RecvOperation

Applicable Products

Hardware Model	Supported
Atlas 350 accelerator cards	x
Atlas A3 inference products / Atlas A3 training products	√
Atlas A2 training products / Atlas A2 inference products	√
Atlas training products	x
Atlas inference products	x
Atlas 200I/500 A2 inference products	x

Description

Receives data from a specified communication card. Send and Recv must be used together.

Figure 1 Send and Recv data transmission and receiving

Definition

      
           struct RecvParam {
    int rank = 0;
    int rankSize = 0;
    int rankRoot = 0;
    uint32_t srcRank = 1;
    std::string backend = "hccl";
    HcclComm hcclComm = nullptr;
    CommMode commMode = COMM_MULTI_PROCESS;
    std::string rankTableFile;
    std::string commDomain;
    uint8_t rsv[64] = {0};
};

Parameters

Member	Type	Default Value	Description
rank	int	0	Rank of the current device within the communicator.
rankSize	int	0	Number of devices.
rankRoot	int	0	Root rank for the operation.
srcRank	uint32_t	1	ID of the destination rank
backend	std::string	hccl	Communication backend indication. Only hccl is supported.
hcclComm	HcclComm	nullptr	Pointer to the HCCL communicator. By default, this parameter is left blank. The ATB is created by users. If the user wants to manage the communicator, the communicator pointer needs to be passed. The ATB uses the passed communicator pointer to execute the communication operator.
commMode	CommMode	COMM_MULTI_PROCESS	Communication mode. For details, see CommMode. In the scenario where hccl multi-thread is applied, a communicator can only be imported externally.
rankTableFile	std::string	-	Path of the configuration file for cluster information, which applies to single-node and multi-node communication. Currently, only the HCCL backend is supported. If a rank table is configured for a single-node system, the rank table is used to initialize the communicator.
commDomain	std::string	-	Communicator name used by a communication device group when there are multiple communicators. Currently, only hccl is supported.
rsv[64]	uint8_t	{0}	Reserved

Input

Parameter	Dimension	Data Type	Format	Description
x	[d0, ..., dn]	"hccl": float16/float/int8/int16/int32/int64/bf16	ND	Input tensor

Output

Parameter	Dimension	Data Type	Format	Description
output	[d0, ..., dn]	"hccl": float16/float/int8/int16/int32/int64/bf16	ND	Output tensor with the same dimensions as the input.

Constraints

rank, rankSize, and rankRoot must meet the following conditions:
- 0 ≤ rank < rankSize
- 0 ≤ rankRoot < rankSize
- 0 ≤ srcRank < rankSize

If there are multiple users, ATB_SHARE_MEMORY_NAME_SUFFIX (see ATB Environment Variables) needs to be used to distinguish the shared memory and synchronize initialization information.
When the communication operator of the ATB exits abnormally, run the following commands to clear the residual data to avoid affecting subsequent operations.
```
rm -rf /dev/shm/sem.lccl*
rm -rf /dev/shm/sem.hccl*
ipcrm -a
```

Parent topic: atb/infer_op_params.h