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1a4d82fc JJ |
1 | // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | //! The arena, a fast but limited type of allocator. | |
12 | //! | |
13 | //! Arenas are a type of allocator that destroy the objects within, all at | |
14 | //! once, once the arena itself is destroyed. They do not support deallocation | |
15 | //! of individual objects while the arena itself is still alive. The benefit | |
16 | //! of an arena is very fast allocation; just a pointer bump. | |
17 | //! | |
9e0c209e SL |
18 | //! This crate implements `TypedArena`, a simple arena that can only hold |
19 | //! objects of a single type. | |
1a4d82fc | 20 | |
e9174d1e | 21 | #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png", |
62682a34 | 22 | html_favicon_url = "https://doc.rust-lang.org/favicon.ico", |
92a42be0 SL |
23 | html_root_url = "https://doc.rust-lang.org/nightly/", |
24 | test(no_crate_inject, attr(deny(warnings))))] | |
1a4d82fc | 25 | |
85aaf69f | 26 | #![feature(alloc)] |
62682a34 | 27 | #![feature(core_intrinsics)] |
32a655c1 | 28 | #![feature(dropck_eyepatch)] |
0bf4aa26 | 29 | #![feature(nll)] |
8faf50e0 | 30 | #![feature(raw_vec_internals)] |
85aaf69f | 31 | #![cfg_attr(test, feature(test))] |
1a4d82fc | 32 | |
9cc50fc6 | 33 | #![allow(deprecated)] |
b039eaaf | 34 | |
1a4d82fc | 35 | extern crate alloc; |
83c7162d XL |
36 | extern crate rustc_data_structures; |
37 | ||
38 | use rustc_data_structures::sync::MTLock; | |
1a4d82fc JJ |
39 | |
40 | use std::cell::{Cell, RefCell}; | |
41 | use std::cmp; | |
1a4d82fc | 42 | use std::intrinsics; |
9cc50fc6 | 43 | use std::marker::{PhantomData, Send}; |
1a4d82fc | 44 | use std::mem; |
1a4d82fc | 45 | use std::ptr; |
c30ab7b3 | 46 | use std::slice; |
e9174d1e | 47 | |
9cc50fc6 | 48 | use alloc::raw_vec::RawVec; |
1a4d82fc | 49 | |
9e0c209e | 50 | /// An arena that can hold objects of only one type. |
1a4d82fc JJ |
51 | pub struct TypedArena<T> { |
52 | /// A pointer to the next object to be allocated. | |
9cc50fc6 | 53 | ptr: Cell<*mut T>, |
1a4d82fc JJ |
54 | |
55 | /// A pointer to the end of the allocated area. When this pointer is | |
56 | /// reached, a new chunk is allocated. | |
9cc50fc6 | 57 | end: Cell<*mut T>, |
1a4d82fc | 58 | |
9e0c209e | 59 | /// A vector of arena chunks. |
9cc50fc6 | 60 | chunks: RefCell<Vec<TypedArenaChunk<T>>>, |
85aaf69f SL |
61 | |
62 | /// Marker indicating that dropping the arena causes its owned | |
63 | /// instances of `T` to be dropped. | |
9cc50fc6 | 64 | _own: PhantomData<T>, |
1a4d82fc JJ |
65 | } |
66 | ||
67 | struct TypedArenaChunk<T> { | |
9e0c209e | 68 | /// The raw storage for the arena chunk. |
9cc50fc6 | 69 | storage: RawVec<T>, |
1a4d82fc JJ |
70 | } |
71 | ||
72 | impl<T> TypedArenaChunk<T> { | |
73 | #[inline] | |
9cc50fc6 | 74 | unsafe fn new(capacity: usize) -> TypedArenaChunk<T> { |
2c00a5a8 XL |
75 | TypedArenaChunk { |
76 | storage: RawVec::with_capacity(capacity), | |
77 | } | |
1a4d82fc JJ |
78 | } |
79 | ||
9cc50fc6 | 80 | /// Destroys this arena chunk. |
1a4d82fc | 81 | #[inline] |
