monitor: Simplify event throttling

The event throttling state machine is hard to understand.  I'm not
sure it's entirely correct.  Rewrite it in a more straightforward
manner:

State 1: No event sent recently (less than evconf->rate ns ago)

    Invariant: evstate->timer is not pending, evstate->qdict is null

    On event: send event, arm timer, goto state 2

State 2: Event sent recently, no additional event being delayed

    Invariant: evstate->timer is pending, evstate->qdict is null

    On event: store it in evstate->qdict, goto state 3

    On timer: goto state 1

State 3: Event sent recently, additional event being delayed

    Invariant: evstate->timer is pending, evstate->qdict is non-null

    On event: store it in evstate->qdict, goto state 3

    On timer: send evstate->qdict, clear evstate->qdict,
              arm timer, goto state 2

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1444921716-9511-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Markus Armbruster
2015-10-15 17:08:31 +02:00
parent 688b4b7de7
commit 93f8f982fe
2 changed files with 32 additions and 35 deletions

View File

@ -1031,9 +1031,9 @@ esp_pci_sbac_write(uint32_t reg, uint32_t val) "sbac: 0x%8.8x -> 0x%8.8x"
# monitor.c
handle_qmp_command(void *mon, const char *cmd_name) "mon %p cmd_name \"%s\""
monitor_protocol_emitter(void *mon) "mon %p"
monitor_protocol_event_handler(uint32_t event, void *data, uint64_t last, uint64_t now) "event=%d data=%p last=%" PRId64 " now=%" PRId64
monitor_protocol_event_handler(uint32_t event, void *qdict) "event=%d data=%p"
monitor_protocol_event_emit(uint32_t event, void *data) "event=%d data=%p"
monitor_protocol_event_queue(uint32_t event, void *data, uint64_t rate, uint64_t last, uint64_t now) "event=%d data=%p rate=%" PRId64 " last=%" PRId64 " now=%" PRId64
monitor_protocol_event_queue(uint32_t event, void *qdict, uint64_t rate) "event=%d data=%p rate=%" PRId64
monitor_protocol_event_throttle(uint32_t event, uint64_t rate) "event=%d rate=%" PRId64
# hw/net/opencores_eth.c