StarPU Handbook

Data Structures | Macros | Functions | Variables
Out Of Core

## Data Structures
struct | starpu_disk_ops

## Macros
#define | STARPU_DISK_SIZE_MIN

## Functions
void | starpu_disk_close (unsigned node, void *obj, size_t size)
void * | starpu_disk_open (unsigned node, void *pos, size_t size)
int | starpu_disk_register (struct starpu_disk_ops *func, void *parameter, starpu_ssize_t size)

## Variables
struct starpu_disk_ops | starpu_disk_stdio_ops
struct starpu_disk_ops | starpu_disk_hdf5_ops
struct starpu_disk_ops | starpu_disk_unistd_ops
struct starpu_disk_ops | starpu_disk_unistd_o_direct_ops
struct starpu_disk_ops | starpu_disk_leveldb_ops
int | starpu_disk_swap_node

## Detailed Description

## Data Structure Documentation

## ◆ starpu_disk_ops

struct starpu_disk_ops

Set of functions to manipulate datas on disk.

### Data Fields
void *(* | plug )(void *parameter, starpu_ssize_t size)
void(* | unplug )(void *base)
int(* | bandwidth )(unsigned node, void *base)
void *(* | alloc )(void *base, size_t size)
void(* | free )(void *base, void *obj, size_t size)
void *(* | open )(void *base, void *pos, size_t size)
void(* | close )(void *base, void *obj, size_t size)
int(* | read )(void *base, void *obj, void *buf, off_t offset, size_t size)
int(* | write )(void *base, void *obj, const void *buf, off_t offset, size_t size)
int(* | full_read )(void *base, void *obj, void **ptr, size_t *size, unsigned dst_node)
int(* | full_write )(void *base, void *obj, void *ptr, size_t size)
void *(* | async_write )(void *base, void *obj, void *buf, off_t offset, size_t size)
void *(* | async_read )(void *base, void *obj, void *buf, off_t offset, size_t size)
void *(* | async_full_read )(void *base, void *obj, void **ptr, size_t *size, unsigned dst_node)
void *(* | async_full_write )(void *base, void *obj, void *ptr, size_t size)
void *(* | copy )(void *base_src, void *obj_src, off_t offset_src, void *base_dst, void *obj_dst, off_t offset_dst, size_t size)
void(* | wait_request )(void *async_channel)
int(* | test_request )(void *async_channel)
void(* | free_request )(void *async_channel)

#### Field Documentation

## ◆ plug

void *(* starpu_disk_ops::plug) (void *parameter, starpu_ssize_t size)

Connect a disk memory at location `parameter` with size `size`, and return a base as void*, which will be passed by StarPU to all other methods.

## ◆ unplug

void(* starpu_disk_ops::unplug) (void *base)

Disconnect a disk memory `base`.

## ◆ bandwidth

int(* starpu_disk_ops::bandwidth) (unsigned node, void *base)

Measure the bandwidth and the latency for the disk `node` and save it. Returns 1 if it could measure it.

## ◆ alloc

void *(* starpu_disk_ops::alloc) (void *base, size_t size)

Create a new location for datas of size `size`. Return an opaque object pointer.

## ◆ free

void(* starpu_disk_ops::free) (void *base, void *obj, size_t size)

Free a data `obj` previously allocated with starpu_disk_ops::alloc.

## ◆ open

void *(* starpu_disk_ops::open) (void *base, void *pos, size_t size)

Open an existing location of datas, at a specific position `pos` dependent on the backend.

## ◆ close

void(* starpu_disk_ops::close) (void *base, void *obj, size_t size)

Close, without deleting it, a location of datas `obj`.

## ◆ read

int(* starpu_disk_ops::read) (void *base, void *obj, void *buf, off_t offset, size_t size)

Read `size` bytes of data from `obj` in `base`, at offset `offset`, and put into `buf`. Return the actual number of read bytes.

## ◆ write

int(* starpu_disk_ops::write) (void *base, void *obj, const void *buf, off_t offset, size_t size)

Write `size` bytes of data to `obj` in `base`, at offset `offset`, from `buf`. Return 0 on success.

## ◆ full_read

int(* starpu_disk_ops::full_read) (void *base, void *obj, void **ptr, size_t *size, unsigned dst_node)

Read all data from `obj` of `base`, from offset 0. Returns it in an allocated buffer `ptr`, of size `size`

## ◆ full_write

int(* starpu_disk_ops::full_write) (void *base, void *obj, void *ptr, size_t size)

Write data in `ptr` to `obj` of `base`, from offset 0, and truncate `obj` to `size`, so that a `full_read` will get it.

## ◆ async_write

void *(* starpu_disk_ops::async_write) (void *base, void *obj, void *buf, off_t offset, size_t size)

Asynchronously write `size` bytes of data to `obj` in `base`, at offset `offset`, from `buf`. Return a void* pointer that StarPU will pass to `xxx_request` methods for testing for the completion.

