java.lang.Object
- org.lwjgl.system.Pointer.Default
- - org.lwjgl.system.Struct
  - - org.lwjgl.system.linux.liburing.IOURingParams

All Implemented Interfaces:

java.lang.AutoCloseable, org.lwjgl.system.NativeResource, org.lwjgl.system.Pointer
```
public class IOURingParams
extends org.lwjgl.system.Struct
implements org.lwjgl.system.NativeResource
```
Passed in for setup. Copied back with updated info on success.
The flags, sq_thread_cpu, and sq_thread_idle fields are used to configure the io_uring instance. If no flags are specified, the io_uring instance is setup for interrupt driven I/O. I/O may be submitted using enter and can be reaped by polling the completion queue.

The rest of the fields are filled in by the kernel, and provide the information necessary to memory map the submission queue, completion queue, and the array of submission queue entries.

sq_off describes the offsets of various ring buffer fields. Taken together, sq_entries and sq_off provide all of the information necessary for accessing the submission queue ring buffer and the submission queue entry array. The submission queue can be mapped with a call like:
```
 ptr = mmap(0, sq_off.array + sq_entries * sizeof(__u32),
            PROT_READ|PROT_WRITE, MAP_SHARED|MAP_POPULATE,
            ring_fd, IORING_OFF_SQ_RING);
```
where sq_off is the io_sqring_offsets structure, and ring_fd is the file descriptor returned from setup. The addition of sq_off.array to the length of the region accounts for the fact that the ring located at the end of the data structure. As an example, the ring buffer head pointer can be accessed by adding sq_off.head to the address returned from mmap(2):
```
 head = ptr + sq_off.head;
```
The array of submission queue entries is mapped with:
```
 sqentries = mmap(0, sq_entries * sizeof(struct io_uring_sqe),
                  PROT_READ|PROT_WRITE, MAP_SHARED|MAP_POPULATE,
                  ring_fd, IORING_OFF_SQES);
```
The completion queue is described by cq_entries and cq_off. The completion queue is simpler, since the entries are not separated from the queue itself, and can be mapped with:
```
 ptr = mmap(0, cq_off.cqes + cq_entries * sizeof(struct io_uring_cqe),        
            PROT_READ|PROT_WRITE, MAP_SHARED|MAP_POPULATE, ring_fd,
            IORING_OFF_CQ_RING);
```
Layout
```
 struct io_uring_params {
     __u32 sq_entries();
     __u32 cq_entries;
     __u32 flags();
     __u32 sq_thread_cpu;
     __u32 sq_thread_idle;
     __u32 features();
     __u32 wq_fd;
     __u32 resv[3];
     struct io_sqring_offsets sq_off();
     struct io_cqring_offsets cq_off;
 }
```

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class IOURingParams.Buffer
An array of IOURingParams structs.
- Nested classes/interfaces inherited from interface org.lwjgl.system.Pointer
  org.lwjgl.system.Pointer.Default
- Nested classes/interfaces inherited from class org.lwjgl.system.Struct
  org.lwjgl.system.Struct.StructValidation

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`ALIGNOF`	The struct alignment in bytes.
`static int`	`CQ_ENTRIES CQ_OFF FEATURES FLAGS RESV`	The struct member offsets.
`static int`	`SIZEOF`	The struct size in bytes.
`static int`	`SQ_ENTRIES SQ_OFF SQ_THREAD_CPU SQ_THREAD_IDLE WQ_FD`	The struct member offsets.

Fields inherited from interface org.lwjgl.system.Pointer
BITS32, BITS64, CLONG_SHIFT, CLONG_SIZE, POINTER_SHIFT, POINTER_SIZE

