diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib/mem.zig | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/src/lib/mem.zig b/src/lib/mem.zig index a9addf6..9e77add 100644 --- a/src/lib/mem.zig +++ b/src/lib/mem.zig @@ -72,6 +72,8 @@ pub fn ChunkAllocator(comptime config: ChunkAllocatorConfig) type { pub fn alloc(ctx: *anyopaque, len: usize, log2_ptr_align: u8, ret_addr: usize) ?[*]u8 { _ = ret_addr; + if (len == 0) return null; + const self: *Self = @ptrCast(@alignCast(ctx)); const ptr_align = @as(usize, 1) << @as(std.mem.Allocator.Log2Align, @intCast(log2_ptr_align)); @@ -110,18 +112,22 @@ pub fn ChunkAllocator(comptime config: ChunkAllocatorConfig) type { pub fn resize(ctx: *anyopaque, buf: []u8, log2_buf_align: u8, new_len: usize, ret_addr: usize) bool { _ = ret_addr; + if (new_len == 0) return false; + const self: *Self = @ptrCast(@alignCast(ctx)); const ptr_align = @as(usize, 1) << @as(std.mem.Allocator.Log2Align, @intCast(log2_buf_align)); + const adjust_off = std.mem.alignPointerOffset(buf.ptr, ptr_align) orelse return false; + const aligned_new_len = new_len + adjust_off; + + const len_ptr: [*]const u8 = @ptrFromInt(buf.len); + const padding_len = std.mem.alignPointerOffset(len_ptr, ptr_align) orelse return false; + const head = self.head orelse return false; const bound = @intFromPtr(head) + (self.pages * paging.page_size); - // fixme: Doesn't account for alignment between header and data. - const chunk = @as(*align(1) Chunk, @ptrCast(buf.ptr - @sizeOf(Chunk))); - - const adjust_off = std.mem.alignPointerOffset(buf.ptr, ptr_align) orelse return false; - const aligned_new_len = new_len + adjust_off; + const chunk = @as(*align(1) Chunk, @ptrCast(buf.ptr - padding_len - @sizeOf(Chunk))); if (aligned_new_len < chunk.len) { const regained = chunk.len - aligned_new_len; |