## ◆ async_read

void *(* starpu_disk_ops::async_read) (void *base, void *obj, void *buf, off_t offset, size_t size)

Asynchronously read `size` bytes of data from `obj` in `base`, at offset `offset`, and put into `buf`. Return a void* pointer that StarPU will pass to `xxx_request` methods for testing for the completion.

## ◆ async_full_read

void *(* starpu_disk_ops::async_full_read) (void *base, void *obj, void **ptr, size_t *size, unsigned dst_node)

Read all data from `obj` of `base`, from offset 0. Return it in an allocated buffer `ptr`, of size `size`

## ◆ async_full_write

void *(* starpu_disk_ops::async_full_write) (void *base, void *obj, void *ptr, size_t size)

Write data in `ptr` to `obj` of `base`, from offset 0, and truncate `obj` to `size`, so that a starpu_disk_ops::full_read will get it.

## ◆ copy

void *(* starpu_disk_ops::copy) (void *base_src, void *obj_src, off_t offset_src, void *base_dst, void *obj_dst, off_t offset_dst, size_t size)

Copy from offset `offset_src` of disk object `obj_src` in `base_src` to offset `offset_dst` of disk object `obj_dst` in `base_dst`. Return a void* pointer that StarPU will pass to `xxx_request` methods for testing for the completion.

## ◆ wait_request

void(* starpu_disk_ops::wait_request) (void *async_channel)

Wait for completion of request `async_channel` returned by a previous asynchronous read, write or copy.

## ◆ test_request

int(* starpu_disk_ops::test_request) (void *async_channel)

Test for completion of request `async_channel` returned by a previous asynchronous read, write or copy. Return 1 on completion, 0 otherwise.

## ◆ free_request

void(* starpu_disk_ops::free_request) (void *async_channel)

Free the request allocated by a previous asynchronous read, write or copy.

## Macro Definition Documentation

## ◆ STARPU_DISK_SIZE_MIN

#define STARPU_DISK_SIZE_MIN

Minimum size of a registered disk. The size of a disk is the last parameter of the function starpu_disk_register().

## Function Documentation

## ◆ starpu_disk_close()

void starpu_disk_close | ( | unsigned | node,
|  | void * | obj,
|  | size_t | size
| ) |  |

Close an existing data opened with starpu_disk_open().

## ◆ starpu_disk_open()

void * starpu_disk_open | ( | unsigned | node,
|  | void * | pos,
|  | size_t | size
| ) |  |

Open an existing file memory in a disk node. `size` is the size of the file. `pos` is the specific position dependent on the backend, given to the `open` method of the disk operations. Return an opaque object pointer.

## ◆ starpu_disk_register()

int starpu_disk_register | ( | struct starpu_disk_ops * | func,
|  | void * | parameter,
|  | starpu_ssize_t | size
| ) |  |

Register a disk memory node with a set of functions to manipulate datas. The `plug` member of `func` will be passed `parameter`, and return a `base` which will be passed to all `func` methods.
SUCCESS: return the disk node.
FAIL: return an error code.
`size` must be at least STARPU_DISK_SIZE_MIN bytes ! `size` being negative means infinite size.

## Variable Documentation

## ◆ starpu_disk_stdio_ops

struct starpu_disk_ops starpu_disk_stdio_ops
| extern

Use the stdio library (fwrite, fread...) to read/write on disk.

Warning: It creates one file per allocation !

Do not support asynchronous transfers.

## ◆ starpu_disk_hdf5_ops

struct starpu_disk_ops starpu_disk_hdf5_ops
| extern

Use the HDF5 library.

It doesn't support multiple opening from different processes.

You may only allow one process to write in the HDF5 file.

If HDF5 library is not compiled with –thread-safe you can't open more than one HDF5 file at the same time.

## ◆ starpu_disk_unistd_ops

struct starpu_disk_ops starpu_disk_unistd_ops
| extern

Use the unistd library (write, read...) to read/write on disk.

Warning: It creates one file per allocation !

## ◆ starpu_disk_unistd_o_direct_ops

struct starpu_disk_ops starpu_disk_unistd_o_direct_ops
| extern

Use the unistd library (write, read...) to read/write on disk with the O_DIRECT flag.

Warning: It creates one file per allocation !

Only available on Linux systems.

## ◆ starpu_disk_leveldb_ops

struct starpu_disk_ops starpu_disk_leveldb_ops
| extern

Use the leveldb created by Google. More information at https://code.google.com/p/leveldb/ Do not support asynchronous transfers.

## ◆ starpu_disk_swap_node

int starpu_disk_swap_node
| extern

Contain the node number of the disk swap, if set up through the STARPU_DISK_SWAP variable.