time.h¶

Defines

EMB_TICK_NS¶

EMB_TIMEOUT_MAX_TICKS¶

EMB_DURATION_(x)¶

EMB_TIMEOUT_(x)¶

EMB_INSTANT_(x)¶

EMB_NS_TO_TICKS(n)¶

EMB_US_TO_TICKS(n)¶

EMB_MS_TO_TICKS(n)¶

EMB_SEC_TO_TICKS(n)¶

EMB_TICKS(n)¶

EMB_NS(n)¶

EMB_US(n)¶

EMB_MS(n)¶

EMB_SEC(n)¶

EMB_NO_WAIT¶

EMB_WAIT_FOREVER¶

EMB_TIMEOUT(d)¶

EMB_TIMEOUT_IS_FOREVER(t)¶

EMB_TIMEOUT_IS_NO_WAIT(t)¶

EMB_DURATION_IS_ZERO(d)¶

Typedefs

typedef struct emb_instant emb_instant_t¶

typedef struct emb_duration emb_duration_t¶

typedef struct emb_timeout emb_timeout_t¶

Functions

static inline uint64_t emb_mul_sat_u64(uint64_t a, uint64_t b)¶

emb_mul_sat_u64() - Multiply unsigned values with saturation.

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-023 Since: 0.2 Stability: yes

Return: a * b, or UINT64_MAX when the mathematical product overflows. This conversion helper is also used by the public duration macros.

Parameters:

a – First unsigned factor.
b – Second unsigned factor.

static inline emb_tick_t emb_ns_to_ticks(uint64_t ns)¶

emb_ns_to_ticks() - Convert nanoseconds to ticks, rounding up.

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-023 KRN-TIM-007 Since: 0.2 Stability: yes

Return: ceil(ns / CONFIG_EMB_TICK_NS), saturated to EMB_TICK_MAX. The addition needed for rounding is itself checked for overflow.

Parameters:

ns – Unsigned nanosecond duration; zero converts to zero.

emb_instant_t emb_time_now(void)¶

emb_time_now() - Read the kernel monotonic clock.

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: KRN-TIM-001 KRN-TIM-032 Since: 0.2 Stability: yes

Return: the current instant; zero before kernel start, wrapping with the configured tick width. Use emb_instant_before() for 32-bit ordering.

emb_timeout_t emb_timeout_from_duration(emb_duration_t d)¶

emb_timeout_from_duration() - A timeout that waits at most d

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-023 KRN-TIM-022 Since: 0.2 Stability: yes

Parameters:

d – The duration; saturates to EMB_TIMEOUT_MAX_TICKS so a finite wait never reads as EMB_WAIT_FOREVER (SPEC-001 §7.3, SPEC-003 §5.2).

emb_instant_t emb_instant_add(emb_instant_t t, emb_duration_t d)¶

emb_instant_add()

- Add a duration to a kernel-clock instant.

Saturates at EMB_TICK_MAX in the 64-bit profile; wraps in the 32-bit profile, whose instant space is circular (SPEC-003 §5.2).

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-022 API-023 KRN-TIM-022 Since: 0.2 Stability: yes

Parameters:

t – Kernel-clock instant to advance.
d – Duration to add; scheduling comparisons still require the 32-bit half-range window.

emb_duration_t emb_instant_sub(emb_instant_t later, emb_instant_t earlier)¶

emb_instant_sub() - later minus earlier, zero when later is not after earlier

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-022 KRN-TIM-003 Since: 0.2 Stability: yes

Parameters:

later – Candidate later instant, within the 32-bit comparison window if applicable.
earlier – Reference instant on the same kernel clock.

bool emb_instant_before(emb_instant_t a, emb_instant_t b)¶

emb_instant_before() - Is a before b

? Wrap-safe in the 32-bit profile.

Context: thread isr prekernel Blocking: no Timing: O(1) Ownership: none Configuration: Requirements: API-022 KRN-TIM-003 KRN-TIM-022 Since: 0.2 Stability: yes

Parameters: