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Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
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=={{header|Java}}== |
=={{header|Java}}== |
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The situation for Java is as described below in the entry for its sister JVM language, Kotlin. |
The situation for Java is as described below in the entry for its sister JVM language, Kotlin. |
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=={{header|Julia}}== |
=={{header|Julia}}== |
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Perl uses reference counting as its method of managing memory use. As soon as the last reference to a value is released, the value may be destroyed and freed, and handed back to the memory pool. However the exact timing of this action is not under programmer control. |
Perl uses reference counting as its method of managing memory use. As soon as the last reference to a value is released, the value may be destroyed and freed, and handed back to the memory pool. However the exact timing of this action is not under programmer control. |
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Within your program, by using <code>undef</code> and <code>delete</code>, you can <i>hint</i> to Perl that it would now be OK to release this memory. Most importantly, such actions should not be confused with releasing memory back to the operating system. In cases where it is necessary to temporarily allocate a large amount of memory, do so via <code>fork</code>, so when the child process exits the memory is truly freed back to the system. |
Within your program, by using <code>undef</code> and <code>delete</code>, you can <i>hint</i> to Perl that it would now be OK to release this memory. Most importantly, such actions should not be confused with releasing memory back to the operating system. In cases where it is necessary to temporarily allocate a large amount of memory, do so via <code>fork</code>, so when the child process exits the memory is truly freed back to the system. |
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⚫ | In general, there is no specific mechanism to do a timely destruction of an object, be it code, data, variables, whatever. Perl 6 does automatic garbage collection on objects that are no longer being used. Unlike previous version of Perl, Perl 6 doesn't use reference counting to track when memory may be garbage collected as that tends to be very difficult to get correct and performant in multi-threaded applications. Rather it performs a "reachability analysis" to determine when objects can be evicted from memory and safely removed. |
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⚫ | Perl 6 objects can provide a "DESTROY" method, but you cannot be sure when (if ever) it will be called. Perl 6 tends to not be very memory frugal. If there is lots of memory to be had, it will cheerfully use lots of it. It gets more aggressive about conserving if memory is tight, but usually will trade memory for performance. If and when garbage collection ''has'' run, the freed memory is then available to to the general OS pool for any process to claim. |
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=={{header|Phix}}== |
=={{header|Phix}}== |
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=={{header|Python}}== |
=={{header|Python}}== |
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The [https://docs.python.org/3.4/reference/simple_stmts.html?highlight=del#grammar-token-del_stmt del] statement can make objects (both code and data), available for reuse. |
The [https://docs.python.org/3.4/reference/simple_stmts.html?highlight=del#grammar-token-del_stmt del] statement can make objects (both code and data), available for reuse. |
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(formerly Perl 6) |
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⚫ | In general, there is no specific mechanism to do a timely destruction of an object, be it code, data, variables, whatever. Perl 6 does automatic garbage collection on objects that are no longer being used. Unlike previous version of Perl, Perl 6 doesn't use reference counting to track when memory may be garbage collected as that tends to be very difficult to get correct and performant in multi-threaded applications. Rather it performs a "reachability analysis" to determine when objects can be evicted from memory and safely removed. |
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⚫ | Perl 6 objects can provide a "DESTROY" method, but you cannot be sure when (if ever) it will be called. Perl 6 tends to not be very memory frugal. If there is lots of memory to be had, it will cheerfully use lots of it. It gets more aggressive about conserving if memory is tight, but usually will trade memory for performance. If and when garbage collection ''has'' run, the freed memory is then available to to the general OS pool for any process to claim. |
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=={{header|Scala}}== |
=={{header|Scala}}== |
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The different phases of the GC can be explicitly invoced to ''reclaim'' unused memory immediately, but it does not guarantee the reclaimed memory is deemed excessive and therefore will be returned to the OS. |
The different phases of the GC can be explicitly invoced to ''reclaim'' unused memory immediately, but it does not guarantee the reclaimed memory is deemed excessive and therefore will be returned to the OS. |
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=={{header|Tcl}}== |
=={{header|Tcl}}== |