42 lines
1.6 KiB
C
42 lines
1.6 KiB
C
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#include "free_local_box.h"
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#include "free_publish_box.h"
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#include "hakmem_tiny.h"
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void tiny_free_local_box(SuperSlab* ss, int slab_idx, TinySlabMeta* meta, void* ptr, uint32_t my_tid) {
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extern _Atomic uint64_t g_free_local_box_calls;
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atomic_fetch_add_explicit(&g_free_local_box_calls, 1, memory_order_relaxed);
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if (!(ss && ss->magic == SUPERSLAB_MAGIC)) return;
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if (slab_idx < 0 || slab_idx >= ss_slabs_capacity(ss)) return;
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(void)my_tid;
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void* prev = meta->freelist;
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*(void**)ptr = prev;
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meta->freelist = ptr;
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// BUGFIX: Memory barrier to ensure freelist visibility before used decrement
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// Without this, other threads can see new freelist but old used count (race)
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atomic_thread_fence(memory_order_release);
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// Optional freelist mask update on first push
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do {
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static int g_mask_en = -1;
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if (__builtin_expect(g_mask_en == -1, 0)) {
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const char* e = getenv("HAKMEM_TINY_FREELIST_MASK");
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g_mask_en = (e && *e && *e != '0') ? 1 : 0;
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}
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if (__builtin_expect(g_mask_en, 0) && prev == NULL) {
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uint32_t bit = (1u << slab_idx);
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atomic_fetch_or_explicit(&ss->freelist_mask, bit, memory_order_release);
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}
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} while (0);
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// Track local free (debug helpers may be no-op)
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tiny_remote_track_on_local_free(ss, slab_idx, ptr, "local_free", my_tid);
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meta->used--;
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ss_active_dec_one(ss);
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if (prev == NULL) {
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// First-free → advertise slab to adopters
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tiny_free_publish_first_free((int)ss->size_class, ss, slab_idx);
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}
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}
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