Add a check for libosl to configure.ac.

[paraslash.git] / signal.c

diff --git a/signal.c b/signal.c
index f9b95f9006dee9c9cd558bb39bc0cc6c90ca1bb1..59a0d45aba7ad975fc287862308891435c4e9095 100644 (file)
--- a/signal.c
+++ b/signal.c
@@ -1,34 +1,22 @@
 /*
 /*

- * Copyright (C) 2004-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2004-2009 Andre Noll <maan@systemlinux.org>

  *
  *

- *     This program is free software; you can redistribute it and/or modify
- *     it under the terms of the GNU General Public License as published by
- *     the Free Software Foundation; either version 2 of the License, or
- *     (at your option) any later version.
- *
- *     This program is distributed in the hope that it will be useful,
- *     but WITHOUT ANY WARRANTY; without even the implied warranty of
- *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *     GNU General Public License for more details.
- *
- *     You should have received a copy of the GNU General Public License
- *     along with this program; if not, write to the Free Software
- *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Licensed under the GPL v2. For licencing details see COPYING.

  */
  */

-/** \file signal.c signal handling functions */
-
+/** \file signal.c Signal handling functions. */

 
 

+#include <signal.h>
+#include <sys/types.h>
+#include <dirent.h>

 
 #include "para.h"
 
 #include "para.h"

+#include "error.h"

 #include "fd.h"
 
 #include "fd.h"
 

-#include <signal.h>
-
-#include "error.h"

 static int signal_pipe[2];
 
 /**
 static int signal_pipe[2];
 
 /**

- * initialize the paraslash signal subsystem
+ * Initialize the paraslash signal subsystem.

  *
  * This function creates a pipe, the signal pipe, to deliver pending
  * signals to the application (Bernstein's trick). It should be called
  *
  * This function creates a pipe, the signal pipe, to deliver pending
  * signals to the application (Bernstein's trick). It should be called


@@ -47,18 +35,20 @@ static int signal_pipe[2];
  */
 int para_signal_init(void)
 {
  */
 int para_signal_init(void)
 {

-       int ret = -E_SIGNAL_PIPE;
-       if (pipe(signal_pipe))
+       int ret;
+       if (pipe(signal_pipe) < 0) {
+               ret = -ERRNO_TO_PARA_ERROR(errno);

                goto err_out;
                goto err_out;

-       ret = mark_fd_nonblock(signal_pipe[0]);
+       }
+       ret = mark_fd_nonblocking(signal_pipe[0]);

        if (ret < 0)
                goto err_out;
        if (ret < 0)
                goto err_out;

-       ret = mark_fd_nonblock(signal_pipe[1]);
+       ret = mark_fd_nonblocking(signal_pipe[1]);

        if (ret < 0)
                goto err_out;
        return signal_pipe[0];
 err_out:
        if (ret < 0)
                goto err_out;
        return signal_pipe[0];
 err_out:

-       PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
+       PARA_EMERG_LOG("%s\n", para_strerror(-ret));

        exit(EXIT_FAILURE);
 }
 
        exit(EXIT_FAILURE);
 }
 


@@ -67,84 +57,143 @@ err_out:
  */
 static void generic_signal_handler(int s)
 {
  */
 static void generic_signal_handler(int s)
 {

-       write(signal_pipe[1], &s, sizeof(int));
-       //fprintf(stderr, "got sig %i, write returned %d\n", s, ret);
+       ssize_t ret = write(signal_pipe[1], &s, sizeof(int));
+
+       if (ret == sizeof(int))
+               return;
+       if (ret < 0)
+               PARA_EMERG_LOG("%s\n", strerror(errno));
+       else
+               PARA_EMERG_LOG("short write to signal pipe\n");
+       exit(EXIT_FAILURE);

 }
 
 /**
 }
 
 /**

- * reap one child
+ * Reap one child.
+ *
+ * \param pid In case a child died, its pid is returned here.

  *
  *

- * call waitpid() and print a log message containing the pid
- * and the cause of the child's death.
+ * Call waitpid() and print a log message containing the pid and the cause of
+ * the child's death.

  *
  *

- * \return Like \p waitpid(), this function returns the process ID of the
- * terminated child; on error, \p -E_WAITPID is returned.
- * \sa waitpid(2)
+ * \return A (negative) paraslash error code on errors, zero, if no child died,
+ * one otherwise. If and only if the function returns one, the content of \a
+ * pid is meaningful.
+ *
+ * \sa waitpid(2).

