git/git

#include "git-compat-util.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"
#include "trace2/tr2_ctr.h"

/*
 * A global counter block to aggregrate values from the partial sums
 * from each thread.
 */
static struct tr2_counter_block final_counter_block; /* access under tr2tls_mutex */

/*
 * Define metadata for each global counter.
 *
 * This array must match the "enum trace2_counter_id" and the values
 * in "struct tr2_counter_block.counter[*]".
 */
static struct tr2_counter_metadata tr2_counter_metadata[TRACE2_NUMBER_OF_COUNTERS] = {
    [TRACE2_COUNTER_ID_TEST1] = {
        .category = "test",
        .name = "test1",
        .want_per_thread_events = 0,
    },
    [TRACE2_COUNTER_ID_TEST2] = {
        .category = "test",
        .name = "test2",
        .want_per_thread_events = 1,
    },
    [TRACE2_COUNTER_ID_PACKED_REFS_JUMPS] = {
        .category = "packed-refs",
        .name = "jumps_made",
        .want_per_thread_events = 0,
    },
    [TRACE2_COUNTER_ID_FSYNC_WRITEOUT_ONLY] = {
        .category = "fsync",
        .name = "writeout-only",
        .want_per_thread_events = 0,
    },
    [TRACE2_COUNTER_ID_FSYNC_HARDWARE_FLUSH] = {
        .category = "fsync",
        .name = "hardware-flush",
        .want_per_thread_events = 0,
    },

    /* Add additional metadata before here. */
};

void tr2_counter_increment(enum trace2_counter_id cid, uint64_t value)
{
    struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
    struct tr2_counter *c = &ctx->counter_block.counter[cid];

    c->value += value;

    ctx->used_any_counter = 1;
    if (tr2_counter_metadata[cid].want_per_thread_events)
        ctx->used_any_per_thread_counter = 1;
}

void tr2_update_final_counters(void)
{
    struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
    enum trace2_counter_id cid;

    if (!ctx->used_any_counter)
        return;

    /*
     * Access `final_counter_block` requires holding `tr2tls_mutex`.
     * We assume that our caller is holding the lock.
     */

    for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++) {
        struct tr2_counter *c_final = &final_counter_block.counter[cid];
        const struct tr2_counter *c = &ctx->counter_block.counter[cid];

        c_final->value += c->value;
    }
}

void tr2_emit_per_thread_counters(tr2_tgt_evt_counter_t *fn_apply)
{
    struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
    enum trace2_counter_id cid;

    if (!ctx->used_any_per_thread_counter)
        return;

    /*
     * For each counter, if the counter wants per-thread events
     * and this thread used it (the value is non-zero), emit it.
     */
    for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++)
        if (tr2_counter_metadata[cid].want_per_thread_events &&
            ctx->counter_block.counter[cid].value)
            fn_apply(&tr2_counter_metadata[cid],
                 &ctx->counter_block.counter[cid],
                 0);
}

void tr2_emit_final_counters(tr2_tgt_evt_counter_t *fn_apply)
{
    enum trace2_counter_id cid;

    /*
     * Access `final_counter_block` requires holding `tr2tls_mutex`.
     * We assume that our caller is holding the lock.
     */

    for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++)
        if (final_counter_block.counter[cid].value)
            fn_apply(&tr2_counter_metadata[cid],
                 &final_counter_block.counter[cid],
                 1);
}