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Move signal handling to libuv event loop

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This removes all signal handling code from os_unix.c to os/signal.c. Now signal
handling is done like this:

- Watchers for signals are registered with libuv default event loop
- `event_poll` continuously calls `poll_uv_loop` to produce events until it
  receives user input, SIGINT or a timeout
- Any signals received in `poll_uv_loop` will push events to a queue that is
  drained and processed by `event_poll`

Signals aren't handled directly in the libuv callback to avoid recursion in the
event loop(which isn't supported by libuv).

The same principle will apply to other events in the future: Push to a queue
from a libuv callback and drain it from `event_poll`
This commit is contained in:
Thiago de Arruda
2014-04-01 08:54:31 -03:00
parent 40879af7bd
commit 774f668c43
10 changed files with 295 additions and 608 deletions
Download Patch File Download Diff File Expand all files Collapse all files

590
src/os_unix.c
View File

@@ -54,6 +54,7 @@
#include "os/event.h"
#include "os/input.h"
#include "os/shell.h"
#include "os/signal.h"
#include "os_unixx.h" /* unix includes for os_unix.c only */
@@ -72,28 +73,6 @@ static int selinux_enabled = -1;
extern int select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
#endif
/*
* end of autoconf section. To be extended...
*/
/* Are the following #ifdefs still required? And why? Is that for X11? */
#if defined(ESIX) || defined(M_UNIX) && !defined(SCO)
# ifdef SIGWINCH
# undef SIGWINCH
# endif
# ifdef TIOCGWINSZ
# undef TIOCGWINSZ
# endif
#endif
#if defined(SIGWINDOW) && !defined(SIGWINCH) /* hpux 9.01 has it */
# define SIGWINCH SIGWINDOW
#endif
static int get_x11_title(int);
static int get_x11_icon(int);
@@ -102,8 +81,6 @@ static int did_set_title = FALSE;
static char_u *oldicon = NULL;
static int did_set_icon = FALSE;
static void may_core_dump(void);
#ifdef HAVE_UNION_WAIT
typedef union wait waitstatus;
#else
@@ -113,130 +90,12 @@ static pid_t wait4pid(pid_t, waitstatus *);
static int RealWaitForChar(int, long, int *);
static void handle_resize(void);
#if defined(SIGWINCH)
static RETSIGTYPE sig_winch SIGPROTOARG;
#endif
#if defined(SIGINT)
static RETSIGTYPE catch_sigint SIGPROTOARG;
#endif
#if defined(SIGPWR)
static RETSIGTYPE catch_sigpwr SIGPROTOARG;
#endif
static RETSIGTYPE deathtrap SIGPROTOARG;
static void catch_int_signal(void);
static void set_signals(void);
static void catch_signals
(RETSIGTYPE (*func_deadly)(), RETSIGTYPE (*func_other)());
static int have_wildcard(int, char_u **);
static int have_dollars(int, char_u **);
static int save_patterns(int num_pat, char_u **pat, int *num_file,
char_u ***file);
#ifndef SIG_ERR
# define SIG_ERR ((RETSIGTYPE (*)())-1)
#endif
/* volatile because it is used in signal handler sig_winch(). */
static volatile int do_resize = FALSE;
/* volatile because it is used in signal handler deathtrap(). */
static volatile int deadly_signal = 0; /* The signal we caught */
#ifdef SYS_SIGLIST_DECLARED
/*
* I have seen
* extern char *_sys_siglist[NSIG];
* on Irix, Linux, NetBSD and Solaris. It contains a nice list of strings
* that describe the signals. That is nearly what we want here. But
* autoconf does only check for sys_siglist (without the underscore), I
* do not want to change everything today.... jw.
* This is why AC_DECL_SYS_SIGLIST is commented out in configure.in
*/
#endif
static struct signalinfo {
int sig; /* Signal number, eg. SIGSEGV etc */
char *name; /* Signal name (not char_u!). */
char deadly; /* Catch as a deadly signal? */
} signal_info[] =
{
#ifdef SIGHUP
{SIGHUP, "HUP", TRUE},
#endif
#ifdef SIGQUIT
{SIGQUIT, "QUIT", TRUE},
#endif
#ifdef SIGILL
{SIGILL, "ILL", TRUE},
#endif
#ifdef SIGTRAP
{SIGTRAP, "TRAP", TRUE},
#endif
#ifdef SIGABRT
{SIGABRT, "ABRT", TRUE},
#endif
#ifdef SIGEMT
{SIGEMT, "EMT", TRUE},
#endif
#ifdef SIGFPE
{SIGFPE, "FPE", TRUE},
#endif
#ifdef SIGBUS
{SIGBUS, "BUS", TRUE},
#endif
#if defined(SIGSEGV)
/* MzScheme uses SEGV in its garbage collector */
{SIGSEGV, "SEGV", TRUE},
#endif
#ifdef SIGSYS
{SIGSYS, "SYS", TRUE},
#endif
#ifdef SIGALRM
{SIGALRM, "ALRM", FALSE}, /* Perl's alarm() can trigger it */
#endif
#ifdef SIGTERM
{SIGTERM, "TERM", TRUE},
#endif
#if defined(SIGVTALRM)
{SIGVTALRM, "VTALRM", TRUE},
#endif
#if defined(SIGPROF) && !defined(WE_ARE_PROFILING)
/* MzScheme uses SIGPROF for its own needs; On Linux with profiling
* this makes Vim exit. WE_ARE_PROFILING is defined in Makefile. */
{SIGPROF, "PROF", TRUE},
#endif
#ifdef SIGXCPU
{SIGXCPU, "XCPU", TRUE},
#endif
#ifdef SIGXFSZ
{SIGXFSZ, "XFSZ", TRUE},
#endif
#ifdef SIGUSR1
{SIGUSR1, "USR1", TRUE},
#endif
#if defined(SIGUSR2) && !defined(FEAT_SYSMOUSE)
/* Used for sysmouse handling */
{SIGUSR2, "USR2", TRUE},
#endif
#ifdef SIGINT
{SIGINT, "INT", FALSE},
#endif
#ifdef SIGWINCH
{SIGWINCH, "WINCH", FALSE},
#endif
#ifdef SIGTSTP
{SIGTSTP, "TSTP", FALSE},
#endif
#ifdef SIGPIPE
{SIGPIPE, "PIPE", FALSE},
#endif
{-1, "Unknown!", FALSE}
};
/*
* Write s[len] to the screen.
@@ -248,99 +107,6 @@ void mch_write(char_u *s, int len)
RealWaitForChar(read_cmd_fd, p_wd, NULL);
}
static void handle_resize()
{
do_resize = FALSE;
shell_resized();
}
#if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
/*
* Support for using the signal stack.
* This helps when we run out of stack space, which causes a SIGSEGV. The
* signal handler then must run on another stack, since the normal stack is
* completely full.
*/
#ifndef SIGSTKSZ
# define SIGSTKSZ 8000 /* just a guess of how much stack is needed... */
#endif
# ifdef HAVE_SIGALTSTACK
static stack_t sigstk; /* for sigaltstack() */
# else
static struct sigstack sigstk; /* for sigstack() */
# endif
static void init_signal_stack(void);
static char *signal_stack;
static void init_signal_stack()
{
if (signal_stack != NULL) {
# ifdef HAVE_SIGALTSTACK
sigstk.ss_sp = signal_stack;
sigstk.ss_size = SIGSTKSZ;
sigstk.ss_flags = 0;
(void)sigaltstack(&sigstk, NULL);
# else
sigstk.ss_sp = signal_stack;
if (stack_grows_downwards)
sigstk.ss_sp += SIGSTKSZ - 1;
sigstk.ss_onstack = 0;
(void)sigstack(&sigstk, NULL);
# endif
}
}
#endif
/*
* We need correct prototypes for a signal function, otherwise mean compilers
* will barf when the second argument to signal() is ``wrong''.
* Let me try it with a few tricky defines from my own osdef.h (jw).
*/
#if defined(SIGWINCH)
static RETSIGTYPE
sig_winch SIGDEFARG(sigarg) {
/* this is not required on all systems, but it doesn't hurt anybody */
signal(SIGWINCH, (RETSIGTYPE (*)())sig_winch);
do_resize = TRUE;
SIGRETURN;
}
#endif
#if defined(SIGINT)
static RETSIGTYPE
catch_sigint SIGDEFARG(sigarg) {
/* this is not required on all systems, but it doesn't hurt anybody */
signal(SIGINT, (RETSIGTYPE (*)())catch_sigint);
got_int = TRUE;
SIGRETURN;
}
#endif
#if defined(SIGPWR)
static RETSIGTYPE
catch_sigpwr SIGDEFARG(sigarg) {
/* this is not required on all systems, but it doesn't hurt anybody */
signal(SIGPWR, (RETSIGTYPE (*)())catch_sigpwr);
/*
* I'm not sure we get the SIGPWR signal when the system is really going
* down or when the batteries are almost empty. Just preserve the swap
* files and don't exit, that can't do any harm.
