diff options
| -rw-r--r-- | src/main.c | 83 |
1 files changed, 78 insertions, 5 deletions
@@ -18,6 +18,9 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA #include "shared.h" #include <time.h> +#include <signal.h> +#include <sys/select.h> +#include <fcntl.h> int server_sockfd; @@ -122,17 +125,51 @@ out: pthread_mutex_unlock(&entry->mutex); } +static bool signals_terminate = false; +static bool signals_reload = false; + +// NOTE: The code assumes that signal_handler will only be called in the main +// thread, which (as far as I know) is always the case on Linux. +void signal_handler(int signum) +{ + if (signum == SIGINT || signum == SIGTERM) + signals_terminate = true; + + if (signum == SIGUSR1) + signals_reload = true; +} + +int handle_signals(void) +{ + if (signals_terminate) { + DEBUG("received a terminating signal\n"); + return 1; + } + + if (signals_reload) { + signals_reload = false; + DEBUG("reload the lists (not yet implemented)\n"); + } + + return 0; +} + #define NUM_WORKERS 8 // FIXME: shouldn't be hardcoded int main(void) { - int error = 0; // return value + int error = 0 /* the exit code */, flags; + struct sigaction sigact = {.sa_handler = signal_handler}; struct sockaddr_in sockaddr; pthread_t workers[NUM_WORKERS]; size_t i; clock_gettime(CLOCK_MONOTONIC_RAW, &time_ref); + sigaction(SIGINT, &sigact, NULL); + sigaction(SIGTERM, &sigact, NULL); + sigaction(SIGUSR1, &sigact, NULL); + if (lists_load("schachts.list", 0)) { eprintf("fatal error: couldn't load the lists\n"); goto error_lists; @@ -145,6 +182,10 @@ int main(void) goto error_socket; } + // FIXME: can fcntl actually fail (in practice)? + flags = fcntl(server_sockfd, F_GETFL, 0); + fcntl(server_sockfd, F_SETFL, flags | O_NONBLOCK); + sockaddr.sin_family = AF_INET; sockaddr.sin_addr.s_addr = INADDR_ANY; sockaddr.sin_port = htons(1337); @@ -159,17 +200,52 @@ int main(void) pthread_create(workers + i, NULL, worker_main, NULL); while (1) { + fd_set readfds; + int rv; char buffer[256]; struct sockaddr_in addr; socklen_t addrlen = sizeof(addr); ssize_t size; uint32_t query; + FD_ZERO(&readfds); + FD_SET(server_sockfd, &readfds); + + // In case the process catches a signal before the main loop + // or outside the select call. + if (signals_terminate) + break; + + // The socket is non-blocking, so wait for incoming data with + // select (not recvfrom). Furthermore, select will return if + // gets interrupted by a signal, which is main loop breaking + // can be easily implemented. + rv = select(1, &readfds, NULL, NULL, NULL); + if (rv == -1 && errno == EINTR) { + interrupted_select: + if (handle_signals()) + break; + continue; + } else if (rv == -1 && errno != EINTR) { + perror("select"); + break; + } + size = recvfrom(server_sockfd, buffer, sizeof(buffer), 0, (void*)&addr, &addrlen); if (size == -1) { + // Sometimes select can wake up even if there's no + // data to read. + if (errno == EWOULDBLOCK || + errno == EAGAIN) + continue; + + // Just in case. + if (errno == EINTR) + goto interrupted_select; + perror("recvfrom"); - goto error_recvfrom; + break; } if ((ntohl(addr.sin_addr.s_addr) & LOCALHOST_MASK) @@ -190,14 +266,11 @@ int main(void) } job_quit(); - for (i = 0; i < NUM_WORKERS; i++) pthread_join(workers[i], NULL); db_destroy(); - // todo: clear all jobs -error_recvfrom: error_bind: shutdown(server_sockfd, SHUT_RDWR); close(server_sockfd); |