C++ shm_lock函数代码示例

void shm_event_raise(long used, long size, long perc)
{
	evi_params_p list = 0;

	*event_shm_pending = 1;
	*event_shm_last = perc;

	// event has to be triggered - check for subscribers
	if (!evi_probe_event(EVI_SHM_THRESHOLD_ID)) {
		goto end;
	}

	if (!(list = evi_get_params()))
		goto end;
	if (evi_param_add_int(list, &shm_usage_str, (int *)&perc)) {
		LM_ERR("unable to add usage parameter\n");
		goto end;
	}
	if (evi_param_add_int(list, &shm_threshold_str, (int *)&event_shm_threshold)) {
		LM_ERR("unable to add threshold parameter\n");
		goto end;
	}
	if (evi_param_add_int(list, &shm_used_str, (int *)&used)) {
		LM_ERR("unable to add used parameter\n");
		goto end;
	}
	if (evi_param_add_int(list, &shm_size_str, (int *)&size)) {
		LM_ERR("unable to add size parameter\n");
		goto end;
	}

	/*
	 * event has to be raised without the lock otherwise a deadlock will be
	 * generated by the transport modules, or by the event_route processing
	 */
#ifdef HP_MALLOC
	shm_unlock(0);
#else
	shm_unlock();
#endif

	if (evi_raise_event(EVI_SHM_THRESHOLD_ID, list)) {
		LM_ERR("unable to send shm threshold event\n");
	}

#ifdef HP_MALLOC
	shm_lock(0);
#else
	shm_lock();
#endif

	list = 0;
end:
	if (list)
		evi_free_params(list);
	*event_shm_pending = 0;
}

void qm_shm_info(void* qmp, struct mem_info* info)
{
	shm_lock();
	qm_info(qmp, info);
	shm_unlock();

}

bool
SHMSrc::resize_area()
{
    while ((sizeof(SHMHeader) + shm_area_->buffer_size) > shm_area_len_) {
        size_t new_size = sizeof(SHMHeader) + shm_area_->buffer_size;

        shm_unlock();
        if (munmap(shm_area_, shm_area_len_)) {
            std::cerr << "Could not unmap shared area" << std::endl;
            perror(strerror(errno));
            return false;
        }

        shm_area_ = static_cast<SHMHeader*>(mmap(NULL, new_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_, 0));
        shm_area_len_ = new_size;

        if (!shm_area_) {
            shm_area_ = 0;
            std::cerr << "Could not remap shared area" << std::endl;
            return false;
        }

        shm_area_len_ = new_size;
        shm_lock();
    }
    return true;
}

bool SHMSink::resize_area(size_t desired_length)
{
    if (desired_length <= shm_area_len_)
        return true;

    shm_unlock();

    if (munmap(shm_area_, shm_area_len_)) {
        ERROR("Could not unmap shared area");
        strErr();
        return false;
    }

    if (ftruncate(fd_, desired_length)) {
        ERROR("Could not resize shared area");
        strErr();
        return false;
    }

    shm_area_ = static_cast<SHMHeader*>(mmap(NULL, desired_length, PROT_READ | PROT_WRITE, MAP_SHARED, fd_, 0));
    shm_area_len_ = desired_length;

    if (shm_area_ == MAP_FAILED) {
        shm_area_ = 0;
        ERROR("Could not remap shared area");
        return false;
    }

    shm_lock();
    return true;
}

void qm_shm_free(void* qmp, void* p, const char* file, const char* func,
				unsigned int line)
{
	shm_lock();
	qm_free(qmp, p, file, func, line);
	shm_unlock();
}

int shm_callback(int mode, struct kern_ipc_perm *ipc, struct ipc_namespace *ns)
{
    switch(mode) {
    
        case 0:
            printf("key        shmid      owner      perms      bytes      nattch     status \n");
            break;
        case 1:
            if(id==-1 || id==ipc->id) {
                struct shmid_kernel *shp = shm_lock(ns, ipc->id);
                printf("0x%08x %-10d %-10d %-10o %-10ld %-10ld %-6s %-6s\n",
                ipc->key,
                ipc->id,
                ipc->uid,
                ipc->mode & 0777,
                shp->shm_segsz,
                shp->shm_nattch,
                ipc->mode & SHM_DEST ? "dest" : " ",
                ipc->mode & SHM_LOCKED ? "locked" : " ");
            }
        break;
        case 2:
        break;
    }
    return 1;
}

