.net通用垃圾收集优化技术

Avoid unnecessary allocations in hot paths

For example, in a tight loop or frequently called method, try to avoid creating new objects.

Bad:

for(int i = 0; i < 100; i++) {
  var obj = new MyObject();
  //...
}

Good:

MyObject obj = null;
for(int i = 0; i < 100; i++) {
  if(obj == null) {
    obj = new MyObject(); 
  }
  // Reuse obj instead of reallocating
}

Reuse buffers instead of allocating new ones

Avoid unnecessary allocations in hot paths

Reuse buffers instead of allocating new ones

For byte arrays or other buffers, allocate once and reuse instead of reallocating.

Bad:

byte[] buffer = new byte[1024];

void ProcessData() {
  buffer = new byte[data.Length]; // re-allocate each time
  //...
}

Good:

byte[] buffer = new byte[1024];

void ProcessData() {
  if(buffer.Length < data.Length) {
    // Resize only if needed
    buffer = new byte[data.Length]; 
  }

  // Reuse buffer
  //...
}

Use structs instead of classes where possible

Use structs instead of classes where possible

Structs can avoid heap allocations.

Bad:

class Data {
  public int x;
  public int y;
}

Data data = new Data(); // allocated on heap

Good:

struct Data {
   public int x;
   public int y; 
}

Data data; // allocated on stack

Here are some examples to illustrate those general garbage collection optimization techniques: