nt-lite/code/kernel/ke_id.c

// Kernel monotonic identifier allocator. Public identities stay 32-bit while the internal cursor detects exhaustion without wrapping.

#include <intrin.h>
#include <kernel/ke_id.h>

// Allocates one 32-bit identifier and permanently advances the allocator.
KSTATUS KeAllocateId32(KE_ID_ALLOCATOR* allocator, uint32_t* idOut) {
    if (!allocator || !idOut)
        return NTLSTATUS_INVALID_PARAMETER;

    while (1) {
        long long next = _InterlockedCompareExchange64(&allocator->Next, 0, 0);
        if ((unsigned long long)next > 0xFFFFFFFFULL)
            return NTLSTATUS_ID_EXHAUSTED;

        long long desired = next + 1;
        if (_InterlockedCompareExchange64(&allocator->Next, desired, next) == next) {
            *idOut = (uint32_t)next;
            return NTLSTATUS_SUCCESS;
        }
    }
}