mirror of https://github.com/python/cpython
Some reorganization (all limit operations & constants together, and all usage
functions and constants together). Make explicit datadesc sections for each of the constants which might appear, and have a description of each. (Descriptions are based on the Linux documentation and sources and the Solaris man pages.) Hopefully Jeremy won't mind, because I didn't ask. ;-)
This commit is contained in:
Fred Drake
parent
a0eaa2200c
commit
e907208b30
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@ -9,62 +9,132 @@ Symbolic constants are used to specify particular system resources and
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to request usage information about either the current process or its
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children.
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Resources usage can be limited using the \code{setrlimit} function
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A single exception is defined for errors:
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\renewcommand{\indexsubitem}{(in module resource)}
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\begin{excdesc}{error}
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The functions described below may raise this error if the underlying
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system call failures unexpectedly.
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\end{excdesc}
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\subsection{Resource Limits}
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Resources usage can be limited using the \code{setrlimit()} function
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described below. Each resource is controlled by a pair of limits: a
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soft limit and a hard limit. The soft limit is the current limit, and
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may be lowered or raised by a process over time. The soft limit can
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never exceed the hard limit. The hard limit can be lowered to any
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value greater than the soft limit, but not raised. (Only process with
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the effective UID of the super-user can raise a hard limit).
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value greater than the soft limit, but not raised. (Only processes with
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the effective UID of the super-user can raise a hard limit.)
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The specific resources that can be limited are system dependent. They
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are described in the \code{getrlimit} man page. Typical resources
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include:
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are described in the \code{getrlimit()} man page. The resources
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listed below are supported when the underlying operating system
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supports them; resources which cannot be checked or controlled by the
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operating system are not defined in this module for those platforms.
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\begin{description}
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\begin{funcdesc}{getrlimit}{resource}
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Returns a tuple \code{(\var{soft}, \var{hard})} with the current
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soft and hard limits of \var{resource}. Raises \code{ValueError} if
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an invalid resource is specified, or \code{resource.error} if the
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underyling system call fails unexpectedly.
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\end{funcdesc}
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\item[RLIMIT_CORE]
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The maximum size (in bytes) of a core file that the current process
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can create.
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\begin{funcdesc}{setrlimit}{resource, limits}
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Sets new limits of consumption of \var{resource}. The \var{limits}
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argument must be a tuple \code{(\var{soft}, \var{hard})} of two
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integers describing the new limits. A value of \code{-1} can be used to
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specify the maximum possible upper limit.
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\item[RLIMIT_CPU]
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The maximum amount of CPU time (in seconds) that a process can use. If
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this limit is exceeded, a \code{SIGXCPU} signal is sent to the
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process. (See the \code{signal} module documentation for information
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about how to catch this signal and do something useful, e.g. flush
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open files to disk.)
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Raises \code{ValueError} if an invalid resource is specified, if the new
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soft limit exceeds the hard limit, or if a process tries to raise its
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hard limit (unless the process has an effective UID of
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super-user). Can also raise a \code{resource.error} if the
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underyling system call fails.
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\end{funcdesc}
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\end{description}
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\begin{datadesc}{RLIMIT_*}
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These symbols define resources whose consumption can be controlled
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using the \code{setrlimit} and \code{getrlimit} functions defined
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using the \code{setrlimit()} and \code{getrlimit()} functions defined
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below. The values of these symbols are exactly the constants used
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by C programs.
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The \UNIX{} man page for \file{getrlimit} lists the available
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The \UNIX{} man page for \code{getrlimit()} lists the available
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resources. Note that not all systems use the same symbol or same
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value to denote the same resource.
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\begin{datadesc}{RLIMIT_CORE}
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The maximum size (in bytes) of a core file that the current process
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can create. This may result in the creation of a partial core file
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if a larger core would be required to contain the entire process
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image.
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\end{datadesc}
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\begin{datadesc}{RUSAGE_*}
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These symbols are passed to the \code{getrusage} function to specify
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whether usage information is being request for the current process,
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\code{RUSAGE_SELF} or its child processes \code{RUSAGE_CHILDREN}. On
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some system, \code{RUSAGE_BOTH} requests information for both.
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\begin{datadesc}{RLIMIT_CPU}
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The maximum amount of CPU time (in seconds) that a process can
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use. If this limit is exceeded, a \code{SIGXCPU} signal is sent to
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the process. (See the \code{signal} module documentation for
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information about how to catch this signal and do something useful,
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e.g. flush open files to disk.)
