From 01e99c0b9ced2310eb3c450da448e8702901b1cd Mon Sep 17 00:00:00 2001 From: jkratoch <> Date: Fri, 31 Jul 2009 07:04:28 +0000 Subject: [PATCH] Start using ppoll(). --- src/orphanripper.c | 143 ++++++++++++++++++++++++++++------------------------- 1 file changed, 77 insertions(+), 66 deletions(-) diff --git a/src/orphanripper.c b/src/orphanripper.c index 9d5d8df..1189df6 100644 --- a/src/orphanripper.c +++ b/src/orphanripper.c @@ -46,28 +46,18 @@ static const char *progname; -static volatile int signal_child_hit = 0; +static volatile int signal_chld_hit = 0; -/* We use it to race-safely emulate ppoll(2) by poll(2). */ -static int pipefd[2]; - -static void signal_child (int signo) +static void signal_chld (int signo) { - int i; - - signal_child_hit = 1; - - assert (pipefd[1] != -1); - i = close (pipefd[1]); - assert (i == 0); - pipefd[1] = -1; + signal_chld_hit = 1; } -static volatile int signal_alarm_hit = 0; +static volatile int signal_alrm_hit = 0; -static void signal_alarm (int signo) +static void signal_alrm (int signo) { - signal_alarm_hit = 1; + signal_alrm_hit = 1; } static char childptyname[LINE_MAX]; @@ -86,26 +76,55 @@ static void print_child_error (const char *reason, char **argv) fputc ('\n', stderr); } +static int read_out (int amaster) +{ + char buf[LINE_MAX]; + ssize_t buf_got; + + buf_got = read (amaster, buf, sizeof buf); + if (buf_got == 0) + return 0; + /* Weird but at least after POLLHUP we get EIO instead of just EOF. */ + if (buf_got == -1 && errno == EIO) + return 0; + if (buf_got < 0) + { + perror ("read (amaster)"); + exit (EXIT_FAILURE); + } + if (write (STDOUT_FILENO, buf, buf_got) != buf_got) + { + perror ("write(2)"); + exit (EXIT_FAILURE); + } + return 1; +} + static int spawn (char **argv, int timeout) { pid_t child_got; int status, amaster, i, rc; struct sigaction act; + sigset_t set; struct termios termios; unsigned alarm_orig; - i = pipe (pipefd); - assert (i == 0); - - /* We do not use signal(2) to be sure we have SA_RESTART set. */ + /* We do not use signal(2) to be sure we do not have SA_RESTART. */ memset (&act, 0, sizeof (act)); - act.sa_handler = signal_child; + act.sa_handler = signal_chld; i = sigemptyset (&act.sa_mask); assert (i == 0); - act.sa_flags = SA_RESTART; + act.sa_flags = 0; /* !SA_RESTART */ i = sigaction (SIGCHLD, &act, NULL); assert (i == 0); + i = sigemptyset (&set); + assert (i == 0); + i = sigaddset (&set, SIGCHLD); + assert (i == 0); + i = sigprocmask (SIG_SETMASK, &set, NULL); + assert (i == 0); + /* With TERMP passed as NULL we get "\n" -> "\r\n". */ termios.c_iflag = IGNBRK | IGNPAR; termios.c_oflag = 0; @@ -126,11 +145,6 @@ static int spawn (char **argv, int timeout) perror ("forkpty(3)"); exit (EXIT_FAILURE); case 0: - i = close (pipefd[0]); - assert (i == 0); - i = close (pipefd[1]); - assert (i == 0); - /* Do not replace STDIN as inferiors query its termios. */ #if 0 i = close (STDIN_FILENO); @@ -168,62 +182,50 @@ static int spawn (char **argv, int timeout) exit (EXIT_FAILURE); } - /* We do not use signal(2) to be sure we have SA_RESTART set. */ - act.sa_handler = signal_alarm; - act.sa_flags &= ~SA_RESTART; + /* We do not use signal(2) to be sure we do not have SA_RESTART. */ + act.sa_handler = signal_alrm; i = sigaction (SIGALRM, &act, NULL); assert (i == 0); alarm_orig = alarm (timeout); assert (alarm_orig == 0); - while (!signal_alarm_hit) + i = sigemptyset (&set); + assert (i == 0); + + while (!signal_alrm_hit) { - struct pollfd pollfd[2]; - char buf[LINE_MAX]; - ssize_t buf_got; - - pollfd[0].fd = amaster; - pollfd[0].events = POLLIN; - pollfd[1].fd = pipefd[0]; - pollfd[1].events = POLLIN; - i = poll (pollfd, LENGTH (pollfd), -1); - if (i == -1 && errno == EINTR) - { - /* Weird but SA_RESTART sometimes does not work. */ - continue; - } - assert (i >= 1); + struct pollfd pollfd; + + pollfd.fd = amaster; + pollfd.events = POLLIN; + i = ppoll (&pollfd, 1, NULL, &set); + if (i == -1 && errno == EINTR && signal_chld_hit) + break; + assert (i == 1); /* Data available? Process it first. */ - if (pollfd[0].revents & POLLIN) + if (pollfd.revents & POLLIN) { - buf_got = read (amaster, buf, sizeof buf); - if (buf_got <= 0) + if (!read_out (amaster)) { - perror ("read (amaster)"); - exit (EXIT_FAILURE); - } - if (write (STDOUT_FILENO, buf, buf_got) != buf_got) - { - perror ("write(2)"); + fprintf (stderr, "%s: Unexpected EOF\n", progname); exit (EXIT_FAILURE); } } - if (pollfd[0].revents & POLLHUP) + if (pollfd.revents & POLLHUP) break; - if ((pollfd[0].revents &= ~POLLIN) != 0) + if ((pollfd.revents &= ~POLLIN) != 0) { fprintf (stderr, "%s: ppoll(2): revents 0x%x\n", progname, - (unsigned) pollfd[0].revents); + (unsigned) pollfd.revents); exit (EXIT_FAILURE); } /* Child exited? */ - if (pollfd[1].revents & POLLHUP) + if (signal_chld_hit) break; - assert (pollfd[1].revents == 0); } - if (signal_alarm_hit) + if (signal_alrm_hit) { i = kill (child, SIGKILL); assert (i == 0); @@ -238,7 +240,7 @@ static int spawn (char **argv, int timeout) fprintf (stderr, "waitpid (%d) = %d: %m\n", (int) child, (int) child_got); exit (EXIT_FAILURE); } - if (signal_alarm_hit) + if (signal_alrm_hit) { char *buf; @@ -268,12 +270,21 @@ static int spawn (char **argv, int timeout) exit (EXIT_FAILURE); } - assert (signal_child_hit != 0); - - assert (pipefd[1] == -1); - i = close (pipefd[0]); + /* In the POLLHUP case we may not have seen SIGCHLD so far. */ + i = sigprocmask (SIG_SETMASK, &set, NULL); assert (i == 0); + assert (signal_chld_hit != 0); + + i = fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */); + if (i != 0) + { + perror ("fcntl (amaster, F_SETFL, O_RDONLY /* !O_NONBLOCK */)"); + exit (EXIT_FAILURE); + } + + while (read_out (amaster)); + /* Do not close the master FD as the child would have `/dev/pts/23 (deleted)' entries which are not expected (and expecting ` (deleted)' would be a race. */ -- 1.8.3.1