Function: ipc_mem_import_by_key

Applicable Products

Product	Supported (√/x)
Ascend 950PR/Ascend 950DT	√
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas training products	√
Atlas inference products	√
Atlas 200I/500 A2 inference products	x

Description

Obtains the key information in the current process and returns the device memory address pointer that can be used by the current process. This API must work with other APIs to implement memory sharing. For details, see the description of Function: ipc_mem_get_export_key.

Prototype

C Prototype

aclError aclrtIpcMemImportByKey(void **devPtr, const char *key, uint64_t flag)

Python Function

dev_ptr, ret = acl.rt.ipc_mem_import_by_key(key, flags)

Parameters

Parameter	Description
key	Str, shared memory key.
flags	Whether to enable data exchange between two devices. The value can be either of the following macros: ACL_RT_IPC_MEM_IMPORT_FLAG_DEFAULT: Default value, which disables data exchange between two devices. If this value is used, you need to call the acl.rt.device_enable_peer_access API to enable data interaction between two devices. ACL_RT_IPC_MEM_IMPORT_FLAG_ENABLE_PEER_ACCESS: Enables data exchange between two devices. If this macro is used, you do not need to call the acl.rt.device_enable_peer_access API. The macros are defined as follows: #define ACL_RT_IPC_MEM_IMPORT_FLAG_DEFAULT 0x0UL #define ACL_RT_IPC_MEM_IMPORT_FLAG_ENABLE_PEER_ACCESS 0x1UL

Parameter

Description

key

Str, shared memory key.

flags

Whether to enable data exchange between two devices.

The value can be either of the following macros:

ACL_RT_IPC_MEM_IMPORT_FLAG_DEFAULT: Default value, which disables data exchange between two devices.
If this value is used, you need to call the acl.rt.device_enable_peer_access API to enable data interaction between two devices.
ACL_RT_IPC_MEM_IMPORT_FLAG_ENABLE_PEER_ACCESS: Enables data exchange between two devices.
If this macro is used, you do not need to call the acl.rt.device_enable_peer_access API.

The macros are defined as follows:

#define ACL_RT_IPC_MEM_IMPORT_FLAG_DEFAULT            0x0UL
#define ACL_RT_IPC_MEM_IMPORT_FLAG_ENABLE_PEER_ACCESS 0x1UL

Return Values

Return Value	Description
dev_ptr	Int, pointer to the device memory address.
ret	Int, error code. 0 on success; else, failure.

Parent topic: Memory Sharing Between IPC Processes