X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=liblttkconsumerd%2Fliblttkconsumerd.c;fp=liblttkconsumerd%2Fliblttkconsumerd.c;h=0000000000000000000000000000000000000000;hp=9ad380c8dab5e8c1be679a0881890e929f355c57;hb=50ecdf72034d220d3b0300d0caa13e6946be555b;hpb=ca3c5ac0cf100d80352a1a81936b5adc47942f35 diff --git a/liblttkconsumerd/liblttkconsumerd.c b/liblttkconsumerd/liblttkconsumerd.c deleted file mode 100644 index 9ad380c8d..000000000 --- a/liblttkconsumerd/liblttkconsumerd.c +++ /dev/null @@ -1,1051 +0,0 @@ -/* - * Copyright (C) 2011 - Julien Desfossez - * Mathieu Desnoyers - * - * 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; 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 - * 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 02111-1307, USA. - */ - -#define _GNU_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "libkernelctl.h" -#include "liblttkconsumerd.h" -#include "lttngerr.h" - -static -struct kconsumerd_global_data { - /* - * kconsumerd_data.lock protects kconsumerd_data.fd_list, - * kconsumerd_data.fds_count, and kconsumerd_data.need_update. It - * ensures the count matches the number of items in the fd_list. - * It ensures the list updates *always* trigger an fd_array - * update (therefore need to make list update vs - * kconsumerd_data.need_update flag update atomic, and also flag - * read, fd array and flag clear atomic). - */ - pthread_mutex_t lock; - /* - * Number of element for the list below. Protected by - * kconsumerd_data.lock. - */ - unsigned int fds_count; - /* - * List of FDs. Protected by kconsumerd_data.lock. - */ - struct kconsumerd_fd_list fd_list; - /* - * Flag specifying if the local array of FDs needs update in the - * poll function. Protected by kconsumerd_data.lock. - */ - unsigned int need_update; -} kconsumerd_data = { - .fd_list.head = CDS_LIST_HEAD_INIT(kconsumerd_data.fd_list.head), -}; - -/* communication with splice */ -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; - -/* socket to communicate errors with sessiond */ -static int kconsumerd_error_socket; - -/* socket to exchange commands with sessiond */ -static char *kconsumerd_command_sock_path; - -/* - * 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 - * - * Set the error socket - */ -void kconsumerd_set_error_socket(int sock) -{ - kconsumerd_error_socket = sock; -} - -/* - * kconsumerd_set_command_socket_path - * - * Set the command socket path - */ -void kconsumerd_set_command_socket_path(char *sock) -{ - kconsumerd_command_sock_path = 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 - */ -static int kconsumerd_find_session_fd(int fd) -{ - struct kconsumerd_fd *iter; - - cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { - if (iter->sessiond_fd == fd) { - DBG("Duplicate session fd %d", fd); - return 1; - } - } - - return 0; -} - -/* - * kconsumerd_del_fd - * - * Remove a fd from the global list protected by a mutex - */ -static void kconsumerd_del_fd(struct kconsumerd_fd *lcf) -{ - pthread_mutex_lock(&kconsumerd_data.lock); - cds_list_del(&lcf->list); - if (kconsumerd_data.fds_count > 0) { - kconsumerd_data.fds_count--; - if (lcf != NULL) { - close(lcf->out_fd); - close(lcf->consumerd_fd); - free(lcf); - lcf = NULL; - } - } - kconsumerd_data.need_update = 1; - pthread_mutex_unlock(&kconsumerd_data.lock); -} - -/* - * kconsumerd_add_fd - * - * Add a fd to the global list protected by a mutex - */ -static int kconsumerd_add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd) -{ - int ret; - struct kconsumerd_fd *tmp_fd; - - pthread_mutex_lock(&kconsumerd_data.lock); - /* Check if already exist */ - ret = kconsumerd_find_session_fd(buf->fd); - if (ret == 1) { - goto end; - } - - tmp_fd = malloc(sizeof(struct kconsumerd_fd)); - tmp_fd->sessiond_fd = buf->fd; - tmp_fd->consumerd_fd = consumerd_fd; - 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, - O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO); - if (ret < 0) { - ERR("Opening %s", tmp_fd->path_name); - perror("open"); - goto end; - } - tmp_fd->out_fd = ret; - tmp_fd->out_fd_offset = 0; - - DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name, - tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd); - - cds_list_add(&tmp_fd->list, &kconsumerd_data.fd_list.head); - kconsumerd_data.fds_count++; - kconsumerd_data.need_update = 