglist[SIGCONT] = "Continued";
# endif
@@ -1646,9 +1717,7 @@ init_signals (bool dumping)
# ifdef SIGGRANT
sys_siglist[SIGGRANT] = "Monitor mode granted";
# endif
-# ifdef SIGHUP
sys_siglist[SIGHUP] = "Hangup";
-# endif
sys_siglist[SIGILL] = "Illegal instruction";
sys_siglist[SIGINT] = "Interrupt";
# ifdef SIGIO
@@ -1660,9 +1729,7 @@ init_signals (bool dumping)
# ifdef SIGIOT
sys_siglist[SIGIOT] = "IOT trap";
# endif
-# ifdef SIGKILL
sys_siglist[SIGKILL] = "Killed";
-# endif
# ifdef SIGLOST
sys_siglist[SIGLOST] = "Resource lost";
# endif
@@ -1675,9 +1742,7 @@ init_signals (bool dumping)
# ifdef SIGPHONE
sys_siglist[SIGWIND] = "SIGPHONE";
# endif
-# ifdef SIGPIPE
sys_siglist[SIGPIPE] = "Broken pipe";
-# endif
# ifdef SIGPOLL
sys_siglist[SIGPOLL] = "Pollable event occurred";
# endif
@@ -1690,9 +1755,7 @@ init_signals (bool dumping)
# ifdef SIGPWR
sys_siglist[SIGPWR] = "Power-fail restart";
# endif
-# ifdef SIGQUIT
sys_siglist[SIGQUIT] = "Quit";
-# endif
# ifdef SIGRETRACT
sys_siglist[SIGRETRACT] = "Need to relinquish monitor mode";
# endif
@@ -1756,7 +1819,7 @@ init_signals (bool dumping)
sys_siglist[SIGXFSZ] = "File size limit exceeded";
# endif
}
-#endif /* !defined HAVE_STRSIGNAL && !defined HAVE_DECL_SYS_SIGLIST */
+#endif /* !HAVE_DECL_SYS_SIGLIST && !_sys_siglist */
/* Don't alter signal handlers if dumping. On some machines,
changing signal handlers sets static data that would make signals
@@ -2162,82 +2225,6 @@ emacs_readlink (char const *filename, char initial_buf[READLINK_BUFSIZE])
&emacs_norealloc_allocator, careadlinkatcwd);
}
-#ifdef USG
-/*
- * All of the following are for USG.
- *
- * On USG systems the system calls are INTERRUPTIBLE by signals
- * that the user program has elected to catch. Thus the system call
- * must be retried in these cases. To handle this without massive
- * changes in the source code, we remap the standard system call names
- * to names for our own functions in sysdep.c that do the system call
- * with retries. Actually, for portability reasons, it is good
- * programming practice, as this example shows, to limit all actual
- * system calls to a single occurrence in the source. Sure, this
- * adds an extra level of function call overhead but it is almost
- * always negligible. Fred Fish, Unisoft Systems Inc.
- */
-
-/*
- * Warning, this function may not duplicate 4.2 action properly
- * under error conditions.
- */
-
-#if !defined (HAVE_GETWD) || defined (BROKEN_GETWD)
-
-#ifndef MAXPATHLEN
-/* In 4.1, param.h fails to define this. */
-#define MAXPATHLEN 1024
-#endif
-
-char *
-getwd (char *pathname)
-{
- char *npath, *spath;
- extern char *getcwd (char *, size_t);
-
- block_input (); /* getcwd uses malloc */
- spath = npath = getcwd ((char *) 0, MAXPATHLEN);
- if (spath == 0)
- {
- unblock_input ();
- return spath;
- }
- /* On Altos 3068, getcwd can return @hostname/dir, so discard
- up to first slash. Should be harmless on other systems. */
- while (*npath && *npath != '/')
- npath++;
- strcpy (pathname, npath);
- free (spath); /* getcwd uses malloc */
- unblock_input ();
- return pathname;
-}
-
-#endif /* !defined (HAVE_GETWD) || defined (BROKEN_GETWD) */
-#endif /* USG */
-
-/* Directory routines for systems that don't have them. */
-
-#ifdef HAVE_DIRENT_H
-
-#include
-
-#if !defined (HAVE_CLOSEDIR)
-
-int
-closedir (DIR *dirp /* stream from opendir */)
-{
- int rtnval;
-
- rtnval = emacs_close (dirp->dd_fd);
- xfree (dirp);
-
- return rtnval;
-}
-#endif /* not HAVE_CLOSEDIR */
-#endif /* HAVE_DIRENT_H */
-
-
/* Return a struct timeval that is roughly equivalent to T.
Use the least timeval not less than T.
Return an extremal value if the result would overflow. */
@@ -2277,40 +2264,27 @@ set_file_times (int fd, const char *filename,
return fdutimens (fd, filename, timespec);
}
-#ifndef HAVE_STRSIGNAL
-char *
-strsignal (int code)
+/* Like strsignal, except async-signal-safe, and this function typically
+ returns a string in the C locale rather than the current locale. */
+char const *
+safe_strsignal (int code)
{
- char *signame = 0;
+ char const *signame = 0;
- if (0 <= code && code < NSIG)
- {
- /* Cast to suppress warning if the table has const char *. */
- signame = (char *) sys_siglist[code];
- }
+ if (0 <= code && code < sys_siglist_entries)
+ signame = sys_siglist[code];
+ if (! signame)
+ signame = "Unknown signal";
return signame;
}
-#endif /* HAVE_STRSIGNAL */
#ifndef DOS_NT
/* For make-serial-process */
int
serial_open (char *port)
{
- int fd = -1;
-
- fd = emacs_open ((char*) port,
- O_RDWR
-#ifdef O_NONBLOCK
- | O_NONBLOCK
-#else
- | O_NDELAY
-#endif
-#ifdef O_NOCTTY
- | O_NOCTTY
-#endif
- , 0);
+ int fd = emacs_open (port, O_RDWR | O_NOCTTY | O_NONBLOCK, 0);
if (fd < 0)
{
error ("Could not open %s: %s",