[ofa-general] Re: [PATCH V2 - libibverbs] Added reference count tocompletion event channels

[Tang, Changqing]

Since you changed the size of structure 'struct ibv_cq', does that mean
code
compiled with OFED 1.1 can not work with OFED 1.2 ?


--CQ 

> -----Original Message-----
> From: general-bounces at lists.openfabrics.org 
> [mailto:general-bounces at lists.openfabrics.org] On Behalf Of 
> Roland Dreier
> Sent: Monday, March 26, 2007 5:17 PM
> To: Dotan Barak
> Cc: openib-general
> Subject: [ofa-general] Re: [PATCH V2 - libibverbs] Added 
> reference count tocompletion event channels
> 
> OK, I got bored and tried to implement this using a mutex in 
> the ibv_context structure.  How does this (compile tested 
> only) patch look?
> 
>  - R.
> 
> 
> diff --git a/include/infiniband/verbs.h 
> b/include/infiniband/verbs.h index 2ae50ab..acc1b82 100644
> --- a/include/infiniband/verbs.h
> +++ b/include/infiniband/verbs.h
> @@ -573,11 +573,14 @@ struct ibv_qp {
>  };
>  
>  struct ibv_comp_channel {
> +	struct ibv_context     *context;
>  	int			fd;
> +	int			refcnt;
>  };
>  
>  struct ibv_cq {
>  	struct ibv_context     *context;
> +	struct ibv_comp_channel *channel;
>  	void		       *cq_context;
>  	uint32_t		handle;
>  	int			cqe;
> @@ -680,12 +683,13 @@ struct ibv_context_ops {  };
>  
>  struct ibv_context {
> -	struct ibv_device         *device;
> -	struct ibv_context_ops	   ops;
> -	int                        cmd_fd;
> -	int                        async_fd;
> -	int                        num_comp_vectors;
> -	void			  *abi_compat;
> +	struct ibv_device      *device;
> +	struct ibv_context_ops	ops;
> +	int			cmd_fd;
> +	int			async_fd;
> +	int			num_comp_vectors;
> +	pthread_mutex_t		mutex;
> +	void		       *abi_compat;
>  };
>  
>  /**
> diff --git a/src/cmd.c b/src/cmd.c
> index f7d3fde..a0bfaad 100644
> --- a/src/cmd.c
> +++ b/src/cmd.c
> @@ -75,7 +75,9 @@ static int ibv_cmd_get_context_v2(struct 
> ibv_context *context,
>  
>  	context->async_fd         = resp->async_fd;
>  	context->num_comp_vectors = 1;
> +	t->channel.context        = context;
>  	t->channel.fd		  = cq_fd;
> +	t->channel.refcnt	  = 0;
>  	context->abi_compat       = t;
>  
>  	return 0;
> diff --git a/src/device.c b/src/device.c index bca1ce9..3abc1eb 100644
> --- a/src/device.c
> +++ b/src/device.c
> @@ -138,6 +138,7 @@ struct ibv_context 
> *__ibv_open_device(struct ibv_device *device)
>  
>  	context->device = device;
>  	context->cmd_fd = cmd_fd;
> +	pthread_mutex_init(&context->mutex, NULL);
>  
>  	return context;
>  
> diff --git a/src/verbs.c b/src/verbs.c
> index 56513e4..5334af1 100644
> --- a/src/verbs.c
> +++ b/src/verbs.c
> @@ -226,7 +226,9 @@ struct ibv_comp_channel 
> *ibv_create_comp_channel(struct ibv_context *context)
>  		return NULL;
>  	}
>  
> -	channel->fd = resp.fd;
> +	channel->context = context;
> +	channel->fd      = resp.fd;
> +	channel->refcnt  = 0;
>  
>  	return channel;
>  }
> @@ -240,23 +242,44 @@ static int 
> ibv_destroy_comp_channel_v2(struct ibv_comp_channel *channel)
>  
>  int ibv_destroy_comp_channel(struct ibv_comp_channel *channel)  {
> -	if (abi_ver <= 2)
> -		return ibv_destroy_comp_channel_v2(channel);
> +	int ret;
> +
> +	pthread_mutex_lock(&channel->context->mutex);
> +
> +	if (channel->refcnt) {
> +		ret = EBUSY;
> +		goto out;
> +	}
> +
> +	if (abi_ver <= 2) {
> +		ret = ibv_destroy_comp_channel_v2(channel);
> +		goto out;
> +	}
>  
>  	close(channel->fd);
>  	free(channel);
> +	ret = 0;
>  
> -	return 0;
> +out:
> +	pthread_mutex_unlock(&channel->context->mutex);
> +
> +	return ret;
>  }
>  
>  struct ibv_cq *__ibv_create_cq(struct ibv_context *context, 
> int cqe, void *cq_context,
>  			       struct ibv_comp_channel 
> *channel, int comp_vector)  {
> -	struct ibv_cq *cq = context->ops.create_cq(context, 
> cqe, channel,
> -						   comp_vector);
> +	struct ibv_cq *cq;
> +
> +	pthread_mutex_lock(&context->mutex);
> +
> +	cq = context->ops.create_cq(context, cqe, channel, comp_vector);
>  
>  	if (cq) {
>  		cq->context    	     	   = context;
> +		cq->channel		   = channel;
> +		if (channel)
> +			++channel->refcnt;
>  		cq->cq_context 	     	   = cq_context;
>  		cq->comp_events_completed  = 0;
>  		cq->async_events_completed = 0;
> @@ -264,6 +287,8 @@ struct ibv_cq *__ibv_create_cq(struct 
> ibv_context *context, int cqe, void *cq_co
>  		pthread_cond_init(&cq->cond, NULL);
>  	}
>  
> +	pthread_mutex_unlock(&context->mutex);
> +
>  	return cq;
>  }
>  default_symver(__ibv_create_cq, ibv_create_cq); @@ -279,7 
> +304,17 @@ default_symver(__ibv_resize_cq, ibv_resize_cq);
>  
>  int __ibv_destroy_cq(struct ibv_cq *cq)  {
> -	return cq->context->ops.destroy_cq(cq);
> +	int ret;
> +
> +	pthread_mutex_lock(&cq->context->mutex);
> +
> +	ret = cq->context->ops.destroy_cq(cq);
> +	if (cq->channel && !ret)
> +		--cq->channel->refcnt;
> +
> +	pthread_mutex_unlock(&cq->context->mutex);
> +
> +	return ret;
>  }
>  default_symver(__ibv_destroy_cq, ibv_destroy_cq);
>  
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