ZeroCopyOperationen

Zero-copy operations, often referred to as zero-copy I/O or zero-copy data transfer, are a class of techniques in computer programming that allow data to be transferred between memory spaces without requiring the central processing unit (CPU) to copy the data. This bypasses the need for the CPU to act as an intermediary, fetching data from one memory location and writing it to another. Instead, zero-copy mechanisms typically leverage operating system features or hardware capabilities to achieve direct memory-to-memory or memory-to-device transfers.

The primary benefit of zero-copy operations is improved performance, particularly in scenarios involving large data volumes or high-throughput I/O. By reducing the number of CPU-intensive data copies, zero-copy can significantly decrease CPU utilization and latency. This is especially advantageous in applications like network servers, file servers, and high-performance computing, where efficient data handling is critical.

Common techniques for implementing zero-copy operations include memory-mapped files, scatter-gather I/O (also known as vector I/O), and direct memory access (DMA) transfers. Memory-mapped files allow a file on disk to be mapped directly into the process's address space, enabling access to file data as if it were in memory without explicit read or write calls. Scatter-gather I/O allows an I/O operation to read from or write to multiple non-contiguous memory buffers in a single system call. DMA, a hardware-level capability, permits peripheral devices to transfer data directly to and from main memory without involving the CPU.