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Diffstat (limited to 'libhw_generic/include/libhw/generic/alarmclock.h')
| -rw-r--r-- | libhw_generic/include/libhw/generic/alarmclock.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/libhw_generic/include/libhw/generic/alarmclock.h b/libhw_generic/include/libhw/generic/alarmclock.h new file mode 100644 index 0000000..02789f5 --- /dev/null +++ b/libhw_generic/include/libhw/generic/alarmclock.h @@ -0,0 +1,92 @@ +/* libhw/generic/alarmclock.h - Device-independent alarmclock definitions + * + * Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com> + * SPDX-License-Identifier: AGPL-3.0-or-later + */ + +#ifndef _LIBHW_GENERIC_ALARMCLOCK_H_ +#define _LIBHW_GENERIC_ALARMCLOCK_H_ + +#include <stdbool.h> /* for bool */ +#include <stdint.h> /* for uint{n}_t and UINT{n}_C */ + +#include <libmisc/private.h> +#include <libobj/obj.h> + +/* Useful constants ***********************************************************/ + +#define NS_PER_S UINT64_C(1000000000) /* needs at least log₂(10⁹) ≈ 29.9 bits */ +#define US_PER_S UINT64_C(1000000) /* needs at least log₂(10⁶) ≈ 19.9 bits */ +#define MS_PER_S UINT64_C(1000) /* needs at least log₂(10³) ≈ 9.9 bits */ + +/* Structs ********************************************************************/ + +struct alarmclock_trigger; +struct alarmclock_trigger { + BEGIN_PRIVATE(LIBHW_GENERIC_ALARMCLOCK_H); + void *alarmclock; + struct alarmclock_trigger *prev, *next; + + uint64_t fire_at_ns; + void (*cb)(void *); + void *cb_arg; + END_PRIVATE(LIBHW_GENERIC_ALARMCLOCK_H); +}; + +/* Interface ******************************************************************/ + +#define alarmclock_LO_IFACE \ + /** \ + * (2⁶⁴-1 nanoseconds is more than 500 years; there is little \ + * risk of this overflowing) \ + */ \ + LO_FUNC(uint64_t, get_time_ns) \ + \ + /** \ + * Returns true on error. \ + * \ + * Implementations may return an error if fire_at_ns is more \ + * than UINT32_MAX µs (72 minutes) in the future. \ + * \ + * If fire_at_ns is in the past, then it will fire \ + * immediately. \ + */ \ + LO_FUNC(bool, add_trigger, struct alarmclock_trigger *trigger, \ + uint64_t fire_at_ns, \ + void (*cb)(void *), \ + void *cb_arg) \ + \ + LO_FUNC(void, del_trigger, struct alarmclock_trigger *trigger) +LO_INTERFACE(alarmclock); + +/* Utilities ******************************************************************/ + +void alarmclock_sleep_until_ns(lo_interface alarmclock clock, uint64_t abstime_ns); + +static inline void alarmclock_sleep_for_ns(lo_interface alarmclock clock, uint64_t delta_ns) { + alarmclock_sleep_until_ns(clock, LO_CALL(clock, get_time_ns) + delta_ns); +} + +static inline void alarmclock_sleep_for_us(lo_interface alarmclock clock, uint64_t delta_us) { + alarmclock_sleep_for_ns(clock, delta_us * (NS_PER_S/US_PER_S)); +} + +static inline void alarmclock_sleep_for_ms(lo_interface alarmclock clock, uint64_t delta_ms) { + alarmclock_sleep_for_ns(clock, delta_ms * (NS_PER_S/MS_PER_S)); +} + +static inline void alarmclock_sleep_for_s(lo_interface alarmclock clock, uint64_t delta_s) { + alarmclock_sleep_for_ns(clock, delta_s * NS_PER_S); +} + +/* Globals ********************************************************************/ + +extern lo_interface alarmclock bootclock; + +#define sleep_until_ns(t) alarmclock_sleep_until_ns(bootclock, t) +#define sleep_for_ns(t) alarmclock_sleep_for_ns(bootclock, t) +#define sleep_for_us(t) alarmclock_sleep_for_us(bootclock, t) +#define sleep_for_ms(t) alarmclock_sleep_for_ms(bootclock, t) +#define sleep_for_s(t) alarmclock_sleep_for_s(bootclock, t) + +#endif /* _LIBHW_GENERIC_ALARMCLOCK_H_ */ |