libstd: De-mut arena

This commit is contained in:
Patrick Walton 2013-04-29 15:23:04 -07:00
parent ba842518a2
commit 6f2e429041
2 changed files with 92 additions and 54 deletions

View File

@ -32,11 +32,11 @@
// overhead when initializing plain-old-data and means we don't need
// to waste time running the destructors of POD.
use list::{MutList, MutCons, MutNil};
use list;
use list::{List, Cons, Nil};
use core::at_vec;
use core::cast::transmute;
use core::cast::{transmute, transmute_mut_region};
use core::cast;
use core::libc::size_t;
use core::ptr;
@ -74,7 +74,7 @@ static tydesc_drop_glue_index: size_t = 3 as size_t;
// will always stay at 0.
struct Chunk {
data: @[u8],
mut fill: uint,
fill: uint,
is_pod: bool,
}
@ -82,9 +82,9 @@ pub struct Arena {
// The head is seperated out from the list as a unbenchmarked
// microoptimization, to avoid needing to case on the list to
// access the head.
priv mut head: Chunk,
priv mut pod_head: Chunk,
priv mut chunks: @List<Chunk>,
priv head: Chunk,
priv pod_head: Chunk,
priv chunks: @mut MutList<Chunk>,
}
#[unsafe_destructor]
@ -92,8 +92,10 @@ impl Drop for Arena {
fn finalize(&self) {
unsafe {
destroy_chunk(&self.head);
for list::each(self.chunks) |chunk| {
if !chunk.is_pod { destroy_chunk(chunk); }
for self.chunks.each |chunk| {
if !chunk.is_pod {
destroy_chunk(chunk);
}
}
}
}
@ -113,7 +115,7 @@ pub fn arena_with_size(initial_size: uint) -> Arena {
Arena {
head: chunk(initial_size, false),
pod_head: chunk(initial_size, true),
chunks: @Nil,
chunks: @mut MutNil,
}
}
@ -170,11 +172,11 @@ unsafe fn un_bitpack_tydesc_ptr(p: uint) -> (*TypeDesc, bool) {
pub impl Arena {
// Functions for the POD part of the arena
priv fn alloc_pod_grow(&self, n_bytes: uint, align: uint) -> *u8 {
priv fn alloc_pod_grow(&mut self, n_bytes: uint, align: uint) -> *u8 {
// Allocate a new chunk.
let chunk_size = at_vec::capacity(self.pod_head.data);
let new_min_chunk_size = uint::max(n_bytes, chunk_size);
self.chunks = @Cons(copy self.pod_head, self.chunks);
self.chunks = @mut MutCons(copy self.pod_head, self.chunks);
self.pod_head =
chunk(uint::next_power_of_two(new_min_chunk_size + 1u), true);
@ -182,27 +184,28 @@ pub impl Arena {
}
#[inline(always)]
priv fn alloc_pod_inner(&self, n_bytes: uint, align: uint) -> *u8 {
let head = &mut self.pod_head;
let start = round_up_to(head.fill, align);
let end = start + n_bytes;
if end > at_vec::capacity(head.data) {
return self.alloc_pod_grow(n_bytes, align);
}
head.fill = end;
//debug!("idx = %u, size = %u, align = %u, fill = %u",
// start, n_bytes, align, head.fill);
priv fn alloc_pod_inner(&mut self, n_bytes: uint, align: uint) -> *u8 {
unsafe {
// XXX: Borrow check
let head = transmute_mut_region(&mut self.pod_head);
let start = round_up_to(head.fill, align);
let end = start + n_bytes;
if end > at_vec::capacity(head.data) {
return self.alloc_pod_grow(n_bytes, align);
}
head.fill = end;
//debug!("idx = %u, size = %u, align = %u, fill = %u",
// start, n_bytes, align, head.fill);
ptr::offset(vec::raw::to_ptr(head.data), start)
}
}
#[inline(always)]
#[cfg(stage0)]
priv fn alloc_pod<T>(&self, op: &fn() -> T) -> &'self T {
priv fn alloc_pod<T>(&mut self, op: &fn() -> T) -> &'self T {
unsafe {
let tydesc = sys::get_type_desc::<T>();
let ptr = self.alloc_pod_inner((*tydesc).size, (*tydesc).align);
@ -216,7 +219,7 @@ pub impl Arena {
#[cfg(stage1)]
#[cfg(stage2)]
#[cfg(stage3)]
priv fn alloc_pod<'a, T>(&'a self, op: &fn() -> T) -> &'a T {
priv fn alloc_pod<'a, T>(&'a mut self, op: &fn() -> T) -> &'a T {
unsafe {
let tydesc = sys::get_type_desc::<T>();
let ptr = self.alloc_pod_inner((*tydesc).size, (*tydesc).align);
@ -227,11 +230,12 @@ pub impl Arena {
}
// Functions for the non-POD part of the arena
priv fn alloc_nonpod_grow(&self, n_bytes: uint, align: uint) -> (*u8, *u8) {
priv fn alloc_nonpod_grow(&mut self, n_bytes: uint, align: uint)
-> (*u8, *u8) {
