kernelopts - Maple Help

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kernelopts

set or query kernel variables and options

 Calling Sequence kernelopts(arg1, arg2, ... )

Parameters

 arg1, arg2, ... - argument(s) of the form name=val or name

Description

 • The kernelopts command is a mechanism for communication between the user and the Maple kernel. Specifically, this command is used to set and query variables that affect the computation of Maple. The variables that can be set and queried are as follows.

 ASSERT assertlevel bindir byteorder bytesalloc bytesused cacheclearlimit cpulimit cputime cputype dagtag datadir datalimit dirsep display_zero_complex_part filelimit floatPi gcbytesavail gcbytesreturned gcmaxthreads gcthreadmemorysize gctimes gctotaltime gmpthreshold gmpversion heaps homedir includepath inline jvmheaplimit keepdebuginfo level limitjvmheap locale mapledir max_record_depth maxdigits maximmediate memusage multithreaded numcpus numactivethreads opaquemodules pathsep pid platform printbytes 'printlevel' processlimit profile readdotm setsort shortlineinfo sparse_sort_cutoff stackalloc stacklimit system toolboxdir toolboxversion traceincidentalassign tracecatch tracelineinfo traceshowspecassign tracesplitmulassign unread username version versionnumber wordsize

 • There is a Maplet interface to the kernelopts routine. For more information, see the Maplets[Examples][KernelOpts] help page.
 • If an argument is of the form name=val then this specifies the setting for the named variable.
 For each argument of this type, kernelopts returns the old value of the argument. This is convenient when you want to change and later restore a value, for example,

 oldNumCPUs := kernelopts(numcpus=4);  # set new value and save old . . . . kernelopts(numcpus=oldNumCPUs);          # restore previous value

 • If an argument is a name then the current value of the named variable is retrieved and returned as the function value.
 • When kernelopts is called with many arguments, it returns an expression sequence containing the values.
 • The cpulimit, datalimit, and stacklimit limit variables must be used carefully. When a limit is reached Maple may shutdown without warning. The option to save may not be given. On some platforms, including all Windows platforms, the detection of limit violations is tied to garbage collection. Therefore, the detection of limit violations is inaccurate for code that rarely invokes garbage collection. If garbage collection is never invoked, Maple does not detect limit violations.
 • The filelimit and processlimit limit variables must also be used carefully. They limit the total number of files or processes that Maple can use. Some internal Maple functions open files or run processes and thus will fail if these limits are too low.
 • The values assigned to the following kernelopts options can be modified by attaching a unit: cacheclearlimit, cpulimit, datalimit, jvmheaplimit, and stacklimit. When the conversion from the given unit to the default unit is not exact the value is rounded down. The units used for these options follow the IEC prefixes and definitions, with the exception of the unit word. For kernelopts a word is the wordsize of the current machine (either 32 or 64 bits). The return value for these options is the previous value in the default unit.
 • Some kernelopts are most useful in the multithreaded Maple engine.  In particular the numcpus and numactivethreads have limited usefulness in the single threaded kernel.
 • The standard set of kernelopts variables is:

