posix_setrlimit() constants

Note:

These constants are available starting with PHP
7.0.0. Please note that some of them may not be available on your
system.

Note:

You may wish to read the below notes in conjunction
with the manpage for setrlimit() on your specific
operating system, as there is variance in how these limits are
interpreted, even across operating systems that claim to implement
POSIX in full.

POSIX_RLIMIT_AS (integer)

The maximum size of the process’s address
space in bytes. See also PHP’s memory_limit
configuration directive.

POSIX_RLIMIT_CORE (integer)

The maximum size of a core file. If the
limit is set to 0, no core file will be generated.

POSIX_RLIMIT_CPU (integer)

The maximum amount of CPU time that the
process can use, in seconds. When the soft limit is hit, a
SIGXCPU signal will be sent, which can be caught with
pcntl_signal(). Depending on the operating
system, additional SIGXCPU signals may be sent each second
until the hard limit is hit, at which point an uncatchable
SIGKILL signal is sent. See
also set_time_limit().

POSIX_RLIMIT_DATA (integer)

The maximum size of the process’s data
segment, in bytes. It is extremely unlikely that this will have any
effect on the execution of PHP unless an extension is in use that
calls brk() or
sbrk().

POSIX_RLIMIT_FSIZE (integer)

The maximum size of files that the
process can create, in bytes.

POSIX_RLIMIT_LOCKS (integer)

The maximum number of locks that the
process can create. This is only supported on extremely old Linux
kernels.

POSIX_RLIMIT_MEMLOCK (integer)

The maximum number of bytes that can be
locked into memory.

POSIX_RLIMIT_MSGQUEUE (integer)

The maximum number of bytes that can be
allocated for POSIX message queues. PHP does not ship with support
for POSIX message queues, so this limit will not have any effect
unless you are using an extension that implements that
support.

POSIX_RLIMIT_NICE (integer)

The maximum value to which the process
can be reniced to. The value that will be used will be 20 –
limit, as resource limit values cannot be
negative.

POSIX_RLIMIT_NOFILE (integer)

A value one greater than the maximum file
descriptor number that can be opened by this process.

POSIX_RLIMIT_NPROC (integer)

The maximum number of processes (and/or
threads, on some operating systems) that can be created for the
real user ID of the process.

POSIX_RLIMIT_RSS (integer)

The maximum size of the process’s
resident set, in pages.

POSIX_RLIMIT_RTPRIO (integer)

The maximum real time priority that can
be set via the sched_setscheduler() and
sched_setparam()
system calls.

POSIX_RLIMIT_RTTIME (integer)

The maximum amount of CPU time, in
microseconds, that the process can consume without making a
blocking system call if it is using real time
scheduling.

POSIX_RLIMIT_SIGPENDING (integer)

The maximum number of signals that can be
queued for the real user ID of the process.

POSIX_RLIMIT_STACK (integer)

The maximum size of the process stack, in
bytes.

POSIX_RLIMIT_INFINITY (integer)

Used to indicate an infinite value for a
resource limit.