我正在学习Redis源码，在zmalloc.c中，size_tzmalloc_size(void*ptr){void*realptr=(char*)ptr-PREFIX_SIZE;size_tsize=*((size_t*)realptr);/*Assumeatleastthatalltheallocationsarepaddedatsizeof(long)by*theunderlyingallocator.*/if(size&(sizeof(long)-1))size+=sizeof(long)-(size&(sizeof(long)-1));returnsize+PREFIX_SI