src/process.h

   1 /* Definitions for asynchronous process control in GNU Emacs.
   2    Copyright (C) 1985, 1994, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #ifdef HAVE_SYS_TYPES_H
  23 #include <sys/types.h>
  24 #endif
  25 #ifdef HAVE_UNISTD_H
  26 #include <unistd.h>
  27 #endif
  28
  29 /* This structure records information about a subprocess
  30    or network connection.
  31
  32    Every field in this structure except for the first two
  33    must be a Lisp_Object, for GC's sake.  */
  34
  35 struct Lisp_Process
  36   {
  37     EMACS_INT size;
  38     struct Lisp_Vector *v_next;
  39     /* Name of subprocess terminal.  */
  40     Lisp_Object tty_name;
  41     /* Name of this process */
  42     Lisp_Object name;
  43     /* List of command arguments that this process was run with.
  44        Is set to t for a stopped network process; nil otherwise. */
  45     Lisp_Object command;
  46     /* (funcall FILTER PROC STRING)  (if FILTER is non-nil)
  47        to dispose of a bunch of chars from the process all at once */
  48     Lisp_Object filter;
  49     /* (funcall SENTINEL PROCESS) when process state changes */
  50     Lisp_Object sentinel;
  51     /* (funcall LOG SERVER CLIENT MESSAGE) when a server process
  52        accepts a connection from a client.  */
  53     Lisp_Object log;
  54     /* Buffer that output is going to */
  55     Lisp_Object buffer;
  56     /* t if this is a real child process.
  57        For a net connection, it is a plist based on the arguments to make-network-process.  */
  58     Lisp_Object childp;
  59     /* Plist for programs to keep per-process state information, parameters, etc.  */
  60     Lisp_Object plist;
  61     /* Marker set to end of last buffer-inserted output from this process */
  62     Lisp_Object mark;
  63     /* Symbol indicating status of process.
  64        This may be a symbol: run, open, or closed.
  65        Or it may be a list, whose car is stop, exit or signal
  66        and whose cdr is a pair (EXIT_CODE . COREDUMP_FLAG)
  67        or (SIGNAL_NUMBER . COREDUMP_FLAG).  */
  68     Lisp_Object status;
  69     /* Coding-system for decoding the input from this process.  */
  70     Lisp_Object decode_coding_system;
  71     /* Working buffer for decoding.  */
  72     Lisp_Object decoding_buf;
  73     /* Coding-system for encoding the output to this process.  */
  74     Lisp_Object encode_coding_system;
  75     /* Working buffer for encoding.  */
  76     Lisp_Object encoding_buf;
  77
  78     /* After this point, there are no Lisp_Objects any more.  */
  79     /* alloc.c assumes that `pid' is the first such non-Lisp slot.  */
  80
  81     /* Number of this process.
  82        allocate_process assumes this is the first non-Lisp_Object field.
  83        A value 0 is used for pseudo-processes such as network connections.  */
  84     pid_t pid;
  85     /* Descriptor by which we read from this process */
  86     int infd;
  87     /* Descriptor by which we write to this process */
  88     int outfd;
  89     /* Event-count of last event in which this process changed status.  */
  90     int tick;
  91     /* Event-count of last such event reported.  */
  92     int update_tick;
  93     /* Size of carryover in decoding.  */
  94     int decoding_carryover;
  95     /* Hysteresis to try to read process output in larger blocks.
  96        On some systems, e.g. GNU/Linux, Emacs is seen as
  97        an interactive app also when reading process output, meaning
  98        that process output can be read in as little as 1 byte at a
  99        time.  Value is micro-seconds to delay reading output from
 100        this process.  Range is 0 .. 50000.  */
 101     int read_output_delay;
 102     /* Should we delay reading output from this process.
 103        Initialized from `Vprocess_adaptive_read_buffering'.
 104        0 = nil, 1 = t, 2 = other.  */
 105     int adaptive_read_buffering : 2;
 106     /* Skip reading this process on next read.  */
 107     int read_output_skip : 1;
 108     /* Non-nil means kill silently if Emacs is exited.
 109        This is the inverse of the `query-on-exit' flag.  */
 110     int kill_without_query : 1;
 111     /* Non-nil if communicating through a pty.  */
 112     int pty_flag : 1;
 113     /* Flag to set coding-system of the process buffer from the
 114        coding_system used to decode process output.  */
 115     int inherit_coding_system_flag : 1;
 116     /* Flag to decide the multibyteness of a string given to the
 117        filter (if any).  It is initialized to the value of
 118        `default-enable-multibyte-characters' when the process is
 119        generated, and can be changed by the function
 120        `set-process-filter-multibyte'. */
 121     int filter_multibyte : 1;
 122     /* Record the process status in the raw form in which it comes from `wait'.
 123        This is to avoid consing in a signal handler.  The `raw_status_new'
 124        flag indicates that `raw_status' contains a new status that still
 125        needs to be synced to `status'.  */
 126     int raw_status_new : 1;
 127     int raw_status;
 128 };
 129
 130 /* Every field in the preceding structure except for the first two
 131    must be a Lisp_Object, for GC's sake.  */
 132
 133 #define ChannelMask(n) (1<<(n))
 134
 135 /* Indexed by descriptor, gives the process (if any) for that descriptor.  */
 136 extern Lisp_Object chan_process[];
 137
 138 /* Alist of elements (NAME . PROCESS).  */
 139 extern Lisp_Object Vprocess_alist;
 140
 141 /* True iff we are about to fork off a synchronous process or if we
 142    are waiting for it.  */
 143 extern int synch_process_alive;
 144
 145 /* Communicate exit status of sync process to from sigchld_handler
 146    to Fcall_process.  */
 147
 148 /* Nonzero => this is a string explaining death of synchronous subprocess.  */
 149 extern char *synch_process_death;
 150
 151 /* Nonzero => this is the signal number that terminated the subprocess.  */
 152 extern int synch_process_termsig;
 153
 154 /* If synch_process_death is zero,
 155    this is exit code of synchronous subprocess.  */
 156 extern int synch_process_retcode;
 157
 158 /* The name of the file open to get a null file, or a data sink.
 159    VMS, MS-DOS, and OS/2 redefine this.  */
 160 #ifndef NULL_DEVICE
 161 #define NULL_DEVICE "/dev/null"
 162 #endif
 163
 164 /* Nonzero means don't run process sentinels.  This is used
 165    when exiting.  */
 166 extern int inhibit_sentinels;
 167
 168 /* arch-tag: dffedfc4-d7bc-4b58-a26f-c16155449c72
 169    (do not change this comment) */