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\end{datadesc}
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\begin{datadesc}{error}
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The functions described below may raise this error if the underlying
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system call failures unexpectedly.
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\begin{datadesc}{RLIMIT_FSIZE}
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The maximum size of a file which the process may create. This only
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affects the stack of the main thread in a multi-threaded process.
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\end{datadesc}
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The resource module defines the following functions:
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\begin{datadesc}{RLIMIT_DATA}
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The maximum size (in bytes) of the process's heap.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_STACK}
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The maximum size (in bytes) of the call stack for the current
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process.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_RSS}
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The maximum resident set size that should be made available to the
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process.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_NPROC}
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The maximum number of processes the current process may create.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_NOFILE}
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The maximum number of open file descriptors for the current
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process.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_OFILE}
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The BSD name for \code{RLIMIT_NOFILE}.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_MEMLOC}
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The maximm address space which may be locked in memory.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_VMEM}
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The largest area of mapped memory which the process may occupy.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_AS}
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The maximum area (in bytes) of address space which may be taken by
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the process.
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\end{datadesc}
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\subsection{Resource Usage}
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These functiona are used to retrieve resource usage information:
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\begin{funcdesc}{getrusage}{who}
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This function returns a large tuple that describes the resources
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consumed by either the current process or its children, as specified
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by the \var{who} parameter. The elements of the return value each
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by the \var{who} parameter. The \var{who} parameter should be
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specified using one of the \code{RUSAGE_}* constants described
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below.
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The elements of the return value each
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describe how a particular system resource has been used, e.g. amount
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of time spent running is user mode or number of times the process was
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swapped out of main memory. Some values are dependent on the clock
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@ -73,7 +143,7 @@ The resource module defines the following functions:
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The first two elements of the return value are floating point values
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representing the amount of time spent executing in user mode and the
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amount of time spent executing in system mode, respectively. The
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remaining values are integers. Consult the \code{getrusage} man page
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remaining values are integers. Consult the \code{getrusage()} man page
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for detailed information about these values. A brief summary is
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presented here:
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@ -97,7 +167,7 @@ The resource module defines the following functions:
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15 & involuntary context switches \\
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\end{tabular}
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This function will raise a ValueError if an invalid \var{who}
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This function will raise a \code{ValueError} if an invalid \var{who}
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parameter is specified. It may also raise a \code{resource.error}
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exception in unusual circumstances.
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\end{funcdesc}
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@ -111,22 +181,22 @@ The resource module defines the following functions:
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bytes.
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\end{funcdesc}
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\begin{funcdesc}{getrlimit}{resource}
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Returns a tuple \code{(\var{soft}, \var{hard})} with the current
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soft and hard limits of \var{resource}. Raises ValueError if
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an invalid resource is specified, or \code{resource.error} if the
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underyling system call fails unexpectedly.
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\end{funcdesc}
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The following \code{RUSAGE_}* symbols are passed to the
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\code{getrusage()} function to specify which processes information
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should be provided for.
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\begin{funcdesc}{setrlimit}{resource\, limits}
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Sets new limits of consumption of \var{resource}. The \var{limits}
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argument must be a tuple \code{(\var{soft}, \var{hard})} of two
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integers describing the new limits. A value of -1 can be used to
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specify the maximum possible upper limit.
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\begin{datadesc}{RUSAGE_SELF}
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\code{RUSAGE_SELF} should be used to
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request information pertaining only to the process itself.
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\end{datadesc}
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Raises ValueError if an invalid resource is specified, if the new
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soft limit exceeds the hard limit, or if a process tries to raise its
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hard limit (unless the process has an effective UID of
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super-user). Can also raise a \code{resource.error} if the
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underyling system call fails.
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\end{funcdesc}
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\begin{datadesc}{RUSAGE_CHILDREN}
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Pass to \code{getrusage()} to request resource information for child
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processes of the calling process.
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\end{datadesc}
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\begin{datadesc}{RUSAGE_BOTH}
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Pass to \code{getrusage()} to request resources consumed by both the
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current process and child processes. May not be available on all
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systems.
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\end{datadesc}
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|
|
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@ -9,62 +9,132 @@ Symbolic constants are used to specify particular system resources and
|
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to request usage information about either the current process or its
|
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children.
|
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|
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Resources usage can be limited using the \code{setrlimit} function
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A single exception is defined for errors:
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\renewcommand{\indexsubitem}{(in module resource)}
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\begin{excdesc}{error}
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The functions described below may raise this error if the underlying
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system call failures unexpectedly.
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\end{excdesc}
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\subsection{Resource Limits}
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|
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Resources usage can be limited using the \code{setrlimit()} function
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described below. Each resource is controlled by a pair of limits: a
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soft limit and a hard limit. The soft limit is the current limit, and
|
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may be lowered or raised by a process over time. The soft limit can
|
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never exceed the hard limit. The hard limit can be lowered to any
|
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value greater than the soft limit, but not raised. (Only process with
|
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the effective UID of the super-user can raise a hard limit).
|
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value greater than the soft limit, but not raised. (Only processes with
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the effective UID of the super-user can raise a hard limit.)
|
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|
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The specific resources that can be limited are system dependent. They
|
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are described in the \code{getrlimit} man page. Typical resources
|
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include:
|
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are described in the \code{getrlimit()} man page. The resources
|
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listed below are supported when the underlying operating system
|
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supports them; resources which cannot be checked or controlled by the
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operating system are not defined in this module for those platforms.
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\begin{description}
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\begin{funcdesc}{getrlimit}{resource}
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Returns a tuple \code{(\var{soft}, \var{hard})} with the current
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soft and hard limits of \var{resource}. Raises \code{ValueError} if
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an invalid resource is specified, or \code{resource.error} if the
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underyling system call fails unexpectedly.
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\end{funcdesc}
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\item[RLIMIT_CORE]
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The maximum size (in bytes) of a core file that the current process
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can create.
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\begin{funcdesc}{setrlimit}{resource, limits}
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Sets new limits of consumption of \var{resource}. The \var{limits}
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argument must be a tuple \code{(\var{soft}, \var{hard})} of two
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integers describing the new limits. A value of \code{-1} can be used to
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specify the maximum possible upper limit.
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\item[RLIMIT_CPU]
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The maximum amount of CPU time (in seconds) that a process can use. If
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this limit is exceeded, a \code{SIGXCPU} signal is sent to the
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process. (See the \code{signal} module documentation for information
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about how to catch this signal and do something useful, e.g. flush
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open files to disk.)
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Raises \code{ValueError} if an invalid resource is specified, if the new
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soft limit exceeds the hard limit, or if a process tries to raise its
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hard limit (unless the process has an effective UID of
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super-user). Can also raise a \code{resource.error} if the
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underyling system call fails.
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\end{funcdesc}
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\end{description}
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\begin{datadesc}{RLIMIT_*}
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These symbols define resources whose consumption can be controlled
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using the \code{setrlimit} and \code{getrlimit} functions defined
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using the \code{setrlimit()} and \code{getrlimit()} functions defined
|
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below. The values of these symbols are exactly the constants used
|
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by C programs.
|
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|
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The \UNIX{} man page for \file{getrlimit} lists the available
|
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The \UNIX{} man page for \code{getrlimit()} lists the available
|
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resources. Note that not all systems use the same symbol or same
|
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value to denote the same resource.
|
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|
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\begin{datadesc}{RLIMIT_CORE}
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The maximum size (in bytes) of a core file that the current process
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can create. This may result in the creation of a partial core file
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if a larger core would be required to contain the entire process
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image.
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\end{datadesc}
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\begin{datadesc}{RUSAGE_*}
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These symbols are passed to the \code{getrusage} function to specify
|
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whether usage information is being request for the current process,
|
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\code{RUSAGE_SELF} or its child processes \code{RUSAGE_CHILDREN}. On
|
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some system, \code{RUSAGE_BOTH} requests information for both.
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\begin{datadesc}{RLIMIT_CPU}
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The maximum amount of CPU time (in seconds) that a process can
|
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use. If this limit is exceeded, a \code{SIGXCPU} signal is sent to
|
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the process. (See the \code{signal} module documentation for
|
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information about how to catch this signal and do something useful,
|
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e.g. flush open files to disk.)
|
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\end{datadesc}
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\begin{datadesc}{error}
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The functions described below may raise this error if the underlying
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system call failures unexpectedly.
|
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\begin{datadesc}{RLIMIT_FSIZE}
|
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The maximum size of a file which the process may create. This only
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affects the stack of the main thread in a multi-threaded process.
|
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\end{datadesc}
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The resource module defines the following functions:
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\begin{datadesc}{RLIMIT_DATA}
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The maximum size (in bytes) of the process's heap.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_STACK}
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The maximum size (in bytes) of the call stack for the current
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process.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_RSS}
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The maximum resident set size that should be made available to the
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process.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_NPROC}
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The maximum number of processes the current process may create.
|
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\end{datadesc}
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\begin{datadesc}{RLIMIT_NOFILE}
|
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The maximum number of open file descriptors for the current
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process.
|
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\end{datadesc}
|
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|
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\begin{datadesc}{RLIMIT_OFILE}
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The BSD name for \code{RLIMIT_NOFILE}.
