misc/adsb-tools
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Switch out custom wakeup system for timerfd.

Browse Source
This commit is contained in:
Ian Gulliver
2016-03-08 21:53:57 -08:00
parent 3985182304
commit b915f38dca
4 changed files with 41 additions and 60 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
adsbus/wakeup.c
View File

@@ -1,83 +1,69 @@
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <time.h>
#include <sys/timerfd.h>
#include <unistd.h>
#include "peer.h"
#include "rand.h"
#include "wakeup.h"
struct wakeup_entry {
int fd;
uint64_t absolute_time_ms;
struct peer *peer;
struct wakeup {
struct peer peer;
struct peer *inner_peer;
struct list_head wakeup_list;
};
static struct list_head wakeup_head = LIST_HEAD_INIT(wakeup_head);
static uint64_t wakeup_get_time_ms() {
struct timespec tp;
assert(!clock_gettime(CLOCK_MONOTONIC_COARSE, &tp));
#define MS_PER_S UINT64_C(1000)
#define NS_PER_MS UINT64_C(1000000)
assert(tp.tv_sec >= 0);
assert(tp.tv_nsec >= 0);
return ((uint64_t) tp.tv_sec * MS_PER_S) + ((uint64_t) tp.tv_nsec / NS_PER_MS);
static void wakeup_handler(struct peer *peer) {
struct wakeup *wakeup = container_of(peer, struct wakeup, peer);
uint64_t events;
assert(read(wakeup->peer.fd, &events, sizeof(events)) == sizeof(events));
assert(events == 1);
peer_close(&wakeup->peer);
peer_call(wakeup->inner_peer);
list_del(&wakeup->wakeup_list);
free(wakeup);
}
void wakeup_init() {
}
void wakeup_cleanup() {
struct wakeup_entry *iter, *next;
struct wakeup *iter, *next;
list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
free(iter);
}
}
int wakeup_get_delay() {
if (list_is_empty(&wakeup_head)) {
return -1;
}
uint64_t now = wakeup_get_time_ms();
struct wakeup_entry *next_to_fire = list_entry(wakeup_head.next, struct wakeup_entry, wakeup_list);
if (next_to_fire->absolute_time_ms > now) {
uint64_t delta = next_to_fire->absolute_time_ms - now;
assert(delta < INT_MAX);
return (int) delta;
} else {
return 0;
}
}
void wakeup_dispatch() {
uint64_t now = wakeup_get_time_ms();
struct wakeup_entry *iter, *next;
list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
if (iter->absolute_time_ms > now) {
break;
}
peer_call(iter->peer);
list_del(&iter->wakeup_list);
free(iter);
}
}
void wakeup_add(struct peer *peer, uint32_t delay_ms) {
struct wakeup_entry *entry = malloc(sizeof(*entry));
entry->absolute_time_ms = wakeup_get_time_ms() + delay_ms;
entry->peer = peer;
struct wakeup *wakeup = malloc(sizeof(*wakeup));
wakeup->inner_peer = peer;
list_add(&wakeup->wakeup_list, &wakeup_head);
struct wakeup_entry *iter, *next;
list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
if (iter->absolute_time_ms > entry->absolute_time_ms) {
list_add(&entry->wakeup_list, &iter->wakeup_list);
return;
}
}
list_add(&entry->wakeup_list, &wakeup_head);
wakeup->peer.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
assert(wakeup->peer.fd >= 0);
#define MS_PER_S UINT64_C(1000)
#define NS_PER_MS UINT64_C(1000000)
const struct itimerspec ts = {
.it_interval = {
.tv_sec = 0,
.tv_nsec = 0,
},
.it_value = {
.tv_sec = delay_ms / MS_PER_S,
.tv_nsec = (delay_ms % MS_PER_S) * NS_PER_MS,
},
};
assert(!timerfd_settime(wakeup->peer.fd, 0, &ts, NULL));
wakeup->peer.event_handler = wakeup_handler;
peer_epoll_add(&wakeup->peer, EPOLLIN);
}
#define RETRY_MIN_MS 2000