#include <stdlib.h>
#include "SynchronizedMailManager.h"

void
SynchronizedMailManager::calc_mask(unsigned int qsize)
{
    mask = 1;
    while(qsize>mask) {
	mask <<= 1;
    }
    size = mask;
    mask--;
}

SynchronizedMailManager::SynchronizedMailManager(unsigned int qsize) {
    read = write = 0;
    calc_mask(qsize);
    queue = Newq(memaddr,size);

    queue_remain  = new Sem(size-1);			//queue内に入る残りの数
    queue_count	= new Sem(0);				//queue内に現在入っている数

}

SynchronizedMailManager::~SynchronizedMailManager()
{
    free(queue);
    delete queue_remain;
    delete queue_count;
}

int 
SynchronizedMailManager::count()
{
    return queue_count->count();
}

void 
SynchronizedMailManager::send(memaddr data)
{
    queue_remain->sem_p();	//資源-1

    queue[write++] = data;
    //maskの範囲を超えた場合、0に戻す
    write &= mask;

    queue_count->sem_v();		//資源+1
}

memaddr 
SynchronizedMailManager::recv()
{
    queue_count->sem_p();		//資源-1
        
    memaddr data;
    data = queue[read++];
    read &= mask;

    queue_remain->sem_v();	//資源+1

    return data;
}

/* end */