gprof: time not counted

I want to use gprof to optimize my program. But in its output, time is not counted for any function. All the entries for time are 0.0 . My program runs for 50s. My operating system is Mac OSX. I used
g++ -g -pg -o execname cppfiles.... to compile. How should I solve it? Thanks!

So do you actually run gprof when your program exits? You also need to do this step as well.

Does your program achieve a normal exit, or is it failing in some way?
Do you see a gmon.out file in the current directory (it's where profile data is written to when the program exits).

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Originally Posted by Salem

So do you actually run gprof when your program exits? You also need to do this step as well.

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I think so. I did
./execname
gprof execname

Quote:

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Originally Posted by Salem

Does your program achieve a normal exit, or is it failing in some way?

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It achieved a normal exit.

Quote:

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Originally Posted by Salem

Do you see a gmon.out file in the current directory (it's where profile data is written to when the program exits).

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Yes, I saw the gmon.out. I can see other all the information, like how many times a function is called, just the time is always 0.

Thanks!

What do the functions do? Are they using 100% CPU? Or just sleeping?

Found some links, seems like you're not the only one.
gprof bug on Mac OS X?
c++ - gprof reports no time accumulated - Stack Overflow
gprof not working [Archive] - The macosxhints Forums