stack

问题 I have a question regarding synchronization of code that is executed by several threads: As far as I know each thread has its own stack, hence, non-static variables exist in different locations in the memory for each thread (for X threads there are X stacks that include all non-static variables). So why there's a need to synchronize anything? I mean, if the code that the threads execute includes some class variable v1, then each thread has its own "instance" of v1 (different memory address),

问题 My logging code uses the return value of backtrace() to determine the current stack depth (for pretty printing purposes), but I can see from profiling that this is a pretty expensive call. I don't suppose there's a cheaper way of doing this? Note that I don't care about the frame addresses, just how many of them there are. edit: These logging functions are used all over a large code-base, so manually tracking the stack depth isn't really an option. 回答1: Walking the stack yourself is pretty

问题 #!/usr/bin/env python # Display window with toDisplayText and timeOut of the window. from Tkinter import * def showNotification(notificationTimeout, textToDisplay): ## Create main window root = Tk() Button(root, text=textToDisplay, activebackground="white", bg="white", command=lambda: root.destroy()).pack(side=LEFT) root.update_idletasks() # Remove window decorations root.overrideredirect(1) timeOut = int(notificationTimeout*1000) # Convert to ms from s ## Run appliction root.after(timeOut

问题 downloaded mean stck zip from mean.io did an npm install after few minutes I got an error. Please see screenshot. what do I do? npm http 200 https://registry.npmjs.org/event-emitter/-/event-e mitter-0.2.2.tgz > mean@1.0.0 postinstall C:\ss\D1\google\04\mean\mean-stack > ./node_modules/bower/bin/bower install '.' is not recognized as an internal or external command, operable program or batch file. npm ERR! weird error 1 npm ERR! not ok code 0 回答1: Looks like mean stacks postinstall script is

问题 C++ ATT Assembly I'm trying to understand the behavior of the following two instructions: pushl %esp And: popl %esp Note that they store the computed value back into %esp . I'm considering these instructions independently, not in sequence. I know that the value stored in %esp is always the value before the increment/decrement, but how could I represent the behavior in assembly language? This is what I've come up with so far: For push: movl %esp, %edx 1. save value of %esp subl $4, %esp 2.

问题 why this little piece of code is giving illegal start of type error in line 6 and 10(for loops).... i can't find any unmatched braces... class StackDemo{ final int size = 10; Stack s = new Stack(size); //Push charecters into the stack for(int i=0; i<size; i++){ s.push((char)'A'+i); } //pop the stack untill its empty for(int i=0; i<size; i++){ System.out.println("Pooped element "+i+" is "+ s.pop()); } } I have the class Stack implemented, 回答1: You can't use for loop in class level. Put them

问题 As far as I know, this isn't caused by an infinite recursion. The program functioned correctly with smaller arrays (it is an audio editor). Now I have increased functionality to allow for larger arrays (up to 5 minutes of audio, 26460000 pieces of 16bit data ~50mb). Since increasing the array's size I am receiving stack overflow errors on one particular function, where it should reverse the playback of an input file by writing the array into a new array backwards, then overwriting the

问题 To clarify the question, please observe the c/c++ code fragment: int a = 10, b = 20, c = 30, d = 40; //consecutive 4 int data values. int* p = &d; //address of variable d. Now, in visual studio (tested on 2013), if value of p == hex_value (which can be viewed in debugger memory window), then, you can observe that, the addresses for other variables a, b, c, and d are each at a 12 byte difference! So, if p == hex_value , then it follows: &c == hex_value + 0xC (note hex C is 12 in decimal) &b ==

问题 How do I parse and evaluate expressions in an infix calculator grammar? I thought of two ways. The 1st involves using two stacks. One is for numbers and the other is for operators, and I would assess the operator precedence and association in order to figure out how to evaluate an expression. The second method involves converting the infix expression to postfix which I have no idea how I'd go about doing. It was just an idea. Currently I set up my program with the intention to use the 1st

问题 I need to know a generic way to distinguish between a call of activity from launcher and a call from another activity from inside my app, or a BACK on the activity stack Anyone? this is bugging me for quite a while now and i need to put it to rest... Thanks in advance JQCorreia 回答1: In the onCreate of your Activity, call getIntent() . If the Activity is started from the launcher (home screen) the values for getAction() will be android.intent.action.MAIN and the getCategories() will return a