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50 lines
1.8 KiB
50 lines
1.8 KiB
#ifndef PRIORITY_QUEUE_H
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#define PRIORITY_QUEUE_H
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#include "lock.h"
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#include "runtime.h"
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#include "worker_thread.h"
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#define MAX 4096
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/**
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* How to get the priority out of the generic element
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* We assume priority is expressed as an unsigned 64-bit integer (i.e. cycles or
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* UNIX time in ms). This is used to maintain a read replica of the highest
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* priority element that can be used to maintain a read replica
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* @param element
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* @returns priority (a uint64_t)
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*/
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typedef uint64_t (*priority_queue_get_priority_fn_t)(void *element);
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/* We assume that priority is expressed in terms of a 64 bit unsigned integral */
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struct priority_queue {
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lock_t lock;
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uint64_t highest_priority;
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void * items[MAX];
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int first_free;
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priority_queue_get_priority_fn_t get_priority_fn;
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};
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/**
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* Checks if a priority queue is empty
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* @param self the priority queue to check
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* @returns true if empty, else otherwise
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*/
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static inline bool
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priority_queue_is_empty(struct priority_queue *self)
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{
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return self->highest_priority == ULONG_MAX;
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}
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void priority_queue_initialize(struct priority_queue *self, priority_queue_get_priority_fn_t get_priority_fn);
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int priority_queue_enqueue(struct priority_queue *self, void *value);
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int priority_queue_dequeue(struct priority_queue *self, void **dequeued_element);
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int priority_queue_dequeue_if_earlier(struct priority_queue *self, void **dequeued_element, uint64_t target_deadline);
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int priority_queue_length(struct priority_queue *self);
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uint64_t priority_queue_peek(struct priority_queue *self);
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int priority_queue_delete(struct priority_queue *self, void *value);
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int priority_queue_top(struct priority_queue *self, void **dequeued_element);
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#endif /* PRIORITY_QUEUE_H */
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