Constructor Summary

Constructors
Constructor Description

IOURingParams(java.nio.ByteBuffer container)
Creates a IOURingParams instance at the current position of the specified ByteBuffer container.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static IOURingParams`	`calloc()`	Returns a new `IOURingParams` instance allocated with `memCalloc`.
`static IOURingParams.Buffer`	`calloc(int capacity)`	Returns a new `IOURingParams.Buffer` instance allocated with `memCalloc`.
`static IOURingParams.Buffer`	`calloc(int capacity, org.lwjgl.system.MemoryStack stack)`	Returns a new `IOURingParams.Buffer` instance allocated on the specified `MemoryStack` and initializes all its bits to zero.
`static IOURingParams`	`calloc(org.lwjgl.system.MemoryStack stack)`	Returns a new `IOURingParams` instance allocated on the specified `MemoryStack` and initializes all its bits to zero.
`int`	`cq_entries()`
`IOURingParams`	`cq_entries(int value)`	Sets the specified value to the `cq_entries` field.
`IOCQRingOffsets`	`cq_off()`
`IOURingParams`	`cq_off(java.util.function.Consumer<IOCQRingOffsets> consumer)`	Passes the `cq_off` field to the specified `Consumer`.
`IOURingParams`	`cq_off(IOCQRingOffsets value)`	Copies the specified `IOCQRingOffsets` to the `cq_off` field.
`static IOURingParams`	`create()`	Returns a new `IOURingParams` instance allocated with `BufferUtils`.
`static IOURingParams.Buffer`	`create(int capacity)`	Returns a new `IOURingParams.Buffer` instance allocated with `BufferUtils`.
`static IOURingParams`	`create(long address)`	Returns a new `IOURingParams` instance for the specified memory address.
`static IOURingParams.Buffer`	`create(long address, int capacity)`	Create a `IOURingParams.Buffer` instance at the specified memory.
`static IOURingParams`	`createSafe(long address)`	Like `create`, but returns `null` if `address` is `NULL`.
`static IOURingParams.Buffer`	`createSafe(long address, int capacity)`	Like `create`, but returns `null` if `address` is `NULL`.
`int`	`features()`	filled in by the kernel, which specifies various features supported by current kernel version.
`IOURingParams`	`features(int value)`	Sets the specified value to the `features()` field.
`int`	`flags()`	one or more of: `SETUP_IOPOLLSETUP_SQPOLLSETUP_SQ_AFFSETUP_CQSIZESETUP_CLAMPSETUP_ATTACH_WQSETUP_R_DISABLED`
`IOURingParams`	`flags(int value)`	Sets the specified value to the `flags()` field.
`static IOURingParams`	`malloc()`	Returns a new `IOURingParams` instance allocated with `memAlloc`.
`static IOURingParams.Buffer`	`malloc(int capacity)`	Returns a new `IOURingParams.Buffer` instance allocated with `memAlloc`.
`static IOURingParams.Buffer`	`malloc(int capacity, org.lwjgl.system.MemoryStack stack)`	Returns a new `IOURingParams.Buffer` instance allocated on the specified `MemoryStack`.
`static IOURingParams`	`malloc(org.lwjgl.system.MemoryStack stack)`	Returns a new `IOURingParams` instance allocated on the specified `MemoryStack`.
`static int`	`ncq_entries(long struct)`	Unsafe version of `cq_entries()`.
`static void`	`ncq_entries(long struct, int value)`	Unsafe version of `cq_entries`.