85aaf69f | 82 | unsafe fn destroy(&mut self, len: usize) { |
9cc50fc6 SL |
83 | // The branch on needs_drop() is an -O1 performance optimization. |
84 | // Without the branch, dropping TypedArena<u8> takes linear time. | |
7cac9316 | 85 | if mem::needs_drop::<T>() { |
1a4d82fc | 86 | let mut start = self.start(); |
9cc50fc6 | 87 | // Destroy all allocated objects. |
85aaf69f | 88 | for _ in 0..len { |
9cc50fc6 SL |
89 | ptr::drop_in_place(start); |
90 | start = start.offset(1); | |
1a4d82fc JJ |
91 | } |
92 | } | |
1a4d82fc JJ |
93 | } |
94 | ||
95 | // Returns a pointer to the first allocated object. | |
96 | #[inline] | |
9cc50fc6 SL |
97 | fn start(&self) -> *mut T { |
98 | self.storage.ptr() | |
1a4d82fc JJ |
99 | } |
100 | ||
101 | // Returns a pointer to the end of the allocated space. | |
102 | #[inline] | |
9cc50fc6 | 103 | fn end(&self) -> *mut T { |
1a4d82fc | 104 | unsafe { |
9cc50fc6 SL |
105 | if mem::size_of::<T>() == 0 { |
106 | // A pointer as large as possible for zero-sized elements. | |
107 | !0 as *mut T | |
108 | } else { | |
b7449926 | 109 | self.start().add(self.storage.cap()) |
9cc50fc6 | 110 | } |
1a4d82fc JJ |
111 | } |
112 | } | |
113 | } | |
114 | ||
9cc50fc6 SL |
115 | const PAGE: usize = 4096; |
116 | ||
0bf4aa26 | 117 | impl<T> Default for TypedArena<T> { |
9e0c209e | 118 | /// Creates a new `TypedArena`. |
0bf4aa26 | 119 | fn default() -> TypedArena<T> { |
9e0c209e SL |
120 | TypedArena { |
121 | // We set both `ptr` and `end` to 0 so that the first call to | |
122 | // alloc() will trigger a grow(). | |
123 | ptr: Cell::new(0 as *mut T), | |
124 | end: Cell::new(0 as *mut T), | |
125 | chunks: RefCell::new(vec![]), | |
126 | _own: PhantomData, | |
1a4d82fc JJ |
127 | } |
128 | } | |
0bf4aa26 | 129 | } |
1a4d82fc | 130 | |
0bf4aa26 | 131 | impl<T> TypedArena<T> { |
1a4d82fc JJ |
132 | /// Allocates an object in the `TypedArena`, returning a reference to it. |
133 | #[inline] | |
134 | pub fn alloc(&self, object: T) -> &mut T { | |
135 | if self.ptr == self.end { | |
c30ab7b3 | 136 | self.grow(1) |
1a4d82fc JJ |
137 | } |
138 | ||
e9174d1e | 139 | unsafe { |
9cc50fc6 | 140 | if mem::size_of::<T>() == 0 { |
2c00a5a8 XL |
141 | self.ptr |
142 | .set(intrinsics::arith_offset(self.ptr.get() as *mut u8, 1) | |
143 | as *mut T); | |
7cac9316 | 144 | let ptr = mem::align_of::<T>() as *mut T; |
9cc50fc6 SL |
145 | // Don't drop the object. This `write` is equivalent to `forget`. |
146 | ptr::write(ptr, object); | |
147 | &mut *ptr | |
148 | } else { | |
149 | let ptr = self.ptr.get(); | |
150 | // Advance the pointer. | |
151 | self.ptr.set(self.ptr.get().offset(1)); | |
152 | // Write into uninitialized memory. | |
153 | ptr::write(ptr, object); | |
154 | &mut *ptr | |
155 | } | |
e9174d1e | 156 | } |
1a4d82fc JJ |
157 | } |
158 | ||
ff7c6d11 | 159 | /// Allocates a slice of objects that are copied into the `TypedArena`, returning a mutable |
c30ab7b3 SL |
160 | /// reference to it. Will panic if passed a zero-sized types. |
161 | /// | |
162 | /// Panics: | |
ff7c6d11 | 163 | /// |
c30ab7b3 SL |