// Allocate a new chunk.
let chunk_size = at_vec::capacity(self.head.data);
let new_min_chunk_size = uint::max(n_bytes, chunk_size);
self.chunks = @Cons(copy self.head, self.chunks);
self.chunks = @mut MutCons(copy self.head, self.chunks);
self.head =
chunk(uint::next_power_of_two(new_min_chunk_size + 1u), false);
@ -239,22 +243,23 @@ pub impl Arena {
}
#[inline(always)]
priv fn alloc_nonpod_inner(&self, n_bytes: uint, align: uint) -> (*u8, *u8) {
let head = &mut self.head;
let tydesc_start = head.fill;
let after_tydesc = head.fill + sys::size_of::<*TypeDesc>();
let start = round_up_to(after_tydesc, align);
let end = start + n_bytes;
if end > at_vec::capacity(head.data) {
return self.alloc_nonpod_grow(n_bytes, align);
}
head.fill = round_up_to(end, sys::pref_align_of::<*TypeDesc>());
//debug!("idx = %u, size = %u, align = %u, fill = %u",
// start, n_bytes, align, head.fill);
priv fn alloc_nonpod_inner(&mut self, n_bytes: uint, align: uint)
-> (*u8, *u8) {
unsafe {
let head = transmute_mut_region(&mut self.head);
let tydesc_start = head.fill;
let after_tydesc = head.fill + sys::size_of::<*TypeDesc>();
let start = round_up_to(after_tydesc, align);
let end = start + n_bytes;
if end > at_vec::capacity(head.data) {
return self.alloc_nonpod_grow(n_bytes, align);
}
head.fill = round_up_to(end, sys::pref_align_of::<*TypeDesc>());
//debug!("idx = %u, size = %u, align = %u, fill = %u",
// start, n_bytes, align, head.fill);
let buf = vec::raw::to_ptr(head.data);
return (ptr::offset(buf, tydesc_start), ptr::offset(buf, start));
}
@ -262,7 +267,7 @@ pub impl Arena {
#[inline(always)]
#[cfg(stage0)]
priv fn alloc_nonpod<T>(&self, op: &fn() -> T) -> &'self T {
priv fn alloc_nonpod<T>(&mut self, op: &fn() -> T) -> &'self T {
unsafe {
let tydesc = sys::get_type_desc::<T>();
let (ty_ptr, ptr) =
@ -286,7 +291,7 @@ pub impl Arena {
#[cfg(stage1)]
#[cfg(stage2)]
#[cfg(stage3)]
priv fn alloc_nonpod<'a, T>(&'a self, op: &fn() -> T) -> &'a T {
priv fn alloc_nonpod<'a, T>(&'a mut self, op: &fn() -> T) -> &'a T {
unsafe {
let tydesc = sys::get_type_desc::<T>();
let (ty_ptr, ptr) =
@ -309,13 +314,16 @@ pub impl Arena {
// The external interface
#[inline(always)]
#[cfg(stage0)]
fn alloc<T>(&self, op: &fn() -> T) -> &'self T {
fn alloc<T>(&mut self, op: &fn() -> T) -> &'self T {
unsafe {
// XXX: Borrow check
let this = transmute_mut_region(self);
if !rusti::needs_drop::<T>() {
self.alloc_pod(op)
} else {
self.alloc_nonpod(op)
return this.alloc_pod(op);
}
// XXX: Borrow check
let this = transmute_mut_region(self);
this.alloc_nonpod(op)
}
}
@ -324,13 +332,16 @@ pub impl Arena {
#[cfg(stage1)]
#[cfg(stage2)]
#[cfg(stage3)]
fn alloc<'a, T>(&'a self, op: &fn() -> T) -> &'a T {
fn alloc<'a, T>(&'a mut self, op: &fn() -> T) -> &'a T {
unsafe {
// XXX: Borrow check
let this = transmute_mut_region(self);
if !rusti::needs_drop::<T>() {
self.alloc_pod(op)
} else {
self.alloc_nonpod(op)
return this.alloc_pod(op);
}
// XXX: Borrow check
let this = transmute_mut_region(self);
this.alloc_nonpod(op)
}
}
}
@ -348,7 +359,9 @@ fn test_arena_destructors() {
}
}
#[test] #[should_fail] #[ignore(cfg(windows))]
#[test]
#[should_fail]
#[ignore(cfg(windows))]
fn test_arena_destructors_fail() {
let arena = Arena();
// Put some stuff in the arena.

View File

@ -16,6 +16,12 @@ pub enum List<T> {
Nil,
}
#[deriving(Eq)]
pub enum MutList<T> {
MutCons(T, @mut MutList<T>),
MutNil,
}
/// Create a list from a vector
pub fn from_vec<T:Copy>(v: &[T]) -> @List<T> {
vec::foldr(v, @Nil::<T>, |h, t| @Cons(*h, t))
@ -147,6 +153,25 @@ pub fn each<T>(l: @List<T>, f: &fn(&T) -> bool) {
}
}
impl<T> MutList<T> {
/// Iterate over a mutable list
pub fn each(@mut self, f: &fn(&mut T) -> bool) {
let mut cur = self;
loop {
let borrowed = &mut *cur;
cur = match *borrowed {
MutCons(ref mut hd, tl) => {
if !f(hd) {
return;
}
tl
}
MutNil => break
}
}
}
}
#[cfg(test)]
mod tests {
use list::*;