`static IOCQRingOffsets`	`ncq_off(long struct)`	Unsafe version of `cq_off()`.
`static void`	`ncq_off(long struct, IOCQRingOffsets value)`	Unsafe version of `cq_off`.
`static int`	`nfeatures(long struct)`	Unsafe version of `features()`.
`static void`	`nfeatures(long struct, int value)`	Unsafe version of `features`.
`static int`	`nflags(long struct)`	Unsafe version of `flags()`.
`static void`	`nflags(long struct, int value)`	Unsafe version of `flags`.
`static java.nio.IntBuffer`	`nresv(long struct)`	Unsafe version of `resv()`.
`static int`	`nresv(long struct, int index)`	Unsafe version of `resv`.
`static void`	`nresv(long struct, int index, int value)`	Unsafe version of `resv`.
`static void`	`nresv(long struct, java.nio.IntBuffer value)`	Unsafe version of `resv`.
`static int`	`nsq_entries(long struct)`	Unsafe version of `sq_entries()`.
`static void`	`nsq_entries(long struct, int value)`	Unsafe version of `sq_entries`.
`static IOSQRingOffsets`	`nsq_off(long struct)`	Unsafe version of `sq_off()`.
`static void`	`nsq_off(long struct, IOSQRingOffsets value)`	Unsafe version of `sq_off`.
`static int`	`nsq_thread_cpu(long struct)`	Unsafe version of `sq_thread_cpu()`.
`static void`	`nsq_thread_cpu(long struct, int value)`	Unsafe version of `sq_thread_cpu`.
`static int`	`nsq_thread_idle(long struct)`	Unsafe version of `sq_thread_idle()`.
`static void`	`nsq_thread_idle(long struct, int value)`	Unsafe version of `sq_thread_idle`.
`static int`	`nwq_fd(long struct)`	Unsafe version of `wq_fd()`.
`static void`	`nwq_fd(long struct, int value)`	Unsafe version of `wq_fd`.
`java.nio.IntBuffer`	`resv()`
`int`	`resv(int index)`
`IOURingParams`	`resv(int index, int value)`	Sets the specified value at the specified index of the `resv` field.
`IOURingParams`	`resv(java.nio.IntBuffer value)`	Copies the specified `IntBuffer` to the `resv` field.
`IOURingParams`	`set(int sq_entries, int cq_entries, int flags, int sq_thread_cpu, int sq_thread_idle, int features, int wq_fd, java.nio.IntBuffer resv, IOSQRingOffsets sq_off, IOCQRingOffsets cq_off)`	Initializes this struct with the specified values.
`IOURingParams`	`set(IOURingParams src)`	Copies the specified struct data to this struct.
`int`	`sizeof()`
`int`	`sq_entries()`	the number of submission queue entries allocated
`IOURingParams`	`sq_entries(int value)`	Sets the specified value to the `sq_entries()` field.
`IOSQRingOffsets`	`sq_off()`	The `flags` field is used by the kernel to communicate state information to the application.
`IOURingParams`	`sq_off(java.util.function.Consumer<IOSQRingOffsets> consumer)`	Passes the `sq_off()` field to the specified `Consumer`.
`IOURingParams`	`sq_off(IOSQRingOffsets value)`	Copies the specified `IOSQRingOffsets` to the `sq_off()` field.
`int`	`sq_thread_cpu()`
`IOURingParams`	`sq_thread_cpu(int value)`	Sets the specified value to the `sq_thread_cpu` field.
`int`	`sq_thread_idle()`
`IOURingParams`	`sq_thread_idle(int value)`	Sets the specified value to the `sq_thread_idle` field.
`int`	`wq_fd()`
`IOURingParams`	`wq_fd(int value)`	Sets the specified value to the `wq_fd` field.