1; -end: - pthread_mutex_unlock(&kconsumerd_data.lock); - return ret; -} - -/* - * kconsumerd_change_fd_state - * - * Update a fd according to what we just received - */ -static void kconsumerd_change_fd_state(int sessiond_fd, - enum kconsumerd_fd_state state) -{ - 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 == sessiond_fd) { - iter->state = state; - break; - } - } - kconsumerd_data.need_update = 1; - pthread_mutex_unlock(&kconsumerd_data.lock); -} - -/* - * kconsumerd_update_poll_array - * - * Allocate the pollfd structure and the local view of the out fds - * to avoid doing a lookup in the linked list and concurrency issues - * when writing is needed. - * Returns the number of fds in the structures - * Called with kconsumerd_data.lock held. - */ -static int kconsumerd_update_poll_array(struct pollfd **pollfd, - struct kconsumerd_fd **local_kconsumerd_fd) -{ - struct kconsumerd_fd *iter; - int i = 0; - - DBG("Updating poll fd array"); - - cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { - DBG("Inside for each"); - if (iter->state == ACTIVE_FD) { - DBG("Active FD %d", iter->consumerd_fd); - (*pollfd)[i].fd = iter->consumerd_fd; - (*pollfd)[i].events = POLLIN | POLLPRI; - local_kconsumerd_fd[i] = iter; - i++; - } - } - - /* - * insert the kconsumerd_poll_pipe at the end of the array and don't - * increment i so nb_fd is the number of real FD - */ - (*pollfd)[i].fd = kconsumerd_poll_pipe[0]; - (*pollfd)[i].events = POLLIN; - return i; -} - - -/* - * kconsumerd_on_read_subbuffer_mmap - * - * mmap the ring buffer, read it and write the data to the tracefile. - * Returns the number of bytes written - */ -static int kconsumerd_on_read_subbuffer_mmap( - struct kconsumerd_fd *kconsumerd_fd, unsigned long len) -{ - unsigned long mmap_len, mmap_offset, padded_len, padding_len; - char *mmap_base; - char *padding = NULL; - long ret = 0; - off_t orig_offset = kconsumerd_fd->out_fd_offset; - int fd = kconsumerd_fd->consumerd_fd; - int outfd = kconsumerd_fd->out_fd; - - /* get the padded subbuffer size to know the padding required */ - ret = kernctl_get_padded_subbuf_size(fd, &padded_len); - if (ret != 0) { - ret = errno; - perror("kernctl_get_padded_subbuf_size"); - goto end; - } - padding_len = padded_len - len; - padding = malloc(padding_len * sizeof(char)); - memset(padding, '\0', padding_len); - - /* get the len of the mmap region */ - ret = kernctl_get_mmap_len(fd, &mmap_len); - if (ret != 0) { - ret = errno; - perror("kernctl_get_mmap_len"); - goto end; - } - - /* get the offset inside the fd to mmap */ - ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); - if (ret != 0) { - ret = errno; - perror("kernctl_get_mmap_read_offset"); - goto end; - } - - mmap_base = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, mmap_offset); - if (mmap_base == MAP_FAILED) { - perror("Error mmaping"); - ret = -1; - goto end; - } - - while (len > 0) { - ret = write(outfd, mmap_base, len); - if (ret >= len) { - len = 0; - } else if (ret < 0) { - ret = errno; - perror("Error in file write"); - goto end; - } - /* This won't block, but will start writeout asynchronously */ - sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, - SYNC_FILE_RANGE_WRITE); - kconsumerd_fd->out_fd_offset += ret; - } - - /* once all the data is written, write the padding to disk */ - ret = write(outfd, padding, padding_len); - if (ret < 0) { - ret = errno; - perror("Error writing padding to file"); - goto end; - } - - /* - * This does a blocking write-and-wait on any page that belongs to the - * subbuffer prior to the one we just wrote. - * Don't care about error values, as these are just hints and ways to - * limit the amount of page cache used. - */ - if (orig_offset >= kconsumerd_fd->max_sb_size) { - sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, - kconsumerd_fd->max_sb_size, - SYNC_FILE_RANGE_WAIT_BEFORE - | SYNC_FILE_RANGE_WRITE - | SYNC_FILE_RANGE_WAIT_AFTER); - - /* - * Give hints to the kernel about how we access the file: - * POSIX_FADV_DONTNEED : we won't re-access data in a near future after - * we write it. - * - * We need to call fadvise again after the file grows because the - * kernel does not seem to apply fadvise to non-existing parts of the - * file. - * - * Call fadvise _after_ having waited for the page writeback to - * complete because the