  */
  */

-pid_t para_reap_child(void)
+int para_reap_child(pid_t *pid)

 {
        int status;
 {
        int status;

-       pid_t pid = waitpid(-1, &status, WNOHANG);
+       *pid = waitpid(-1, &status, WNOHANG);

 
 

-       if (pid <= 0) {
-               if (pid < 0)
-                       pid = -E_WAITPID;
-               return pid;
-       }
+       if (!*pid)
+               return 0;
+       if (*pid < 0)
+               return -ERRNO_TO_PARA_ERROR(errno);

        if (WIFEXITED(status))
        if (WIFEXITED(status))

-               PARA_DEBUG_LOG("child %i exited. Exit status: %i\n", pid,
+               PARA_DEBUG_LOG("child %i exited. Exit status: %i\n", (int)*pid,

                        WEXITSTATUS(status));
        else if (WIFSIGNALED(status))
                        WEXITSTATUS(status));
        else if (WIFSIGNALED(status))

-               PARA_DEBUG_LOG("child %i was killed by signal %i\n", pid,
+               PARA_DEBUG_LOG("child %i was killed by signal %i\n", (int)*pid,

                        WTERMSIG(status));
        else
                        WTERMSIG(status));
        else

-               PARA_WARNING_LOG("child %i terminated abormally\n", pid);
-       return pid;
+               PARA_WARNING_LOG("child %i terminated abormally\n", (int)*pid);
+       return 1;

 }
 
 /**
 }
 
 /**

- * paraslash's zombie killer
+ * Paraslash's zombie killer.

  *
  * It just calls \p para_reap_child() until there are no more children left to
  * reap.
  */
 void para_reap_children(void)
 {
  *
  * It just calls \p para_reap_child() until there are no more children left to
  * reap.
  */
 void para_reap_children(void)
 {

-       while (para_reap_child() > 0)
+       pid_t pid;
+
+       while (para_reap_child(&pid) > 0)

                ; /* nothing */
 }
 
 /**
                ; /* nothing */
 }
 
 /**

- * wrapper around signal(2)
- * \param sig the number of the signal to catch
+ * Install the given handler for the given signal.
+ *
+ * \param sig The number of the signal to catch.
+ * \param handler to be installed, \p SIG_IGN, or \p SIG_DFL.

  *
  *

- * This installs the generic signal handler for the given signal.
- * \return This function returns 1 on success and \p -E_SIGNAL_SIG_ERR on errors.
- * \sa signal(2)
+ * This either succeeds or calls exit(EXIT_FAILURE).
+ *
+ * \sa sigaction(2).

  */
  */

-int para_install_sighandler(int sig)
+void para_sigaction(int sig, void (*handler)(int))

 {
 {

+       struct sigaction act;
+

        PARA_DEBUG_LOG("catching signal %d\n", sig);
        PARA_DEBUG_LOG("catching signal %d\n", sig);

-       return signal(sig, &generic_signal_handler) == SIG_ERR?  -E_SIGNAL_SIG_ERR : 1;
+       act.sa_handler = handler;
+       sigemptyset(&act.sa_mask);
+       act.sa_flags = 0;
+       if (sig == SIGALRM) {
+               #ifdef SA_INTERRUPT /* SunOS */
+                       act.sa_flags |= SA_INTERRUPT;
+               #endif
+       } else {
+               #ifdef SA_RESTART /* BSD */
+                       act.sa_flags |= SA_RESTART;
+               #endif
+       }
+       if (sigaction(sig, &act, NULL) >= 0)
+               return;
+       PARA_EMERG_LOG("failed to install signal handler for signal %d\n",
+               sig);
+       exit(EXIT_FAILURE);

 }
 
 /**
 }
 
 /**

- * return number of next pending signal
+ * Install the generic signal handler for the given signal number.
+ *
+ * \param sig The number of the signal to catch.
+ *
+ * \sa signal(2), sigaction(2).
+ */
+void para_install_sighandler(int sig)
+{
+       para_sigaction(sig, &generic_signal_handler);
+}
+
+/**
+ * Return the number of next pending signal.

  *
  * This should be called if the fd for the signal pipe is ready for reading.
  *
  *
  * This should be called if the fd for the signal pipe is ready for reading.
  *

- * \return On success, the number of the received signal is returned. \p
- * -E_SIGNAL_READ is returned if a read error occured while reading the signal
- * pipe.  If the read was interrupted by another signal the function returns 0.
+ * \return On success, the number of the received signal is returned.  If the
+ * read returned zero or was interrupted by another signal the function returns
+ * 0.  Otherwise, a negative error value is returned.

  */
 int para_next_signal(void)
 {
        int s;
  */
 int para_next_signal(void)
 {
        int s;

-       ssize_t r;
+       ssize_t r = read(signal_pipe[0], &s, sizeof(s));

 
 

-       if ((r = read(signal_pipe[0], &s, sizeof(s)) == sizeof(s)) > 0) {
-               PARA_DEBUG_LOG("next signal: %d\n", s);
-               return s;
+       if (!r) {
+               PARA_CRIT_LOG("read from signal pipe returned zero\n");
+               return 0;

        }
        }

-       return r < 0 && (errno != EAGAIN)? 0 : -E_SIGNAL_READ;
+       if (r < 0) {
+               if (errno == EAGAIN || errno == EINTR)
+                       return 0;
+               return -ERRNO_TO_PARA_ERROR(errno);
+       }
+       assert(r == sizeof(s));
+       PARA_DEBUG_LOG("next signal: %d\n", s);
+       return s;
+}
+
+/**
+ * Close the write end of the signal pipe.
+ */
+void para_signal_shutdown(void)
+{
+       close(signal_pipe[1]);

 }
 }