*/
ml_sync_all(FALSE, FALSE);
SIGRETURN;
}
#endif
#if defined(FEAT_LIBCALL) || defined(PROTO)
/*
* A simplistic version of setjmp() that only allows one level of using.
* Don't call twice before calling mch_endjmp()!.
@@ -363,9 +129,6 @@ catch_sigpwr SIGDEFARG(sigarg) {
*/
void mch_startjmp()
{
#ifdef SIGHASARG
lc_signal = 0;
#endif
lc_active = TRUE;
}
@@ -374,165 +137,6 @@ void mch_endjmp()
lc_active = FALSE;
}
void mch_didjmp()
{
# if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
/* On FreeBSD the signal stack has to be reset after using siglongjmp(),
* otherwise catching the signal only works once. */
init_signal_stack();
# endif
}
#endif
/*
* This function handles deadly signals.
* It tries to preserve any swap files and exit properly.
* (partly from Elvis).
* NOTE: Avoid unsafe functions, such as allocating memory, they can result in
* a deadlock.
*/
static RETSIGTYPE
deathtrap SIGDEFARG(sigarg) {
static int entered = 0; /* count the number of times we got here.
Note: when memory has been corrupted
this may get an arbitrary value! */
#ifdef SIGHASARG
int i;
#endif
/*
* Catch a crash in protected code.
* Restores the environment saved in lc_jump_env, which looks like
* SETJMP() returns 1.
*/
if (lc_active) {
#if defined(SIGHASARG)
lc_signal = sigarg;
#endif
lc_active = FALSE; /* don't jump again */
LONGJMP(lc_jump_env, 1);
/* NOTREACHED */
}
#ifdef SIGHASARG
# ifdef SIGQUIT
/* While in os_delay() we go to cooked mode to allow a CTRL-C to
* interrupt us. But in cooked mode we may also get SIGQUIT, e.g., when
* pressing CTRL-\, but we don't want Vim to exit then. */
if (in_os_delay && sigarg == SIGQUIT)
SIGRETURN;
# endif
/* When SIGHUP, SIGQUIT, etc. are blocked: postpone the effect and return
* here. This avoids that a non-reentrant function is interrupted, e.g.,
* free(). Calling free() again may then cause a crash. */
if (entered == 0
&& (0
# ifdef SIGHUP
|| sigarg == SIGHUP
# endif
# ifdef SIGQUIT
|| sigarg == SIGQUIT
# endif
# ifdef SIGTERM
|| sigarg == SIGTERM
# endif
# ifdef SIGPWR
|| sigarg == SIGPWR
# endif
# ifdef SIGUSR1
|| sigarg == SIGUSR1
# endif
# ifdef SIGUSR2
|| sigarg == SIGUSR2
# endif
)
&& !vim_handle_signal(sigarg))
SIGRETURN;
#endif
/* Remember how often we have been called. */
++entered;
/* Set the v:dying variable. */
set_vim_var_nr(VV_DYING, (long)entered);
#ifdef SIGHASARG
/* try to find the name of this signal */
for (i = 0; signal_info[i].sig != -1; i++)
if (sigarg == signal_info[i].sig)
break;
deadly_signal = sigarg;
#endif
full_screen = FALSE; /* don't write message to the GUI, it might be
* part of the problem... */
/*
* If something goes wrong after entering here, we may get here again.
* When this happens, give a message and try to exit nicely (resetting the
* terminal mode, etc.)
* When this happens twice, just exit, don't even try to give a message,
* stack may be corrupt or something weird.
* When this still happens again (or memory was corrupted in such a way
* that "entered" was clobbered) use _exit(), don't try freeing resources.
