ncGraphAllocate()

Info	Value
Header	mvnc.h
Library	libmvnc.so
Version	2.0
See also	struct ncGraphHandle_t, ncGraphCreate(), ncGraphDestroy(), ncGraphAllocateWithFifos(), ncGraphAllocateWithFifosEx()

Overview

This function allocates a network graph to the specified device. Each graph can only be allocated to a single device.

Upon successful return from this function, the graph will be ready to perform inferences.

ncGraphDestroy() frees the memory allocated with this function.

Prototype

ncStatus_t ncGraphAllocate(struct ncDeviceHandle_t *deviceHandle,
                           struct ncGraphHandle_t *graphHandle,
                           const void *graphBuffer, unsigned int graphBufferLength);

Parameters

Name	Type	Description
deviceHandle	struct ncDeviceHandle_t*	A pointer to an initialized and opened ncDeviceHandle_t struct for the device to which the graph will be allocated. The device state must be NC_DEVICE_OPENED.
graphHandle	struct ncGraphHandle_t*	A pointer to an initialized ncGraphHandle_t struct for the graph that will be allocated. The graph state must be NC_GRAPH_CREATED.
graphBuffer	const void*	A pointer to a buffer that contains raw data read from a neural network graph file that was created with the NCSDK mvNCCompile tool.
graphBufferLength	unsigned int	The size, in bytes, of the buffer allocated to the graphBuffer parameter.

Return

An appropriate value from the ncStatus_t enumeration.

Notes

The initialized ncGraphHandle_t struct must be passed to this function or ncGraphAllocateWithFifos()/ncGraphAllocateWithFifosEx() before it can be passed to any API function other than ncGraphGetOption() or ncGraphSetOption(). When the graph has been allocated, the graph state will be NC_GRAPH_ALLOCATED.
ncGraphAllocateWithFifos() or ncGraphAllocateWithFifosEx() can be used to easily initialize and allocate an input and an output FIFO in addition to allocating a graph to a device; these internally call ncFifoCreate() and ncFifoAllocate() for both ncFifoHandle_t structs and ncGraphAllocate() for the graph.

Example

#include <stdio.h>
#include <stdlib.h>
#include <mvnc.h>

int main(int argc, char** argv)
{
    ncStatus_t retCode;
    struct ncDeviceHandle_t* deviceHandlePtr;
    struct ncGraphHandle_t* graphHandlePtr;
    
    ncDeviceCreate(0, &deviceHandlePtr);
    ncDeviceOpen(deviceHandlePtr);
    ncGraphCreate("My Graph", &graphHandlePtr);
    
    unsigned int graphSizeInBytes = 0;
    void* graphInMemoryPtr = LoadGraphFile("./graph", &graphSizeInBytes);

    retCode = ncGraphAllocate(deviceHandlePtr, graphHandlePtr, graphInMemoryPtr, graphSizeInBytes);
    if (retCode != NC_OK)
    {   
        // Could not allocate graph 
        printf("Error allocating graph [%d]\n", retCode);
    }
    else
    {
        // Graph is allocated and can be used for inference now.
        printf("Graph allocated OK!\n");
    }

    // clean up the graph and device
    ncGraphDestroy(&graphHandlePtr);
    ncDeviceClose(deviceHandlePtr);
    ncDeviceDestroy(&deviceHandlePtr);
}