mnemosyne-local 0.6.0

//! The cold free path taken when a page or segment changes state.

use crate::LocalAllocatorSelector;
use crate::per_cpu;
use core::ptr::NonNull;
use mnemosyne_arena::HasSegmentPool;
use mnemosyne_core::types::{Block, Page, Segment};

#[cold]
#[inline(never)]
pub(super) unsafe fn thread_free_cold<B: HasSegmentPool + LocalAllocatorSelector<B>>(
    ptr: *mut u8,
    page: *mut Page,
    block: *mut Block,
) {
    // SAFETY: `page` is the live page metadata the caller located for a block of
    // this allocator, and `parent_segment_of` masks it to its live segment header;
    // both reads are of initialization-time fields.
    let encrypted = unsafe { Segment::free_list_encrypted(Page::parent_segment_of(page)) };
    if B::ENABLE_CPU_CACHE
        && per_cpu::try_free_cpu(ptr, unsafe { (*page).size_class } as usize, encrypted)
    {
        #[cfg(feature = "dealloc-probe")]
        crate::dealloc_counters::record(crate::dealloc_counters::DeallocPath::ColdOrRecursing);
        return;
    }

    // SAFETY: `block` came from this allocator under the same
    // backend; non-nullness is the allocator invariant. The page-
    // local atomic free list takes ownership of the pointer.
    unsafe {
        (*page)
            .thread_free
            .push_dynamic(NonNull::new_unchecked(block), encrypted);
    }
    #[cfg(feature = "dealloc-probe")]
    crate::dealloc_counters::record(crate::dealloc_counters::DeallocPath::ColdOrRecursing);
}