diff options
Diffstat (limited to 'src/sysdep.c')
| -rw-r--r-- | src/sysdep.c | 243 |
1 files changed, 69 insertions, 174 deletions
diff --git a/src/sysdep.c b/src/sysdep.c index 06dc41b511e..5291c5d59aa 100644 --- a/src/sysdep.c +++ b/src/sysdep.c @@ -101,7 +101,6 @@ along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ #define _P_WAIT 0 int _cdecl _spawnlp (int, const char *, const char *, ...); int _cdecl _getpid (void); -extern char *getwd (char *); #endif #include "syssignal.h" @@ -134,12 +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 @@ -155,7 +154,6 @@ get_current_dir_name (void) return NULL; strcpy (buf, pwd); } -#ifdef HAVE_GETCWD else { size_t buf_size = 1024; @@ -179,22 +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 @@ -284,45 +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) + pid_t pid; + + /* 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) { - 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; - } + /* 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) - - { - pid_t pgrp = getpgrp (); - 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 @@ -1036,8 +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)] = @@ -1055,7 +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. @@ -1275,8 +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)); @@ -1284,11 +1286,9 @@ reset_sys_modes (struct tty_display_info *tty_out) old_fcntl_owner[fileno (tty_out->input)]); } #endif /* F_SETOWN */ -#if 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), @@ -1513,9 +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 @@ -1695,18 +1693,11 @@ init_signals (bool dumping) # 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 @@ -1726,9 +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 @@ -1740,9 +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 @@ -1755,9 +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 @@ -1770,9 +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 @@ -2242,82 +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 <dirent.h> - -#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. */ @@ -2377,19 +2284,7 @@ safe_strsignal (int code) int serial_open (char *port) { - int fd = -1; - - fd = emacs_open ((char*) port, - O_RDWR -#if O_NONBLOCK - | O_NONBLOCK -#else - | O_NDELAY -#endif -#if 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", |