dirty page writeback semantic is not well - * defined. So it can be expected to lead to lower throughput in - * streaming. - */ - posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, - kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); - } - goto end; - -end: - if (padding != NULL) { - free(padding); - } - return ret; -} - -/* - * kconsumerd_on_read_subbuffer - * - * Splice the data from the ring buffer to the tracefile. - * Returns the number of bytes spliced - */ -static int kconsumerd_on_read_subbuffer( - struct kconsumerd_fd *kconsumerd_fd, unsigned long len) -{ - long ret = 0; - loff_t offset = 0; - off_t orig_offset = kconsumerd_fd->out_fd_offset; - int fd = kconsumerd_fd->consumerd_fd; - int outfd = kconsumerd_fd->out_fd; - - while (len > 0) { - DBG("splice chan to pipe offset %lu (fd : %d)", - (unsigned long)offset, fd); - ret = splice(fd, &offset, kconsumerd_thread_pipe[1], NULL, len, - SPLICE_F_MOVE | SPLICE_F_MORE); - DBG("splice chan to pipe ret %ld", ret); - if (ret < 0) { - ret = errno; - perror("Error in relay splice"); - goto splice_error; - } - - ret = splice(kconsumerd_thread_pipe[0], NULL, outfd, NULL, ret, - SPLICE_F_MOVE | SPLICE_F_MORE); - DBG("splice pipe to file %ld", ret); - if (ret < 0) { - ret = errno; - perror("Error in file splice"); - goto splice_error; - } - if (ret >= len) { - len = 0; - } - /* This won't block, but will start writeout asynchronously */ - sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, - SYNC_FILE_RANGE_WRITE); - kconsumerd_fd->out_fd_offset += ret; - } - - /* - * This does a blocking write-and-wait on any page that belongs to the - * subbuffer prior to the one we just wrote. - * Don't care about error values, as these are just hints and ways to - * limit the amount of page cache used. - */ - if (orig_offset >= kconsumerd_fd->max_sb_size) { - sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, - kconsumerd_fd->max_sb_size, - SYNC_FILE_RANGE_WAIT_BEFORE - | SYNC_FILE_RANGE_WRITE - | SYNC_FILE_RANGE_WAIT_AFTER); - /* - * Give hints to the kernel about how we access the file: - * POSIX_FADV_DONTNEED : we won't re-access data in a near future after - * we write it. - * - * We need to call fadvise again after the file grows because the - * kernel does not seem to apply fadvise to non-existing parts of the - * file. - * - * Call fadvise _after_ having waited for the page writeback to - * complete because the dirty page writeback semantic is not well - * defined. So it can be expected to lead to lower throughput in - * streaming. - */ - posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, - kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); - } - goto end; - -splice_error: - /* send the appropriate error description to sessiond */ - switch(ret) { - case EBADF: - kconsumerd_send_error(KCONSUMERD_SPLICE_EBADF); - break; - case EINVAL: - kconsumerd_send_error(KCONSUMERD_SPLICE_EINVAL); - break; - case ENOMEM: - kconsumerd_send_error(KCONSUMERD_SPLICE_ENOMEM); - break; - case ESPIPE: - kconsumerd_send_error(KCONSUMERD_SPLICE_ESPIPE); - break; - } - -end: - return ret; -} - -/* - * kconsumerd_read_subbuffer - * - * Consume data on a file descriptor and write it on a trace file - */ -static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) -{ - unsigned long len; - int err; - long ret = 0; - int infd = kconsumerd_fd->consumerd_fd; - - DBG("In kconsumerd_read_subbuffer (infd : %d)", infd); - /* Get the next subbuffer */ - err = kernctl_get_next_subbuf(infd); - if (err != 0) { - ret = errno; - perror("Reserving sub buffer failed (everything is normal, " - "it is due to concurrency)"); - goto end; - } - - switch (DEFAULT_KERNEL_CHANNEL_OUTPUT) { - case LTTNG_EVENT_SPLICE: - /* read the whole subbuffer */ - err = kernctl_get_padded_subbuf_size(infd, &len); - if (err != 0) { - ret = errno; - perror("Getting sub-buffer len failed."); - goto end; - } - - /* splice the subbuffer to the tracefile */ - ret = kconsumerd_on_read_subbuffer(kconsumerd_fd, len); - if (ret < 0) { - /* - * display the error but continue processing to try - * to release the subbuffer - */ - ERR("Error splicing to tracefile"); - } - break; - case LTTNG_EVENT_MMAP: - /* read the used subbuffer size */ - err = kernctl_get_subbuf_size(infd, &len); - if (err != 0) { - ret = errno; - perror("Getting sub-buffer len