/* Process handling * * Copyright © 2013, Benoît Knecht * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef __PROCESS_H__ #define __PROCESS_H__ #include #include "clients.h" struct child { pid_t pid; time_t age; struct client_cache_s *client; }; extern struct child *children; extern int number_of_children; /** * Fork a new child (just like fork()) but keep track of how many childs are * already running, and refuse fo fork if there are too many. * @return -1 if it couldn't fork, 0 in the child process, the pid of the * child process in the parent process. */ pid_t process_fork(struct client_cache_s *client); /** * Handler to be called upon receiving SIGCHLD. This signal is received by the * parent process when a child terminates, and this handler updates the number * of running childs accordingly. * @param signal The signal number. */ void process_handle_child_termination(int signal); /** * Daemonize the current process by forking itself and redirecting standard * input, standard output and standard error to /dev/null. * @return The pid of the process. */ int process_daemonize(void); /** * Check if the process corresponding to the pid found in the pid file is * running. * @param fname The path to the pid file. * @return 0 if no other instance is running, -1 if the file name is invalid, * -2 if another instance is running. */ int process_check_if_running(const char *fname); /** * Kill all child processes */ void process_reap_children(void); #endif // __PROCESS_H__