164 | /// - Zero-sized types |
165 | /// - Zero-length slices | |
166 | #[inline] | |
167 | pub fn alloc_slice(&self, slice: &[T]) -> &mut [T] | |
2c00a5a8 XL |
168 | where |
169 | T: Copy, | |
170 | { | |
c30ab7b3 SL |
171 | assert!(mem::size_of::<T>() != 0); |
172 | assert!(slice.len() != 0); | |
173 | ||
174 | let available_capacity_bytes = self.end.get() as usize - self.ptr.get() as usize; | |
175 | let at_least_bytes = slice.len() * mem::size_of::<T>(); | |
176 | if available_capacity_bytes < at_least_bytes { | |
177 | self.grow(slice.len()); | |
178 | } | |
179 | ||
180 | unsafe { | |
181 | let start_ptr = self.ptr.get(); | |
182 | let arena_slice = slice::from_raw_parts_mut(start_ptr, slice.len()); | |
b7449926 | 183 | self.ptr.set(start_ptr.add(arena_slice.len())); |
c30ab7b3 SL |
184 | arena_slice.copy_from_slice(slice); |
185 | arena_slice | |
186 | } | |
187 | } | |
188 | ||
1a4d82fc JJ |
189 | /// Grows the arena. |
190 | #[inline(never)] | |
9cc50fc6 | 191 | #[cold] |
c30ab7b3 | 192 | fn grow(&self, n: usize) { |
1a4d82fc | 193 | unsafe { |
9cc50fc6 | 194 | let mut chunks = self.chunks.borrow_mut(); |
c30ab7b3 | 195 | let (chunk, mut new_capacity); |
9e0c209e | 196 | if let Some(last_chunk) = chunks.last_mut() { |
c30ab7b3 SL |
197 | let used_bytes = self.ptr.get() as usize - last_chunk.start() as usize; |
198 | let currently_used_cap = used_bytes / mem::size_of::<T>(); | |
199 | if last_chunk.storage.reserve_in_place(currently_used_cap, n) { | |
9e0c209e SL |
200 | self.end.set(last_chunk.end()); |
201 | return; | |
202 | } else { | |
32a655c1 | 203 | new_capacity = last_chunk.storage.cap(); |
c30ab7b3 | 204 | loop { |
32a655c1 | 205 | new_capacity = new_capacity.checked_mul(2).unwrap(); |
c30ab7b3 SL |
206 | if new_capacity >= currently_used_cap + n { |
207 | break; | |
208 | } | |
209 | } | |
9e0c209e | 210 | } |
9cc50fc6 | 211 | } else { |
9e0c209e | 212 | let elem_size = cmp::max(1, mem::size_of::<T>()); |
c30ab7b3 | 213 | new_capacity = cmp::max(n, PAGE / elem_size); |
9cc50fc6 | 214 | } |
9e0c209e SL |
215 | chunk = TypedArenaChunk::<T>::new(new_capacity); |
216 | self.ptr.set(chunk.start()); | |
217 | self.end.set(chunk.end()); | |
218 | chunks.push(chunk); | |
9cc50fc6 SL |
219 | } |
220 | } | |
9e0c209e | 221 | |
9cc50fc6 SL |
222 | /// Clears the arena. Deallocates all but the longest chunk which may be reused. |
223 | pub fn clear(&mut self) { | |
224 | unsafe { | |
225 | // Clear the last chunk, which is partially filled. | |
226 | let mut chunks_borrow = self.chunks.borrow_mut(); | |
9e0c209e SL |
227 | if let Some(mut last_chunk) = chunks_borrow.pop() { |
228 | self.clear_last_chunk(&mut last_chunk); | |
229 | // If `T` is ZST, code below has no effect. | |
230 | for mut chunk in chunks_borrow.drain(..) { | |
231 | let cap = chunk.storage.cap(); | |
232 | chunk.destroy(cap); | |
233 | } | |
234 | chunks_borrow.push(last_chunk); | |
9cc50fc6 SL |
235 | } |
236 | } | |
237 | } | |
238 | ||
239 | // Drops the contents of the last chunk. The last chunk is partially empty, unlike all other | |
240 | // chunks. | |