Methods inherited from interface org.lwjgl.system.NativeResource
close, free

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Methods inherited from class org.lwjgl.system.Pointer.Default
address, equals, hashCode, toString

Methods inherited from class org.lwjgl.system.Struct
clear, free, isNull, validate

- Field Detail
  - SIZEOF
    
    The struct size in bytes.
  - ALIGNOF
    
    The struct alignment in bytes.
  - SQ_ENTRIES, CQ_ENTRIES, FLAGS, SQ_THREAD_CPU, SQ_THREAD_IDLE, FEATURES, WQ_FD, RESV, SQ_OFF, CQ_OFF
    
    The struct member offsets.
- Constructor Detail
  - IOURingParams
```
public IOURingParams(java.nio.ByteBuffer container)
```
    Creates a IOURingParams instance at the current position of the specified ByteBuffer container. Changes to the buffer's content will be visible to the struct instance and vice versa.
    The created instance holds a strong reference to the container object.
- Method Detail
  - sizeof
```
public int sizeof()
```
    Specified by:
    
    sizeof in class org.lwjgl.system.Struct
  - sq_entries
```
public int sq_entries()
```
    the number of submission queue entries allocated
  - cq_entries
```
public int cq_entries()
```
    Returns:
    
    the value of the cq_entries field.
  - flags
```
public int flags()
```
    one or more of:
    SETUP_IOPOLL SETUP_SQPOLL SETUP_SQ_AFF SETUP_CQSIZE SETUP_CLAMP SETUP_ATTACH_WQ
    SETUP_R_DISABLED
  - sq_thread_cpu
```
public int sq_thread_cpu()
```
    Returns:
    
    the value of the sq_thread_cpu field.
  - sq_thread_idle
```
public int sq_thread_idle()
```
    Returns:
    
    the value of the sq_thread_idle field.
  - features
```
public int features()
```
    filled in by the kernel, which specifies various features supported by current kernel version. One or more of:
    FEAT_SINGLE_MMAP FEAT_NODROP FEAT_SUBMIT_STABLE FEAT_RW_CUR_POS FEAT_CUR_PERSONALITY
    FEAT_FAST_POLL FEAT_POLL_32BITS FEAT_SQPOLL_NONFIXED FEAT_EXT_ARG FEAT_NATIVE_WORKERS
    FEAT_RSRC_TAGS FEAT_CQE_SKIP
  - wq_fd
```
public int wq_fd()
```
    Returns:
    
    the value of the wq_fd field.
  - resv
```
public java.nio.IntBuffer resv()
```
    Returns:
    
    a IntBuffer view of the resv field.
  - resv
```
public int resv(int index)
```
    Returns:
    
    the value at the specified index of the resv field.
  - sq_off
```
public IOSQRingOffsets sq_off()
```
    The flags field is used by the kernel to communicate state information to the application. Currently, it is used to inform the application when a call to enter is necessary.
    The dropped member is incremented for each invalid submission queue entry encountered in the ring buffer.
    
    The head and tail track the ring buffer state. The tail is incremented by the application when submitting new I/O, and the head is incremented by the kernel when the I/O has been successfully submitted. Determining the index of the head or tail into the ring is accomplished by applying a mask:
    
    index = tail & ring_mask;
  - cq_off
```
public IOCQRingOffsets cq_off()
```
    Returns:
    
    a IOCQRingOffsets view of the cq_off field.
  - sq_entries
```
public IOURingParams sq_entries(int value)
```
    Sets the specified value to the sq_entries() field.
  - cq_entries
```
public IOURingParams cq_entries(int value)
```
    Sets the specified value to the cq_entries field.
  - flags
```
public IOURingParams flags(int value)
```
    Sets the specified value to the flags() field.
  - sq_thread_cpu
```
public IOURingParams sq_thread_cpu(int value)
```
    Sets the specified value to the sq_thread_cpu field.
  - sq_thread_idle
```
public IOURingParams sq_thread_idle(int value)
```
    Sets the specified value to the sq_thread_idle field.
  - features
```
public IOURingParams features(int value)
```
    Sets the specified value to the features() field.
  - wq_fd
```
public IOURingParams wq_fd(int value)
```
    Sets the specified value to the wq_fd field.
  - resv
```
public IOURingParams resv(java.nio.IntBuffer value)
```
    Copies the specified IntBuffer to the resv field.
  - resv
```
public IOURingParams resv(int index,
                          int value)
```
    Sets the specified value at the specified index of the resv field.
  - sq_off
```
public IOURingParams sq_off(IOSQRingOffsets value)
```
    Copies the specified IOSQRingOffsets to the sq_off() field.
  - sq_off
```
public IOURingParams sq_off(java.util.function.Consumer<IOSQRingOffsets> consumer)
```
    Passes the sq_off() field to the specified Consumer.
  - cq_off
```
public IOURingParams cq_off(IOCQRingOffsets value)
```
    Copies the specified IOCQRingOffsets to the cq_off field.
  - cq_off
```
public IOURingParams cq_off(java.util.function.Consumer<IOCQRingOffsets> consumer)
```
    Passes the cq_off field to the specified Consumer.
  - set
```
public IOURingParams set(int sq_entries,
                         int cq_entries,
                         int flags,
                         int sq_thread_cpu,
                         int sq_thread_idle,
                         int features,
                         int wq_fd,
                         java.nio.IntBuffer resv,
                         IOSQRingOffsets sq_off,
                         IOCQRingOffsets cq_off)
```
    Initializes this struct with the specified values.
  - set
```
public IOURingParams set(IOURingParams src)
```
    Copies the specified struct data to this struct.
    
