clock

问题 Is it possible to get microseconds in Java 8? The Java 8 LocalDateTime class has a .getNano() method which is meant to return nanoseconds , but on both Linux(Ubuntu) and OS X (10.11.5) it only returns milliseconds (when I ran it it returned 301000000 which equals 301 milliseconds ) and I really need to be able to get microseconds . I know that it is possible to get nanoseconds (and therefore get microseconds from it) on my computer as the javascript method process.hrtime() returns a precise

问题 I have written a very small code to measure the time taken by my multiplication algorithm : clock_t begin, end; float time_spent; begin = clock(); a = b*c; end = clock(); time_spent = (float)(end - begin)/CLOCKS_PER_SEC; I am working with mingw under Windows. I am guessing that end = clock() will give me the clock ticks at that particular moment. Subtracting it from begin will give me clock ticks consumed by multiplication. When I divide with CLOCKS_PER_SEC , I will get the total amount of

问题 I have a distributed program written in java. I want my nodes access a synchronized physical clock. I know NTP is a protocol for physical clock synchronization. I know that I can install it on linux by sudo apt-get ntp. My question is when I install it, how can I access this synchronized clock in my java program? I mean what happens when I install ntp on my machine? my system clock will be sync? Thanks :) 回答1: When you setup ntp, System time will be synchronized with the ntp server time. When

问题 I have seen many posts about using the clock() function to determine the amount of elapsed time in a program with code looking something like: start_time = clock(); //code to be timed . . . end_time = clock(); elapsed_time = (end_time - start_time) / CLOCKS_PER_SEC; The value of CLOCKS_PER_SEC is almost surely not the actual number of clock ticks per second so I am a bit wary of the result. Without worrying about threading and I/O, is the output of the clock() function being scaled in some

问题 I have seen many posts about using the clock() function to determine the amount of elapsed time in a program with code looking something like: start_time = clock(); //code to be timed . . . end_time = clock(); elapsed_time = (end_time - start_time) / CLOCKS_PER_SEC; The value of CLOCKS_PER_SEC is almost surely not the actual number of clock ticks per second so I am a bit wary of the result. Without worrying about threading and I/O, is the output of the clock() function being scaled in some

问题 I'm writing a Cocoa OS X (Leopard 10.5+) end-user program that's using timestamps to calculate statistics for how long something is being displayed on the screen. Time is calculated periodically while the program runs using a repeating NSTimer. [NSDate date] is used to capture timestamps, Start and Finish . Calculating the difference between the two dates in seconds is trivial. A problem occurs if an end-user or ntp changes the system clock. [NSDate date] relies on the system clock, so if it

问题 I'm writing a Cocoa OS X (Leopard 10.5+) end-user program that's using timestamps to calculate statistics for how long something is being displayed on the screen. Time is calculated periodically while the program runs using a repeating NSTimer. [NSDate date] is used to capture timestamps, Start and Finish . Calculating the difference between the two dates in seconds is trivial. A problem occurs if an end-user or ntp changes the system clock. [NSDate date] relies on the system clock, so if it

问题 My problem is whenever I try to compile using Makefile I get the following : make: Warning: File `Board.c' has modification time 1.3e+03 s in the future gcc -Wall -c -Wvla -lm Board.c -o Board.o gcc -Wall -c -Wvla -lm PlayBoard.c -o PlayBoard.o gcc -lm ErrorHandle.o Board.o PlayBoard.o -g -o PlayBoard make: warning: Clock skew detected. Your build may be incomplete. My Makefile is : CC = gcc FLAGS = -Wall -c -Wvla PlayBoard: ErrorHandle.o Board.o PlayBoard.o $(CC) -lm ErrorHandle.o Board.o

问题 have a clock I want to display in a TextView. I would have thought there was a few nice functions to do this, but I couldn't find anything. I ended up implementing my own way that uses a Handler. What I'm asking though, is there a better (more efficient) way to display a real time updating clock? private Runnable mUpdateClockTask = new Runnable() { public void run() { setTime(); mClockHandler.postDelayed(this, 1000); } }; That's my handler, which runs every second, and then my set time and

问题 There is a really interesting note here: http://en.cppreference.com/w/cpp/chrono/c/clock "Only the difference between two values returned by different calls to std::clock is meaningful, as the beginning of the std::clock era does not have to coincide with the start of the program. std::clock time may advance faster or slower than the wall clock, depending on the execution resources given to the program by the operating system. For example, if the CPU is shared by other processes, std::clock