241 | fn clear_last_chunk(&self, last_chunk: &mut TypedArenaChunk<T>) { | |
242 | // Determine how much was filled. | |
243 | let start = last_chunk.start() as usize; | |
244 | // We obtain the value of the pointer to the first uninitialized element. | |
245 | let end = self.ptr.get() as usize; | |
246 | // We then calculate the number of elements to be dropped in the last chunk, | |
247 | // which is the filled area's length. | |
248 | let diff = if mem::size_of::<T>() == 0 { | |
249 | // `T` is ZST. It can't have a drop flag, so the value here doesn't matter. We get | |
250 | // the number of zero-sized values in the last and only chunk, just out of caution. | |
251 | // Recall that `end` was incremented for each allocated value. | |
252 | end - start | |
253 | } else { | |
254 | (end - start) / mem::size_of::<T>() | |
255 | }; | |
256 | // Pass that to the `destroy` method. | |
257 | unsafe { | |
258 | last_chunk.destroy(diff); | |
1a4d82fc | 259 | } |
9cc50fc6 SL |
260 | // Reset the chunk. |
261 | self.ptr.set(last_chunk.start()); | |
1a4d82fc JJ |
262 | } |
263 | } | |
264 | ||
32a655c1 | 265 | unsafe impl<#[may_dangle] T> Drop for TypedArena<T> { |
1a4d82fc JJ |
266 | fn drop(&mut self) { |
267 | unsafe { | |
268 | // Determine how much was filled. | |
9cc50fc6 | 269 | let mut chunks_borrow = self.chunks.borrow_mut(); |
9e0c209e SL |
270 | if let Some(mut last_chunk) = chunks_borrow.pop() { |
271 | // Drop the contents of the last chunk. | |
272 | self.clear_last_chunk(&mut last_chunk); | |
273 | // The last chunk will be dropped. Destroy all other chunks. | |
274 | for chunk in chunks_borrow.iter_mut() { | |
275 | let cap = chunk.storage.cap(); | |
276 | chunk.destroy(cap); | |
277 | } | |
9cc50fc6 SL |
278 | } |
279 | // RawVec handles deallocation of `last_chunk` and `self.chunks`. | |
1a4d82fc JJ |
280 | } |
281 | } | |
282 | } | |
283 | ||
9cc50fc6 SL |
284 | unsafe impl<T: Send> Send for TypedArena<T> {} |
285 | ||
32a655c1 SL |
286 | pub struct DroplessArena { |
287 | /// A pointer to the next object to be allocated. | |
288 | ptr: Cell<*mut u8>, | |
289 | ||
290 | /// A pointer to the end of the allocated area. When this pointer is | |
291 | /// reached, a new chunk is allocated. | |
292 | end: Cell<*mut u8>, | |
293 | ||
294 | /// A vector of arena chunks. | |
295 | chunks: RefCell<Vec<TypedArenaChunk<u8>>>, | |
296 | } | |
297 | ||
83c7162d XL |
298 | unsafe impl Send for DroplessArena {} |
299 | ||
0bf4aa26 XL |
300 | impl Default for DroplessArena { |
301 | fn default() -> DroplessArena { | |
32a655c1 SL |
302 | DroplessArena { |
303 | ptr: Cell::new(0 as *mut u8), | |
304 | end: Cell::new(0 as *mut u8), | |
0bf4aa26 | 305 | chunks: Default::default(), |
32a655c1 SL |
306 | } |
307 | } | |
0bf4aa26 | 308 | } |
32a655c1 | 309 | |
0bf4aa26 | 310 | impl DroplessArena { |
32a655c1 SL |
311 | pub fn in_arena<T: ?Sized>(&self, ptr: *const T) -> bool { |
312 | let ptr = ptr as *const u8 as *mut u8; | |
313 | for chunk in &*self.chunks.borrow() { | |
314 | if chunk.start() <= ptr && ptr < chunk.end() { | |
315 | return true; | |
