# fixed-size-alloc

**Repository Path**: supermoons/fixed-size-alloc

## Basic Information

- **Project Name**: fixed-size-alloc
- **Description**: fixed size alloc
- **Primary Language**: C++
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2019-10-11
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# fixed-size-alloc
fixed size alloc

# Example

```cpp
int main()
{
     int times = 10000000;
    {
        fixed_size_alloc<64, 4192> fsa;
        auto start = microsecond();
        for (int i = 0; i < times; ++i)
        {
            void* buf1 = fsa.alloc(16);
            void* buf2 = fsa.alloc(16);
            void* buf3 = fsa.alloc(32);
            void* buf4 = fsa.alloc(32);
            void* buf5 = fsa.alloc(64);
            not_null(buf1);
            not_null(buf2);
            not_null(buf3);
            not_null(buf4);
            not_null(buf5);
            memcpy(buf1, &i, sizeof(i));
            memcpy(buf2, &i, sizeof(i));
            memcpy(buf3, &i, sizeof(i));
            memcpy(buf4, &i, sizeof(i));
            memcpy(buf5, &i, sizeof(i));
            fsa.free(buf1);
            fsa.free(buf2);
            fsa.free(buf3);
            fsa.free(buf4);
            fsa.free(buf5);
        }

        std::cout << "fixed_size_alloc cost " << microsecond() - start << "us" << std::endl;
    }

    {
        auto start = microsecond();
        for (int i = 0; i < times; ++i)
        {
            void* buf1 = ::malloc(16);
            void* buf2 = ::malloc(16);
            void* buf3 = ::malloc(32);
            void* buf4 = ::malloc(32);
            void* buf5 = ::malloc(64);
            not_null(buf1);
            not_null(buf2);
            not_null(buf3);
            not_null(buf4);
            not_null(buf5);
            memcpy(buf1, &i, sizeof(i));
            memcpy(buf2, &i, sizeof(i));
            memcpy(buf3, &i, sizeof(i));
            memcpy(buf4, &i, sizeof(i));
            memcpy(buf5, &i, sizeof(i));
            ::free(buf1);
            ::free(buf2);
            ::free(buf3);
            ::free(buf4);
            ::free(buf5);
        }
        std::cout << "malloc cost " << microsecond() - start << "us" << std::endl;
    }
    return 0;
}

```

# Result
```
//Some cases 20 times faster than malloc
fixed_size_alloc cost 115497us
malloc cost 3371072us
```