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\end{datadesc}
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\begin{datadesc}{RLIMIT_MEMLOC}
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The maximm address space which may be locked in memory.
|
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\end{datadesc}
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|
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\begin{datadesc}{RLIMIT_VMEM}
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The largest area of mapped memory which the process may occupy.
|
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\end{datadesc}
|
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|
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\begin{datadesc}{RLIMIT_AS}
|
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The maximum area (in bytes) of address space which may be taken by
|
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the process.
|
||||
\end{datadesc}
|
||||
|
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\subsection{Resource Usage}
|
||||
|
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These functiona are used to retrieve resource usage information:
|
||||
|
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\begin{funcdesc}{getrusage}{who}
|
||||
This function returns a large tuple that describes the resources
|
||||
consumed by either the current process or its children, as specified
|
||||
by the \var{who} parameter. The elements of the return value each
|
||||
by the \var{who} parameter. The \var{who} parameter should be
|
||||
specified using one of the \code{RUSAGE_}* constants described
|
||||
below.
|
||||
|
||||
The elements of the return value each
|
||||
describe how a particular system resource has been used, e.g. amount
|
||||
of time spent running is user mode or number of times the process was
|
||||
swapped out of main memory. Some values are dependent on the clock
|
||||
|
|
@ -73,7 +143,7 @@ The resource module defines the following functions:
|
|||
The first two elements of the return value are floating point values
|
||||
representing the amount of time spent executing in user mode and the
|
||||
amount of time spent executing in system mode, respectively. The
|
||||
remaining values are integers. Consult the \code{getrusage} man page
|
||||
remaining values are integers. Consult the \code{getrusage()} man page
|
||||
for detailed information about these values. A brief summary is
|
||||
presented here:
|
||||
|
||||
|
|
@ -97,7 +167,7 @@ The resource module defines the following functions:
|
|||
15 & involuntary context switches \\
|
||||
\end{tabular}
|
||||
|
||||
This function will raise a ValueError if an invalid \var{who}
|
||||
This function will raise a \code{ValueError} if an invalid \var{who}
|
||||
parameter is specified. It may also raise a \code{resource.error}
|
||||
exception in unusual circumstances.
|
||||
\end{funcdesc}
|
||||
|
|
@ -111,22 +181,22 @@ The resource module defines the following functions:
|
|||
bytes.
|
||||
\end{funcdesc}
|
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|
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\begin{funcdesc}{getrlimit}{resource}
|
||||
Returns a tuple \code{(\var{soft}, \var{hard})} with the current
|
||||
soft and hard limits of \var{resource}. Raises ValueError if
|
||||
an invalid resource is specified, or \code{resource.error} if the
|
||||
underyling system call fails unexpectedly.
|
||||
\end{funcdesc}
|
||||
The following \code{RUSAGE_}* symbols are passed to the
|
||||
\code{getrusage()} function to specify which processes information
|
||||
should be provided for.
|
||||
|
||||
\begin{funcdesc}{setrlimit}{resource\, limits}
|
||||
Sets new limits of consumption of \var{resource}. The \var{limits}
|
||||
argument must be a tuple \code{(\var{soft}, \var{hard})} of two
|
||||
integers describing the new limits. A value of -1 can be used to
|
||||
specify the maximum possible upper limit.
|
||||
\begin{datadesc}{RUSAGE_SELF}
|
||||
\code{RUSAGE_SELF} should be used to
|
||||
request information pertaining only to the process itself.
|
||||
\end{datadesc}
|
||||
|
||||
Raises ValueError if an invalid resource is specified, if the new
|
||||
soft limit exceeds the hard limit, or if a process tries to raise its
|
||||
hard limit (unless the process has an effective UID of
|
||||
super-user). Can also raise a \code{resource.error} if the
|
||||
underyling system call fails.
|
||||
\end{funcdesc}
|
||||
\begin{datadesc}{RUSAGE_CHILDREN}
|
||||
Pass to \code{getrusage()} to request resource information for child
|
||||
processes of the calling process.
|
||||
\end{datadesc}
|
||||
|
||||
\begin{datadesc}{RUSAGE_BOTH}
|
||||
Pass to \code{getrusage()} to request resources consumed by both the
|
||||
current process and child processes. May not be available on all
|
||||
systems.
|
||||
\end{datadesc}
|
||||
|
|
|
|||
Loading…
Reference in New Issue