-XX:[+|-]HitachiVerboseGCPrintDeleteOnExit (Heap size output option used by java.io.File.deleteOnExit())

Format

-XX:+HitachiVerboseGCPrintDeleteOnExit

This option outputs the cumulative heap size allocated by invoking the java.io.File.deleteOnExit() method and the method invocation count.

-XX:-HitachiVerboseGCPrintDeleteOnExit

This option does not output the cumulative heap size allocated by invoking the java.io.File.deleteOnExit() method and the method invocation count.

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Description

Specifies whether to output the cumulative heap size that JavaVM allocates by invoking the java.io.File.deleteOnExit() method and the method invocation count, to the JavaVM log file.

The path information for a specified file is allocated to a heap each time the java.io.File.deleteOnExit()method is invoked; however, the allocated area is not released until the process ends; and therefore, might lead to compression of memory. If you specify the -XX:+HitachiVerboseGCPrintDeleteOnExit option, JavaVM can invoke the java.io.File.deleteOnExit() method, output the allocated heap size to a log, and monitor the size. The method invocation count can also be output concurrently as the supplementary information to understand the invocation status of java.io.File.deleteOnExit().

The information that is output helps to understand the heap size allocated by invoking the java.io.File.deleteOnExit() and to investigate the cause of memory shortage when an error occurs. You can also use this information to check the changes in the increase of the heap size allocated by invoking the java.io.File.deleteOnExit() and to check for any signs of memory compression during operations, in the development and testing phase before the start of operations.

Note that an error message is displayed when an error occurs.

Default value

• -XX:+HitachiVerboseGCPrintDeleteOnExit

Prerequisite options

• -XX:+HitachiVerboseGC

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Output format

The output format of the JavaVM log file is as follows:

[id] date (Skip Full:full_count, Copy:copy_count, Inc:inc_count) [gc_kind gc_info, gc_time secs][Eden: eden_info][Survivor: survivor_info][Tenured: tenured_info] [Metaspace: metaspace_info][class space: class_space_info][cause:cause_info] [User: user_cpu secs][Sys: system_cpu secs][IM: jvm_alloc_size, mmap_total_size, malloc_total_size][TC: thread_count][DOE: doe_alloc_size, called_count]

The output contents are explained below. Note that the following explains the items output by this option. For items other than explained below, see the output format described in -XX:[+|-]HitachiVerboseGC (Option for extended verbosegc information output).

doe_alloc_size

Specifies the cumulative heap size allocated by invoking the java.io.File.deleteOnExit()method.

called_count

Specifies the invocation count of the java.io.File.deleteOnExit() method.

The output format of the error message displayed when an error occurs is as follows:

[DOE] date Error occurred during processing of java.io.File.deleteOnExit's heap size output function. (maintenance-information)
[DOE]java.io.File.deleteOnExit's heap size output function stopped.

The following is the contents of the error message:

DOE

Specifies an identifier indicating that an error occurred in the heap size output function of the java.io.File.deleteOnExit().

date

Specifies the date when the error occurred.

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Examples of output

• The following is an example of output of the JavaVM log file:

  [VGC]<Wed Jan 27 13:03:36 2010>(Skip Full:0,Copy:0)[GC 489K->152K(3520K), 0.0156080 secs][DefNew::Eden: 489K->0K(2048K)][DefNew::Survivor: 0K->63K(64K)][Tenured: 0K->88K(1408K)][Metaspace: 3634K(4492K, 4492K)->3634K(4492K, 4492K)][class space: 356K(388K, 388K)->356K(388K, 388K)][cause:ObjAllocFail][IM: 729K, 928K, 0K] [TC: 509][DOE: 16K, 170]

• The following is an example of output of the error message:

  [DOE]<Wed Jan 27 13:03:36 2010> Error occurred during processing of java.io.File.deleteOnExit's heap size output function. (FindClass:java.lang.String)
  [DOE]java.io.File.deleteOnExit's heap size output function stopped.

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Precautions

• The cumulative heap size and method invocation count is not calculated in the following cases even when the java.io.File.deleteOnExit() is invoked:

  • If the SecurityException exception occurs when the java.io.File.deleteOnExit() is invoked (This exception occurs when the SecurityManager.checkDelete() method of the security manager is not allowed access to delete files. In this case, an exception is thrown at method entrance and no heap is allocated).

  • When java.io.File.deleteOnExit() is invoked from applications created using the batch application executing infrastructure of Application Server.

  • When java.io.File.deleteOnExit() is invoked by using the File instance created with the same path name string.

• Note the following points when you check the heap size output by this functionality:

  • The heap type allocated by java.io.File.deleteOnExit() is Java heap.

  • The heap size is output in kilobytes and a size of less than 1 KB is rounded down. The heap size allocated when the java.io.File.deleteOnExit() method is invoked once ranges from tens of bytes to 100 bytes, depending on the length of the file path; therefore, the output results of heap size might not increase with each invocation of the java.io.File.deleteOnExit() method. In this case, you can check the execution of the method from the method invocation count.

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