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// Copyright (c) 2020-2022 Via Technology Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use super::context::Context;
use super::Result;
use cl3::device::{
CL_DEVICE_SVM_ATOMICS, CL_DEVICE_SVM_COARSE_GRAIN_BUFFER, CL_DEVICE_SVM_FINE_GRAIN_BUFFER,
CL_DEVICE_SVM_FINE_GRAIN_SYSTEM,
};
use cl3::memory::{
svm_alloc, svm_free, CL_MEM_READ_WRITE, CL_MEM_SVM_ATOMICS, CL_MEM_SVM_FINE_GRAIN_BUFFER,
};
use cl3::types::{cl_device_svm_capabilities, cl_svm_mem_flags, cl_uint};
use libc::c_void;
#[cfg(feature = "serde")]
use serde::de::{Deserialize, DeserializeSeed, Deserializer, Error, SeqAccess, Visitor};
#[cfg(feature = "serde")]
use serde::ser::{Serialize, SerializeSeq, Serializer};
use std::alloc::{self, Layout};
use std::fmt;
use std::fmt::Debug;
use std::iter::IntoIterator;
use std::marker::PhantomData;
use std::mem;
use std::ops::{Deref, DerefMut};
use std::ptr;
#[allow(unused_imports)]
use std::result;
struct SvmRawVec<'a, T> {
ptr: *mut T,
cap: usize,
context: &'a Context,
fine_grain_buffer: bool,
fine_grain_system: bool,
atomics: bool,
}
unsafe impl<'a, T: Send> Send for SvmRawVec<'a, T> {}
unsafe impl<'a, T: Sync> Sync for SvmRawVec<'a, T> {}
impl<'a, T> SvmRawVec<'a, T> {
fn new(context: &'a Context, svm_capabilities: cl_device_svm_capabilities) -> Self {
assert!(0 < mem::size_of::<T>(), "No Zero Sized Types!");
assert!(
0 != svm_capabilities
& (CL_DEVICE_SVM_COARSE_GRAIN_BUFFER | CL_DEVICE_SVM_FINE_GRAIN_BUFFER),
"No OpenCL SVM, use OpenCL buffers"
);
let fine_grain_buffer: bool = svm_capabilities & CL_DEVICE_SVM_FINE_GRAIN_BUFFER != 0;
let fine_grain_system: bool = svm_capabilities & CL_DEVICE_SVM_FINE_GRAIN_SYSTEM != 0;
let atomics: bool = (fine_grain_buffer || fine_grain_system)
&& (svm_capabilities & CL_DEVICE_SVM_ATOMICS != 0);
SvmRawVec {
ptr: ptr::null_mut(),
cap: 0,
context,
fine_grain_buffer,
fine_grain_system,
atomics,
}
}
fn with_capacity(
context: &'a Context,
svm_capabilities: cl_device_svm_capabilities,
capacity: usize,
) -> Result<Self> {
let mut v = Self::new(context, svm_capabilities);
v.grow(capacity)?;
Ok(v)
}
fn with_capacity_zeroed(
context: &'a Context,
svm_capabilities: cl_device_svm_capabilities,
capacity: usize,
) -> Result<Self> {
let mut v = Self::with_capacity(context, svm_capabilities, capacity)?;
v.zero(capacity);
Ok(v)
}
fn grow(&mut self, count: usize) -> Result<()> {
let elem_size = mem::size_of::<T>();
let mut new_cap = count;
// if pushing or inserting, double the capacity
if (0 < self.cap) && (count - self.cap == 1) {
new_cap = 2 * self.cap;
}
let size = elem_size * new_cap;
// Ensure within capacity.
assert!(size <= (isize::MAX as usize) / 2, "capacity overflow");
// allocation, determine whether to use svm_alloc or not
let ptr = if self.fine_grain_system {
let new_layout = Layout::array::<T>(new_cap).unwrap();
let new_ptr = unsafe { alloc::alloc(new_layout) as *mut c_void };
if new_ptr.is_null() {
alloc::handle_alloc_error(new_layout);
}
new_ptr
} else {
let svm_mem_flags: cl_svm_mem_flags = if self.fine_grain_buffer {
if self.atomics {
CL_MEM_SVM_FINE_GRAIN_BUFFER | CL_MEM_READ_WRITE | CL_MEM_SVM_ATOMICS
} else {
CL_MEM_SVM_FINE_GRAIN_BUFFER | CL_MEM_READ_WRITE
}
} else {
CL_MEM_READ_WRITE
};
let alignment = mem::align_of::<T>();
unsafe {
svm_alloc(
self.context.get(),
svm_mem_flags,
size,
alignment as cl_uint,
)?