failed."); - goto end; - } - /* write the subbuffer to the tracefile */ - ret = kconsumerd_on_read_subbuffer_mmap(kconsumerd_fd, len); - if (ret < 0) { - /* - * display the error but continue processing to try - * to release the subbuffer - */ - ERR("Error writing to tracefile"); - } - break; - default: - ERR("Unknown output method"); - ret = -1; - } - - err = kernctl_put_next_subbuf(infd); - if (err != 0) { - ret = errno; - if (errno == EFAULT) { - perror("Error in unreserving sub buffer\n"); - } else if (errno == EIO) { - /* Should never happen with newer LTTng versions */ - perror("Reader has been pushed by the writer, last sub-buffer corrupted."); - } - goto end; - } - -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 - * - * Receives an array of file descriptors and the associated - * structures describing each fd (path name). - * Returns the size of received data - */ -static int kconsumerd_consumerd_recv_fd(int sfd, - struct pollfd *kconsumerd_sockpoll, int size, - enum kconsumerd_command cmd_type) -{ - struct iovec iov[1]; - int ret = 0, i, tmp2; - struct cmsghdr *cmsg; - int nb_fd; - char recv_fd[CMSG_SPACE(sizeof(int))]; - struct lttcomm_kconsumerd_msg lkm; - - /* 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++) { - struct msghdr msg = { 0 }; - - /* Prepare to receive the structures */ - iov[0].iov_base = &lkm; - iov[0].iov_len = sizeof(lkm); - msg.msg_iov = iov; - msg.msg_iovlen = 1; - - msg.msg_control = recv_fd; - 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; - } - - if (ret != (size / nb_fd)) { - ERR("Received only %d, expected %d", ret, size); - kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); - goto end; - } - - cmsg = CMSG_FIRSTHDR(&msg); - if (!cmsg) { - ERR("Invalid control message header"); - ret = -1; - 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, ((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; - } - break; - case UPDATE_STREAM: - kconsumerd_change_fd_state(lkm.fd, lkm.state); - break; - default: - break; - } - /* 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); - ret = -1; - goto end; - } - } - -end: - return ret; -} - -/* - * kconsumerd_thread_poll_fds - * - * This thread polls the fds in the ltt_fd_list to consume the data - * and write it to tracefile if necessary. - */ -void *kconsumerd_thread_poll_fds(void *data) -{ - int num_rdy, num_hup, high_prio, ret, i; - struct pollfd *pollfd = NULL; - /* local view of the fds */ - struct kconsumerd_fd **local_kconsumerd_fd = NULL; - /* local view of kconsumerd_data.fds_count */ - int nb_fd = 0; - char tmp; - int tmp2; - - ret = pipe(kconsumerd_thread_pipe); - if (ret < 0) { - perror("Error creating pipe"); - goto end; - } - - local_kconsumerd_fd = malloc(sizeof(struct kconsumerd_fd)); - - while (1) { - high_prio = 0; - num_hup = 0; - - /* - * the ltt_fd_list has been updated, we need to update our - * local array as well - */ - pthread_mutex_lock(&kconsumerd_data.lock); - if (kconsumerd_data.need_update) { - if (pollfd != NULL) { - free(pollfd); - pollfd = NULL; - } - if (local_kconsumerd_fd != NULL) { - free(local_kconsumerd_fd); - local_kconsumerd_fd = NULL; - } - - /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ - pollfd = malloc((kconsumerd_data.fds_count + 1) * sizeof(struct pollfd)); - if (pollfd == NULL) { - perror("pollfd malloc"); - pthread_mutex_unlock(&kconsumerd_data.lock); - goto end; - } - - /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ - local_kconsumerd_fd = malloc((kconsumerd_data.fds_count + 1) * - sizeof(struct kconsumerd_fd)); - if (local_kconsumerd_fd == NULL) { - perror("local_kconsumerd_fd malloc"); - pthread_mutex_unlock(&kconsumerd_data.lock); - goto end; - } - ret = kconsumerd_update_poll_array(&pollfd, local_kconsumerd_fd); - if (ret < 0) { - ERR("Error in allocating pollfd or local_outfds"); - kconsumerd_send_error(KCONSUMERD_POLL_ERROR); - pthread_mutex_unlock(&kconsumerd_data.lock); - goto end; - } - nb_fd = ret; - kconsumerd_data.need_update = 0; - } - pthread_mutex_unlock(&kconsumerd_data.lock); - - /* poll on the array of fds */ - DBG("polling on %d fd", nb_fd + 1); - num_rdy = poll(pollfd, nb_fd + 1, kconsumerd_poll_timeout); - DBG("poll num_rdy : %d", num_rdy); - if (num_rdy == -1) { - perror("Poll error"); - kconsumerd_send_error(KCONSUMERD_POLL_ERROR); - goto end; - } else