 NAME VALUES EXPLANATION ASSERT boolean If true, ASSERT functions are evaluated as expected. If false (default), ASSERT functions are ignored. ASSERT is obsolete (but still supported) and has been replaced by assertlevel. assertlevel 0, 1, 2 0 - assertions are not checked 1 -  only calls to the ASSERT function are checked 2 - calls to the ASSERT function, as well as assignment type assertions are checked. The default value is 0. bindir string The path to the system binary directory of the Maple installation. This value cannot be set. byteorder string Either "little endian" or "big endian". This value cannot be set. bytesalloc integer Total number of bytes allocated by the Maple mathematical kernel. This value cannot be set. bytesused integer Total number of bytes used by the Maple mathematical kernel. This value cannot be set. cacheclearlimit integer The data limit, in kibibytes, for maintaining temporary elements in cache tables. A check is performed whenever memory is allocated from the system. If the total amount of memory allocated exceeds this limit, cache tables will be automatically cleared of all temporary elements on the next garbage collection. Values passed for this option can be given with a Unit of information. cpulimit integer The total amount of CPU time, in seconds that Maple may consume. Maple aborts if this time limit is exceeded. If the value is 0 or it is not given the current limit is returned. Limits may be raised or lowered. Maple limits cannot be raised above any system imposed hard limits. Values passed for this option can be given with a Unit of time. cputime float Total CPU time used since the beginning of the session. This value cannot be set. cputype string A string describing the CPU type that the current version of Maple was built for.  This is most useful on APPLE_UNIVERSAL_OSX where there are multiple possible CPU types for the same value of kernelopts( system ). dagtag name or integer This option is more like a function in that it always requires a value and always returns a value. If the value is an integer, a name is returned. If the value is a name, an integer is returned. This facility is used to map between internal data structure ID numbers and their names. (See the assemble function.) datadir string Location of the data directory containing auxiliary files such as text files, XML Schemas, and DTDs. Cannot be set. datalimit integer The total amount of heap memory in kibibytes that Maple may consume. Maple aborts if this limit is exceeded. If the value is 0 or it is not given the current limit is returned. Limits may be raised or lowered. Maple limits may not be raised above system imposed hard limits. This option is not supported on all platforms. Values passed for this option can be given with a Unit of information. dirsep string Returns the directory separator character for the architecture on which Maple is running. Cannot be set. display_zero_complex_part boolean When set to false complex numbers of the form a+0*I are displayed without the 0*I part. The default value for this option is true. filelimit integer The maximum number of files that Maple can have open at one time.  If the value is 0 or it is not given the current limit is returned. Important: This limit also affects internal Maple functions. floatPi boolean Controls whether Pi is evaluated to a floating-point number when it is in an expression that contains other floating-point numbers. The default is true. gcbytesavail integer Number of bytes available after the last invocation of garbage collection. This value cannot be set. gcbytesreturned integer Number of bytes returned by the last invocation of garbage collection. This value cannot be set. gcfreq integer Deprecated as of Maple 16. gcmaxthreads integer The maximum number of threads Maple should use for the parallel garbage collector. The default is numcpus or 4, whichever is lower. gcthreadmemorysize integer Maple determines how many threads to use for its parallel garbage collector by dividing number of bytes allocated, kernelopts(bytesalloc), by the value of gcthreadmemorysize, rounded up. The default value is 128 MiB. gctimes integer Number of times that garbage collection has been invoked. This value cannot be set. gctotaltime float The total amount of time spent performing garbage collections in CPU time. gctotaltime[real] float The total amount of time spent performing garbage collections in real time. gmpthreshold integer The threshold when the GNU Multiple Precision (GMP) library will be used for integer arithmetic. Maple represents all integers as either immediate or GMP integers. Therefore, kernelopts(maximmediate) may be more useful. kernelopts(gmpthreshold) is defined to be floor(log[10](kernelopts(maximmediate))). Thus, integers with greater than kernelopts(gmpthreshold) digits are represented as GMP integers. This value cannot be set. gmpversion string The version of the GNU Multiple Precision (GMP) library used for long integer arithmetic. This value cannot be set. heaps table Returns the type, starting address, ending address, the size in kibibytes of all the memory heaps currently used by the memory allocator and the thread identifier of the heap owner.  The types are one of thread-local, global or large.  Maple employs a multi-level allocator that distributes memory from different heap types based on the requested size. Allocations 4KB and less are serviced from a thread-local heap. Requests for blocks of memory greater than 4KB up to 1MB are handed out from the global heap.  Finally, blocks of memory greater than 1MB are individually allocated from a large heap unto themselves. homedir string The path to the current user's home directory. This value cannot be set. includepath string or list An ordered list of directories (separated by "," or ";") specifying the search path for included files. The initial value can be overridden by supplying an include path at the command line by using the -I option.  