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sleeper: handle out of order cont/term signals #54

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sleeper: handle out of order cont/term signals #54

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107 changes: 92 additions & 15 deletions sleeper.c
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Original file line number Diff line number Diff line change
@@ -1,39 +1,84 @@
#include <unistd.h>
#include <signal.h>
#include "ndelay.h"
#include "strerr.h"
#include "error.h"
#include "byte.h"
#include "sig.h"
#include "str.h"
#include <unistd.h>

static int selfpipe[2];

static void catch_sig(int sig)
{
int ignored;
char c;

c = (char)sig;
ignored = write(selfpipe[1],&c,1);
(void)ignored;
}

static void show_sig(int sig)
{
char buf[7+14+2] = "Caught ";
const char *name;
int ignored;
int i;

switch (sig) {
case SIGALRM: name = "ALRM"; break;
case SIGCONT: name = "CONT"; break;
case SIGHUP: name = "HUP"; break;
case SIGINT: name = "INT"; break;
case SIGQUIT: name = "QUIT"; break;
case SIGTERM: name = "TERM"; break;
case SIGUSR1: name = "USR1"; break;
case SIGUSR2: name = "USR2"; break;
case SIGWINCH: name = "WINCH"; break;
default: name = "unknown signal";
case SIGALRM: name = "ALRM"; break;
case SIGCONT: name = "CONT"; break;
case SIGHUP: name = "HUP"; break;
case SIGINT: name = "INT"; break;
case SIGQUIT: name = "QUIT"; break;
case SIGTERM: name = "TERM"; break;
case SIGUSR1: name = "USR1"; break;
case SIGUSR2: name = "USR2"; break;
case SIGWINCH: name = "WINCH"; break;
default: name = "unknown signal";
}
i = str_len(name);
byte_copy(buf+7,i,name);
i += 7;
buf[i++] = '\n';
ignored = write(1,buf,i);
if (sig != SIGCONT)
_exit(1);
(void)ignored;
}

static void show_err()
{
int ignored;

ignored = write(1,"invalid signal\n",15);
return;
(void)ignored;
}

static void show_one(int sig)
{
show_sig(sig);
return;
}

static void show_two(int sig1, int sig2)
{
show_sig(sig1);
show_sig(sig2);
return;
}

int main(void)
{
int r;
int nc, nt, oc, ot;
int new_sig, old_sig=0;
char buf;

if (pipe(selfpipe) == -1)
strerr_die1sys(111,"sleeper: fatal: unable to create pipe");
ndelay_on(selfpipe[1]);

sig_catch(SIGALRM,catch_sig);
sig_catch(SIGCONT,catch_sig);
sig_catch(SIGHUP,catch_sig);
Expand All @@ -43,6 +88,38 @@ int main(void)
sig_catch(SIGUSR1,catch_sig);
sig_catch(SIGUSR2,catch_sig);
sig_catch(SIGWINCH,catch_sig);
sleep(9999);
return 0;

for (;;) {
r = read(selfpipe[0],&buf,1);
if (!r) break;
if (r == -1) {
if (errno == error_intr) continue;
break;
}

new_sig = (int)buf;

nc = new_sig == SIGCONT;
nt = new_sig == SIGTERM;
oc = old_sig == SIGCONT;
ot = old_sig == SIGTERM;

if (!nc && !nt && !oc && !ot) {show_one(new_sig); break; }
if (!nc && !nt && !oc && ot) {show_two(SIGTERM, new_sig); break; }
if (!nc && !nt && oc && !ot) {show_two(SIGCONT, new_sig); break; }
if (!nc && !nt && oc && ot) {show_err(); break; }
if (!nc && nt && !oc && !ot) {old_sig = SIGTERM; continue;}
if (!nc && nt && !oc && ot) {show_one(SIGTERM); continue;}
if (!nc && nt && oc && !ot) {show_two(SIGCONT, SIGTERM); break; }
if (!nc && nt && oc && ot) {show_err(); break; }
if ( nc && !nt && !oc && !ot) {old_sig = SIGCONT; continue;}
if ( nc && !nt && !oc && ot) {show_two(SIGCONT, SIGTERM); break; }
if ( nc && !nt && oc && !ot) {show_one(SIGCONT); continue;}
if ( nc && !nt && oc && ot) {show_err(); break; }
if ( nc && nt && !oc && !ot) {show_err(); break; }
if ( nc && nt && !oc && ot) {show_err(); break; }
if ( nc && nt && oc && !ot) {show_err(); break; }
if ( nc && nt && oc && ot) {show_err(); break; }
}
_exit(0);
}