deinitLeakedBucket

fn deinitLeakedBucket(s: *SafeAllocator, b: *Bucket, log: bool) usize {
    var leaks: usize = 0;

    const expected = @atomicLoad(Bucket.AllocCount, &b.alloc_count, .acquire);
    if (expected.n == 0) assert(expected.filling);

    var footer = b.lastAlloc(s, b.fill).?;
    while (true) {
        const modify = @atomicRmw(
            AllocFooter.Modify,
            &footer.modify,
            .Xchg,
            undefined,
            .monotonic,
        ).storedXor(&footer.modify);

        const bad_modify = modify != .none and modify != .freed;
        if (bad_modify or footer.actualChecksum(s) != footer.checksum ^ s.canary) {
            panic("corrupted footer metadata in bucket at *{x}", .{@intFromPtr(&footer)});
        }

        switch (modify) {
            .none => {
                leaks += 1;
                if (log) scoped_log.err("leaked {f} allocated at: {f}", .{ FormatMemory{
                    .memory = footer.userMemory(),
                    .alignment = footer.userAlign(),
                }, formatStackTrace(footer.allocTrace(s)) });
            },
            .freed => s.checkFreed(footer),
            else => unreachable,
        }

        footer = footer.bucketPrev(b, s) orelse break;
    }
    s.backing.rawFree(b.bytes(s), @fromBackingInt(@intCast(s.bucket_size_log2)), 0);

    assert(leaks == expected.n);
    return leaks;
}