    Parameters:
    
    src - the source struct
    
    Returns:
    
    this struct
  - malloc
```
public static IOURingParams malloc()
```
    Returns a new IOURingParams instance allocated with memAlloc. The instance must be explicitly freed.
  - calloc
```
public static IOURingParams calloc()
```
    Returns a new IOURingParams instance allocated with memCalloc. The instance must be explicitly freed.
  - create
```
public static IOURingParams create()
```
    Returns a new IOURingParams instance allocated with BufferUtils.
  - create
```
public static IOURingParams create(long address)
```
    Returns a new IOURingParams instance for the specified memory address.
  - createSafe
```
@Nullable
public static IOURingParams createSafe(long address)
```
    Like create, but returns null if address is NULL.
  - malloc
```
public static IOURingParams.Buffer malloc(int capacity)
```
    Returns a new IOURingParams.Buffer instance allocated with memAlloc. The instance must be explicitly freed.
    
    Parameters:
    
    capacity - the buffer capacity
  - calloc
```
public static IOURingParams.Buffer calloc(int capacity)
```
    Returns a new IOURingParams.Buffer instance allocated with memCalloc. The instance must be explicitly freed.
    
    Parameters:
    
    capacity - the buffer capacity
  - create
```
public static IOURingParams.Buffer create(int capacity)
```
    Returns a new IOURingParams.Buffer instance allocated with BufferUtils.
    
    Parameters:
    
    capacity - the buffer capacity
  - create
```
public static IOURingParams.Buffer create(long address,
                                          int capacity)
```
    Create a IOURingParams.Buffer instance at the specified memory.
    
    Parameters:
    
    address - the memory address
    
    capacity - the buffer capacity
  - createSafe
```
@Nullable
public static IOURingParams.Buffer createSafe(long address,
                                              int capacity)
```
    Like create, but returns null if address is NULL.
  - malloc
```
public static IOURingParams malloc(org.lwjgl.system.MemoryStack stack)
```
    Returns a new IOURingParams instance allocated on the specified MemoryStack.
    
    Parameters:
    
    stack - the stack from which to allocate
  - calloc
```
public static IOURingParams calloc(org.lwjgl.system.MemoryStack stack)
```
    Returns a new IOURingParams instance allocated on the specified MemoryStack and initializes all its bits to zero.
    
    Parameters:
    
    stack - the stack from which to allocate
  - malloc
```
public static IOURingParams.Buffer malloc(int capacity,
                                          org.lwjgl.system.MemoryStack stack)
```
    Returns a new IOURingParams.Buffer instance allocated on the specified MemoryStack.
    
    Parameters:
    
    stack - the stack from which to allocate
    
    capacity - the buffer capacity
  - calloc
```
public static IOURingParams.Buffer calloc(int capacity,
                                          org.lwjgl.system.MemoryStack stack)
```
    Returns a new IOURingParams.Buffer instance allocated on the specified MemoryStack and initializes all its bits to zero.
    
    Parameters:
    