When modifying the include path via kernelopts, the path should not be prefixed with "-I". The maximum number of include path entries is 25. inline boolean Specifies whether or not procedures with option inline are in-line expanded. The default value is true. jvmheaplimit integer The total amount of heap memory, in kibibytes, the Java external calling virtual machine is allowed to use. This option is effective only if the limitjvmheap kernel option is true. Values passed for this option can be given with a Unit of information. keepdebuginfo boolean If true (the default), debugging information stored in a procedure read from a library archive or source file is retained, allowing source level debugging (if the source code is available). If false, the debugging information is discarded. level integer Internal depth of recursion/computation indicator. This value cannot be set. limitjvmheap boolean If true, Maple limits the heap for the Java external calling virtual machine. The actual limit can be specified using the jvmheaplimit kernel option. The default value is false. locale string The current locale (subset of environment settings that depend on language and cultural conventions) for localization. This value cannot be set. mapledir string The path to the root of the Maple installation. This value cannot be set. maxdigits integer The maximum allowable setting of Digits. This value cannot be set. max_record_depth integer The maximum depth of nested Records that are displayed. maximmediate integer The largest integer that can be represented in immediate-integer form (represented in a word, instead of a pointer to a multi-word data structure). Cannot be set. memusage list Displays a matrix of memory usage by Maple internal objects. Each row contains the object type name, the number of objects of that type, and the number of bytes of storage occupied by such objects. Cannot be set. multithreaded boolean Returns true if the current engine is multithreaded and false otherwise. Cannot be set. numcpus integer Returns the number of CPUs that Maple will automatically optimize for.  By default this will be the actual number of CPUs that the machines has (treating hyperthreaded CPUs as 1 CPU).  This value can be set. numactivethreads integer Returns the number of active threads.  An active thread is any thread that is executing code, and is not paused on a mutex or condition variable and is not waiting for another thread to finish.  The number of active threads can change at any time. Cannot be set. opaquemodules boolean Specifies whether local members of a module are accessible outside the module. Setting this to false makes it easier to debug code that uses modules. The default value is true. pathsep string Returns the path separator character for the architecture on which Maple is running. Cannot be set. pid integer Returns the process ID of the kernel. Cannot be set. platform string One of "unix" or "windows" depending on the underlying operating system. Note that for Mac OS X the platform is "unix". Use kernelopts(system) to distinguish Mac OS X from other "unix" subsystems. Cannot be set. printbytes boolean Print the "bytes used.." message after every garbage collection (tty version). Default value is true. 'printlevel' integer An alternative interface to the printlevel environment variable. The default value is 1. processlimit integer The maximum number of external processes that Maple can have running at one time. If the value is 0 or it is not given the current limit is returned.  Important: This limit also affects internal Maple functions. profile boolean Produce resource information upon every call and exit from every function. The output is used as input for exprofile and excallgraph. The default is false. readdotm boolean Read Maple .m files located in directories listed in libname. The default is false. setsort integer Gives the current setting of the --setsort option provided on the command line.  See the maple help page for details. This value cannot be set. shortlineinfo boolean When source file and line number information is displayed in error messages or during tracing, the full path of the source file is shown if this option is false. If set to true, only the actual file name of the source file is displayed. sparse_sort_cutoff integer The number of inserts into a sparse rtable with hardware datatype before the index vectors are automatically resorted. The default value is 590. stackalloc integer Total number of kibibytes of stack memory currently allocated by the Maple kernel. This value cannot be set. stacklimit integer The total amount of stack space, in kibibytes that Maple may consume. Maple aborts if this limit is exceeded. If the value is 0 or it is not given the current limit is returned. Limits may be raised or lowered. Maple limits may not be raised above any system defined hard limits. This option is not supported on all platforms. Values passed for this option can be given with a Unit of information. system string One of "APPLE UNIVERSAL OSX", "IBM INTEL LINUX", "IBM INTEL NT", "X86 64 WINDOWS" or "X86 64 LINUX" depending on the underlying operating system. Cannot be set. toolboxdir string Returns the path to the first directory in the toolbox search path with the given name. When no value is specified, a list of all available toolbox paths is returned. toolboxversion string Returns a list containing version information for each of the toolboxes installed on your system.  Each sublist in the result contains the toolbox feature name, the build date, and a build identifier. When a specific toolbox name is specified, the version information for only that toolbox is returned. tracecatch boolean Activates tracing of caught exceptions. If true, then a notification is printed whenever an exception is caught by a catch statement. This notification indicates where the exception was caught, where it was thrown, and the exception message and arguments. traceincidentalassign boolean If true, causes assignments that are side-effects of built-in functions to appear in trace output. See trace for more information. tracelineinfo integer If non-zero, displays source file and line number information during tracing. See trace for more information. traceshowspecassign boolean If true, causes some assignments shown during tracing to appear in a distinctive way. See trace for more information. tracesplitmulassign boolean If true, causes multiple assignments shown during tracing to appear individually. See trace for more information. unread 'symbol' Marks the specified symbol as unread, meaning that the next access to that symbol will be re-read from the Maple library. username string Returns the username of the user that is running the kernel. Cannot be set. version symbol Version, compilation date, and build ID of the kernel. Cannot be set. For details on querying version information, see version. versionnumber string Major version number of the kernel. This will be a string such as "2050" and will not include any minor version number extensions. wordsize integer Returns the size of words (in bits) used by Maple data structures. This is usually 32 or 64. Cannot be set.

