RR(S): 8026334: hs_err improvement: Print elapsed time in a humanly readable format

[Kevin Walls]

Hi,

I'd like to get a review of this change:

It's adding a human-readable breakdown of the elapsed time, which is 
currently printed in raw seconds in the hs_err file (it's the last item 
printed).

This is on behalf of Masato Yoshido who has worked on it. Further 
details below, including a method that was used for manual testing.

bug:
https://bugs.openjdk.java.net/browse/JDK-8026334

webrev:
http://cr.openjdk.java.net/~kevinw/8026334/webrev.00/

Many thanks,
Kevin
Masato


[Change details]

- Time format will change as follows:

   (from)
   elapsed time: %d seconds

   (to)
   elapsed time: %d seconds (%dd %dh %dm %ds)

- The reason why I leave the original elapsed time format is:
   -- We don’t need to remove the original format. If we remove it, ones
      who want time information in seconds need to calculate from day-,
      hour-, minute- and second-parts.

- There is no code doing exactly the same thing. Another code to which
   we might be able to apply calculation similar to this conversion is
   the GC log with -XX:+PrintGCTimeStamps. However, the elapsed time
   in GC log is a floating point number, while the time in hs_err log
   is an integer since there is a problem when %f is used in printf
   on Linux platform (See comments in os::print_date_and_time function).
   Therefore, the same code as this cannot simply be share with GC log.


[Test]

(1) Tested only part of code of elapsed time calculation and printing.

--- test_print_time.cpp ---
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

void print_date_and_time(double t) {
   int eltime = (int)t;  // elapsed time in seconds
   int eldays, elhours, elminutes, elseconds;  // for printing elapsed time in a humanly readable format
   eldays = eltime / 86400;
   elhours = (eltime - eldays * 86400) / 3600;
   elminutes = (eltime - eldays * 86400 - elhours * 3600) / 60;
   elseconds = (eltime - eldays * 86400 - elhours * 3600 - elminutes * 60);
   printf("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elminutes, elseconds);
   printf("\n");
}

int main(int argc, char *argv[]) {
   print_date_and_time((double)86399);
   print_date_and_time((double)86400);
   print_date_and_time((double)86401);
   printf("\n");

   print_date_and_time((double)86399.999);
   print_date_and_time((double)86400.999);
   print_date_and_time((double)86401.999);
   printf("\n");

   print_date_and_time((double)(-86399));
   print_date_and_time((double)(-86400));
   print_date_and_time((double)(-86401));
   printf("\n");

   print_date_and_time((double)INT_MAX);
   print_date_and_time((double)(INT_MAX+1));
   print_date_and_time((double)UINT_MAX);
}
---

--- Run the test program
$ ./test_print_time
elapsed time: 86399 seconds (0d 23h 59m 59s)
elapsed time: 86400 seconds (1d 0h 0m 0s)
elapsed time: 86401 seconds (1d 0h 0m 1s)

elapsed time: 86399 seconds (0d 23h 59m 59s)
elapsed time: 86400 seconds (1d 0h 0m 0s)
elapsed time: 86401 seconds (1d 0h 0m 1s)

elapsed time: -86399 seconds (0d -23h -59m -59s)
elapsed time: -86400 seconds (-1d 0h 0m 0s)
elapsed time: -86401 seconds (-1d 0h 0m -1s)

elapsed time: 2147483647 seconds (24855d 3h 14m 7s)
elapsed time: -2147483648 seconds (-24855d -3h -14m -8s)
elapsed time: -2147483648 seconds (-24855d -3h -14m -8s)
---


(2) Tested using a JNI program causing Segmentation Violation.
     Tested on the following platforms:
       solaris sparcv9
       solaris x64
       linux x86
       linux x64
       windows x86
       windows x64
       macosx x64
     hs_err_pid<pid>.log file was successfully generated with expected
     “elapsed time” line on each platform.


--- TestCrash.java ---
public class TestCrash {
   static {
     System.loadLibrary("testcrash");
   }

   public static native void crash();

   public static void main(String[] args) {
     try {
       Thread.sleep(61000);
     } catch (InterruptedException e) {
       e.printStackTrace();
     }
     crash();
   }
}
---

--- TestCrash.c ---
#include <jni.h>

#ifdef __cplusplus
extern "C" {
#endif
/*
  * Class:     TestCrash
  * Method:    crash
  * Signature: ()V
  */
JNIEXPORT void JNICALL Java_TestCrash_crash(JNIEnv *env, jclass cls) {
   const char *p = "Hello, world!";
   *(char *)p = 'a';
}

#ifdef __cplusplus
}
#endif
---


Thanks and best regards,
Masato