Databases
StackOverflow2013
Postsdbo
POJava VM suddenly exiting without apparent reason
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POJava VM suddenly exiting without apparent reason
    primarykey
    data
    text
    <p>I have a problem with my Java progam suddenly exiting, without any exception thrown or the program finishing normally.</p> <p>I'm writing a program to solve <a href="http://projecteuler.net" rel="nofollow noreferrer">Project Euler</a>'s <a href="http://projecteuler.net/index.php?section=problems&amp;id=14" rel="nofollow noreferrer">14th problem</a>. This is what I got:</p> <pre><code>private static final int INITIAL_CACHE_SIZE = 30000; private static Map&lt;Long, Integer&gt; cache = new HashMap&lt;Long, Integer&gt;(INITIAL_CACHE_SIZE); public void main(String... args) { long number = 0; int maxSize = 0; for (long i = 1; i &lt;= TARGET; i++) { int size = size(i); if (size &gt; maxSize) { maxSize = size; number = i; } } } private static int size(long i) { if (i == 1L) { return 1; } final int size = size(process(i)) + 1; return size; } private static long process(long n) { return n % 2 == 0 ? n/2 : 3*n + 1; } </code></pre> <p>This runs fine, and finishes correctly in about 5 seconds when using a TARGET of 1 000 000.</p> <p>I wanted to optimize by adding a cache, so I changed the size method to this:</p> <pre><code>private static int size(long i) { if (i == 1L) { return 1; } if (cache.containsKey(i)) { return cache.get(i); } final int size = size(process(i)) + 1; cache.put(i, size); return size; } </code></pre> <p>Now when I run it, it simply stops (process exits) when I get to 555144. Same number every time. No exception, error, Java VM crash or anything is thrown.</p> <p>Changing the cache size doesn't seem to have any effect either, so how could the cache introduction cause this error?</p> <p>If I enforce the cache size to be not just initial, but permanent like so:</p> <pre><code> if (i &lt; CACHE_SIZE) { cache.put(i, size); } </code></pre> <p>the bug no longer occurs. Edit: When I set the cache size to like 2M, the bug starts showing again.</p> <p>Can anyone reproduce this, and maybe even provide a suggestion as to why it happens?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USKara
    1. USJorn
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POJava VM suddenly exiting without apparent reason
      1. USJoseph Gordon
      1. VTFavorite
    2. VO
      singulars
      1. POJava VM suddenly exiting without apparent reason
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhat OS are you running on?
      singulars
      1. POJava VM suddenly exiting without apparent reason
      1. USAndy White
    2. COI'm running on Windows Vista Business and JDK 1.6.0_03
      singulars
      1. POJava VM suddenly exiting without apparent reason
      1. USJorn
    3. COYou might want to try updating the jdk and seeing if you get the same behavior. They are now on update 16 to 1.6.
      singulars
      1. POJava VM suddenly exiting without apparent reason
      1. USdigitaljoel
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload