1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234
use crate::shapes::{Shape, Unit};
use crate::tensor::{cache::TensorCache, cpu::LendingIterator, storage_traits::*, Tensor};
use rand::{rngs::StdRng, Rng, SeedableRng};
use std::{sync::Arc, vec::Vec};
#[cfg(feature = "no-std")]
use spin::Mutex;
#[cfg(not(feature = "no-std"))]
use std::sync::Mutex;
/// A pointer to a block of bytes on the heap. Used in conjunction with [TensorCache].
#[derive(Copy, Clone, Debug)]
pub(crate) struct BytesPtr(pub(crate) *mut u8);
unsafe impl Send for BytesPtr {}
unsafe impl Sync for BytesPtr {}
/// A device that stores data on the heap.
///
/// The [Default] impl seeds the underlying rng with seed of 0.
///
/// Use [Cpu::seed_from_u64] to control what seed is used.
#[derive(Clone, Debug)]
pub struct Cpu {
/// A thread safe random number generator.
pub(crate) rng: Arc<Mutex<StdRng>>,
/// A thread safe cache of memory allocations that can be reused.
pub(crate) cache: Arc<TensorCache<BytesPtr>>,
}
impl Default for Cpu {
fn default() -> Self {
Self {
rng: Arc::new(Mutex::new(StdRng::seed_from_u64(0))),
cache: Arc::new(Default::default()),
}
}
}
impl Cpu {
/// Constructs rng with the given seed.
pub fn seed_from_u64(seed: u64) -> Self {
Self {
rng: Arc::new(Mutex::new(StdRng::seed_from_u64(seed))),
cache: Arc::new(Default::default()),
}
}
}
#[derive(Debug, Clone, Copy)]
pub enum CpuError {
/// Device is out of memory
OutOfMemory,
/// Not enough elements were provided when creating a tensor
WrongNumElements,
}
impl std::fmt::Display for CpuError {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
match self {
Self::OutOfMemory => f.write_str("CpuError::OutOfMemory"),
Self::WrongNumElements => f.write_str("CpuError::WrongNumElements"),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for CpuError {}
impl HasErr for Cpu {
type Err = CpuError;
}
/// A [Vec] that can be cloned without allocating new memory.
/// When [Drop]ed it will insert it's data into the cache.
#[derive(Debug)]
pub struct CachableVec<E> {
/// The data stored in this vector.
pub(crate) data: Vec<E>,
/// A cache of memory allocations that can be reused.
pub(crate) cache: Arc<TensorCache<BytesPtr>>,
}
impl<E: Clone> Clone for CachableVec<E> {
fn clone(&self) -> Self {
let numel = self.data.len();
self.cache.try_pop::<E>(numel).map_or_else(
|| Self {
data: self.data.clone(),
cache: self.cache.clone(),
},
|allocation| {
assert!(numel < isize::MAX as usize);
// SAFETY:
// - ✅ "ptr must have been allocated using the global allocator, such as via the alloc::alloc function."
// - ✅ handled by tensor cache "T needs to have the same alignment as what ptr was allocated with."
// - ✅ handled by tensor cache "The size of T times the capacity needs to be the same size as the pointer was allocated with."
// - ✅ "length needs to be less than or equal to capacity."
// - ✅ all the dtypes for this are builtin numbers "The first length values must be properly initialized values of type T."
// - ✅ "capacity needs to be the capacity that the pointer was allocated with."