}
};
// reallocation, copy old data to new pointer and free old memory
if 0 < self.cap {
unsafe { ptr::copy(self.ptr, ptr as *mut T, self.cap) };
if self.fine_grain_system {
let layout = Layout::array::<T>(self.cap).unwrap();
unsafe {
alloc::dealloc(self.ptr as *mut u8, layout);
}
} else {
unsafe { svm_free(self.context.get(), self.ptr as *mut c_void) };
}
}
self.ptr = ptr as *mut T;
self.cap = new_cap;
Ok(())
}
fn zero(&mut self, count: usize) {
unsafe { ptr::write_bytes(self.ptr, 0u8, count) };
}
}
impl<'a, T> Drop for SvmRawVec<'a, T> {
fn drop(&mut self) {
if !self.ptr.is_null() {
if self.fine_grain_system {
let layout = Layout::array::<T>(self.cap).unwrap();
unsafe {
alloc::dealloc(self.ptr as *mut u8, layout);
}
} else {
unsafe { svm_free(self.context.get(), self.ptr as *mut c_void) };
}
self.ptr = ptr::null_mut();
}
}
}
/// An OpenCL Shared Virtual Memory (SVM) vector.
/// It has the lifetime of the [Context] that it was constructed from.
/// Note: T cannot be a "zero sized type" (ZST).
///
/// There are three types of Shared Virtual Memory:
/// - CL_DEVICE_SVM_COARSE_GRAIN_BUFFER: OpenCL buffer memory objects can be shared.
/// - CL_DEVICE_SVM_FINE_GRAIN_BUFFER: individual memory objects in an OpenCL buffer can be shared.
/// - CL_DEVICE_SVM_FINE_GRAIN_SYSTEM: individual memory objects *anywhere* in **host** memory can be shared.
///
/// This `SvmVec` struct is designed to support CL_DEVICE_SVM_COARSE_GRAIN_BUFFER
/// and CL_DEVICE_SVM_FINE_GRAIN_BUFFER.
/// A [Context] that supports CL_DEVICE_SVM_FINE_GRAIN_SYSTEM can (and should!)
/// use a standard Rust vector instead.
///
/// Intel provided an excellent overview of Shared Virtual Memory here:
/// [OpenCL 2.0 Shared Virtual Memory Overview](https://software.intel.com/content/www/us/en/develop/articles/opencl-20-shared-virtual-memory-overview.html).
/// A PDF version is available here: [SVM Overview](https://github.com/kenba/opencl3/blob/main/docs/svmoverview.pdf).
///
/// To summarise, a CL_DEVICE_SVM_COARSE_GRAIN_BUFFER requires the SVM to be *mapped*
/// before being read or written by the host and *unmapped* afterward, while
/// CL_DEVICE_SVM_FINE_GRAIN_BUFFER can be used like a standard Rust vector.
///
/// The `is_fine_grained method` can be used to determine whether an `SvmVec` supports
/// CL_DEVICE_SVM_FINE_GRAIN_BUFFER and should be used to control SVM map and unmap
/// operations, e.g.:
/// ```no_run
/// # use cl3::device::CL_DEVICE_TYPE_GPU;
/// # use opencl3::command_queue::CommandQueue;
/// # use opencl3::context::Context;
/// # use opencl3::device::Device;
/// # use opencl3::kernel::{ExecuteKernel, Kernel};
/// # use opencl3::memory::{CL_MAP_WRITE};
/// # use opencl3::platform::get_platforms;
/// # use opencl3::svm::SvmVec;
/// # use opencl3::types::*;
/// # use opencl3::Result;
///
/// # fn main() -> Result<()> {
/// # let platforms = get_platforms().unwrap();
/// # let devices = platforms[0].get_devices(CL_DEVICE_TYPE_GPU).unwrap();
/// # let device = Device::new(devices[0]);
/// # let context = Context::from_device(&device).unwrap();
/// # let queue = CommandQueue::create_default_with_properties(&context, 0, 0).unwrap();
/// // The input data
/// const ARRAY_SIZE: usize = 8;
/// let value_array: [cl_int; ARRAY_SIZE] = [3, 2, 5, 9, 7, 1, 4, 2];
///
/// // Create an OpenCL SVM vector
/// let mut test_values = SvmVec::<cl_int>::allocate(&context, ARRAY_SIZE)?;
///
/// // Map test_values if not an CL_MEM_SVM_FINE_GRAIN_BUFFER
/// if !test_values.is_fine_grained() {
/// unsafe { queue.enqueue_svm_map(CL_BLOCKING, CL_MAP_WRITE, &mut test_values, &[])?};
/// }
///
/// // Copy input data into the OpenCL SVM vector
/// test_values.clone_from_slice(&value_array);
///
/// // Unmap test_values if not an CL_MEM_SVM_FINE_GRAIN_BUFFER
/// if !test_values.is_fine_grained() {
/// let unmap_test_values_event = unsafe { queue.enqueue_svm_unmap(&test_values, &[])?};
/// unmap_test_values_event.wait()?;
/// }
/// # Ok(())
/// # }
/// ```
pub struct SvmVec<'a, T> {
buf: SvmRawVec<'a, T>,
len: usize,
}
impl<'a, T> SvmVec<'a, T> {
fn ptr(&self) -> *mut T {
self.buf.ptr
}
/// The capacity of the vector.
