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, 2008  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 of the License, or
  10 (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifdef HAVE_SYS_TYPES_H
  21 #include <sys/types.h>
  22 #endif
  23 #ifdef HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26
  27 /* This structure records information about a subprocess
  28    or network connection.
  29
  30    Every field in this structure except for the first two
  31    must be a Lisp_Object, for GC's sake.  */
  32
  33 struct Lisp_Process
  34   {
  35     EMACS_UINT size;
  36     struct Lisp_Vector *v_next;
  37     /* Name of subprocess terminal.  */
  38     Lisp_Object tty_name;
  39     /* Name of this process */
  40     Lisp_Object name;
  41     /* List of command arguments that this process was run with.
  42        Is set to t for a stopped network process; nil otherwise. */
  43     Lisp_Object command;
  44     /* (funcall FILTER PROC STRING)  (if FILTER is non-nil)
  45        to dispose of a bunch of chars from the process all at once */
  46     Lisp_Object filter;
  47     /* (funcall SENTINEL PROCESS) when process state changes */
  48     Lisp_Object sentinel;
  49     /* (funcall LOG SERVER CLIENT MESSAGE) when a server process
  50        accepts a connection from a client.  */
  51     Lisp_Object log;
  52     /* Buffer that output is going to */
  53     Lisp_Object buffer;
  54     /* t if this is a real child process.  For a network or serial
  55        connection, it is a plist based on the arguments to
  56        make-network-process or make-serial-process.  */
  57     Lisp_Object childp;
  58     /* Plist for programs to keep per-process state information, parameters, etc.  */
  59     Lisp_Object plist;
  60     /* Symbol indicating the type of process: real, network, serial  */
  61     Lisp_Object type;
  62     /* Marker set to end of last buffer-inserted output from this process */
  63     Lisp_Object mark;
  64     /* Symbol indicating status of process.
  65        This may be a symbol: run, open, or closed.
  66        Or it may be a list, whose car is stop, exit or signal
  67        and whose cdr is a pair (EXIT_CODE . COREDUMP_FLAG)
  68        or (SIGNAL_NUMBER . COREDUMP_FLAG).  */
  69     Lisp_Object status;
  70     /* Coding-system for decoding the input from this process.  */
  71     Lisp_Object decode_coding_system;
  72     /* Working buffer for decoding.  */
  73     Lisp_Object decoding_buf;
  74     /* Coding-system for encoding the output to this process.  */
  75     Lisp_Object encode_coding_system;
  76     /* Working buffer for encoding.  */
  77     Lisp_Object encoding_buf;
  78
  79     /* After this point, there are no Lisp_Objects any more.  */
  80     /* alloc.c assumes that `pid' is the first such non-Lisp slot.  */
  81
  82     /* Number of this process.
  83        allocate_process assumes this is the first non-Lisp_Object field.
  84        A value 0 is used for pseudo-processes such as network or serial
  85        connections.  */
  86     pid_t pid;
  87     /* Descriptor by which we read from this process */
  88     int infd;
  89     /* Descriptor by which we write to this process */
  90     int outfd;
  91     /* Event-count of last event in which this process changed status.  */
  92     int tick;
  93     /* Event-count of last such event reported.  */
  94     int update_tick;
  95     /* Size of carryover in decoding.  */
  96     int decoding_carryover;
  97     /* Hysteresis to try to read process output in larger blocks.
  98        On some systems, e.g. GNU/Linux, Emacs is seen as
  99        an interactive app also when reading process output, meaning
 100        that process output can be read in as little as 1 byte at a
 101        time.  Value is micro-seconds to delay reading output from
 102        this process.  Range is 0 .. 50000.  */
 103     int read_output_delay;
 104     /* Should we delay reading output from this process.
 105        Initialized from `Vprocess_adaptive_read_buffering'.
 106        0 = nil, 1 = t, 2 = other.  */
 107     unsigned int adaptive_read_buffering : 2;
 108     /* Skip reading this process on next read.  */
 109     unsigned int read_output_skip : 1;
 110     /* Non-nil means kill silently if Emacs is exited.
 111        This is the inverse of the `query-on-exit' flag.  */
 112     unsigned int kill_without_query : 1;
 113     /* Non-nil if communicating through a pty.  */
 114     unsigned int pty_flag : 1;
 115     /* Flag to set coding-system of the process buffer from the
 116        coding_system used to decode process output.  */
 117     unsigned int inherit_coding_system_flag : 1;
 118     /* Record the process status in the raw form in which it comes from `wait'.
 119        This is to avoid consing in a signal handler.  The `raw_status_new'
 120        flag indicates that `raw_status' contains a new status that still
 121        needs to be synced to `status'.  */
 122     unsigned int raw_status_new : 1;
 123     int raw_status;
 124 };
 125
 126 /* Every field in the preceding structure except for the first two
 127    must be a Lisp_Object, for GC's sake.  */
 128
 129 #define ChannelMask(n) (1<<(n))
 130
 131 /* Indexed by descriptor, gives the process (if any) for that descriptor.  */
 132 extern Lisp_Object chan_process[];
 133
 134 /* Alist of elements (NAME . PROCESS).  */
 135 extern Lisp_Object Vprocess_alist;
 136
 137 /* True if we are about to fork off a synchronous process or if we
 138    are waiting for it.  */
 139 extern int synch_process_alive;
 140
 141 /* Communicate exit status of sync process to from sigchld_handler
 142    to Fcall_process.  */
 143
 144 /* Nonzero => this is a string explaining death of synchronous subprocess.  */
 145 extern char *synch_process_death;
 146
 147 /* Nonzero => this is the signal number that terminated the subprocess.  */
 148 extern int synch_process_termsig;
 149
 150 /* If synch_process_death is zero,
 151    this is exit code of synchronous subprocess.  */
 152 extern int synch_process_retcode;
 153
 154 /* The name of the file open to get a null file, or a data sink.
 155    VMS, MS-DOS, and OS/2 redefine this.  */
 156 #ifndef NULL_DEVICE
 157 #define NULL_DEVICE "/dev/null"
 158 #endif
 159
 160 /* Nonzero means don't run process sentinels.  This is used
 161    when exiting.  */
 162 extern int inhibit_sentinels;
 163
 164 /* arch-tag: dffedfc4-d7bc-4b58-a26f-c16155449c72
 165    (do not change this comment) */