event-spread.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#define __USE_GNU
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/eventfd.h>
#include <sys/signalfd.h>
#include <linux/kernel.h>
#include <linux/circ_buf.h>
#include <linux/list.h>
#include <monitor.h>
#include <tep.h>
#include <net.h>

#define BUF_LEN (1 << 16)

enum block_type {
    TYPE_TCP,
    TYPE_CDEV,
    TYPE_FILE,
};

static struct cdev_wait_list {
    int sfd;
    struct list_head wait_head;
} cdev_wait_list = {-1, LIST_HEAD_INIT(cdev_wait_list.wait_head)};

struct cdev_block { // chardev
    int fd;
    bool connected;
    const char *filename;
    struct list_head wait_link;

    // EPOLLOUT
    struct perf_record_lost lost_event;
    // struct circ_buf circ;
    char *buf; // BUF_LEN
    int head;  // write event
    int tail;  // read and write to cdev

    // EPOLLIN
    char *event_copy;
    int read;
};

struct event_block {
    struct list_head link;
    struct event_block_list *eb_list;
    enum block_type type;
    union {
        struct tcp_block {
            void *tcp; // broadcast or receive
            struct tcp_socket_ops ops;
            const char *ip;
            const char *port;
        } tcp;
        struct cdev_block cdev;
        struct file_block {
            FILE *file; // broadcast or receive
            size_t pos;
            const char *filename;
            int notifyfd;
        } file;
    } u;
    // receive
    int remote_id;
    int pid_pos;
    int cpu_pos;
    int stream_id_pos;
    int common_type_pos;
};

struct event_block_list {
    struct list_head block_list;
    struct tp *tp;
    bool broadcast;
    bool freeing;
};

static inline void block_free(struct event_block *block);
static inline void block_broadcast(struct event_block *block, const void *buf, size_t len, int flags);
static void handle_cdev_event(int fd, unsigned int revents, void *ptr);


static int fcntl_setfl(int fd, unsigned int flags, bool set)
{
    unsigned int oldflags, newflags;

    if ((oldflags = fcntl(fd, F_GETFL)) < 0) return -1;

    newflags = oldflags;
    if (set) newflags |= flags;
    else     newflags &= ~flags;
    if (oldflags == newflags) return 0;

    if (fcntl(fd, F_SETFL, newflags) < 0) return -1;
    if ((flags = fcntl(fd, F_GETFL)) < 0) return -1;

    return newflags == flags ? 0 : -1;
}

static inline int fcntl_setown(int fd, int who)
{
    return fcntl(fd, F_SETOWN, who);
}

static inline int fcntl_setsig(int fd, int sig)
{
    return fcntl(fd, F_SETSIG, sig);
}

static int block_event_convert(struct event_block *block, union perf_event *event)
{
    struct tp *tp = block->eb_list->tp;
    struct perf_event_attr *attr;
    void *data;
    u64 sample_type;
    int cpuidx = 0;
    int pos = 0;
    int common_type_pos = 0;
    int vcpu = -1;

    if (unlikely(!tp->evsel))
        return -1;

    attr = perf_evsel__attr(tp->evsel);
    if (unlikely(attr->sample_period == 0))
        return -1;

   /*
    *  { u64           id;   } && PERF_SAMPLE_IDENTIFIER
    *  { u64           ip;   } && PERF_SAMPLE_IP
    *  { u32           pid, tid; } && PERF_SAMPLE_TID
    *  { u64           time;     } && PERF_SAMPLE_TIME
    *  { u64           addr;     } && PERF_SAMPLE_ADDR
    *  { u64           id;   } && PERF_SAMPLE_ID
    *  { u64           stream_id;} && PERF_SAMPLE_STREAM_ID
    *  { u32           cpu, res; } && PERF_SAMPLE_CPU
    *  { u64           period;   } && PERF_SAMPLE_PERIOD
    *  { struct read_format    values;   } && PERF_SAMPLE_READ
    *  { u64           nr,
    *    u64           ips[nr];  } && PERF_SAMPLE_CALLCHAIN
    *  { u32			size;
    *    char                  data[size];}&& PERF_SAMPLE_RAW
    */
    data = (void *)event->sample.array;
    sample_type = attr->sample_type;