316 | } | |
317 | } | |
318 | ||
319 | false | |
320 | } | |
321 | ||
94b46f34 | 322 | fn align(&self, align: usize) { |
32a655c1 SL |
323 | let final_address = ((self.ptr.get() as usize) + align - 1) & !(align - 1); |
324 | self.ptr.set(final_address as *mut u8); | |
325 | assert!(self.ptr <= self.end); | |
326 | } | |
327 | ||
328 | #[inline(never)] | |
329 | #[cold] | |
94b46f34 | 330 | fn grow(&self, needed_bytes: usize) { |
32a655c1 SL |
331 | unsafe { |
332 | let mut chunks = self.chunks.borrow_mut(); | |
333 | let (chunk, mut new_capacity); | |
334 | if let Some(last_chunk) = chunks.last_mut() { | |
335 | let used_bytes = self.ptr.get() as usize - last_chunk.start() as usize; | |
2c00a5a8 XL |
336 | if last_chunk |
337 | .storage | |
338 | .reserve_in_place(used_bytes, needed_bytes) | |
339 | { | |
32a655c1 SL |
340 | self.end.set(last_chunk.end()); |
341 | return; | |
342 | } else { | |
343 | new_capacity = last_chunk.storage.cap(); | |
344 | loop { | |
345 | new_capacity = new_capacity.checked_mul(2).unwrap(); | |
346 | if new_capacity >= used_bytes + needed_bytes { | |
347 | break; | |
348 | } | |
349 | } | |
350 | } | |
351 | } else { | |
352 | new_capacity = cmp::max(needed_bytes, PAGE); | |
353 | } | |
354 | chunk = TypedArenaChunk::<u8>::new(new_capacity); | |
355 | self.ptr.set(chunk.start()); | |
356 | self.end.set(chunk.end()); | |
357 | chunks.push(chunk); | |
358 | } | |
359 | } | |
360 | ||
361 | #[inline] | |
94b46f34 | 362 | pub fn alloc_raw(&self, bytes: usize, align: usize) -> &mut [u8] { |
32a655c1 | 363 | unsafe { |
94b46f34 XL |
364 | assert!(bytes != 0); |
365 | ||
366 | self.align(align); | |
32a655c1 | 367 | |
94b46f34 | 368 | let future_end = intrinsics::arith_offset(self.ptr.get(), bytes as isize); |
32a655c1 | 369 | if (future_end as *mut u8) >= self.end.get() { |
94b46f34 | 370 | self.grow(bytes); |
32a655c1 SL |
371 | } |
372 | ||
373 | let ptr = self.ptr.get(); | |
374 | // Set the pointer past ourselves | |
2c00a5a8 | 375 | self.ptr.set( |
94b46f34 | 376 | intrinsics::arith_offset(self.ptr.get(), bytes as isize) as *mut u8, |
2c00a5a8 | 377 | ); |
94b46f34 XL |
378 | slice::from_raw_parts_mut(ptr, bytes) |
379 | } | |
380 | } | |
381 | ||
382 | #[inline] | |
383 | pub fn alloc<T>(&self, object: T) -> &mut T { | |
384 | assert!(!mem::needs_drop::<T>()); | |
385 | ||
386 | let mem = self.alloc_raw( | |
387 | mem::size_of::<T>(), | |
388 | mem::align_of::<T>()) as *mut _ as *mut T; | |
389 | ||
390 | unsafe { | |
32a655c1 | 391 | // Write into uninitialized memory. |
94b46f34 XL |
392 | ptr::write(mem, object); |
393 | &mut *mem | |
32a655c1 SL |
394 | } |
395 | } | |
396 | ||
397 | /// Allocates a slice of objects that are copied into the `DroplessArena`, returning a mutable | |
398 | /// reference to it. Will panic if passed a zero-sized type. | |
399 | /// | |
400 | /// Panics: | |
ff7c6d11 | 401 | /// |
32a655c1 SL |
402 | /// - Zero-sized types |
403 | /// - Zero-length slices | |
404 | #[inline] | |
405 | pub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T] | |
2c00a5a8 XL |
406 | where |
