vm/memory/allocation.hpp 第135行，关于 JVM 内存使用类型的定义，源码如下：
135136137138139140141142143144145146147148149150151152153154155156157158159160 | /* * Memory types */enum MemoryType { // Memory type by sub systems. It occupies lower byte. mtJavaHeap = 0x00, // Java heap mtClass = 0x01, // memory class for Java classes mtThread = 0x02, // memory for thread objects mtThreadStack = 0x03, mtCode = 0x04, // memory for generated code mtGC = 0x05, // memory for GC mtCompiler = 0x06, // memory for compiler mtInternal = 0x07, // memory used by VM, but does not belong to // any of above categories, and not used for // native memory tracking mtOther = 0x08, // memory not used by VM mtSymbol = 0x09, // symbol mtNMT = 0x0A, // memory used by native memory tracking mtClassShared = 0x0B, // class data sharing mtChunk = 0x0C, // chunk that holds content of arenas mtTest = 0x0D, // Test type for verifying NMT mtTracing = 0x0E, // memory used for Tracing mtNone = 0x0F, // undefined mt_number_of_types = 0x10 // number of memory types (mtDontTrack // is not included as validate type)}; |
vm/memory/generation.hpp 第38行，关于 JVM 支持的 GC 分代组合配置，源码如下：
38394041424344454647484950515253545556575859606162 | // A Generation models a heap area for similarly-aged objects.// It will contain one ore more spaces holding the actual objects.//// The Generation class hierarchy://// Generation - abstract base class// - DefNewGeneration - allocation area (copy collected)// - ParNewGeneration - a DefNewGeneration that is collected by// several threads// - CardGeneration - abstract class adding offset array behavior// - OneContigSpaceCardGeneration - abstract class holding a single// contiguous space with card marking// - TenuredGeneration - tenured (old object) space (markSweepCompact)// - ConcurrentMarkSweepGeneration - Mostly Concurrent Mark Sweep Generation// (Detlefs-Printezis refinement of// Boehm-Demers-Schenker)//// The system configurations currently allowed are://// DefNewGeneration + TenuredGeneration// DefNewGeneration + ConcurrentMarkSweepGeneration//// ParNewGeneration + TenuredGeneration// ParNewGeneration + ConcurrentMarkSweepGeneration// |
vm/memory/generation.hpp 第132行，关于 GC 分代类型名称，源码如下：
132133134135136137138139140141 | // The set of possible generation kinds.enum Name { ASParNew, ASConcurrentMarkSweep, DefNew, ParNew, MarkSweepCompact, ConcurrentMarkSweep, Other}; |