    if (block->pid_pos == -1 && block->cpu_pos == -1 && block->stream_id_pos == -1 && block->common_type_pos == -1) {
        if (sample_type & PERF_SAMPLE_IDENTIFIER)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_IP)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_TID) {
            block->pid_pos = pos;
            pos += sizeof(u32) + sizeof(u32);
        }
        if (sample_type & PERF_SAMPLE_TIME)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_ADDR)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_ID)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_STREAM_ID) {
            block->stream_id_pos = pos;
            pos += sizeof(u64);
        }
        if (sample_type & PERF_SAMPLE_CPU) {
            block->cpu_pos = pos;
            pos += sizeof(u32) + sizeof(u32);
        }
        if (sample_type & PERF_SAMPLE_PERIOD)
            pos += sizeof(u64);
        if (sample_type & PERF_SAMPLE_READ)
            pos += perf_evsel__read_size(tp->evsel);
        block->common_type_pos = pos;
    }

    if (block->cpu_pos != -1) {
        vcpu = *(u32 *)(data + block->cpu_pos);
        cpuidx = perf_cpu_map__idx(perf_evsel__cpus(tp->evsel), vcpu);
        if (cpuidx < 0)
            cpuidx = 0;

        // Guest vcpu => Host tid
        if (tp->vcpu && block->pid_pos != -1) {
            // u32           pid, tid;
            *(u32 *)(data + block->pid_pos) = tp->vcpu->thread_id[vcpu];
            *(u32 *)(data + block->pid_pos + sizeof(u32)) = tp->vcpu->thread_id[vcpu];
        }
    }

    if (sample_type & PERF_SAMPLE_STREAM_ID) {
        //u64           stream_id;
        *(u64 *)(data + block->stream_id_pos) = perf_evsel__get_id(tp->evsel, cpuidx, 0);
    }

    if (tp->id != block->remote_id) {
        common_type_pos = block->common_type_pos;
        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
            struct {
                u64 nr;
                u64 ips[];
            } *callchain = data + common_type_pos;
            common_type_pos += (callchain->nr + 1) * sizeof(u64);
        }
        if (sample_type & PERF_SAMPLE_RAW) {
            common_type_pos += sizeof(u32);
            //unsigned short common_type;
            //unsigned char common_flags;
            //unsigned char common_preempt_count;
            //int common_pid;
            *(unsigned short *)(data + common_type_pos) = tp->id;
            if (tp->vcpu && vcpu >= 0)
                *(int *)(data + common_type_pos + sizeof(u16) + sizeof(u8) + sizeof(u8)) = tp->vcpu->thread_id[vcpu];
        }
    }
    return cpuidx;
}

static int block_process_event(struct event_block *block, union perf_event *event)
{
    struct tp *tp = block->eb_list->tp;
    int ins = 0;

    switch (event->header.type) {
        case PERF_RECORD_TP: {
                struct perf_record_tp *record = (void *)event;
                struct perf_event_attr *attr = tp->evsel ? perf_evsel__attr(tp->evsel) : NULL;

                if (strcmp((char *)record + record->sys_offset, tp->sys) ||
                    strcmp((char *)record + record->name_offset, tp->name)) {
                    fprintf(stderr, "tp sys:name does not match %s:%s, unable to receive pull-events.\n",
                                    (char *)record + record->sys_offset, (char *)record + record->name_offset);
                    goto failed;
                }
                if (!attr || attr->sample_period == 0 || record->sample_period == 0) {
                    fprintf(stderr, "tp is non-sampling, unable to receive pull-events.\n");
                    goto failed;
                }
                if (attr->sample_type != record->sample_type) {
                    fprintf(stderr, "tp sample_type(%llu) mismatch, unable to receive pull-events.\n",
                                    attr->sample_type ^ record->sample_type);
                    goto failed;
                }
                if (record->sample_type & PERF_SAMPLE_CALLCHAIN) {
                    fprintf(stderr, "tp has PERF_SAMPLE_CALLCHAIN enabled, unable to receive pull-events.\n");
                    goto failed;
                }
                if (tep__event_size(tp->id) != record->event_size) {
                    fprintf(stderr, "tp event_size mismatch, unable to receive pull-events.\n");
                    goto failed;
                }

