bytecode

问题 Say I run a Python (2.7, though I'm not sure that makes a difference here) script. Instead of terminating the script, I tab out, or somehow switch back to my editing environment. I can then modify the script and save it, but this changes nothing in the still-running script. Does Python load all source files into memory completely at launch? I am under the impression that this is how the Python interpreter works, but this contradicts my other views of the Python interpreter: I have heard that

问题 This is the source code I have: public class Koray { public static void main(String [] args) { System.out.println("This is a sample program."); } } And when I compile this, I get the bytecode. When I look at the bytecode with a Hexadecimal viewer I see part: 19 54 68 69 73 20 69 73 20 61 20 73 61 6D 70 6C 65 20 70 72 6F 67 72 61 6D 2E which can be read as This is a sample program. if the bytes are interpreted as characters. And when I do javap -c Koray.class do disassemble this class I see:

问题 This is the source code I have: public class Koray { public static void main(String [] args) { System.out.println("This is a sample program."); } } And when I compile this, I get the bytecode. When I look at the bytecode with a Hexadecimal viewer I see part: 19 54 68 69 73 20 69 73 20 61 20 73 61 6D 70 6C 65 20 70 72 6F 67 72 61 6D 2E which can be read as This is a sample program. if the bytes are interpreted as characters. And when I do javap -c Koray.class do disassemble this class I see:

问题 The problem is to create a dynamic enhanced version of existing objects. I cannot modify the object's Class . Instead I have to: subclass it wrap the existing object in the new Class delegate all the original method calls to the wrapped object implement all methods that are defined by another interface The interface to add to existing objects is: public interface EnhancedNode { Node getNode(); void setNode(Node node); Set getRules(); void setRules(Set rules); Map getGroups(); void setGroups

问题 The problem is to create a dynamic enhanced version of existing objects. I cannot modify the object's Class . Instead I have to: subclass it wrap the existing object in the new Class delegate all the original method calls to the wrapped object implement all methods that are defined by another interface The interface to add to existing objects is: public interface EnhancedNode { Node getNode(); void setNode(Node node); Set getRules(); void setRules(Set rules); Map getGroups(); void setGroups

问题 I'm working on a project where we're doing a lot of remote object transfer between a Java service and clients written in other various languages. Given our current constraints I've decided to see what it would take to generate code based on an existing Java class. Basically I need to take a .class file (or a collection of them) parse the bytecode to determine all of the data members and perhaps getters/setters and then write something that can output code in a different language to create a

问题 I realize the benefits of bytecode vs. native code (portability). But say you always know that your code will run on a x86 architecture, why not then compile for x86 and get the performance benefit? Note that I am assuming there is a performance gain to native code compilation. Some folks have answered that there could in fact be no gain which is news to me.. 回答1: Because the performance gain (if any) is not worth the trouble. Also, garbage collection is very important for performance.

问题 What is the actual relation between assembly, machine code, bytecode, and opcode? I have read most of the SO questions about assembly and machine code, such as this, but they are too high level and do not show examples of actual assembly code being transformed into machine code. As a result, I still don't understand how it works at a deeper level. The ideal answer to this question would show a specific example of some assembly code, such as the snippet below, and how each assembly instruction

问题 I've embedded lua together with a bytecode chunk into a project written in C. Now when I extend my lua code base by adding .lua files, is there a way to keep this code in a single bytecode chunk? (I know how to load multiple bytecode chunks. But making it load a single chunk and then forgetting about the glue code would just seem comfortable.) I tried to use textual inclusion, but it seems there's no keyword for this in Lua. "Require" and "dofile" look at the files at run time, so the

问题 Python has a flag -O that you can execute the interpreter with. The option will generate "optimized" bytecode (written to .pyo files), and given twice, it will discard docstrings. From Python's man page: -O Turn on basic optimizations. This changes the filename extension for compiled (bytecode) files from .pyc to .pyo. Given twice, causes docstrings to be discarded. This option's two major features as I see it are: Strip all assert statements. This trades defense against corrupt program state