21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/methodCounters.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/growableArray.hpp"
  40 
  41 // A Method* represents a Java method.
  42 //
  43 // Memory layout (each line represents a word). Note that most applications load thousands of methods,
  44 // so keeping the size of this structure small has a big impact on footprint.
  45 //
  46 // We put all oops and method_size first for better gc cache locality.
  47 //
  48 // The actual bytecodes are inlined after the end of the Method struct.
  49 //
  50 // There are bits in the access_flags telling whether inlined tables are present.
  51 // Note that accessing the line number and local variable tables is not performance critical at all.
  52 // Accessing the checked exceptions table is used by reflection, so we put that last to make access
  53 // to it fast.
  54 //
  55 // The line number table is compressed and inlined following the byte codes. It is found as the first
  56 // byte following the byte codes. The checked exceptions table and the local variable table are inlined
  57 // after the line number table, and indexed from the end of the method. We do not compress the checked
  58 // exceptions table since the average length is less than 2, and do not bother to compress the local
  59 // variable table either since it is mostly absent.
  60 //
  61 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)
  62 //
  63 // |------------------------------------------------------|
  64 // | header                                               |
  65 // | klass                                                |
  66 // |------------------------------------------------------|
  67 // | ConstMethod*                   (oop)                 |
  68 // |------------------------------------------------------|
  69 // | methodData                     (oop)                 |
  70 // | methodCounters                                       |
  71 // |------------------------------------------------------|
  72 // | access_flags                                         |
  73 // | vtable_index                                         |
  74 // |------------------------------------------------------|
  75 // | result_index (C++ interpreter only)                  |
  76 // |------------------------------------------------------|
  77 // | method_size             |   intrinsic_id|   flags    |
  78 // |------------------------------------------------------|
  79 // | code                           (pointer)             |
  80 // | i2i                            (pointer)             |
  81 // | adapter                        (pointer)             |
  82 // | from_compiled_entry            (pointer)             |
  83 // | from_interpreted_entry         (pointer)             |
  84 // |------------------------------------------------------|
  85 // | native_function       (present only if native)       |
  86 // | signature_handler     (present only if native)       |
  87 // |------------------------------------------------------|
  88 
  89 
  90 class CheckedExceptionElement;
  91 class LocalVariableTableElement;
  92 class AdapterHandlerEntry;
  93 class MethodData;
  94 class MethodCounters;
  95 class ConstMethod;
  96 class InlineTableSizes;
  97 class KlassSizeStats;

  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OOPS_METHODOOP_HPP
  26 #define SHARE_VM_OOPS_METHODOOP_HPP
  27 
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/compressedStream.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "interpreter/invocationCounter.hpp"
  32 #include "oops/annotations.hpp"
  33 #include "oops/constantPool.hpp"
  34 #include "oops/methodCounters.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/oop.hpp"
  37 #include "oops/typeArrayOop.hpp"
  38 #include "utilities/accessFlags.hpp"
  39 #include "utilities/growableArray.hpp"
  40 
  41 // A Method represents a Java method.
  42 //
  43 // Memory layout (each line represents a word). Note that most applications load thousands of methods,
  44 // so keeping the size of this structure small has a big impact on footprint.
  45 //


  46 // The actual bytecodes are inlined after the end of the Method struct.
  47 //
  48 // There are bits in the access_flags telling whether inlined tables are present.
  49 // Note that accessing the line number and local variable tables is not performance critical at all.
  50 // Accessing the checked exceptions table is used by reflection, so we put that last to make access
  51 // to it fast.
  52 //
  53 // The line number table is compressed and inlined following the byte codes. It is found as the first
  54 // byte following the byte codes. The checked exceptions table and the local variable table are inlined
  55 // after the line number table, and indexed from the end of the method. We do not compress the checked
  56 // exceptions table since the average length is less than 2, and do not bother to compress the local
  57 // variable table either since it is mostly absent.
  58 //
  59 // Note that native_function and signature_handler has to be at fixed offsets (required by the interpreter)
  60 //
  61 // |------------------------------------------------------|
  62 // | header                                               |
  63 // | klass                                                |
  64 // |------------------------------------------------------|
  65 // | ConstMethod*                   (metadata)            |
  66 // |------------------------------------------------------|
  67 // | MethodData*                    (metadata)            |
  68 // | MethodCounters                                       |
  69 // |------------------------------------------------------|
  70 // | access_flags                                         |
  71 // | vtable_index                                         |
  72 // |------------------------------------------------------|
  73 // | result_index (C++ interpreter only)                  |
  74 // |------------------------------------------------------|
  75 // | method_size             | intrinsic_id  |   flags    |
  76 // |------------------------------------------------------|
  77 // | code                           (pointer)             |
  78 // | i2i                            (pointer)             |
  79 // | adapter                        (pointer)             |
  80 // | from_compiled_entry            (pointer)             |
  81 // | from_interpreted_entry         (pointer)             |
  82 // |------------------------------------------------------|
  83 // | native_function       (present only if native)       |
  84 // | signature_handler     (present only if native)       |
  85 // |------------------------------------------------------|
  86 
  87 
  88 class CheckedExceptionElement;
  89 class LocalVariableTableElement;
  90 class AdapterHandlerEntry;
  91 class MethodData;
  92 class MethodCounters;
  93 class ConstMethod;
  94 class InlineTableSizes;
  95 class KlassSizeStats;