Thread Safety

 • The kernelopts command is thread safe as of Maple 15, however different variables behave differently when set by multiple threads.
 • The following variables have a global effect, thus the most recent setting of these variables will take effect.  Without explicit synchronization you may not be able to determine what settings are in effect at any particular time.

 ASSERT assertlevel cacheclearlimit cpulimit datalimit display_zero_complex_part filelimit floatPi includepath inline max_record_depth maxdigits opaquemodules printbytes 'printlevel' processlimit profile readdotm sparse_sort_cutoff stacklimit unread

 • The following variables can be safely accessed from any thread:

 bindir byteorder bytesalloc bytesused cputime cputype dagtag datadir dirsep gcbytesavail gcbytesreturned gcmaxthreads gcthreadmemorysize gctimes gctotaltime gmpthreshold gmpversion heaps homedir inline level locale mapledir maxdigits maximmediate memusage multithreaded numcpus numactivethreads pathsep pid platform stackalloc stacklimit system toolboxdir toolboxversion username version wordsize

Examples

 > $\mathrm{kernelopts}\left(\mathrm{maxdigits}\right)$
 ${38654705646}$ (1)
 > $\mathrm{kernelopts}\left(\mathrm{wordsize}\right)$
 ${64}$ (2)
 > $\mathrm{kernelopts}\left(\mathrm{dagtag}=4\right)$
 ${\mathrm{FLOAT}}$ (3)
 > $\mathrm{kernelopts}\left(\mathrm{dagtag}=\mathrm{SERIES}\right)$
 ${15}$ (4)
 > $\mathrm{kernelopts}\left(\mathrm{cputime}\right)$
 ${0.253610000000000}$ (5)
 > $\mathrm{kernelopts}\left(\mathrm{datalimit}=256\mathrm{Unit}\left(\mathrm{megabyte}\right)\right):$
 > $\mathrm{kernelopts}\left(\mathrm{datalimit}=256\mathrm{Unit}\left(\mathrm{mebibyte}\right)\right)$
 ${250000}$ (6)
 > $\mathrm{kernelopts}\left(\mathrm{datalimit}=250000\mathrm{Unit}\left(\mathrm{kibibyte}\right)\right)$
 ${262144}$ (7)
 > $\mathrm{kernelopts}\left(\mathrm{datalimit}\right)$
 ${250000}$ (8)
 > $\mathrm{kernelopts}\left(\mathrm{cpulimit}=10\mathrm{Unit}\left(\mathrm{minute}\right)\right):$
 > $\mathrm{kernelopts}\left(\mathrm{cpulimit}\right)$
 ${600}$ (9)
 > $\mathrm{\pi }\cdot 1.1$
 ${3.455751919}$ (10)
 > $\mathrm{kernelopts}\left(\mathrm{floatPi}=\mathrm{false}\right):$
 > $\mathrm{\pi }\cdot 1.1$
 ${1.1}{}{\mathrm{\pi }}$ (11)

Compatibility

 • The tracelineinfo and shortlineinfo options are new in Maple 2020.
 • The tracecatch option of debugopts was moved to kernelopts in Maple 2020.
 • The kernelopts command was updated in Maple 2020.

 See Also