                block->remote_id = record->id;
                return 0;

            failed:
                block_free(block);
                return -1;
            }
        case PERF_RECORD_SAMPLE:
            ins = block_event_convert(block, event);
            if (ins < 0) return 0;
            else break;
        default:
            break;
    }

    perf_event_process_record(event, ins, true, true);
    return 0;
}

static int tcp_process_event(union perf_event *event, struct tcp_socket_ops *ops)
{
    struct event_block *block = container_of(ops, struct event_block, u.tcp.ops);
    return block_process_event(block, event);
}

static int tcp_disconnect(struct tcp_socket_ops *ops)
{
    struct event_block *block = container_of(ops, struct event_block, u.tcp.ops);
    block_free(block);
    return 0;
}

static int perf_record_tp_init(struct tp *tp, struct perf_record_tp *record)
{
    struct perf_event_attr *attr;

    if (!tp->evsel)
        return -1;

    attr = perf_evsel__attr(tp->evsel);

    // send sys:name, perf_event_attr, /FILTER/ATTR/

    record->header.size = sizeof(*record) + strlen(tp->sys) + strlen(tp->name) + 2;
    record->header.type = PERF_RECORD_TP;
    record->header.misc = 0;

    record->id = tp->id;
    record->sys_offset = sizeof(*record);
    record->name_offset = sizeof(*record) + strlen(tp->sys) + 1;
    record->sample_period = attr->sample_period;
    record->sample_type = attr->sample_type;
    record->event_size = tep__event_size(tp->id);
    record->unused = 0;

    return 0;
}

static int tcp_new_client(struct tcp_socket_ops *ops)
{
    struct event_block *block = NULL;
    struct tp *tp = NULL;
    struct perf_record_tp record;

    if (!ops->server_ops)
        return 0;

    block = container_of(ops->server_ops, struct event_block, u.tcp.ops);
    tp = block->eb_list->tp;
    if (perf_record_tp_init(tp, &record) < 0)
        return 0;

    if (tcp_send(ops->client, &record, sizeof(record), MSG_MORE) == 0 &&
        tcp_send(ops->client, tp->sys, strlen(tp->sys)+1, MSG_MORE) == 0 &&
        tcp_send(ops->client, tp->name, strlen(tp->name)+1, 0) == 0)
        return 0;
    else
        return -1;
}

static void handle_cdev_sigio(int fd, unsigned int revents, void *ptr)
{
    struct event_block *block = NULL;
    struct cdev_block *cdev = NULL;
    struct signalfd_siginfo fdsi;
    int s, found = 0;
    unsigned int events;

    s = read(fd, &fdsi, sizeof(struct signalfd_siginfo));
    if (s != sizeof(fdsi)) return ;
    if (fdsi.ssi_signo != SIGIO) return ;

    list_for_each_entry(block, &cdev_wait_list.wait_head, u.cdev.wait_link) {
        cdev = &block->u.cdev;
        if (cdev->fd == fdsi.ssi_fd && (fdsi.ssi_band & EPOLLOUT)) {
            found = 1;
            break;
        }
    }
    if (found) {
        fcntl_setfl(cdev->fd, FASYNC, 0);
        fcntl_setsig(cdev->fd, 0);
        fcntl_setown(cdev->fd, 0);
        list_del_init(&cdev->wait_link);
        events = (block->eb_list->broadcast ? EPOLLOUT : EPOLLIN) | EPOLLHUP;
        main_epoll_add(cdev->fd, events, block, handle_cdev_event);
        printf("Cdev %s is connected\n", cdev->filename);
    }
    if (list_empty(&cdev_wait_list.wait_head)) {
        sigset_t mask;