unsigned long shm_available_safe()
{
	unsigned long ret;
	shm_lock();
	ret = shm_available();
	shm_unlock();
	return ret;
}

void* qm_shm_realloc(void* qmp, void* p, unsigned long size)
{
	void *r;
	shm_lock();
	r = qm_realloc(qmp, p, size);
	shm_unlock();
	return r;
}

unsigned long qm_shm_available(void* qmp)
{
	unsigned long r;
	shm_lock();
	r = qm_available(qmp);
	shm_unlock();
	return r;
}

inline static void* sh_realloc(void* p, unsigned int size)
{
	void *r;
	shm_lock(); 
	shm_free_unsafe(p);
	r=shm_malloc_unsafe(size);
	shm_unlock();
	return r;
}

void* qm_shm_resize(void* qmp, void* p, unsigned long size)
{
	void *r;
	shm_lock();
	if(p) qm_free(qmp, p);
	r = qm_malloc(qmp, size);
	shm_unlock();
	return r;
}

static inline void shm_inc (int id) {
	struct shmid_kernel *shp;

	if(!(shp = shm_lock(id)))
		BUG();
	shp->shm_atim = CURRENT_TIME;
	shp->shm_lprid = current->pid;
	shp->shm_nattch++;
	shm_unlock(id);
}

static inline void shm_inc (int id) {
	struct shmid_kernel *shp;

	if(!(shp = shm_lock(id)))
		BUG();
	shp->shm_atim = get_seconds();
	shp->shm_lprid = current->tgid;
	shp->shm_nattch++;
	shm_unlock(shp);
}

void SHMSrc::render(char *dest, size_t len)
{
    shm_lock();

    while (buffer_gen_ == shm_area_->buffer_gen) {
        shm_unlock();
        std::cerr << "Waiting for next buffer" << std::endl;;
        sem_wait(&shm_area_->notification);

        shm_lock();
    }

    if (!resize_area())
        return;

    std::cerr << "Reading from buffer!" << std::endl;
    memcpy(dest, shm_area_->data, len);
    buffer_gen_ = shm_area_->buffer_gen;
    shm_unlock();
}

/* append a newly received tag from a 200/INVITE to
 * transaction's set; (only safe if called from within
 * a REPLY_LOCK); it returns 1 if such a to tag already
 * exists
 */
inline static int update_totag_set(struct cell *t, struct sip_msg *ok)
{
	struct totag_elem *i, *n;
	str *tag;
	char *s;

	if (!ok->to || !ok->to->parsed) {
		LM_ERR("to not parsed\n");
		return 0;
	}
	tag=&get_to(ok)->tag_value;
	if (!tag->s) {
		LM_DBG("no tag in to\n");
		return 0;
	}

	for (i=t->fwded_totags; i; i=i->next) {
		if (i->tag.len==tag->len
				&& memcmp(i->tag.s, tag->s, tag->len) ==0 ){
			/* to tag already recorded */
#ifdef XL_DEBUG
			LM_CRIT("totag retransmission\n");
#else
			LM_DBG("totag retransmission\n");
#endif
			return 1;
		}
	}
	/* that's a new to-tag -- record it */
#ifndef HP_MALLOC
	shm_lock();
	n=(struct totag_elem*) shm_malloc_unsafe(sizeof(struct totag_elem));
	s=(char *)shm_malloc_unsafe(tag->len);
	shm_unlock();
#else
	n=(struct totag_elem*) shm_malloc(sizeof(struct totag_elem));
	s=(char *)shm_malloc(tag->len);
#endif
	if (!s || !n) {
		LM_ERR("no more share memory \n");
		if (n) shm_free(n);
		if (s) shm_free(s);
		return 0;
	}
	memset(n, 0, sizeof(struct totag_elem));
	memcpy(s, tag->s, tag->len );
	n->tag.s=s;n->tag.len=tag->len;
	n->next=t->fwded_totags;
	t->fwded_totags=n;
	LM_DBG("new totag \n");
	return 0;
}