tomato-testing/toxcore/mono_time.h
Green Sky a3126d581b Squashed 'external/toxcore/c-toxcore/' changes from 67badf694..82460b212
82460b212 feat: add ngc events
24b54722a fix: Ensure we have allocators available for the error paths.
48dbcfebc cleanup: Remove redundant `-DSODIUM_EXPORT` from definitions.
0cef46ee9 cleanup: Fix a few more clang-tidy warnings.
0c5b918e9 cleanup: Fix a few more clang-tidy warnings.
4d3c97f49 cleanup: Enforce stricter identifier naming using clang-tidy.
a549807df refactor: Add `mem` module to allow tests to override allocators.
6133fb153 chore: Add devcontainer setup for codespaces.
620e07ecd chore: Set a timeout for tests started using Conan
c0ec33b16 chore: Migrate Windows CI from Appveyor to Azure DevOps
8ed47f3ef fix incorrect documentation
a1e245841 docs: Fix doxygen config and remove some redundant comments.
b0f633185 chore: Fix the Android CI job
7469a529b fix: Add missing `#include <array>`.
2b1a6b0d2 add missing ngc constants getter declarations and definitions
2e02d5637 chore: Add missing module dependencies.
REVERT: 67badf694 feat: add ngc events

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 82460b2124216af1ac9d63060de310a682a2fd15
2023-10-10 19:37:39 +02:00

98 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2016-2020 The TokTok team.
* Copyright © 2014 Tox project.
*/
#ifndef C_TOXCORE_TOXCORE_MONO_TIME_H
#define C_TOXCORE_TOXCORE_MONO_TIME_H
#include <stdbool.h>
#include <stdint.h>
#include "attributes.h"
#include "mem.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* The timer portion of the toxcore event loop.
*
* We update the time exactly once per tox_iterate call. Programs built on lower
* level APIs such as the DHT bootstrap node must update the time manually in
* each iteration.
*
* Time is kept per Tox instance, not globally, even though "time" as a concept
* is global. This is because by definition `mono_time` represents the time at
* the start of an iteration, and also by definition the time when all network
* events for the current iteration occurred. This affects mainly two situations:
*
* 1. Two timers started in the same iteration: e.g. two timers set to expire in
* 10 seconds will both expire at the same time, i.e. about 10 seconds later.
* If the time were global, `mono_time` would be a random number that is
* either the time at the start of an iteration, or 1 second later (since the
* timer resolution is 1 second). This can happen when one update happens at
* e.g. 10:00:00.995 and a few milliseconds later a concurrently running
* instance updates the time at 10:00:01.005, making one timer expire a
* second after the other.
* 2. One timer based on an event: if we want to encode a behaviour of a timer
* expiring e.g. 10 seconds after a network event occurred, we simply start a
* timer in the event handler. If a concurrent instance updates the time
* underneath us, it may instead expire 9 seconds after the event.
*
* Both these situations cause incorrect behaviour randomly. In practice,
* toxcore is somewhat robust against strange timer behaviour, but the
* implementation should at least theoretically match the specification.
*/
typedef struct Mono_Time Mono_Time;
typedef uint64_t mono_time_current_time_cb(void *user_data);
non_null(1) nullable(2, 3)
Mono_Time *mono_time_new(const Memory *mem, mono_time_current_time_cb *current_time_callback, void *user_data);
non_null(1) nullable(2)
void mono_time_free(const Memory *mem, Mono_Time *mono_time);
/**
* Update mono_time; subsequent calls to mono_time_get or mono_time_is_timeout
* will use the time at the call to mono_time_update.
*/
non_null()
void mono_time_update(Mono_Time *mono_time);
/**
* Return unix time since epoch in seconds.
*/
non_null()
uint64_t mono_time_get(const Mono_Time *mono_time);
/**
* Return true iff timestamp is at least timeout seconds in the past.
*/
non_null()
bool mono_time_is_timeout(const Mono_Time *mono_time, uint64_t timestamp, uint64_t timeout);
/**
* Return current monotonic time in milliseconds (ms). The starting point is
* unspecified.
*/
non_null()
uint64_t current_time_monotonic(Mono_Time *mono_time);
/**
* Override implementation of `current_time_monotonic()` (for tests).
*
* The caller is obligated to ensure that `current_time_monotonic()` continues
* to increase monotonically.
*/
non_null(1) nullable(2, 3)
void mono_time_set_current_time_callback(Mono_Time *mono_time,
mono_time_current_time_cb *current_time_callback, void *user_data);
#ifdef __cplusplus
}
#endif
#endif // C_TOXCORE_TOXCORE_MONO_TIME_H