407 | T: Copy, | |
408 | { | |
7cac9316 | 409 | assert!(!mem::needs_drop::<T>()); |
32a655c1 SL |
410 | assert!(mem::size_of::<T>() != 0); |
411 | assert!(slice.len() != 0); | |
32a655c1 | 412 | |
94b46f34 XL |
413 | let mem = self.alloc_raw( |
414 | slice.len() * mem::size_of::<T>(), | |
415 | mem::align_of::<T>()) as *mut _ as *mut T; | |
32a655c1 SL |
416 | |
417 | unsafe { | |
94b46f34 | 418 | let arena_slice = slice::from_raw_parts_mut(mem, slice.len()); |
32a655c1 SL |
419 | arena_slice.copy_from_slice(slice); |
420 | arena_slice | |
421 | } | |
422 | } | |
423 | } | |
424 | ||
0bf4aa26 XL |
425 | #[derive(Default)] |
426 | // FIXME(@Zoxc): this type is entirely unused in rustc | |
83c7162d XL |
427 | pub struct SyncTypedArena<T> { |
428 | lock: MTLock<TypedArena<T>>, | |
429 | } | |
430 | ||
431 | impl<T> SyncTypedArena<T> { | |
83c7162d XL |
432 | #[inline(always)] |
433 | pub fn alloc(&self, object: T) -> &mut T { | |
434 | // Extend the lifetime of the result since it's limited to the lock guard | |
435 | unsafe { &mut *(self.lock.lock().alloc(object) as *mut T) } | |
436 | } | |
437 | ||
438 | #[inline(always)] | |
439 | pub fn alloc_slice(&self, slice: &[T]) -> &mut [T] | |
440 | where | |
441 | T: Copy, | |
442 | { | |
443 | // Extend the lifetime of the result since it's limited to the lock guard | |
444 | unsafe { &mut *(self.lock.lock().alloc_slice(slice) as *mut [T]) } | |
445 | } | |
446 | ||
447 | #[inline(always)] | |
448 | pub fn clear(&mut self) { | |
449 | self.lock.get_mut().clear(); | |
450 | } | |
451 | } | |
452 | ||
0bf4aa26 | 453 | #[derive(Default)] |
83c7162d XL |
454 | pub struct SyncDroplessArena { |
455 | lock: MTLock<DroplessArena>, | |
456 | } | |
457 | ||
458 | impl SyncDroplessArena { | |
83c7162d XL |
459 | #[inline(always)] |
460 | pub fn in_arena<T: ?Sized>(&self, ptr: *const T) -> bool { | |
461 | self.lock.lock().in_arena(ptr) | |
462 | } | |
463 | ||
94b46f34 XL |
464 | #[inline(always)] |
465 | pub fn alloc_raw(&self, bytes: usize, align: usize) -> &mut [u8] { | |
466 | // Extend the lifetime of the result since it's limited to the lock guard | |
467 | unsafe { &mut *(self.lock.lock().alloc_raw(bytes, align) as *mut [u8]) } | |
468 | } | |
469 | ||
83c7162d XL |
470 | #[inline(always)] |
471 | pub fn alloc<T>(&self, object: T) -> &mut T { | |
472 | // Extend the lifetime of the result since it's limited to the lock guard | |
473 | unsafe { &mut *(self.lock.lock().alloc(object) as *mut T) } | |
474 | } | |
475 | ||
476 | #[inline(always)] | |
477 | pub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T] | |
478 | where | |
479 | T: Copy, | |
480 | { | |
481 | // Extend the lifetime of the result since it's limited to the lock guard | |
482 | unsafe { &mut *(self.lock.lock().alloc_slice(slice) as *mut [T]) } | |
483 | } | |
484 | } | |
485 | ||
1a4d82fc JJ |
486 | #[cfg(test)] |
487 | mod tests { | |
488 | extern crate test; | |
489 | use self::test::Bencher; | |
54a0048b | 490 | use super::TypedArena; |
9cc50fc6 | 491 | use std::cell::Cell; |
1a4d82fc JJ |
492 | |
493 | #[allow(dead_code)] | |
9cc50fc6 | 494 | #[derive(Debug, Eq, PartialEq)] |
1a4d82fc | 495 | struct Point { |
85aaf69f SL |
496 | x: i32, |
497 | y: i32, | |
498 | z: i32, | |
499 | } | |
500 | ||
9e0c209e SL |
501 | #[test] |
502 | pub fn test_unused() { | |
0bf4aa26 | 503 | let arena: TypedArena<Point> = TypedArena::default(); |
9e0c209e SL |
504 | assert!(arena.chunks.borrow().is_empty()); |
505 | } | |
506 | ||
85aaf69f SL |
507 | #[test] |
508 | fn test_arena_alloc_nested() { | |
b039eaaf SL |
509 | struct Inner { |
510 | value: u8, | |
511 | } | |
512 | struct Outer<'a> { | |
513 | inner: &'a Inner, | |
514 | } | |
515 | enum EI<'e> { | |
516 | I(Inner), | |
517 | O(Outer<'e>), | |
518 | } | |
85aaf69f SL |
519 | |
520 | struct Wrap<'a>(TypedArena<EI<'a>>); | |
521 | ||
522 | impl<'a> Wrap<'a> { | |
b039eaaf | 523 | fn alloc_inner<F: Fn() -> Inner>(&self, f: F) -> &Inner { |
85aaf69f SL |
524 | let r: &EI = self.0.alloc(EI::I(f())); |
525 | if let &EI::I(ref i) = r { | |
526 | i | |
527 | } else { | |
528 | panic!("mismatch"); | |
529 | } | |
530 | } | |
b039eaaf | 531 | fn alloc_outer<F: Fn() -> Outer<'a>>(&self, f: F) -> &Outer { |
85aaf69f SL |
532 | let r: &EI = self.0.alloc(EI::O(f())); |
533 | if let &EI::O(ref o) = r { | |
534 | o | |
535 | } else { | |
536 | panic!("mismatch"); | |
537 | } | |
538 | } | |
539 | } | |
540 | ||
0bf4aa26 | 541 | let arena = Wrap(TypedArena::default()); |
85aaf69f | 542 | |
2c00a5a8 XL |
543 | let result = arena.alloc_outer(|| Outer { |
544 | inner: arena.alloc_inner(|| Inner { value: 10 }), | |
545 | }); | |
85aaf69f SL |
546 | |
547 | assert_eq!(result.inner.value, 10); | |
1a4d82fc JJ |
548 | } |
549 | ||
550 | #[test] | |
551 | pub fn test_copy() { | |
0bf4aa26 | 552 | let arena = TypedArena::default(); |
85aaf69f | 553 | for _ in 0..100000 { |
b039eaaf | 554 | arena.alloc(Point { x: 1, y: 2, z: 3 }); |
1a4d82fc JJ |
555 | } |
556 | } | |
557 | ||
558 | #[bench] | |
559 | pub fn bench_copy(b: &mut Bencher) { | |
0bf4aa26 | 560 | let arena = TypedArena::default(); |
b039eaaf | 561 | b.iter(|| arena.alloc(Point { x: 1, y: 2, z: 3 })) |
1a4d82fc JJ |
562 | } |
563 | ||
564 | #[bench] | |
565 | pub fn bench_copy_nonarena(b: &mut Bencher) { | |
566 | b.iter(|| { | |
9cc50fc6 | 567 | let _: Box<_> = Box::new(Point { x: 1, y: 2, z: 3 }); |
1a4d82fc JJ |
568 | }) |
569 | } | |
570 | ||
1a4d82fc JJ |
571 | #[allow(dead_code)] |
572 | struct Noncopy { | |
573 | string: String, | |
85aaf69f | 574 | array: Vec<i32>, |
1a4d82fc JJ |
575 | } |
576 | ||
577 | #[test] | |
578 | pub fn test_noncopy() { | |
0bf4aa26 | 579 | let arena = TypedArena::default(); |
85aaf69f | 580 | for _ in 0..100000 { |
1a4d82fc JJ |
581 | arena.alloc(Noncopy { |
582 | string: "hello world".to_string(), | |
92a42be0 | 583 | array: vec![1, 2, 3, 4, 5], |
1a4d82fc JJ |
584 | }); |
585 | } | |
586 | } | |
587 | ||
9cc50fc6 SL |
588 | #[test] |
589 | pub fn test_typed_arena_zero_sized() { | |
0bf4aa26 | 590 | let arena = TypedArena::default(); |
9cc50fc6 SL |
591 | for _ in 0..100000 { |
592 | arena.alloc(()); | |
593 | } | |
594 | } | |