        sigemptyset(&mask);
        sigaddset(&mask, SIGIO);
        sigprocmask(SIG_UNBLOCK, &mask, NULL);

        main_epoll_del(cdev_wait_list.sfd);
        cdev_wait_list.sfd = -1;
    }
}

/*
 * cdev is required to support the FASYNC capability.
 * Currently only virtio-ports are available.
 */
static int cdev_wait_connected(struct event_block *block)
{
    struct cdev_block *cdev = &block->u.cdev;
    sigset_t mask;
    int sfd = -1;

    sigemptyset(&mask);
    sigaddset(&mask, SIGIO);
    if (list_empty(&cdev_wait_list.wait_head)) {
        sigprocmask(SIG_BLOCK, &mask, NULL);

        if ((sfd = signalfd(-1, &mask, SFD_NONBLOCK)) < 0) goto e1;
        if (main_epoll_add(sfd, EPOLLIN, NULL, handle_cdev_sigio) < 0) goto e2;
        cdev_wait_list.sfd = sfd;
    }

    if (fcntl_setown(cdev->fd, getpid()) < 0) goto e3;
    if (fcntl_setsig(cdev->fd, SIGIO) < 0) goto e4;
    if (fcntl_setfl(cdev->fd, FASYNC, 1) < 0) goto e5;

    list_add_tail(&cdev->wait_link, &cdev_wait_list.wait_head);
    return 0;

e5: fcntl_setsig(cdev->fd, 0);
e4: fcntl_setown(cdev->fd, 0);
e3: if (sfd > 0) {
        main_epoll_del(sfd);
        cdev_wait_list.sfd = -1;
    } else
        return -1;

e2: close(sfd);
e1: sigprocmask(SIG_UNBLOCK, &mask, NULL);
    return -1;
}

static int cdev_write_header(struct event_block *block)
{
    struct tp *tp = block->eb_list->tp;
    struct perf_record_tp record;

    if (perf_record_tp_init(tp, &record) < 0)
        return 0;

    block_broadcast(block, &record, sizeof(record), 0);
    block_broadcast(block, tp->sys, strlen(tp->sys)+1, 0);
    block_broadcast(block, tp->name, strlen(tp->name)+1, 0);
    return 0;
}

static void handle_cdev_event(int fd, unsigned int revents, void *ptr)
{
    struct event_block *block = ptr;
    struct cdev_block *cdev = &block->u.cdev;

    // Handle EPOLLIN first to fully read out the received events, then EPOLLHUP.
    if (revents & EPOLLIN) {
        union perf_event *event;
        int ret;

        while (true) {
            ret = read(cdev->fd, cdev->event_copy+cdev->read, BUF_LEN-cdev->read);
            if (unlikely(ret <= 0)) {
                // The return value will be 0 when the host is disconnected.
                if (ret == 0)
                    break;
                if (errno != EAGAIN)
                    fprintf(stderr, "Unable read from %s: %s\n", cdev->filename, strerror(errno));
                break;
            }

            cdev->connected = 1;
            cdev->read += ret;
            event = (void *)cdev->event_copy;
            while (cdev->read >= sizeof(struct perf_event_header) &&
                cdev->read >= event->header.size) {
                cdev->read -= event->header.size;
                if (unlikely(block_process_event(block, event) < 0))
                    return;
                event = (void *)event + event->header.size;
            }
            if (cdev->read) {
                memcpy(cdev->event_copy, event, cdev->read);
            }
        }
    }

    if (revents & EPOLLHUP) {
        // reset circ_buf
        cdev->head = 0;
        cdev->tail = 0;
        memset(&cdev->lost_event, 0, sizeof(struct perf_record_lost));
        main_epoll_del(cdev->fd);