    stack - the stack from which to allocate
    
    capacity - the buffer capacity
  - nsq_entries
```
public static int nsq_entries(long struct)
```
    Unsafe version of sq_entries().
  - ncq_entries
```
public static int ncq_entries(long struct)
```
    Unsafe version of cq_entries().
  - nflags
```
public static int nflags(long struct)
```
    Unsafe version of flags().
  - nsq_thread_cpu
```
public static int nsq_thread_cpu(long struct)
```
    Unsafe version of sq_thread_cpu().
  - nsq_thread_idle
```
public static int nsq_thread_idle(long struct)
```
    Unsafe version of sq_thread_idle().
  - nfeatures
```
public static int nfeatures(long struct)
```
    Unsafe version of features().
  - nwq_fd
```
public static int nwq_fd(long struct)
```
    Unsafe version of wq_fd().
  - nresv
```
public static java.nio.IntBuffer nresv(long struct)
```
    Unsafe version of resv().
  - nresv
```
public static int nresv(long struct,
                        int index)
```
    Unsafe version of resv.
  - nsq_off
```
public static IOSQRingOffsets nsq_off(long struct)
```
    Unsafe version of sq_off().
  - ncq_off
```
public static IOCQRingOffsets ncq_off(long struct)
```
    Unsafe version of cq_off().
  - nsq_entries
```
public static void nsq_entries(long struct,
                               int value)
```
    Unsafe version of sq_entries.
  - ncq_entries
```
public static void ncq_entries(long struct,
                               int value)
```
    Unsafe version of cq_entries.
  - nflags
```
public static void nflags(long struct,
                          int value)
```
    Unsafe version of flags.
  - nsq_thread_cpu
```
public static void nsq_thread_cpu(long struct,
                                  int value)
```
    Unsafe version of sq_thread_cpu.
  - nsq_thread_idle
```
public static void nsq_thread_idle(long struct,
                                   int value)
```
    Unsafe version of sq_thread_idle.
  - nfeatures
```
public static void nfeatures(long struct,
                             int value)
```
    Unsafe version of features.
  - nwq_fd
```
public static void nwq_fd(long struct,
                          int value)
```
    Unsafe version of wq_fd.
  - nresv
```
public static void nresv(long struct,
                         java.nio.IntBuffer value)
```
    Unsafe version of resv.
  - nresv
```
public static void nresv(long struct,
                         int index,
                         int value)
```
    Unsafe version of resv.
  - nsq_off
```
public static void nsq_off(long struct,
                           IOSQRingOffsets value)
```
    Unsafe version of sq_off.
  - ncq_off
```
public static void ncq_off(long struct,
                           IOCQRingOffsets value)
```
    Unsafe version of cq_off.

`SETUP_IOPOLL`	`SETUP_SQPOLL`	`SETUP_SQ_AFF`	`SETUP_CQSIZE`	`SETUP_CLAMP`	`SETUP_ATTACH_WQ`
`SETUP_R_DISABLED`

`FEAT_SINGLE_MMAP`	`FEAT_NODROP`	`FEAT_SUBMIT_STABLE`	`FEAT_RW_CUR_POS`	`FEAT_CUR_PERSONALITY`
`FEAT_FAST_POLL`	`FEAT_POLL_32BITS`	`FEAT_SQPOLL_NONFIXED`	`FEAT_EXT_ARG`	`FEAT_NATIVE_WORKERS`
`FEAT_RSRC_TAGS`	`FEAT_CQE_SKIP`

Class IOURingParams

Layout

Nested Class Summary

Nested classes/interfaces inherited from interface org.lwjgl.system.Pointer

Nested classes/interfaces inherited from class org.lwjgl.system.Struct

Field Summary

Fields inherited from interface org.lwjgl.system.Pointer

Constructor Summary

Method Summary

Methods inherited from interface org.lwjgl.system.NativeResource

Methods inherited from class java.lang.Object

Methods inherited from class org.lwjgl.system.Pointer.Default

Methods inherited from class org.lwjgl.system.Struct

Field Detail

SIZEOF

ALIGNOF

SQ_ENTRIES, CQ_ENTRIES, FLAGS, SQ_THREAD_CPU, SQ_THREAD_IDLE, FEATURES, WQ_FD, RESV, SQ_OFF, CQ_OFF

Constructor Detail

IOURingParams

Method Detail

sizeof

sq_entries

cq_entries

flags

sq_thread_cpu

sq_thread_idle

features

wq_fd

resv

resv

sq_off

cq_off

sq_entries

cq_entries

flags

sq_thread_cpu

sq_thread_idle

features

wq_fd

resv

resv

sq_off

sq_off

cq_off

cq_off

set

set

malloc

calloc

create

create

createSafe

malloc

calloc

create

create

createSafe

malloc

calloc

malloc

calloc

nsq_entries

ncq_entries

nflags

nsq_thread_cpu

nsq_thread_idle

nfeatures

nwq_fd

nresv

nresv

nsq_off

ncq_off

nsq_entries

ncq_entries

nflags

nsq_thread_cpu

nsq_thread_idle

nfeatures

nwq_fd

nresv