a3.c

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <pthread.h>
#include <sched.h>
#include <emmintrin.h>

#include "q3.h"
//#include "q.h"
//#include "qlock.h"

static struct msg *msgs;
static int *msg_flags;

#define POP_CNT     7
#define PUSH_CNT    7

#define MSG_CNT     (PUSH_CNT * 1000000)

static inline uint64_t
rdtsc(void)
{
    union {
        uint64_t tsc_64;
        struct {
            uint32_t lo_32;
            uint32_t hi_32;
        };
    } tsc;

    asm volatile("rdtsc" :
        "=a" (tsc.lo_32),
        "=d" (tsc.hi_32));
    return tsc.tsc_64;
}

static volatile int quit = 0;
static volatile int pop_total = 0;
static volatile int push_total = 0;

static volatile uint64_t push_cycles = 0;
static volatile uint64_t pop_cycles = 0;

#define delay(c) do {                   \
    if ((c) == 0) break;                \
    uint64_t start = rdtsc();           \
    uint64_t now = start;               \
    while (now - start < (c)) {         \
        _mm_pause();                    \
        now = rdtsc();                  \
    }                                   \
} while (0)


static void *
pop_task(void *arg)
{
    struct queue *q = arg;
    uint64_t start = rdtsc();
    int cnt = 0;

    while (!quit) {
        struct msg *m = pop(q);
        if (m) {
            cnt++;
            msg_flags[(m - msgs)] = 1;
        }
        //delay(2000);
    }

    pop_cycles += rdtsc() - start;
    __sync_fetch_and_add(&pop_total, cnt);

    return NULL;
}

static void *
pop_flush_task(void *arg)
{
    struct queue *q = arg;
    uint64_t start = rdtsc();

    while (!quit) {
        struct msg *m = pop(q);
        if (m) {
            __sync_fetch_and_add(&pop_total, 1);
            msg_flags[(m - msgs)] = 1;
        }
        if (pop_total == MSG_CNT)
            quit = 1;
    }

    pop_cycles += rdtsc() - start;

    return NULL;
}

static volatile int push_msg_idx = 0;

static void *
push_task(void *arg)
{
    struct queue *q = arg;
    uint64_t start = rdtsc();
    int i;

    for (i = 0; i < MSG_CNT / PUSH_CNT; i++) {
        int idx = __sync_fetch_and_add(&push_msg_idx, 1);
        while (push(q, msgs + idx) == -1);
    }

    push_cycles += rdtsc() - start;
    __sync_fetch_and_add(&push_total,  MSG_CNT / PUSH_CNT);
    if (push_total == MSG_CNT)
        quit = 1;

    return NULL;
}

/* topology for Xeon E5-2670 Sandybridge */
static const int socket_top[] = {
    1,  2,  3,  4,  5,  6,  7,
    16, 17, 18, 19, 20, 21, 22, 23,
    8,  9,  10, 11, 12, 13, 14, 15,
    24, 25, 26, 27, 28, 29, 30, 31
};

#define CORE_ID(i)      socket_top[(i)]


static int
start_thread(int id,
             void *(*cb)(void *),
             void *arg,
             pthread_t *tid)
{
    pthread_t kid;
    pthread_attr_t attr;
    cpu_set_t cpuset;
    int core_id;

    if (id < 0 || id >= sizeof(socket_top) / sizeof(int))
        return -1;


    if (pthread_attr_init(&attr))
        return -1;

    CPU_ZERO(&cpuset);
    core_id = CORE_ID(id);
    CPU_SET(core_id, &cpuset);

    if (pthread_create(&kid, &attr, cb, arg))
        return -1;
    if (pthread_setaffinity_np(kid, sizeof(cpu_set_t), &cpuset))
        return -1;

    if (tid)
        *tid = kid;

    return 0;
}

static int
setaffinity(int core_id)
{
    cpu_set_t cpuset;
    pthread_t me = pthread_self();

    CPU_ZERO(&cpuset);
    CPU_SET(core_id, &cpuset);

    if (pthread_setaffinity_np(me, sizeof(cpu_set_t), &cpuset))
        return -1;

    return 0;
}

int
main(void)
{
    struct queue *q = qinit();
    int i;
    pthread_t kids[POP_CNT + PUSH_CNT];

    setaffinity(0);

    msgs = calloc(MSG_CNT, sizeof(struct msg));
    msg_flags = calloc(MSG_CNT, sizeof(int));

    for (i = 0; i < POP_CNT; i++)
        start_thread(i, pop_task, q, &kids[i]);
    for (; i < POP_CNT + PUSH_CNT; i++)
        start_thread(i, push_task, q, &kids[i]);
    for (i = 0; i < POP_CNT + PUSH_CNT; i++)
        pthread_join(kids[i], NULL);

    quit = 0;

    if (pop_total < MSG_CNT) {
        printf("flushing: %d\n", MSG_CNT - pop_total);
        for (i = 0; i < POP_CNT; i++)
            start_thread(i, pop_flush_task, q, &kids[i]);
        for (i = 0; i < POP_CNT; i++)
            pthread_join(kids[i], NULL);
    }

    printf("pop total: %d\n", pop_total);
    printf("pop cycles/msg: %lu\n", pop_cycles / pop_total);
    printf("push cycles/msg: %lu\n", push_cycles / MSG_CNT);
    printf("push idx: %d\n", push_msg_idx);

    /* sanity test */
    int miss = 0;
    for (i = 0; i < MSG_CNT; i++) {
        if (msg_flags[i] != 1) {
            miss++;
        }
    }
    printf("total %d miss\n", miss);

    return 0;
}