cuda.bindings._v2.driver.ipc_open_mem_handle_v2#

cuda.bindings._v2.driver.ipc_open_mem_handle_v2(handle, unsigned int flags) → uint64_t#

Opens an interprocess memory handle exported from another process and returns a device pointer usable in the local process.

Maps memory exported from another process with cuIpcGetMemHandle into the current device address space. For contexts on different devices cuIpcOpenMemHandle can attempt to enable peer access between the devices as if the user called cuCtxEnablePeerAccess. This behavior is controlled by the CU_IPC_MEM_LAZY_ENABLE_PEER_ACCESS flag. cuDeviceCanAccessPeer can determine if a mapping is possible. Contexts that may open CUipcMemHandles are restricted in the following way. CUipcMemHandles from each CUdevice in a given process may only be opened by one CUcontext per CUdevice per other process. If the memory handle has already been opened by the current context, the reference count on the handle is incremented by 1 and the existing device pointer is returned. Memory returned from cuIpcOpenMemHandle must be freed with cuIpcCloseMemHandle. Calling cuMemFree on an exported memory region before calling cuIpcCloseMemHandle in the importing context will result in undefined behavior. IPC functionality is restricted to devices with support for unified addressing on Linux and Windows operating systems. IPC functionality on Windows is supported for compatibility purposes but not recommended as it comes with performance cost. Users can test their device for IPC functionality by calling cuapiDeviceGetAttribute with CU_DEVICE_ATTRIBUTE_IPC_EVENT_SUPPORTED.

Parameters:

handle (CUipcMemHandle_v1) – CUipcMemHandle to open.
flags (unsigned int) – flags for this operation. Must be specified as CU_IPC_MEM_LAZY_ENABLE_PEER_ACCESS.

Returns:

Returned device pointer.

Return type:

uint64_t

Note

No guarantees are made about the address returned in *pdptr. In particular, multiple processes may not receive the same address for the same handle.