hakmem/core/hakmem_tiny_remote_target.c

#include "hakmem_tiny_remote_target.h"
#include "hakmem_tiny.h"  // For TinySlab definition

// Global variables
// BG Remote variables REMOVED (dead code cleanup 2025-11-27)
_Atomic uintptr_t g_remote_target_head[TINY_NUM_CLASSES];
_Atomic uint32_t g_remote_target_len[TINY_NUM_CLASSES];

void remote_target_enqueue(int class_idx, TinySlab* slab) {
    // Best-effort: mark as enqueued once to avoid duplicate pushes
    unsigned was = atomic_exchange_explicit(&slab->remote_queued, 1u, memory_order_acq_rel);
    if (was) return;
    // Link into per-class Treiber stack
    uintptr_t old_head;
    do {
        old_head = atomic_load_explicit(&g_remote_target_head[class_idx], memory_order_acquire);
        slab->remote_q_next = (TinySlab*)old_head;
    } while (!atomic_compare_exchange_weak_explicit(&g_remote_target_head[class_idx], &old_head,
                                                    (uintptr_t)slab,
                                                    memory_order_release, memory_order_relaxed));
    atomic_fetch_add_explicit(&g_remote_target_len[class_idx], 1u, memory_order_relaxed);
}

TinySlab* remote_target_pop(int class_idx) {
    uintptr_t head;
    TinySlab* node;
    do {
        head = atomic_load_explicit(&g_remote_target_head[class_idx], memory_order_acquire);
        if (head == 0) return NULL;
        node = (TinySlab*)head;
    } while (!atomic_compare_exchange_weak_explicit(&g_remote_target_head[class_idx], &head,
                                                    (uintptr_t)node->remote_q_next,
                                                    memory_order_acq_rel, memory_order_relaxed));
    // Mark dequeued so it can be re-enqueued later if needed
    atomic_store_explicit(&node->remote_queued, 0u, memory_order_release);
    atomic_fetch_sub_explicit(&g_remote_target_len[class_idx], 1u, memory_order_relaxed);
    node->remote_q_next = NULL;
    return node;
}