*/
if (entered >= 3) {
reset_signals(); /* don't catch any signals anymore */
may_core_dump();
if (entered >= 4)
_exit(8);
exit(7);
}
if (entered == 2) {
/* No translation, it may call malloc(). */
OUT_STR("Vim: Double signal, exiting\n");
out_flush();
getout(1);
}
/* No translation, it may call malloc(). */
#ifdef SIGHASARG
sprintf((char *)IObuff, "Vim: Caught deadly signal %s\n",
signal_info[i].name);
#else
sprintf((char *)IObuff, "Vim: Caught deadly signal\n");
#endif
/* Preserve files and exit. This sets the really_exiting flag to prevent
* calling free(). */
preserve_exit();
SIGRETURN;
}
#if defined(_REENTRANT) && defined(SIGCONT)
/*
* On Solaris with multi-threading, suspending might not work immediately.
* Catch the SIGCONT signal, which will be used as an indication whether the
* suspending has been done or not.
*
* On Linux, signal is not always handled immediately either.
* See https://bugs.launchpad.net/bugs/291373
*
* volatile because it is used in signal handler sigcont_handler().
*/
static volatile int sigcont_received;
static RETSIGTYPE sigcont_handler SIGPROTOARG;
/*
* signal handler for SIGCONT
*/
static RETSIGTYPE
sigcont_handler SIGDEFARG(sigarg) {
sigcont_received = TRUE;
SIGRETURN;
}
#endif
/*
* If the machine has job control, use it to suspend the program,
* otherwise fake it by starting a new shell.
@@ -589,7 +193,6 @@ void mch_init()
Rows = 24;
out_flush();
set_signals();
#ifdef MACOS_CONVERT
mac_conv_init();
@@ -598,159 +201,6 @@ void mch_init()
event_init();
}
static void set_signals()
{
#if defined(SIGWINCH)
/*
* WINDOW CHANGE signal is handled with sig_winch().
*/
signal(SIGWINCH, (RETSIGTYPE (*)())sig_winch);
#endif
/*
* We want the STOP signal to work, to make mch_suspend() work.
* For "rvim" the STOP signal is ignored.
*/
#ifdef SIGTSTP
signal(SIGTSTP, restricted ? SIG_IGN : SIG_DFL);
#endif
#if defined(_REENTRANT) && defined(SIGCONT)
signal(SIGCONT, sigcont_handler);
#endif
/*
* We want to ignore breaking of PIPEs.
*/
#ifdef SIGPIPE
signal(SIGPIPE, SIG_IGN);
#endif
#ifdef SIGINT
catch_int_signal();
#endif
/*
* Ignore alarm signals (Perl's alarm() generates it).
*/
#ifdef SIGALRM
signal(SIGALRM, SIG_IGN);
#endif
/*
* Catch SIGPWR (power failure?) to preserve the swap files, so that no
* work will be lost.
*/
#ifdef SIGPWR
signal(SIGPWR, (RETSIGTYPE (*)())catch_sigpwr);
#endif
/*
* Arrange for other signals to gracefully shutdown Vim.
*/
catch_signals(deathtrap, SIG_ERR);
}
#if defined(SIGINT) || defined(PROTO)
/*
* Catch CTRL-C (only works while in Cooked mode).
*/
static void catch_int_signal()
{
signal(SIGINT, (RETSIGTYPE (*)())catch_sigint);
}
#endif
void reset_signals()
{
catch_signals(SIG_DFL, SIG_DFL);
#if defined(_REENTRANT) && defined(SIGCONT)
/* SIGCONT isn't in the list, because its default action is ignore */
signal(SIGCONT, SIG_DFL);
#endif
}
static void catch_signals(
RETSIGTYPE (*func_deadly)(),
RETSIGTYPE (*func_other)()
)
{
int i;
for (i = 0; signal_info[i].sig != -1; i++)
if (signal_info[i].deadly) {
#if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION)
struct sigaction sa;
/* Setup to use the alternate stack for the signal function. */
sa.sa_handler = func_deadly;
sigemptyset(&sa.sa_mask);
# if defined(__linux__) && defined(_REENTRANT)
/* On Linux, with glibc compiled for kernel 2.2, there is a bug in
* thread handling in combination with using the alternate stack:
* pthread library functions try to use the stack pointer to
* identify the current thread, causing a SEGV signal, which
* recursively calls deathtrap() and hangs. */
sa.sa_flags = 0;
# else
sa.sa_flags = SA_ONSTACK;
# endif
sigaction(signal_info[i].sig, &sa, NULL);
#else
# if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGVEC)
struct sigvec sv;
/* Setup to use the alternate stack for the signal function. */
sv.sv_handler = func_deadly;
sv.sv_mask = 0;
sv.sv_flags = SV_ONSTACK;
sigvec(signal_info[i].sig, &sv, NULL);
# else
signal(signal_info[i].sig, func_deadly);
# endif
#endif
} else if (func_other != SIG_ERR)
signal(signal_info[i].sig, func_other);
}
/*
* Handling of SIGHUP, SIGQUIT and SIGTERM:
* "when" == a signal: when busy, postpone and return FALSE, otherwise
* return TRUE
* "when" == SIGNAL_BLOCK: Going to be busy, block signals
* "when" == SIGNAL_UNBLOCK: Going to wait, unblock signals, use postponed
* signal
* Returns TRUE when Vim should exit.