pub fn cap(&self) -> usize {
self.buf.cap
}
/// The length of the vector.
pub fn len(&self) -> usize {
self.len
}
/// Whether the vector is empty
pub fn is_empty(&self) -> bool {
self.len == 0
}
/// Whether the vector is fine grain buffer
pub fn is_fine_grain_buffer(&self) -> bool {
self.buf.fine_grain_buffer
}
/// Whether the vector is fine grain system
pub fn is_fine_grain_system(&self) -> bool {
self.buf.fine_grain_system
}
/// Whether the vector is fine grained
pub fn is_fine_grained(&self) -> bool {
self.buf.fine_grain_buffer || self.buf.fine_grain_system
}
/// Whether the vector can use atomics
pub fn has_atomics(&self) -> bool {
self.buf.atomics
}
/// Clear the vector, i.e. empty it.
pub fn clear(&mut self) {
self.len = 0;
}
/// Set the length of the vector.
/// If new_len > len, the new memory will be uninitialised.
///
/// # Safety
/// May fail to grow buf if memory is not available for new_len.
pub fn set_len(&mut self, new_len: usize) -> Result<()> {
if self.cap() < new_len {
self.buf.grow(new_len)?;
}
self.len = new_len;
Ok(())
}
/// Construct an empty SvmVec from a [Context].
/// The SvmVec has the lifetime of the [Context].
///
/// # Panics
///
/// The cl_device_svm_capabilities of the [Context] must include
/// CL_DEVICE_SVM_COARSE_GRAIN_BUFFER or CL_DEVICE_SVM_FINE_GRAIN_BUFFER.
/// The cl_device_svm_capabilities must *not* include CL_DEVICE_SVM_FINE_GRAIN_SYSTEM,
/// a standard Rust `Vec!` should be used instead.
pub fn new(context: &'a Context) -> Self {
let svm_capabilities = context.get_svm_mem_capability();
SvmVec {
buf: SvmRawVec::new(context, svm_capabilities),
len: 0,
}
}
/// Construct an SvmVec with the given len of values from a [Context].
///
/// returns a Result containing an SvmVec with len values of **uninitialised**
/// memory, or the OpenCL error.
////
/// # Panics
///
/// The cl_device_svm_capabilities of the [Context] must include
/// CL_DEVICE_SVM_COARSE_GRAIN_BUFFER or CL_DEVICE_SVM_FINE_GRAIN_BUFFER.
/// The cl_device_svm_capabilities must *not* include CL_DEVICE_SVM_FINE_GRAIN_SYSTEM,
/// a standard Rust `Vec!` should be used instead.
pub fn allocate(context: &'a Context, len: usize) -> Result<Self> {
let svm_capabilities = context.get_svm_mem_capability();
Ok(SvmVec {
buf: SvmRawVec::with_capacity(context, svm_capabilities, len)?,
len,
})
}
/// Construct an empty SvmVec with the given capacity from a [Context].
///
/// returns a Result containing an empty SvmVec, or the OpenCL error.
///
/// # Panics
///
/// The cl_device_svm_capabilities of the [Context] must include
/// CL_DEVICE_SVM_COARSE_GRAIN_BUFFER or CL_DEVICE_SVM_FINE_GRAIN_BUFFER.
/// The cl_device_svm_capabilities must *not* include CL_DEVICE_SVM_FINE_GRAIN_SYSTEM,
/// a standard Rust `Vec!` should be used instead.
pub fn with_capacity(context: &'a Context, capacity: usize) -> Result<Self> {
let svm_capabilities = context.get_svm_mem_capability();
Ok(SvmVec {
buf: SvmRawVec::with_capacity(context, svm_capabilities, capacity)?,
len: 0,
})
}
/// Construct an SvmVec with the given len of values from a [Context] and
/// the svm_capabilities of the device (or devices) in the [Context].
///
/// # Panics
///
/// The function will panic if the cl_device_svm_capabilities of the [Context]
/// does **not** include CL_DEVICE_SVM_FINE_GRAIN_BUFFER.
///
/// returns a Result containing an SvmVec with len values of zeroed
/// memory, or the OpenCL error.
pub fn allocate_zeroed(context: &'a Context, len: usize) -> Result<Self> {
let svm_capabilities = context.get_svm_mem_capability();
let fine_grain_buffer: bool = svm_capabilities & CL_DEVICE_SVM_FINE_GRAIN_BUFFER != 0;
assert!(
fine_grain_buffer,
"SVM is not fine grained, use `allocate` instead."
);
Ok(SvmVec {
buf: SvmRawVec::with_capacity_zeroed(context, svm_capabilities, len)?,
len,
})
}
/// Reserve vector capacity.
/// returns an empty Result or the OpenCL error.
pub fn reserve(&mut self, capacity: usize) -> Result<()> {
self.buf.grow(capacity)
}
/// Push a value onto the vector.
///
/// # Panics
///
/// The function will panic if a coarse grain buffer attempts to grow the vector.
pub fn push(&mut self, elem: T) {
if self.len == self.cap() {
assert!(
self.is_fine_grained(),
"SVM is not fine grained, cannot grow the vector."
);
self.buf.grow(self.len + 1).unwrap();
}
unsafe {
ptr::write(self.ptr().add(self.len), elem);
}
// Can't fail, we'll OOM first.
self.len += 1;
}
/// Pop a value from the vector.
pub fn pop(&mut self) -> Option<T> {
if self.len == 0 {
None
} else {
self.len -= 1;
unsafe { Some(ptr::read(self.ptr().add(self.len))) }
}
}
/// Insert a value into the vector at index.
///
/// # Panics
///
/// The function will panic if the index is out of bounds or
/// if a coarse grain buffer attempts to grow the vector.
pub fn insert(&mut self, index: usize, elem: T) {
assert!(index <= self.len, "index out of bounds");
if self.cap() == self.len {
assert!(
self.is_fine_grained(),
"SVM is not fine grained, cannot grow the vector."
);
self.buf.grow(self.len + 1).unwrap();
}
unsafe {
if index < self.len {
ptr::copy(
self.ptr().add(index),
self.ptr().add(index + 1),
self.len - index,
);
}
ptr::write(self.ptr().add(index), elem);
self.len += 1;
}
}
/// Remove a value from the vector at index.
///
/// # Panics
///
/// The function will panic if the index is out of bounds.
pub fn remove(&mut self, index: usize) -> T {
assert!(index < self.len, "index out of bounds");
unsafe {
self.len -= 1;
let result = ptr::read(self.ptr().add(index));
ptr::copy(
self.ptr().add(index + 1),
self.ptr().add(index),
self.len - index,
);
result
}
}
/// Drain the vector.
pub fn drain(&mut self) -> Drain<T> {
unsafe {
let iter = RawValIter::new(self);
// this is a mem::forget safety thing. If Drain is forgotten, we just
// leak the whole Vec's contents. Also we need to do this *eventually*
// anyway, so why not do it now?
self.len = 0;
Drain {
iter,
vec: PhantomData,
}
}
}
}
impl<'a, T> IntoIterator for SvmVec<'a, T> {
type Item = T;
type IntoIter = IntoIter<'a, Self::Item>;
fn into_iter(self) -> Self::IntoIter {
unsafe {
let iter = RawValIter::new(&self);
let buf = ptr::read(&self.buf);
mem::forget(self);
Self::IntoIter { iter, _buf: buf }
}
}
}
impl<'a, T> Drop for SvmVec<'a, T> {
fn drop(&mut self) {
while self.pop().is_some() {}
// allocation is handled by SvmRawVec
}
}
impl<'a, T> Deref for SvmVec<'a, T> {
type Target = [T];
fn deref(&self) -> &[T] {
unsafe { std::slice::from_raw_parts(self.ptr(), self.len) }
}
}
impl<'a, T> DerefMut for SvmVec<'a, T> {
fn deref_mut(&mut self) -> &mut [T] {
unsafe { std::slice::from_raw_parts_mut(self.ptr(), self.len) }
}
}
impl<'a, T: Debug> fmt::Debug for SvmVec<'a, T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&**self, f)
}
}
/// A DeserializeSeed implementation that uses stateful deserialization to
/// append array elements onto the end of an existing SvmVec.
