setrlimit(2) DG/UX 4.30 setrlimit(2)
NAME
setrlimit - Set system resource consumption limits.
SYNOPSIS
#include <sys/time.h>
#include <sys/resource.h>
int setrlimit (resource, rlp)
int resource;
struct rlimit * rlp;
PARAMETERS
resource Identifies the resource for which the limits
are to be set.
rlp A pointer to a structure into which the limit
values are to be placed.
DESCRIPTION
The current setting of the limits on consumption of system
resources by the calling process may be changed with this
system call.
The <resource> parameter is one of the following:
RLIMIT_CPU
The maximum amount of cpu time (in seconds) used by the
process.
RLIMIT_FSIZE
The largest offset, in bytes, at which the process may
write to a file.
RLIMIT_DATA
The maximum size, in bytes, of the data segment for a
process; the limit is the sum of the virtual address
spaces occupied by the initial data area, data area
allocated using sbrk, and data area occupied by
attached shared memory segments.
RLIMIT_STACK
The maximum size, in bytes, of the stack segment for a
process; this defines how far a program's stack segment
may be extended, either automatically by the system, or
explicitly by a user with the sbrk system call.
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setrlimit(2) DG/UX 4.30 setrlimit(2)
RLIMIT_CORE
The largest size, in bytes, of a core file which may be
created.
RLIMIT_RSS
The maximum size, in bytes, a process's resident set
size may grow to. This is an advisory limit on the
amount of physical memory to be given to a process; if
memory is tight, the system will prefer to take memory
from processes which are exceeding their declared
resident set size.
RLIMIT_NOFILE The maximum number of open channels a process
may have at any given time.
A resource limit is specified as a soft limit and a hard
limit. When a soft limit is exceeded a process may receive
a signal (for example, if the cpu time is exceeded), but it
will be allowed to continue execution until it reaches the
hard limit (or modifies its resource limit). Both the hard
and soft limit are set by this system call, subject to the
access restrictions described below.
ACCESS CONTROL
The argument <rlp> must address an area of the calling
process's address space that is valid and has read access.
The calling process may, without restriction, change the
soft limit to any value between 0 and the hard limit,
inclusive, and irreversibly lower the hard limit. The
calling process may increase the hard limit only if its
effective-user-id is 0.
RETURN VALUE
0 Successful completion.
-1 An error occurred. Errno is set to indicate
the error.
EXCEPTIONS
Errno may be set to one of the following error codes:
EFAULT The address specified for <rlp> is illegal.
EINVAL The value of <resource> is not one of the
allowed values.
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setrlimit(2) DG/UX 4.30 setrlimit(2)
EINVAL The caller attempted to set the soft limit
larger than the hard limit.
SEE ALSO
The related system call: getrlimit, ulimit.
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