*/
int vim_handle_signal(int sig)
{
static int got_signal = 0;
static int blocked = TRUE;
switch (sig) {
case SIGNAL_BLOCK: blocked = TRUE;
break;
case SIGNAL_UNBLOCK: blocked = FALSE;
if (got_signal != 0) {
kill(getpid(), got_signal);
got_signal = 0;
}
break;
default: if (!blocked)
return TRUE; /* exit! */
got_signal = sig;
#ifdef SIGPWR
if (sig != SIGPWR)
#endif
got_int = TRUE; /* break any loops */
break;
}
return FALSE;
}
/*
* Check_win checks whether we have an interactive stdout.
*/
@@ -1153,26 +603,11 @@ int mch_nodetype(char_u *name)
void mch_early_init()
{
/*
* Setup an alternative stack for signals. Helps to catch signals when
* running out of stack space.
* Use of sigaltstack() is preferred, it's more portable.
* Ignore any errors.
*/
#if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
signal_stack = (char *)alloc(SIGSTKSZ);
init_signal_stack();
#endif
time_init();
}
#if defined(EXITFREE) || defined(PROTO)
void mch_free_mem() {
# if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
vim_free(signal_stack);
signal_stack = NULL;
# endif
vim_free(oldtitle);
vim_free(oldicon);
}
@@ -1239,7 +674,6 @@ void mch_exit(int r)
}
out_flush();
ml_close_all(TRUE); /* remove all memfiles */
may_core_dump();
#ifdef MACOS_CONVERT
mac_conv_cleanup();
@@ -1254,14 +688,6 @@ void mch_exit(int r)
exit(r);
}
static void may_core_dump()
{
if (deadly_signal != 0) {
signal(deadly_signal, SIG_DFL);
kill(getpid(), deadly_signal); /* Die using the signal we caught */
}
}
void mch_settmode(int tmode)
{
static int first = TRUE;
@@ -1749,7 +1175,7 @@ int mch_call_shell(char_u *cmd, ShellOpts opts, char_u *extra_shell_arg)
}
}
} else if (pid == 0) { /* child */
reset_signals(); /* handle signals normally */
signal_stop(); /* handle signals normally */
if (opts & (kShellOptHideMess | kShellOptExpand)) {
int fd;
@@ -1846,8 +1272,7 @@ int mch_call_shell(char_u *cmd, ShellOpts opts, char_u *extra_shell_arg)
* While child is running, ignore terminating signals.
* Do catch CTRL-C, so that "got_int" is set.
*/
catch_signals(SIG_IGN, SIG_ERR);
catch_int_signal();
signal_reject_deadly();
/*
* For the GUI we redirect stdin, stdout and stderr to our window.
@@ -2266,7 +1691,7 @@ finished:
if (tmode == TMODE_RAW)
settmode(TMODE_RAW);
did_settmode = TRUE;
set_signals();
signal_accept_deadly();
if (WIFEXITED(status)) {
/* LINTED avoid "bitwise operation on signed value" */
@@ -2365,9 +1790,7 @@ select_eintr:
# ifdef EINTR
if (ret == -1 && errno == EINTR) {
/* Check whether window has been resized, EINTR may be caused by
* SIGWINCH. */
if (do_resize)
handle_resize();
* SIGWINCH. FIXME this is broken for now */
/* Interrupted by a signal, need to try again. We ignore msec
* here, because we do want to check even after a timeout if
@@ -3035,7 +2458,6 @@ int *number_result;
# if defined(USE_DLOPEN)
dlerr = NULL;
# endif
mch_didjmp();
} else
{
retval_str = NULL;
@@ -3127,5 +2549,3 @@ int *number_result;