Function whileBlockedCron

app/redis-6.2.6/src/server.c:2298–2340

This function fill in the role of serverCron during RDB or AOF loading, and * also during blocked scripts. * It attempts to do its duties at a similar rate as the configured server.hz, * and updates cronloops variable so that similarly to serverCron, the * run_with_period can be used. */

 * and updates cronloops variable so that similarly to serverCron, the
 * run_with_period can be used. */
void whileBlockedCron() {
    /* Here we may want to perform some cron jobs (normally done server.hz times
     * per second). */

    /* Since this function depends on a call to blockingOperationStarts, let's
     * make sure it was done. */
    serverAssert(server.blocked_last_cron);

    /* In case we where called too soon, leave right away. This way one time
     * jobs after the loop below don't need an if. and we don't bother to start
     * latency monitor if this function is called too often. */
    if (server.blocked_last_cron >= server.mstime)
        return;

    mstime_t latency;
    latencyStartMonitor(latency);

    /* In some cases we may be called with big intervals, so we may need to do
     * extra work here. This is because some of the functions in serverCron rely
     * on the fact that it is performed every 10 ms or so. For instance, if
     * activeDefragCycle needs to utilize 25% cpu, it will utilize 2.5ms, so we
     * need to call it multiple times. */
    long hz_ms = 1000/server.hz;
    while (server.blocked_last_cron < server.mstime) {

        /* Defrag keys gradually. */
        activeDefragCycle();

        server.blocked_last_cron += hz_ms;

        /* Increment cronloop so that run_with_period works. */
        server.cronloops++;
    }

    /* Other cron jobs do not need to be done in a loop. No need to check
     * server.blocked_last_cron since we have an early exit at the top. */

    /* Update memory stats during loading (excluding blocked scripts) */
    if (server.loading) cronUpdateMemoryStats();

    latencyEndMonitor(latency);
    latencyAddSampleIfNeeded("while-blocked-cron",latency);
}

extern int ProcessingEventsWhileBlocked;