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40 lines
1.5 KiB
C
40 lines
1.5 KiB
C
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#ifndef NSYNC_COUNTER_H_
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#define NSYNC_COUNTER_H_
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#include "third_party/nsync/atomic.h"
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#include "third_party/nsync/time.h"
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COSMOPOLITAN_C_START_
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/* An nsync_counter represents an unsigned integer that can count up and down,
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and wake waiters when zero. */
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typedef struct nsync_counter_s_ *nsync_counter;
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/* Return a freshly allocated nsync_counter with the specified value,
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of NULL if an nsync_counter cannot be created.
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Any non-NULL returned value should be passed to nsync_counter_free() when no
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longer needed. */
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nsync_counter nsync_counter_new(uint32_t value);
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/* Free resources associated with c. Requires that c was allocated by
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nsync_counter_new(), and no concurrent or future operations are applied to
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c. */
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void nsync_counter_free(nsync_counter c);
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/* Add delta to c, and return its new value. It is a checkable runtime error
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to decrement c below 0, or to increment c (i.e., apply a delta > 0) after a
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waiter has waited. */
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uint32_t nsync_counter_add(nsync_counter c, int32_t delta);
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/* Return the current value of c. */
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uint32_t nsync_counter_value(nsync_counter c);
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/* Wait until c has value 0, or until abs_deadline, then return
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the value of c. It is a checkable runtime error to increment c after
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a waiter may have been woken due to the counter reaching zero.
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If abs_deadline==nsync_time_no_deadline, the deadline
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is far in the future. */
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uint32_t nsync_counter_wait(nsync_counter c, nsync_time abs_deadline);
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COSMOPOLITAN_C_END_
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#endif /* NSYNC_COUNTER_H_ */
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