From ccf53949b21636c0472c902fb158c9ca4653776c Mon Sep 17 00:00:00 2001
From: Talha Qamar <qamartalha@proton.me>
Date: Sat, 1 Feb 2025 06:50:35 +0500
Subject: [PATCH] We now have realloc
---
src/lily/alloc/arena.hb | 34 +++++++++++++++++++++++++---------
1 file changed, 25 insertions(+), 9 deletions(-)
diff --git a/src/lily/alloc/arena.hb b/src/lily/alloc/arena.hb
index 12cef79..57b1d40 100644
--- a/src/lily/alloc/arena.hb
+++ b/src/lily/alloc/arena.hb
@@ -1,4 +1,4 @@
-.{Config, Target, Type, log, collections: .{Vec}} := @use("../lib.hb");
+.{Config, Target, Type, log, collections: .{Vec}, alloc: .{RawAllocator}} := @use("../lib.hb");
Allocation := struct {
ptr: ^u8,
@@ -9,18 +9,24 @@ ArenaAllocator := struct {
ptr: ^u8,
size: uint,
allocated: uint,
+ allocations: Vec(Allocation, RawAllocator),
+ raw: RawAllocator,
new := fn(): Self {
size := Target.page_size()
// todo(?): spec should accept ?Self as return type
ptr := @unwrap(Target.alloc_zeroed(size))
- return .(ptr, size, 0)
+ raw := RawAllocator.new()
+ vec := Vec(Allocation, RawAllocator).new(&raw)
+ return .(ptr, size, 0, vec, raw)
}
deinit := fn(self: ^Self): void {
match Target.current() {
.LibC => Target.dealloc(self.ptr),
.AbleOS => Target.dealloc(self.ptr, self.size),
}
+ self.vec.deinit()
+ self.raw.deinit()
log.debug("deinit: allocator")
}
alloc := fn(self: ^Self, $T: type, count: uint): ?^T {
@@ -33,6 +39,7 @@ ArenaAllocator := struct {
self.ptr = @unwrap(ptr)
}
allocation := self.ptr + self.allocated
+ self.allocations.push(.(allocation, count * @sizeof(T)))
self.allocated = self.allocated + count * @sizeof(T)
log.debug("allocated")
return @bitcast(allocation)
@@ -41,21 +48,30 @@ ArenaAllocator := struct {
return self.alloc(T, count)
}
realloc := fn(self: ^Self, $T: type, ptr: ^T, count: uint): ?^T {
- log.error("Don't call realloc on the arena allocator");
- die
+ old_size := self._find_size(ptr)
+ if old_size == null {
+ return null
+ }
+ if old_size > @sizeof(T) * count {
+ if Config.debug_assertions() {
+ log.warn("arena allocator: new_size is smaller than old_size")
+ }
+ return ptr
+ }
+ new_ptr := self.alloc(T, count)
+ Target.memcpy(new_ptr, ptr, old_size)
+ return new_ptr
}
dealloc := fn(self: ^Self, $T: type, ptr: ^T): void {
log.debug("freed")
}
- _find_and_remove := fn(self: ^Self, ptr: ^u8): ?Allocation {
+
+ _find_size := fn(self: ^Self, ptr: ^u8): ?uint {
i := 0
loop if i == self.allocations.len() break else {
defer i += 1
alloced := self.allocations.get_unchecked(i)
- if alloced.ptr == ptr {
- _ = self.allocations.swap_remove(i)
- return alloced
- }
+ return alloced.len
}
return null
}