#pragma once
// ke_queue.h - fixed-depth message queue
// Processes share an address space, so a pointer in Param[] is valid
// on both sides. The queue is only a synchronisation and ordering tool.
#include <stdint.h>
#include <stdbool.h>
#include <ob_object.h>
#include <ke_spinlock.h>
#include <ke_list.h>
#include <ke_status.h>

#define QUEUE_MESSAGE_SIZE   64     /* bytes, fixed */
#define QUEUE_DEPTH          256

typedef struct QUEUE_MESSAGE {
    uint32_t Type;
    uint32_t Flags;
    uint64_t Param[6];      /* 48 bytes of payload */
} QUEUE_MESSAGE;            /* total: 64 bytes     */

typedef struct QUEUE {
    OBJECT          Header;
    SPINLOCK        Lock;
    QUEUE_MESSAGE   Ring[QUEUE_DEPTH];
    uint32_t        Head, Tail, Count;
    LIST_ENTRY      SendWaiters;
    LIST_ENTRY      RecvWaiters;
} QUEUE;

KSTATUS KeQueueCreate(QUEUE **out);
KSTATUS KeSendMessage(QUEUE* queue, const QUEUE_MESSAGE* msg, bool blocking);
KSTATUS KeReceiveMessage(QUEUE* queue, QUEUE_MESSAGE* msg, bool blocking);