// - ✅ "The allocated size in bytes must be no larger than isize::MAX. See the safety documentation of pointer::offset."
let mut data = unsafe { Vec::from_raw_parts(allocation.0 as *mut E, numel, numel) };
data.clone_from(&self.data);
Self {
data,
cache: self.cache.clone(),
}
},
)
}
}
impl<E> Drop for CachableVec<E> {
fn drop(&mut self) {
if self.cache.is_enabled() {
let mut data = std::mem::take(&mut self.data);
data.shrink_to_fit();
let numel = data.len();
let ptr = data.as_mut_ptr() as *mut u8;
std::mem::forget(data);
self.cache.insert::<E>(numel, BytesPtr(ptr));
}
}
}
impl<E> std::ops::Deref for CachableVec<E> {
type Target = Vec<E>;
fn deref(&self) -> &Self::Target {
&self.data
}
}
impl<E> std::ops::DerefMut for CachableVec<E> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.data
}
}
impl RandomU64 for Cpu {
fn random_u64(&self) -> u64 {
#[cfg(not(feature = "no-std"))]
{
self.rng.lock().unwrap().gen()
}
#[cfg(feature = "no-std")]
{
self.rng.lock().gen()
}
}
}
impl<E: Unit> Storage<E> for Cpu {
type Vec = CachableVec<E>;
fn try_alloc_len(&self, len: usize) -> Result<Self::Vec, Self::Err> {
self.try_alloc_zeros(len)
}
fn len(&self, v: &Self::Vec) -> usize {
v.len()
}
fn tensor_to_vec<S: Shape, T>(&self, tensor: &Tensor<S, E, Self, T>) -> Vec<E> {
let mut buf = Vec::with_capacity(tensor.shape.num_elements());
let mut iter = tensor.iter();
while let Some(v) = iter.next() {
buf.push(*v);
}
buf
}
}
impl Synchronize for Cpu {
fn try_synchronize(&self) -> Result<(), Self::Err> {
Ok(())
}
}
impl Cache for Cpu {
fn try_enable_cache(&self) -> Result<(), Self::Err> {
self.cache.enable();
Ok(())
}
fn try_disable_cache(&self) -> Result<(), Self::Err> {
self.cache.disable();
self.try_empty_cache()
}
fn try_empty_cache(&self) -> Result<(), Self::Err> {
#[cfg(not(feature = "no-std"))]
let mut cache = self.cache.allocations.write().unwrap();
#[cfg(feature = "no-std")]
let mut cache = self.cache.allocations.write();
for (&key, allocations) in cache.iter_mut() {
assert!(key.num_bytes % key.size == 0);
assert!(key.num_bytes < isize::MAX as usize);
let len = key.num_bytes / key.size;
let cap = len;
for alloc in allocations.drain(..) {
// SAFETY:
// - "ptr must have been allocated using the global allocator, such as via the alloc::alloc function."
// - ✅ cpu uses global allocator
// - "T needs to have the same alignment as what ptr was allocated with."
// - ✅ we are matching on the alignment below
// - "The size of T times the capacity needs to be the same size as the pointer was allocated with."
// - ✅ covered by `key.num_bytes / key.size` and the `key.num_bytes % key.size == 0` assertion above
// - "length needs to be less than or equal to capacity."
// - ✅ they are equal
// - "The first length values must be properly initialized values of type T."
// - ✅ any bit pattern is valid for unsigned ints used below
// - "capacity needs to be the capacity that the pointer was allocated with."
// - ✅ handled by assertion above (key.num_bytes % key.size == 0)
// - "The allocated size in bytes must be no larger than isize::MAX. See the safety documentation of pointer::offset."
// - ✅ handled by assertion above
debug_assert_eq!(std::alloc::Layout::new::<u8>().align(), 1);
debug_assert_eq!(std::alloc::Layout::new::<u16>().align(), 2);
debug_assert_eq!(std::alloc::Layout::new::<u32>().align(), 4);
debug_assert_eq!(std::alloc::Layout::new::<u64>().align(), 8);
match key.alignment {
1 => unsafe { drop(Vec::from_raw_parts(alloc.0, len, cap)) },
2 => unsafe { drop(Vec::from_raw_parts(alloc.0 as *mut u16, len, cap)) },
4 => unsafe { drop(Vec::from_raw_parts(alloc.0 as *mut u32, len, cap)) },
8 => unsafe { drop(Vec::from_raw_parts(alloc.0 as *mut u64, len, cap)) },
_ => unreachable!(),
};
}
}
cache.clear();
Ok(())
}
}