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Move buffer param into function 

Needed for thread-safe mode, otherwise there will be borrow
problems with trying to borrow immutably, while already
borrowed mutably.
This commit is contained in:
Michael Mueller 2019-06-19 17:41:02 +02:00
parent 7fe6ef4e35
commit 7546d3026d
No known key found for this signature in database
GPG Key ID: 95756F716F423159
1 changed files with 28 additions and 39 deletions
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67
src/memory.rs
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@ -204,9 +204,10 @@ impl MemoryInstance {
/// Get value from memory at given offset.
pub fn get_value<T: LittleEndianConvert>(&self, offset: u32) -> Result<T, Error> {
let mut buffer = self.buffer.borrow_mut();
let region =
self.checked_region(&mut buffer, offset as usize, ::core::mem::size_of::<T>())?;
self.checked_region(offset as usize, ::core::mem::size_of::<T>())?;
let buffer = self.buffer.borrow();
Ok(T::from_little_endian(&buffer[region.range()]).expect("Slice size is checked"))
}
@ -217,9 +218,9 @@ impl MemoryInstance {
///
/// [`get_into`]: #method.get_into
pub fn get(&self, offset: u32, size: usize) -> Result<Vec<u8>, Error> {
let mut buffer = self.buffer.borrow_mut();
let region = self.checked_region(&mut buffer, offset as usize, size)?;
let region = self.checked_region(offset as usize, size)?;
let buffer = self.buffer.borrow();
Ok(buffer[region.range()].to_vec())
}
@ -229,9 +230,9 @@ impl MemoryInstance {
///
/// Returns `Err` if the specified region is out of bounds.
pub fn get_into(&self, offset: u32, target: &mut [u8]) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let region = self.checked_region(&mut buffer, offset as usize, target.len())?;
let region = self.checked_region(offset as usize, target.len())?;
let buffer = self.buffer.borrow();
target.copy_from_slice(&buffer[region.range()]);
Ok(())
@ -239,14 +240,14 @@ impl MemoryInstance {
/// Copy data in the memory at given offset.
pub fn set(&self, offset: u32, value: &[u8]) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let range = self
.checked_region(&mut buffer, offset as usize, value.len())?
.checked_region(offset as usize, value.len())?
.range();
if offset < self.lowest_used.get() {
self.lowest_used.set(offset);
}
let mut buffer = self.buffer.borrow_mut();
buffer[range].copy_from_slice(value);
Ok(())
@ -254,13 +255,13 @@ impl MemoryInstance {
/// Copy value in the memory at given offset.
pub fn set_value<T: LittleEndianConvert>(&self, offset: u32, value: T) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let range = self
.checked_region(&mut buffer, offset as usize, ::core::mem::size_of::<T>())?
.checked_region(offset as usize, ::core::mem::size_of::<T>())?
.range();
if offset < self.lowest_used.get() {
self.lowest_used.set(offset);
}
let mut buffer = self.buffer.borrow_mut();
value.into_little_endian(&mut buffer[range]);
Ok(())
}
@ -299,15 +300,12 @@ impl MemoryInstance {
Ok(size_before_grow)
}
fn checked_region<B>(
fn checked_region(
&self,
buffer: &mut B,
offset: usize,
size: usize,
) -> Result<CheckedRegion, Error>
where
B: ::core::ops::DerefMut<Target = Vec<u8>>,
{
) -> Result<CheckedRegion, Error> {
let mut buffer = self.buffer.borrow_mut();
let end = offset.checked_add(size).ok_or_else(|| {
Error::Memory(format!(
"trying to access memory block of size {} from offset {}",
@ -334,17 +332,13 @@ impl MemoryInstance {
})
}
fn checked_region_pair<B>(
fn checked_region_pair(
&self,
buffer: &mut B,
offset1: usize,
size1: usize,
offset2: usize,
size2: usize,
) -> Result<(CheckedRegion, CheckedRegion), Error>
where
B: ::core::ops::DerefMut<Target = Vec<u8>>,
{
) -> Result<(CheckedRegion, CheckedRegion), Error> {
let end1 = offset1.checked_add(size1).ok_or_else(|| {
Error::Memory(format!(
"trying to access memory block of size {} from offset {}",
@ -359,6 +353,7 @@ impl MemoryInstance {
))
})?;
let mut buffer = self.buffer.borrow_mut();
let max = cmp::max(end1, end2);
if max <= self.current_size.get() && buffer.len() < max {
buffer.resize(max, 0);
@ -402,15 +397,14 @@ impl MemoryInstance {
///
/// Returns `Err` if either of specified regions is out of bounds.
pub fn copy(&self, src_offset: usize, dst_offset: usize, len: usize) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let (read_region, write_region) =
self.checked_region_pair(&mut buffer, src_offset, len, dst_offset, len)?;
self.checked_region_pair(src_offset, len, dst_offset, len)?;
if dst_offset < self.lowest_used.get() as usize {
self.lowest_used.set(dst_offset as u32);
}
let mut buffer = self.buffer.borrow_mut();
unsafe {
::core::ptr::copy(
buffer[read_region.range()].as_ptr(),
@ -439,10 +433,8 @@ impl MemoryInstance {
dst_offset: usize,
len: usize,
) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let (read_region, write_region) =
self.checked_region_pair(&mut buffer, src_offset, len, dst_offset, len)?;
self.checked_region_pair(src_offset, len, dst_offset, len)?;
if read_region.intersects(&write_region) {
return Err(Error::Memory(format!(
@ -454,6 +446,7 @@ impl MemoryInstance {
self.lowest_used.set(dst_offset as u32);
}
let mut buffer = self.buffer.borrow_mut();
unsafe {
::core::ptr::copy_nonoverlapping(
buffer[read_region.range()].as_ptr(),
@ -475,28 +468,25 @@ impl MemoryInstance {
dst_offset: usize,
len: usize,
) -> Result<(), Error> {
if Rc::ptr_eq(&src.0, &dst.0) {
if ::MyRc::ptr_eq(&src.0, &dst.0) {
// `transfer` is invoked with with same source and destination. Let's assume that regions may
// overlap and use `copy`.
return src.copy(src_offset, dst_offset, len);
}
// Because memory references point to different memory instances, it is safe to `borrow_mut`
// both buffers at once (modulo `with_direct_access_mut`).
let mut src_buffer = src.buffer.borrow_mut();
let mut dst_buffer = dst.buffer.borrow_mut();
let src_range = src
.checked_region(&mut src_buffer, src_offset, len)?
.checked_region(src_offset, len)?
.range();
let dst_range = dst
.checked_region(&mut dst_buffer, dst_offset, len)?
.checked_region(dst_offset, len)?
.range();
if dst_offset < dst.lowest_used.get() as usize {
dst.lowest_used.set(dst_offset as u32);
}
let mut dst_buffer = dst.buffer.borrow_mut();
let src_buffer = src.buffer.borrow();
dst_buffer[dst_range].copy_from_slice(&src_buffer[src_range]);
Ok(())
@ -510,14 +500,13 @@ impl MemoryInstance {
///
/// Returns `Err` if the specified region is out of bounds.
pub fn clear(&self, offset: usize, new_val: u8, len: usize) -> Result<(), Error> {
let mut buffer = self.buffer.borrow_mut();
let range = self.checked_region(&mut buffer, offset, len)?.range();
let range = self.checked_region(offset, len)?.range();
if offset < self.lowest_used.get() as usize {
self.lowest_used.set(offset as u32);
}
let mut buffer = self.buffer.borrow_mut();
for val in &mut buffer[range] {
*val = new_val
}