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39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
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#pragma once
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#include "arch.h" // For size_t
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#include "config.h" // For MG_ENABLE_ATOMIC
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#if MG_ENABLE_ATOMIC
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#include <stdatomic.h>
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#elif !defined(_Atomic)
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#define _Atomic
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#endif
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// Single producer, single consumer non-blocking queue
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//
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// Producer:
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// void *buf;
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// while (mg_queue_space(q, &buf) < len) WAIT(); // Wait for free space
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// memcpy(buf, data, len); // Copy data to the queue
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// mg_queue_add(q, len); // Advance q->head
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//
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// Consumer:
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// void *buf;
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// while ((len = mg_queue_next(q, &buf)) == MG_QUEUE_EMPTY) WAIT();
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// mg_hexdump(buf, len); // Handle message
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// mg_queue_del(q); // Delete message
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//
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struct mg_queue {
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char *buf;
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size_t len;
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volatile _Atomic size_t tail;
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volatile _Atomic size_t head;
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};
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#define MG_QUEUE_EMPTY ((size_t) ~0ul) // Next message size when queue is empty
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void mg_queue_add(struct mg_queue *, size_t len); // Advance head
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void mg_queue_del(struct mg_queue *); // Advance tail
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size_t mg_queue_space(struct mg_queue *, char **); // Get free space
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size_t mg_queue_next(struct mg_queue *, char **); // Get next message size
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