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Avoid hangs in accept-process-output.

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* lisp.h, process.c (wait_reading_process_input):
Return int, not bool.  All uses changed.
* process.c (SELECT_CANT_DO_WRITE_MASK):
Remove macro, replacing with ...
(SELECT_CAN_DO_WRITE_MASK): ... new constant, with inverted sense.
All uses changed.
(status_notify): New arg WAIT_PROC.  Return int, not void.
All uses changed.

Fixes: debbugs:17647
This commit is contained in:
Paul Eggert 2014-06-13 08:55:48 -07:00
parent 99961a049f
commit 05d282102d
3 changed files with 78 additions and 62 deletions
Download patch file Download diff file Expand all files Collapse all files

12
src/ChangeLog
View file

@ -1,3 +1,15 @@
2014-06-13 Paul Eggert <eggert@cs.ucla.edu>
Avoid hangs in accept-process-output (Bug#17647).
* lisp.h, process.c (wait_reading_process_input):
Return int, not bool. All uses changed.
* process.c (SELECT_CANT_DO_WRITE_MASK):
Remove macro, replacing with ...
(SELECT_CAN_DO_WRITE_MASK): ... new constant, with inverted sense.
All uses changed.
(status_notify): New arg WAIT_PROC. Return int, not void.
All uses changed.
2014-06-13 Eli Zaretskii <eliz@gnu.org>
* menu.c (Fx_popup_menu): Don't call the frame's menu_show_hook if

6
src/lisp.h
View file

@ -4178,10 +4178,8 @@ extern bool running_asynch_code;
/* Defined in process.c. */
extern Lisp_Object QCtype, Qlocal;
extern void kill_buffer_processes (Lisp_Object);
extern bool wait_reading_process_output (intmax_t, int, int, bool,
Lisp_Object,
struct Lisp_Process *,
int);
extern int wait_reading_process_output (intmax_t, int, int, bool, Lisp_Object,
struct Lisp_Process *, int);
/* Max value for the first argument of wait_reading_process_output. */
#if __GNUC__ == 3 || (__GNUC__ == 4 && __GNUC_MINOR__ <= 5)
/* Work around a bug in GCC 3.4.2, known to be fixed in GCC 4.6.3.

122
src/process.c
View file

@ -224,8 +224,9 @@ static EMACS_INT update_tick;
/* Only W32 has this, it really means that select can't take write mask. */
#ifdef BROKEN_NON_BLOCKING_CONNECT
#undef NON_BLOCKING_CONNECT
#define SELECT_CANT_DO_WRITE_MASK
enum { SELECT_CAN_DO_WRITE_MASK = false };
#else
enum { SELECT_CAN_DO_WRITE_MASK = true };
#ifndef NON_BLOCKING_CONNECT
#ifdef HAVE_SELECT
#if defined (HAVE_GETPEERNAME) || defined (GNU_LINUX)
@ -281,7 +282,7 @@ static void create_process (Lisp_Object, char **, Lisp_Object);
static bool keyboard_bit_set (fd_set *);
#endif
static void deactivate_process (Lisp_Object);
static void status_notify (struct Lisp_Process *);
static int status_notify (struct Lisp_Process *, struct Lisp_Process *);
static int read_process_output (Lisp_Object, int);
static void handle_child_signal (int);
static void create_pty (Lisp_Object);
@ -860,7 +861,7 @@ nil, indicating the current buffer's process. */)
{
pset_status (p, list2 (Qexit, make_number (0)));
p->tick = ++process_tick;
status_notify (p);
status_notify (p, NULL);
redisplay_preserve_echo_area (13);
}
else
@ -880,7 +881,7 @@ nil, indicating the current buffer's process. */)
pset_status (p, list2 (Qsignal, make_number (SIGKILL)));
p->tick = ++process_tick;
status_notify (p);
status_notify (p, NULL);
redisplay_preserve_echo_area (13);
}
}
@ -3986,12 +3987,13 @@ is nil, from any process) before the timeout expired. */)
nsecs = 0;
return
(wait_reading_process_output (secs, nsecs, 0, 0,
((wait_reading_process_output (secs, nsecs, 0, 0,
Qnil,
!NILP (process) ? XPROCESS (process) : NULL,
NILP (just_this_one) ? 0 :
!INTEGERP (just_this_one) ? 1 : -1)
? Qt : Qnil);
<= 0)
? Qnil : Qt);
}
/* Accept a connection for server process SERVER on CHANNEL. */
@ -4262,10 +4264,11 @@ wait_reading_process_output_1 (void)
(suspending output from other processes). A negative value
means don't run any timers either.
Return true if we received input from WAIT_PROC, or from any
process if WAIT_PROC is null. */
Return positive if we received input from WAIT_PROC (or from any
process if WAIT_PROC is null), zero if we attempted to receive
input but got none, and negative if we didn't even try. */
bool
int
wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
bool do_display,
Lisp_Object wait_for_cell,
@ -4280,8 +4283,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
int xerrno;
Lisp_Object proc;
struct timespec timeout, end_time;
int wait_channel = -1;
bool got_some_input = 0;
int got_some_input = -1;
ptrdiff_t count = SPECPDL_INDEX ();
FD_ZERO (&Available);
@ -4292,10 +4294,6 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
&& EQ (XCAR (wait_proc->status), Qexit)))
message1 ("Blocking call to accept-process-output with quit inhibited!!");
/* If wait_proc is a process to watch, set wait_channel accordingly. */
if (wait_proc != NULL)
wait_channel = wait_proc->infd;
record_unwind_protect_int (wait_reading_process_output_unwind,
waiting_for_user_input_p);
waiting_for_user_input_p = read_kbd;
@ -4332,6 +4330,10 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
if (! NILP (wait_for_cell) && ! NILP (XCAR (wait_for_cell)))
break;
/* After reading input, vacuum up any leftovers without waiting. */
if (0 <= got_some_input)
nsecs = -1;
/* Compute time from now till when time limit is up. */
/* Exit if already run out. */
if (nsecs < 0)
@ -4450,7 +4452,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
/* It's okay for us to do this and then continue with
the loop, since timeout has already been zeroed out. */
clear_waiting_for_input ();
status_notify (NULL);
got_some_input = status_notify (NULL, wait_proc);
if (do_display) redisplay_preserve_echo_area (13);
}
}
@ -4472,18 +4474,23 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
while (wait_proc->infd >= 0)
{
int nread = read_process_output (proc, wait_proc->infd);
if (nread == 0)
break;
if (nread > 0)
got_some_input = read_some_bytes = 1;
else if (nread == -1 && (errno == EIO || errno == EAGAIN))
break;
if (nread < 0)
{
if (errno == EIO || errno == EAGAIN)
break;
#ifdef EWOULDBLOCK
else if (nread == -1 && EWOULDBLOCK == errno)
break;
if (errno == EWOULDBLOCK)
break;
#endif
}
else
{
if (got_some_input < nread)
got_some_input = nread;
if (nread == 0)
break;
read_some_bytes = true;
}
}
if (read_some_bytes && do_display)
redisplay_preserve_echo_area (10);
@ -4514,12 +4521,8 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
else
Available = input_wait_mask;
Writeok = write_mask;
#ifdef SELECT_CANT_DO_WRITE_MASK