595 | ||
9cc50fc6 SL |
596 | #[test] |
597 | pub fn test_typed_arena_clear() { | |
0bf4aa26 | 598 | let mut arena = TypedArena::default(); |
9cc50fc6 SL |
599 | for _ in 0..10 { |
600 | arena.clear(); | |
601 | for _ in 0..10000 { | |
602 | arena.alloc(Point { x: 1, y: 2, z: 3 }); | |
603 | } | |
604 | } | |
605 | } | |
606 | ||
9cc50fc6 SL |
607 | // Drop tests |
608 | ||
609 | struct DropCounter<'a> { | |
610 | count: &'a Cell<u32>, | |
611 | } | |
612 | ||
613 | impl<'a> Drop for DropCounter<'a> { | |
614 | fn drop(&mut self) { | |
615 | self.count.set(self.count.get() + 1); | |
616 | } | |
617 | } | |
618 | ||
9cc50fc6 SL |
619 | #[test] |
620 | fn test_typed_arena_drop_count() { | |
621 | let counter = Cell::new(0); | |
622 | { | |
0bf4aa26 | 623 | let arena: TypedArena<DropCounter> = TypedArena::default(); |
9cc50fc6 SL |
624 | for _ in 0..100 { |
625 | // Allocate something with drop glue to make sure it doesn't leak. | |
626 | arena.alloc(DropCounter { count: &counter }); | |
627 | } | |
628 | }; | |
629 | assert_eq!(counter.get(), 100); | |
630 | } | |
631 | ||
632 | #[test] | |
633 | fn test_typed_arena_drop_on_clear() { | |
634 | let counter = Cell::new(0); | |
0bf4aa26 | 635 | let mut arena: TypedArena<DropCounter> = TypedArena::default(); |
9cc50fc6 SL |
636 | for i in 0..10 { |
637 | for _ in 0..100 { | |
638 | // Allocate something with drop glue to make sure it doesn't leak. | |
639 | arena.alloc(DropCounter { count: &counter }); | |
640 | } | |
641 | arena.clear(); | |
642 | assert_eq!(counter.get(), i * 100 + 100); | |
643 | } | |
644 | } | |
645 | ||
646 | thread_local! { | |
647 | static DROP_COUNTER: Cell<u32> = Cell::new(0) | |
648 | } | |
649 | ||
650 | struct SmallDroppable; | |
651 | ||
652 | impl Drop for SmallDroppable { | |
653 | fn drop(&mut self) { | |
654 | DROP_COUNTER.with(|c| c.set(c.get() + 1)); | |
655 | } | |
656 | } | |
657 | ||
9cc50fc6 SL |
658 | #[test] |
659 | fn test_typed_arena_drop_small_count() { | |
660 | DROP_COUNTER.with(|c| c.set(0)); | |
661 | { | |
0bf4aa26 | 662 | let arena: TypedArena<SmallDroppable> = TypedArena::default(); |
9cc50fc6 SL |
663 | for _ in 0..100 { |
664 | // Allocate something with drop glue to make sure it doesn't leak. | |
665 | arena.alloc(SmallDroppable); | |
666 | } | |
667 | // dropping | |
668 | }; | |
669 | assert_eq!(DROP_COUNTER.with(|c| c.get()), 100); | |
670 | } | |
671 | ||
1a4d82fc JJ |
672 | #[bench] |
673 | pub fn bench_noncopy(b: &mut Bencher) { | |
0bf4aa26 | 674 | let arena = TypedArena::default(); |
1a4d82fc JJ |
675 | b.iter(|| { |
676 | arena.alloc(Noncopy { | |
677 | string: "hello world".to_string(), | |
92a42be0 | 678 | array: vec![1, 2, 3, 4, 5], |
1a4d82fc JJ |
679 | }) |
680 | }) | |
681 | } | |
682 | ||
683 | #[bench] | |
684 | pub fn bench_noncopy_nonarena(b: &mut Bencher) { | |
685 | b.iter(|| { | |
9cc50fc6 | 686 | let _: Box<_> = Box::new(Noncopy { |
1a4d82fc | 687 | string: "hello world".to_string(), |
92a42be0 | 688 | array: vec![1, 2, 3, 4, 5], |
9cc50fc6 | 689 | }); |
1a4d82fc JJ |
690 | }) |
691 | } | |
1a4d82fc | 692 | } |