if (num_rdy == 0) { - DBG("Polling thread timed out"); - goto end; - } - - /* No FDs and kconsumerd_quit, kconsumerd_cleanup the thread */ - if (nb_fd == 0 && kconsumerd_quit == 1) { - goto end; - } - - /* - * If the kconsumerd_poll_pipe triggered poll go - * directly to the beginning of the loop to update the - * array. We want to prioritize array update over - * low-priority reads. - */ - 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; - } - - /* Take care of high priority channels first. */ - for (i = 0; i < nb_fd; i++) { - switch(pollfd[i].revents) { - case POLLERR: - ERR("Error returned in polling fd %d.", pollfd[i].fd); - kconsumerd_del_fd(local_kconsumerd_fd[i]); - num_hup++; - break; - case POLLHUP: - DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); - kconsumerd_del_fd(local_kconsumerd_fd[i]); - num_hup++; - break; - case POLLNVAL: - ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); - kconsumerd_del_fd(local_kconsumerd_fd[i]); - num_hup++; - break; - case POLLPRI: - DBG("Urgent read on fd %d", pollfd[i].fd); - high_prio = 1; - ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); - /* it's ok to have an unavailable sub-buffer */ - if (ret == EAGAIN) { - ret = 0; - } - break; - } - } - - /* If every buffer FD has hung up, we end the read loop here */ - if (nb_fd > 0 && num_hup == nb_fd) { - DBG("every buffer FD has hung up\n"); - if (kconsumerd_quit == 1) { - goto end; - } - continue; - } - - /* Take care of low priority channels. */ - if (high_prio == 0) { - for (i = 0; i < nb_fd; i++) { - if (pollfd[i].revents == POLLIN) { - DBG("Normal read on fd %d", pollfd[i].fd); - ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); - /* it's ok to have an unavailable subbuffer */ - if (ret == EAGAIN) { - ret = 0; - } - } - } - } - } -end: - DBG("polling thread exiting"); - if (pollfd != NULL) { - free(pollfd); - pollfd = NULL; - } - if (local_kconsumerd_fd != NULL) { - free(local_kconsumerd_fd); - local_kconsumerd_fd = NULL; - } - return NULL; -} - -/* - * kconsumerd_init(void) - * - * 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_init(void) -{ - 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; -} - -/* - * kconsumerd_thread_receive_fds - * - * This thread listens on the consumerd socket and - * receives the file descriptors from ltt-sessiond - */ -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); - client_socket = lttcomm_create_unix_sock(kconsumerd_command_sock_path); - if (client_socket < 0) { - ERR("Cannot create command socket"); - goto end; - } - - ret = lttcomm_listen_unix_sock(client_socket); - if (ret < 0) { - goto end; - } - - DBG("Sending ready command to ltt-sessiond"); - ret = kconsumerd_send_error(KCONSUMERD_COMMAND_SOCK_READY); - if (ret < 0) { - ERR("Error sending ready command to ltt-sessiond"); - 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)); - if (ret <= 0) { - ERR("Communication interrupted on command socket"); - goto end; - } - if (tmp.cmd_type == STOP) { - 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, kconsumerd_sockpoll, - tmp.payload_size, tmp.cmd_type); - if (ret <= 0) { - ERR("Receiving the FD, exiting"); - goto end; - } - DBG("received fds on sock"); - } - -end: - DBG("kconsumerd_thread_receive_fds exiting"); - - /* - * when all fds have hung up, the polling thread - * can exit cleanly - */ - kconsumerd_quit = 1; - - /* - * 2s of grace period, if no polling events occur during - * this period, the polling thread will exit even if there - * are still open FDs (should not happen, but safety mechanism). - */ - kconsumerd_poll_timeout = KCONSUMERD_POLL_GRACE_PERIOD; - - /* wake up the polling thread */ - ret = write(kconsumerd_poll_pipe[1], "4", 1); - if (ret < 0) { - perror("poll pipe write"); - } - return NULL; -} - -/* - * kconsumerd_cleanup - * - * Cleanup the daemon's socket on exit - */ -void kconsumerd_cleanup(void) -{ - struct kconsumerd_fd *iter, *tmp; - - /* remove the socket file */ - unlink(kconsumerd_command_sock_path); - - /* - * 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 - * - * send return code to ltt-sessiond - */ -int kconsumerd_send_error(enum lttcomm_return_code cmd) -{ - if (kconsumerd_error_socket > 0) { - return lttcomm_send_unix_sock(kconsumerd_error_socket, &cmd, - sizeof(enum lttcomm_sessiond_command)); - } - - return 0; -}