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agra
2026-02-20 21:50:49 +02:00
parent 2f95810f9d
commit efa60fa670
12 changed files with 148 additions and 103 deletions
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64
examples/modules/allocators.sx
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@@ -27,53 +27,49 @@ gpa_free :: (ctx: *void, ptr: *void) {
}
gpa_create :: (gpa: *GPA) -> Allocator {
ctx : *void = xx gpa;
Allocator.{ ctx = ctx, alloc = gpa_alloc, free = gpa_free };
Allocator.{ ctx = gpa, alloc = gpa_alloc, free = gpa_free };
}
// --- Arena: multi-chunk bump allocator (Zig-inspired) ---
ArenaChunk :: struct {
next: *void; // *ArenaChunk
cap: s64; // total chunk size including this header
next: *ArenaChunk;
cap: s64;
}
Arena :: struct {
first: *void; // *ArenaChunk — head of list (newest first)
end_index: s64; // bump position within current chunk's usable area
parent: Allocator; // backing allocator
first: *ArenaChunk;
end_index: s64;
parent: Allocator;
}
arena_add_chunk :: (a: *Arena, min_size: s64) {
first_i : s64 = xx a.first;
prev_cap := if first_i != 0 then { c : *ArenaChunk = xx a.first; c.cap; } else 0;
prev_cap := if a.first != null then a.first.cap else 0;
needed := min_size + 16 + 16;
len := (prev_cap + needed) * 3 / 2;
raw := a.parent.alloc(a.parent.ctx, len);
chunk : *ArenaChunk = xx raw;
chunk.next = a.first;
chunk.cap = len;
a.first = xx chunk;
a.first = chunk;
a.end_index = 0;
}
arena_alloc :: (ctx: *void, size: s64) -> *void {
a : *Arena = xx ctx;
aligned := (size + 7) & (0 - 8);
first_i : s64 = xx a.first;
if first_i != 0 {
chunk : *ArenaChunk = xx a.first;
usable := chunk.cap - 16;
if a.first != null {
usable := a.first.cap - 16;
if a.end_index + aligned <= usable {
buf : [*]u8 = xx a.first;
ptr : *void = xx @buf[16 + a.end_index];
ptr := @buf[16 + a.end_index];
a.end_index = a.end_index + aligned;
return ptr;
}
}
arena_add_chunk(a, aligned);
buf : [*]u8 = xx a.first;
ptr : *void = xx @buf[16 + a.end_index];
ptr := @buf[16 + a.end_index];
a.end_index = a.end_index + aligned;
ptr;
}
@@ -86,34 +82,29 @@ arena_create :: (a: *Arena, parent: Allocator, size: s64) -> Allocator {
a.end_index = 0;
a.parent = parent;
arena_add_chunk(a, size);
ctx : *void = xx a;
Allocator.{ ctx = ctx, alloc = arena_alloc, free = arena_free };
Allocator.{ ctx = a, alloc = arena_alloc, free = arena_free };
}
arena_reset :: (a: *Arena) {
// Keep first chunk (newest/largest), free the rest
first_i : s64 = xx a.first;
if first_i != 0 {
chunk : *ArenaChunk = xx a.first;
it : s64 = xx chunk.next;
while it != 0 {
c : *ArenaChunk = xx it;
next_i : s64 = xx c.next;
a.parent.free(a.parent.ctx, xx c);
it = next_i;
if a.first != null {
it := a.first.next;
while it != null {
next := it.next;
a.parent.free(a.parent.ctx, it);
it = next;
}
chunk.next = null;
a.first.next = null;
}
a.end_index = 0;
}
arena_deinit :: (a: *Arena) {
it : s64 = xx a.first;
while it != 0 {
c : *ArenaChunk = xx it;
next_i : s64 = xx c.next;
a.parent.free(a.parent.ctx, xx c);
it = next_i;
it := a.first;
while it != null {
next := it.next;
a.parent.free(a.parent.ctx, it);
it = next;
}
a.first = null;
a.end_index = 0;
@@ -133,7 +124,7 @@ buf_alloc :: (ctx: *void, size: s64) -> *void {
if b.pos + aligned > b.len {
return null;
}
ptr : *void = xx @b.buf[b.pos];
ptr := @b.buf[b.pos];
b.pos = b.pos + aligned;
ptr;
}
@@ -145,8 +136,7 @@ buf_create :: (b: *BufAlloc, buf: [*]u8, len: s64) -> Allocator {
b.buf = buf;
b.len = len;
b.pos = 0;
ctx : *void = xx b;
Allocator.{ ctx = ctx, alloc = buf_alloc, free = buf_free };
Allocator.{ ctx = b, alloc = buf_alloc, free = buf_free };
}
buf_reset :: (b: *BufAlloc) {