/// The pre-existing state ("seed") in this case is the SvmVec<'b, T>.
#[cfg(feature = "serde")]
pub struct ExtendSvmVec<'a, 'b, T: 'a>(pub &'a mut SvmVec<'b, T>);
#[cfg(feature = "serde")]
impl<'de, 'a, 'b, T> DeserializeSeed<'de> for ExtendSvmVec<'a, 'b, T>
where
T: Deserialize<'de>,
{
// The return type of the `deserialize` method. Since this implementation
// appends onto an existing SvmVec the return type is ().
type Value = ();
fn deserialize<D>(self, deserializer: D) -> result::Result<Self::Value, D::Error>
where
D: Deserializer<'de>,
{
// Visitor implementation to walk an array of the deserializer input.
struct ExtendSvmVecVisitor<'a, 'b, T: 'a>(&'a mut SvmVec<'b, T>);
impl<'de, 'a, 'b, T> Visitor<'de> for ExtendSvmVecVisitor<'a, 'b, T>
where
T: Deserialize<'de>,
{
type Value = ();
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("an array")
}
fn visit_seq<A>(self, mut seq: A) -> result::Result<(), A::Error>
where
A: SeqAccess<'de>,
{
// reserve SvmVec memory if the size of the deserializer array is known
if let Some(size) = seq.size_hint() {
let len = self.0.len + size;
self.0.reserve(len).map_err(A::Error::custom)?;
}
// Visit each element in the array and push it onto the existing SvmVec
while let Some(elem) = seq.next_element()? {
self.0.push(elem);
}
Ok(())
}
}
deserializer.deserialize_seq(ExtendSvmVecVisitor(self.0))
}
}
#[cfg(feature = "serde")]
impl<'a, T> Serialize for SvmVec<'a, T>
where
T: Serialize,
{
fn serialize<S>(&self, serializer: S) -> result::Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut seq = serializer.serialize_seq(Some(self.len()))?;
for element in self.iter() {
seq.serialize_element(element)?;
}
seq.end()
}
}
struct RawValIter<T> {
start: *const T,
end: *const T,
}
unsafe impl<T: Send> Send for RawValIter<T> {}
impl<T> RawValIter<T> {
unsafe fn new(slice: &[T]) -> Self {
RawValIter {
start: slice.as_ptr(),
end: if mem::size_of::<T>() == 0 {
((slice.as_ptr() as usize) + slice.len()) as *const _
} else if slice.is_empty() {
slice.as_ptr()
} else {
slice.as_ptr().add(slice.len())
},
}
}
}
impl<T> Iterator for RawValIter<T> {
type Item = T;
fn next(&mut self) -> Option<T> {
if self.start == self.end {
None
} else {
unsafe {
let result = ptr::read(self.start);
self.start = if mem::size_of::<T>() == 0 {
(self.start as usize + 1) as *const _
} else {
self.start.offset(1)
};
Some(result)
}
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let elem_size = mem::size_of::<T>();
let len =
(self.end as usize - self.start as usize) / if elem_size == 0 { 1 } else { elem_size };
(len, Some(len))
}
}
impl<T> DoubleEndedIterator for RawValIter<T> {
fn next_back(&mut self) -> Option<T> {
if self.start == self.end {
None
} else {
unsafe {
self.end = if mem::size_of::<T>() == 0 {
(self.end as usize - 1) as *const _
} else {
self.end.offset(-1)
};
Some(ptr::read(self.end))
}
}
}
}
pub struct IntoIter<'a, T> {
_buf: SvmRawVec<'a, T>, // we don't actually care about this. Just need it to live.
iter: RawValIter<T>,
}
impl<'a, T> Iterator for IntoIter<'a, T> {
type Item = T;
fn next(&mut self) -> Option<T> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, T> DoubleEndedIterator for IntoIter<'a, T> {
fn next_back(&mut self) -> Option<T> {
self.iter.next_back()
}
}
impl<'a, T> Drop for IntoIter<'a, T> {
fn drop(&mut self) {
for _ in &mut *self {}
}
}
pub struct Drain<'a, T: 'a> {
vec: PhantomData<&'a mut SvmVec<'a, T>>,
iter: RawValIter<T>,
}
impl<'a, T> Iterator for Drain<'a, T> {
type Item = T;
fn next(&mut self) -> Option<T> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, T> DoubleEndedIterator for Drain<'a, T> {
fn next_back(&mut self) -> Option<T> {
self.iter.next_back()
}
}
impl<'a, T> Drop for Drain<'a, T> {
fn drop(&mut self) {
// pre-drain the iter
for _ in &mut self.iter {}
}
}