        // reopen.
        // There may be some dirty data in cdev, which can be refreshed by reopening.
        if (cdev->connected == 1) {
            cdev->connected = 0;
            close(cdev->fd);
            cdev->fd = open(cdev->filename, (block->eb_list->broadcast ? O_WRONLY : O_RDONLY) | O_NONBLOCK);
        }

        if (cdev->fd < 0 ||
            cdev_wait_connected(block) < 0)
            block_free(block);
        else
            printf("Cdev %s has hang up\n", cdev->filename);
        return ;
    }

    if (revents & EPOLLOUT) {
        int cnt;
        ssize_t wr;

        if (unlikely(cdev->connected == 0)) {
            cdev->connected = 1;
            cdev_write_header(block);
        }
    retry:
        cnt = CIRC_CNT_TO_END(cdev->head, cdev->tail, BUF_LEN);
        if (cnt == 0) {
            // write lost event
            if (cdev->lost_event.lost > 0) {
                block_broadcast(block, &cdev->lost_event, sizeof(struct perf_record_lost), 0);
                cdev->lost_event.lost = 0;
            } else
                main_epoll_add(fd, EPOLLHUP, block, handle_cdev_event);
            return ;
        }
        wr = write(cdev->fd, cdev->buf + (cdev->tail & (BUF_LEN-1)), cnt);
        if (wr <= 0) {
            if (wr < 0 && errno != EAGAIN)
                fprintf(stderr, "Unable write to %s: %s\n", cdev->filename, strerror(errno));
            return ;
        }
        cdev->tail = (cdev->tail + wr) & (BUF_LEN-1);
        goto retry;
    }
}

static int file_write_header(struct event_block *block)
{
    struct tp *tp = block->eb_list->tp;
    struct perf_record_tp record;
    FILE *file = block->u.file.file;
    size_t pos = 0;

    if (perf_record_tp_init(tp, &record) < 0)
        return 0;

    pos += fwrite(&record, 1, sizeof(record), file);
    pos += fwrite(tp->sys, 1, strlen(tp->sys)+1, file);
    pos += fwrite(tp->name, 1, strlen(tp->name)+1, file);
    block->u.file.pos = pos;
    fflush(file);
    return 0;
}

static void handle_file_event(int fd, unsigned int revents, void *ptr)
{
    struct event_block *block = ptr;
    FILE *file = block->u.file.file;
    char event_copy[PERF_SAMPLE_MAX_SIZE];
    union perf_event *event = (void *)event_copy;
    int len, i;

    for (i = 0; i < 64; i++) {
        len = fread(event_copy, 1, sizeof(struct perf_event_header), file);
        if (len == sizeof(struct perf_event_header))
            len += fread(event_copy+len, 1, event->header.size-len, file);
        if (len != event->header.size)
            goto err;
        if (block_process_event(block, event) < 0)
            break;
    }
    return ;

err:
    block_free(block);
    return;
}

static int block_new(struct event_block_list *eb_list, char *value)
{
    struct event_block *block = NULL;
    char *ip = NULL;
    char *port;
    FILE *file = NULL;
    struct stat st;

    port = strchr(value, ':');
    if (port) {
        *port ++ = '\0';
        if (*value) ip = value;
    } else
        port = value;
    if (!*port) goto err_return;

    if (!(block = malloc(sizeof(*block)))) return -1;
    memset(block, 0, sizeof(*block));

    block->eb_list = eb_list;
    list_add_tail(&block->link, &eb_list->block_list);

    block->pid_pos = -1;
    block->cpu_pos = -1;
    block->stream_id_pos = -1;
    block->common_type_pos = -1;

    /*
     * Detect whether it is a tcp server or client.
     */
    block->u.tcp.ip = ip;
    block->u.tcp.port = port;
    block->u.tcp.ops.process_event = tcp_process_event;
    block->u.tcp.ops.disconnect = tcp_disconnect;
    block->u.tcp.ops.new_client = tcp_new_client;
    block->u.tcp.tcp = (eb_list->broadcast ? tcp_server : tcp_connect)(ip, port, &block->u.tcp.ops);
    if (block->u.tcp.tcp) {
        block->type = TYPE_TCP;
        return 0;
    }

