On Fri, 11 Feb 2005 20:12:08 -0500, christopher diggins wrote:
Does "your task" here mean the current thread or does it mean the current process (or does it depend)? Either or.
Thank you very much for the explanation. What advantage would wall-clock-time have for profiling tasks? It would allow you to include how much time is spent sleeping or blocked in your profiled time. Ordinarily, when a task goes to sleep or blocks for any reason (disk I/O, waiting for a lock, etc) the kernel cuts short the process/thread's timeslice, meaning std::clock() would not count it, wall_clock would.
For example: #include <unistd.h> int main() { int i; for (i=0; i<5; ++i) sleep(1); return 0; } results in: $ time ./blah real 0m5.012s user 0m0.001s sys 0m0.001s As I said, I can see advantages for both - sometimes you want to know how much of your time is in a specific area of code (including waiting for stuff), and sometimes you want to know how expensive a piece of code (from a CPU perspective) is. -- PreZ :) Founder. The Neuromancy Society (http://www.neuromancy.net)