Function parentProcess

cpp/3_CUDA_Features/memMapIPCDrv/memMapIpc.cpp:434–612

}

static void parentProcess(char *app)
{
    int                  devCount, i, nprocesses = 0;
    volatile shmStruct  *shm = NULL;
    sharedMemoryInfo     info;
    std::vector<Process> processes;
    char                 pidString[20] = {0};
    char                 lshmName[40]  = {0};

    // Use current process ID to create a unique shared memory name for Linux multi-process
#ifdef __linux__
    pid_t pid;
    pid = getpid();
    snprintf(pidString, sizeof(pidString), "%d", pid);
#endif
    strcat(lshmName, shmName);
    strcat(lshmName, pidString);

    printf("PP: lshmName = %s\n", lshmName);

    checkCudaErrors(cuDeviceGetCount(&devCount));
    std::vector<CUdevice> devices(devCount);

    if (sharedMemoryCreate(lshmName, sizeof(*shm), &info) != 0) {
        printf("Failed to create shared memory slab\n");
        exit(EXIT_FAILURE);
    }

    shm = (volatile shmStruct *)info.addr;
    memset((void *)shm, 0, sizeof(*shm));

    for (i = 0; i < devCount; i++) {
        checkCudaErrors(cuDeviceGet(&devices[i], i));
    }

    std::vector<CUcontext>     ctxs;
    std::vector<unsigned char> selectedDevices;

    // Pick all the devices that can access each other's memory for this test
    // Keep in mind that CUDA has minimal support for fork() without a
    // corresponding exec() in the child process, but in this case our
    // spawnProcess will always exec, so no need to worry.
    for (i = 0; i < devCount; i++) {
        bool allPeers = true;
        int  deviceComputeMode;
        int  deviceSupportsIpcHandle;
        int  attributeVal = 0;

        checkCudaErrors(cuDeviceGet(&devices[i], i));
        checkCudaErrors(cuDeviceGetAttribute(&deviceComputeMode, CU_DEVICE_ATTRIBUTE_COMPUTE_MODE, devices[i]));
        checkCudaErrors(
            cuDeviceGetAttribute(&attributeVal, CU_DEVICE_ATTRIBUTE_VIRTUAL_ADDRESS_MANAGEMENT_SUPPORTED, devices[i]));
#if defined(__linux__) || defined(__QNX__)
        checkCudaErrors(cuDeviceGetAttribute(
            &deviceSupportsIpcHandle, CU_DEVICE_ATTRIBUTE_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR_SUPPORTED, devices[i]));
#else
        checkCudaErrors(cuDeviceGetAttribute(
            &deviceSupportsIpcHandle, CU_DEVICE_ATTRIBUTE_HANDLE_TYPE_WIN32_HANDLE_SUPPORTED, devices[i]));