    /*
     * Check if it is a cdev.
     * Currently only virtio_console are supported, /dev/virtio-ports/.
     */
    if (stat(port, &st) == 0 &&
        S_ISCHR(st.st_mode)) {
        int fd = open(port, (eb_list->broadcast ? O_WRONLY : O_RDONLY) | O_NONBLOCK);
        unsigned int events = (eb_list->broadcast ? EPOLLOUT : EPOLLIN) | EPOLLHUP;
        if (fd >= 0 &&
            main_epoll_add(fd, events, block, handle_cdev_event) == 0) {
            // main_epoll_add < 0 && errno == EPERM, The file fd does not support epoll.
            block->u.cdev.fd = fd;
            block->u.cdev.connected = 0;
            block->u.cdev.filename = port;
            INIT_LIST_HEAD(&block->u.cdev.wait_link);
            block->u.cdev.head = 0;
            block->u.cdev.tail = 0;
            memset(&block->u.cdev.lost_event, 0, sizeof(struct perf_record_lost));
            block->u.cdev.buf = malloc(BUF_LEN);
            block->u.cdev.event_copy = block->u.cdev.buf;
            block->u.cdev.read = 0;
            block->type = TYPE_CDEV;
            if (block->u.cdev.buf) {
                printf("Open cdev %s\n", block->u.cdev.filename);
                return 0;
            } else {
                main_epoll_del(fd);
                close(fd);
                goto failed;
            }
        }
    }

    /*
     * Check if it is a file.
     */
    if ((file = fopen(port, eb_list->broadcast ? "w+" : "r"))) {
        block->u.file.file = file;
        block->u.file.pos = 0;
        block->u.file.filename = port;
        block->type = TYPE_FILE;
        if (!eb_list->broadcast) {
            block->u.file.notifyfd = eventfd(1, EFD_NONBLOCK);
            if (block->u.file.notifyfd < 0)
                goto failed;
            main_epoll_add(block->u.file.notifyfd, EPOLLIN, block, handle_file_event);
        } else
            block->u.file.notifyfd = -1;
        printf("Open file %s\n", block->u.file.filename);
        return 0;
    }

failed:
    // failed
    list_del(&block->link);
    if (file) fclose(file);
    free(block);
err_return:
    fprintf(stderr, "The pull=%s attribute is incorrect.\n", value);
    return -1;
}

static void block_free(struct event_block *block)
{
    struct event_block_list *eb_list = block->eb_list;

    switch (block->type) {
        case TYPE_TCP:
            tcp_close(block->u.tcp.tcp);
            break;
        case TYPE_CDEV:
            if (!list_empty(&block->u.cdev.wait_link))
                list_del(&block->u.cdev.wait_link);
            if (block->u.cdev.fd >= 0) {
                main_epoll_del(block->u.cdev.fd);
                close(block->u.cdev.fd);
            }
            free(block->u.cdev.buf);
            printf("Close cdev %s\n", block->u.cdev.filename);
            break;
        case TYPE_FILE:
            if (block->u.file.notifyfd >= 0)
                main_epoll_del(block->u.file.notifyfd);
            fclose(block->u.file.file);
            printf("Close file %s\n", block->u.file.filename);
            break;
        default:
            break;
    }
    list_del(&block->link);
    free(block);

    if (!eb_list->freeing &&
        !eb_list->broadcast && list_empty(&eb_list->block_list)) {
        struct tp *tp = eb_list->tp;
        printf("%s:%s re-enable kernel events\n", tp->sys, tp->name);
        if (tp->evsel) {
            perf_evsel__keep_disable(tp->evsel, false);
            perf_evsel__enable(tp->evsel);
            tp->kernel = true;
        }
    }
}