check_write = 0;
#else
check_write = 1;
#endif
check_delay = wait_channel >= 0 ? 0 : process_output_delay_count;
check_delay = wait_proc ? 0 : process_output_delay_count;
check_write = SELECT_CAN_DO_WRITE_MASK;
}
/* If frame size has changed or the window is newly mapped,
@ -4545,6 +4548,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
{
nfds = read_kbd ? 0 : 1;
no_avail = 1;
FD_ZERO (&Available);
}
if (!no_avail)
@ -4554,7 +4558,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
/* Set the timeout for adaptive read buffering if any
process has non-zero read_output_skip and non-zero
read_output_delay, and we are not reading output for a
specific wait_channel. It is not executed if
specific process. It is not executed if
Vprocess_adaptive_read_buffering is nil. */
if (process_output_skip && check_delay > 0)
{
@ -4667,12 +4671,6 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
report_file_errno ("Failed select", Qnil, xerrno);
}
if (no_avail)
{
FD_ZERO (&Available);
check_write = 0;
}
/* Check for keyboard input */
/* If there is any, return immediately
to give it higher priority than subprocesses */
@ -4739,9 +4737,6 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
handle_input_available_signal (SIGIO);
#endif
if (! wait_proc)
got_some_input |= nfds > 0;
/* If checking input just got us a size-change event from X,
obey it now if we should. */
if (read_kbd || ! NILP (wait_for_cell))
@ -4773,12 +4768,6 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
/* If waiting for this channel, arrange to return as
soon as no more input to be processed. No more
waiting. */
if (wait_channel == channel)
{
wait_channel = -1;
nsecs = -1;
got_some_input = 1;
}
proc = chan_process[channel];
if (NILP (proc))
continue;
@ -4794,6 +4783,8 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
buffered-ahead character if we have one. */
nread = read_process_output (proc, channel);
if ((!wait_proc || wait_proc == XPROCESS (proc)) && got_some_input < nread)
got_some_input = nread;
if (nread > 0)
{
/* Since read_process_output can run a filter,
@ -5814,7 +5805,7 @@ process_send_signal (Lisp_Object process, int signo, Lisp_Object current_group,
p->tick = ++process_tick;
if (!nomsg)
{
status_notify (NULL);
status_notify (NULL, NULL);
redisplay_preserve_echo_area (13);
}
}
@ -6337,14 +6328,20 @@ exec_sentinel (Lisp_Object proc, Lisp_Object reason)
/* Report all recent events of a change in process status
(either run the sentinel or output a message).
This is usually done while Emacs is waiting for keyboard input
but can be done at other times. */
but can be done at other times.
static void
status_notify (struct Lisp_Process *deleting_process)
Return positive if any input was received from WAIT_PROC (or from
any process if WAIT_PROC is null), zero if input was attempted but
none received, and negative if we didn't even try. */
static int
status_notify (struct Lisp_Process *deleting_process,
struct Lisp_Process *wait_proc)
{
register Lisp_Object proc;
Lisp_Object proc;
Lisp_Object tail, msg;
struct gcpro gcpro1, gcpro2;
int got_some_input = -1;
tail = Qnil;
msg = Qnil;
@ -6374,8 +6371,14 @@ status_notify (struct Lisp_Process *deleting_process)
/* Network or serial process not stopped: */
&& ! EQ (p->command, Qt)
&& p->infd >= 0
&& p != deleting_process
&& read_process_output (proc, p->infd) > 0);
&& p != deleting_process)
{
int nread = read_process_output (proc, p->infd);
if (got_some_input < nread)
got_some_input = nread;
if (nread <= 0)
break;
}
/* Get the text to use for the message. */
if (p->raw_status_new)
@ -6407,6 +6410,7 @@ status_notify (struct Lisp_Process *deleting_process)
update_mode_lines = 24; /* In case buffers use %s in mode-line-format. */
UNGCPRO;
return got_some_input;
}
DEFUN ("internal-default-process-sentinel", Finternal_default_process_sentinel,
@ -6618,9 +6622,11 @@ extern int sys_select (int, fd_set *, fd_set *, fd_set *,
DO_DISPLAY means redisplay should be done to show subprocess
output that arrives.
Return true if we received input from any process. */
Return positive if we received input from WAIT_PROC (or from any
process if WAIT_PROC is null), zero if we attempted to receive
input but got none, and negative if we didn't even try. */
bool
int
wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
bool do_display,
Lisp_Object wait_for_cell,
@ -6808,7 +6814,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
start_polling ();
return 0;
return -1;
}
#endif /* not subprocesses */