泊松表面重建中主函数中部分代码分析-关于内存设置

 1 //总体来看是和内存设置有关的
 2 #if defined(WIN32) && defined(MAX_MEMORY_GB)
 3     if( MAX_MEMORY_GB>0 )
 4     {
 5         //SIZE_T是ULONG_PTR类型又是unsigned __int64类型取值范围为2到2的64次方，貌似和64为操作系统支持的理论内存值有关系
 6         SIZE_T peakMemory = 1;
 7         peakMemory <<= 30;//peakMemory等于peakMemory（1）乘以2的30次方，2的30次方就是1GB，也就是说peakMemory是1GB
 8         peakMemory *= MAX_MEMORY_GB;
 9         //%.2f宽度无限制，小数点后保留两位
10         printf( "Limiting memory usage to %.2f GB\n" , float( peakMemory>>30 ) );
11         //创建了一个工作对象（lpJobAttributes，lpName）安全属性+工作对象名称
12         HANDLE h = CreateJobObject( NULL , NULL );
13         AssignProcessToJobObject( h , GetCurrentProcess() );
14 
15         JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli = { 0 };
16         jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_JOB_MEMORY;
17         jeli.JobMemoryLimit = peakMemory;
18         if( !SetInformationJobObject( h , JobObjectExtendedLimitInformation , &jeli , sizeof( jeli ) ) )
19             fprintf( stderr , "Failed to set memory limit\n" );
20     }
21 #endif // defined(WIN32) && defined(MAX_MEMORY_GB)