X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=liblttkconsumerd%2Fliblttkconsumerd.c;h=9ad380c8dab5e8c1be679a0881890e929f355c57;hp=c1bad734dd4bbe1d616d777fb6c9e773e3885783;hb=ca3c5ac0cf100d80352a1a81936b5adc47942f35;hpb=242cd1874f3d8f678e795eea4d35552eff683ed8 diff --git a/liblttkconsumerd/liblttkconsumerd.c b/liblttkconsumerd/liblttkconsumerd.c index c1bad734d..9ad380c8d 100644 --- a/liblttkconsumerd/liblttkconsumerd.c +++ b/liblttkconsumerd/liblttkconsumerd.c @@ -4,8 +4,8 @@ * * 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. + * as published by the Free Software Foundation; only version 2 + * of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -28,6 +28,7 @@ #include #include #include +#include #include "libkernelctl.h" #include "liblttkconsumerd.h" @@ -69,6 +70,9 @@ static int kconsumerd_thread_pipe[2]; /* pipe to wake the poll thread when necessary */ static int kconsumerd_poll_pipe[2]; +/* to let the signal handler wake up the fd receiver thread */ +static int kconsumerd_should_quit[2]; + /* timeout parameter, to control the polling thread grace period */ static int kconsumerd_poll_timeout = -1; @@ -78,8 +82,13 @@ static int kconsumerd_error_socket; /* socket to exchange commands with sessiond */ static char *kconsumerd_command_sock_path; -/* flag to inform the polling thread to kconsumerd_quit when all fd hung up */ -static int kconsumerd_quit = 0; +/* + * flag to inform the polling thread to quit when all fd hung up. + * Updated by the kconsumerd_thread_receive_fds when it notices that all + * fds has hung up. Also updated by the signal handler + * (kconsumerd_should_exit()). Read by the polling threads. + */ +static volatile int kconsumerd_quit = 0; /* * kconsumerd_set_error_socket @@ -105,6 +114,7 @@ void kconsumerd_set_command_socket_path(char *sock) * kconsumerd_find_session_fd * * Find a session fd in the global list. + * The kconsumerd_data.lock must be locked during this call * * Return 1 if found else 0 */ @@ -112,15 +122,12 @@ static int kconsumerd_find_session_fd(int fd) { struct kconsumerd_fd *iter; - pthread_mutex_lock(&kconsumerd_data.lock); cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { if (iter->sessiond_fd == fd) { DBG("Duplicate session fd %d", fd); - pthread_mutex_unlock(&kconsumerd_data.lock); return 1; } } - pthread_mutex_unlock(&kconsumerd_data.lock); return 0; } @@ -170,6 +177,7 @@ static int kconsumerd_add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_f tmp_fd->state = buf->state; tmp_fd->max_sb_size = buf->max_sb_size; strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX); + tmp_fd->path_name[PATH_MAX - 1] = '\0'; /* Opening the tracefile in write mode */ ret = open(tmp_fd->path_name, @@ -484,7 +492,7 @@ static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) } switch (DEFAULT_KERNEL_CHANNEL_OUTPUT) { - case LTTNG_KERNEL_SPLICE: + case LTTNG_EVENT_SPLICE: /* read the whole subbuffer */ err = kernctl_get_padded_subbuf_size(infd, &len); if (err != 0) { @@ -503,7 +511,7 @@ static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) ERR("Error splicing to tracefile"); } break; - case LTTNG_KERNEL_MMAP: + case LTTNG_EVENT_MMAP: /* read the used subbuffer size */ err = kernctl_get_subbuf_size(infd, &len); if (err != 0) { @@ -542,6 +550,32 @@ end: return ret; } +/* + * kconsumerd_poll_socket + * + * Poll on the should_quit pipe and the command socket + * return -1 on error and should exit, 0 if data is + * available on the command socket + */ +int kconsumerd_poll_socket(struct pollfd *kconsumerd_sockpoll) +{ + int num_rdy; + + num_rdy = poll(kconsumerd_sockpoll, 2, -1); + if (num_rdy == -1) { + perror("Poll error"); + goto exit; + } + if (kconsumerd_sockpoll[0].revents == POLLIN) { + DBG("kconsumerd_should_quit wake up"); + goto exit; + } + return 0; + +exit: + return -1; +} + /* * kconsumerd_consumerd_recv_fd * @@ -549,10 +583,10 @@ end: * structures describing each fd (path name). * Returns the size of received data */ -static int kconsumerd_consumerd_recv_fd(int sfd, int size, +static int kconsumerd_consumerd_recv_fd(int sfd, + struct pollfd *kconsumerd_sockpoll, int size, enum kconsumerd_command cmd_type) { - struct msghdr msg; struct iovec iov[1]; int ret = 0, i, tmp2; struct cmsghdr *cmsg; @@ -563,8 +597,11 @@ static int kconsumerd_consumerd_recv_fd(int sfd, int size, /* the number of fds we are about to receive */ nb_fd = size / sizeof(struct lttcomm_kconsumerd_msg); + /* + * nb_fd is the number of fds we receive. One fd per recvmsg. + */ for (i = 0; i < nb_fd; i++) { - memset(&msg, 0, sizeof(msg)); + struct msghdr msg = { 0 }; /* Prepare to receive the structures */ iov[0].iov_base = &lkm; @@ -576,6 +613,10 @@ static int kconsumerd_consumerd_recv_fd(int sfd, int size, msg.msg_controllen = sizeof(recv_fd); DBG("Waiting to receive fd"); + if (kconsumerd_poll_socket(kconsumerd_sockpoll) < 0) { + goto end; + } + if ((ret = recvmsg(sfd, &msg, 0)) < 0) { perror("recvmsg"); continue; @@ -594,12 +635,13 @@ static int kconsumerd_consumerd_recv_fd(int sfd, int size, kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); goto end; } + /* if we received fds */ if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { switch (cmd_type) { case ADD_STREAM: - DBG("kconsumerd_add_fd %s (%d)", lkm.path_name, (CMSG_DATA(cmsg)[0])); - ret = kconsumerd_add_fd(&lkm, (CMSG_DATA(cmsg)[0])); + DBG("kconsumerd_add_fd %s (%d)", lkm.path_name, ((int *) CMSG_DATA(cmsg))[0]); + ret = kconsumerd_add_fd(&lkm, ((int *) CMSG_DATA(cmsg))[0]); if (ret < 0) { kconsumerd_send_error(KCONSUMERD_OUTFD_ERROR); goto end; @@ -613,6 +655,9 @@ static int kconsumerd_consumerd_recv_fd(int sfd, int size, } /* signal the poll thread */ tmp2 = write(kconsumerd_poll_pipe[1], "4", 1); + if (tmp2 < 0) { + perror("write kconsumerd poll"); + } } else { ERR("Didn't received any fd"); kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); @@ -724,6 +769,9 @@ void *kconsumerd_thread_poll_fds(void *data) if (pollfd[nb_fd].revents == POLLIN) { DBG("kconsumerd_poll_pipe wake up"); tmp2 = read(kconsumerd_poll_pipe[0], &tmp, 1); + if (tmp2 < 0) { + perror("read kconsumerd poll"); + } continue; } @@ -790,18 +838,38 @@ end: free(local_kconsumerd_fd); local_kconsumerd_fd = NULL; } - kconsumerd_cleanup(); return NULL; } /* - * kconsumerd_create_poll_pipe + * kconsumerd_init(void) * - * create the pipe to wake to polling thread when needed + * initialise the necessary environnement : + * - inform the polling thread to update the polling array + * - create the poll_pipe + * - create the should_quit pipe (for signal handler) */ -int kconsumerd_create_poll_pipe() +int kconsumerd_init(void) { - return pipe(kconsumerd_poll_pipe); + int ret; + + /* need to update the polling array at init time */ + kconsumerd_data.need_update = 1; + + ret = pipe(kconsumerd_poll_pipe); + if (ret < 0) { + perror("Error creating poll pipe"); + goto end; + } + + ret = pipe(kconsumerd_should_quit); + if (ret < 0) { + perror("Error creating recv pipe"); + goto end; + } + +end: + return ret; } /* @@ -814,6 +882,12 @@ void *kconsumerd_thread_receive_fds(void *data) { int sock, client_socket, ret; struct lttcomm_kconsumerd_header tmp; + /* + * structure to poll for incoming data on communication socket + * avoids making blocking sockets + */ + struct pollfd kconsumerd_sockpoll[2]; + DBG("Creating command socket %s", kconsumerd_command_sock_path); unlink(kconsumerd_command_sock_path); @@ -835,13 +909,45 @@ void *kconsumerd_thread_receive_fds(void *data) goto end; } + ret = fcntl(client_socket, F_SETFL, O_NONBLOCK); + if (ret < 0) { + perror("fcntl O_NONBLOCK"); + goto end; + } + + /* prepare the FDs to poll : to client socket and the should_quit pipe */ + kconsumerd_sockpoll[0].fd = kconsumerd_should_quit[0]; + kconsumerd_sockpoll[0].events = POLLIN | POLLPRI; + kconsumerd_sockpoll[1].fd = client_socket; + kconsumerd_sockpoll[1].events = POLLIN | POLLPRI; + + if (kconsumerd_poll_socket(kconsumerd_sockpoll) < 0) { + goto end; + } + DBG("Connection on client_socket"); + /* Blocking call, waiting for transmission */ sock = lttcomm_accept_unix_sock(client_socket); if (sock <= 0) { WARN("On accept"); goto end; } + ret = fcntl(sock, F_SETFL, O_NONBLOCK); + if (ret < 0) { + perror("fcntl O_NONBLOCK"); + goto end; + } + + /* update the polling structure to poll on the established socket */ + kconsumerd_sockpoll[1].fd = sock; + kconsumerd_sockpoll[1].events = POLLIN | POLLPRI; + while (1) { + if (kconsumerd_poll_socket(kconsumerd_sockpoll) < 0) { + goto end; + } + DBG("Incoming fds on sock"); + /* We first get the number of fd we are about to receive */ ret = lttcomm_recv_unix_sock(sock, &tmp, sizeof(struct lttcomm_kconsumerd_header)); @@ -853,12 +959,19 @@ void *kconsumerd_thread_receive_fds(void *data) DBG("Received STOP command"); goto end; } + if (kconsumerd_quit) { + DBG("kconsumerd_thread_receive_fds received quit from signal"); + goto end; + } + /* we received a command to add or update fds */ - ret = kconsumerd_consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type); + ret = kconsumerd_consumerd_recv_fd(sock, kconsumerd_sockpoll, + tmp.payload_size, tmp.cmd_type); if (ret <= 0) { ERR("Receiving the FD, exiting"); goto end; } + DBG("received fds on sock"); } end: @@ -890,19 +1003,38 @@ end: * * Cleanup the daemon's socket on exit */ -void kconsumerd_cleanup() +void kconsumerd_cleanup(void) { - struct kconsumerd_fd *iter; + struct kconsumerd_fd *iter, *tmp; /* remove the socket file */ unlink(kconsumerd_command_sock_path); - /* close all outfd */ - cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { + /* + * close all outfd. Called when there are no more threads + * running (after joining on the threads), no need to protect + * list iteration with mutex. + */ + cds_list_for_each_entry_safe(iter, tmp, &kconsumerd_data.fd_list.head, list) { kconsumerd_del_fd(iter); } } +/* + * kconsumerd_should_exit + * + * Called from signal handler. + */ +void kconsumerd_should_exit(void) +{ + int ret; + kconsumerd_quit = 1; + ret = write(kconsumerd_should_quit[1], "4", 1); + if (ret < 0) { + perror("write kconsumerd quit"); + } +} + /* * kconsumerd_send_error *