static inline void block_broadcast(struct event_block *block, const void *buf, size_t len, int flags)
{
    switch (block->type) {
        case TYPE_TCP:
            tcp_server_broadcast(block->u.tcp.tcp, buf, len, flags);
            break;
        case TYPE_CDEV: {
            struct cdev_block *cdev = &block->u.cdev;
            if (cdev->connected) {
                int add = 0;
                if (CIRC_SPACE(cdev->head, cdev->tail, BUF_LEN) < len) {
                    handle_cdev_event(cdev->fd, EPOLLOUT, block);
                }
                add = CIRC_CNT(cdev->head, cdev->tail, BUF_LEN) == 0;
                if (likely(CIRC_SPACE(cdev->head, cdev->tail, BUF_LEN) >= len)) {
                    int space = CIRC_SPACE_TO_END(cdev->head, cdev->tail, BUF_LEN);
                    space = min((int)len, space);
                    len -= space;
                    memcpy(cdev->buf + (cdev->head & (BUF_LEN-1)), buf, space);
                    if (len)
                        memcpy(cdev->buf, buf + space, len);
                    cdev->head = (cdev->head + space + len) & (BUF_LEN-1);
                    if (add)
                        main_epoll_add(cdev->fd, EPOLLOUT | EPOLLHUP, block, handle_cdev_event);
                } else {
                    // lost event
                    cdev->lost_event.header.size = sizeof(struct perf_record_lost);
                    cdev->lost_event.header.type = PERF_RECORD_LOST;
                    cdev->lost_event.header.misc = 0;
                    cdev->lost_event.id          = 0;
                    cdev->lost_event.lost        ++ ;
                }
            }
            } break;
        case TYPE_FILE:
            if (block->u.file.pos == 0)
                file_write_header(block);
            block->u.file.pos += fwrite(buf, 1, len, block->u.file.file);
            break;
        default:
            break;
    }
}

static void block_list_free(struct tp *tp, bool broadcast)
{
    struct event_block_list *eb_list = (broadcast ? tp->broadcast : tp->receive);
    struct event_block *block, *next;

    if (!eb_list)
        return ;

    eb_list->freeing = 1;
    list_for_each_entry_safe(block, next, &eb_list->block_list, link) {
        block_free(block);
    }
    free(eb_list);

    if (broadcast) tp->broadcast = NULL;
    else tp->receive = NULL;
}

static int block_list_new(struct tp *tp, char *s, bool broadcast)
{
    struct event_block_list *eb_list = (broadcast ? tp->broadcast : tp->receive);
    char *sep;

    if (eb_list == NULL) {
        if (!(eb_list = malloc(sizeof(*eb_list)))) return -1;
        memset(eb_list, 0, sizeof(*eb_list));

        INIT_LIST_HEAD(&eb_list->block_list);
        eb_list->tp = tp;
        eb_list->broadcast = broadcast;
        eb_list->freeing = 0;

        if (broadcast) tp->broadcast = eb_list;
        else tp->receive = eb_list;
    }

    while ((sep = strchr(s, ',')) != NULL) {
        *sep = '\0';
        if (block_new(eb_list, s) < 0) goto err;
        s = sep + 1;
    }
    if (block_new(eb_list, s) < 0) goto err;

    return 0;

err:
    block_list_free(tp, broadcast);
    return -1;
}


int tp_broadcast_new(struct tp *tp, char *s)
{
    return block_list_new(tp, s, true);
}

void tp_broadcast_free(struct tp *tp)
{
    block_list_free(tp, true);
}

int tp_broadcast_event(struct tp *tp, union perf_event *event)
{
    struct event_block_list *eb_list = tp->broadcast;
    struct event_block *block;

    if (!eb_list)
        return 0;

    list_for_each_entry(block, &eb_list->block_list, link) {
        block_broadcast(block, event, event->header.size, 0);
    }
    return 1;
}

int tp_receive_new(struct tp *tp, char *s)
{
    return block_list_new(tp, s, false);
}

void tp_receive_free(struct tp *tp)
{
    block_list_free(tp, false);
}