mozilla-central/third_party/rust/nix/src/sys/resource.rs

Source code

Revision control

Copy as Markdown

Other Tools

//! Configure the process resource limits.
use cfg_if::cfg_if;
use libc::{c_int, c_long, rusage};
use crate::errno::Errno;
use crate::sys::time::TimeVal;
use crate::Result;
pub use libc::rlim_t;
pub use libc::RLIM_INFINITY;
use std::mem;
cfg_if! {
if #[cfg(any(
all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")),
target_os = "hurd"
))]{
use libc::{__rlimit_resource_t, rlimit};
} else if #[cfg(any(
bsd,
target_os = "android",
target_os = "aix",
all(target_os = "linux", not(target_env = "gnu"))
))]{
use libc::rlimit;
}
}
libc_enum! {
/// Types of process resources.
///
/// The Resource enum is platform dependent. Check different platform
/// manuals for more details. Some platform links have been provided for
/// easier reference (non-exhaustive).
///
// linux-gnu uses u_int as resource enum, which is implemented in libc as
// well.
//
#[cfg_attr(any(
all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")),
target_os = "hurd"
), repr(u32))]
#[cfg_attr(any(
bsd,
target_os = "android",
target_os = "aix",
all(target_os = "linux", not(any(target_env = "gnu", target_env = "uclibc")))
), repr(i32))]
#[non_exhaustive]
pub enum Resource {
#[cfg(not(any(target_os = "freebsd", netbsdlike)))]
/// The maximum amount (in bytes) of virtual memory the process is
/// allowed to map.
RLIMIT_AS,
/// The largest size (in bytes) core(5) file that may be created.
RLIMIT_CORE,
/// The maximum amount of cpu time (in seconds) to be used by each
/// process.
RLIMIT_CPU,
/// The maximum size (in bytes) of the data segment for a process
RLIMIT_DATA,
/// The largest size (in bytes) file that may be created.
RLIMIT_FSIZE,
/// The maximum number of open files for this process.
RLIMIT_NOFILE,
/// The maximum size (in bytes) of the stack segment for a process.
RLIMIT_STACK,
#[cfg(target_os = "freebsd")]
/// The maximum number of kqueues this user id is allowed to create.
RLIMIT_KQUEUES,
#[cfg(linux_android)]
/// A limit on the combined number of flock locks and fcntl leases that
/// this process may establish.
RLIMIT_LOCKS,
#[cfg(any(linux_android, target_os = "freebsd", netbsdlike))]
/// The maximum size (in bytes) which a process may lock into memory
/// using the mlock(2) system call.
RLIMIT_MEMLOCK,
#[cfg(linux_android)]
/// A limit on the number of bytes that can be allocated for POSIX
/// message queues for the real user ID of the calling process.
RLIMIT_MSGQUEUE,
#[cfg(linux_android)]
/// A ceiling to which the process's nice value can be raised using
/// setpriority or nice.
RLIMIT_NICE,
#[cfg(any(
linux_android,
target_os = "freebsd",
netbsdlike,
target_os = "aix",
))]
/// The maximum number of simultaneous processes for this user id.
RLIMIT_NPROC,
#[cfg(target_os = "freebsd")]
/// The maximum number of pseudo-terminals this user id is allowed to
/// create.
RLIMIT_NPTS,
#[cfg(any(linux_android,
target_os = "freebsd",
netbsdlike,
target_os = "aix",
))]
/// When there is memory pressure and swap is available, prioritize
/// eviction of a process' resident pages beyond this amount (in bytes).
RLIMIT_RSS,
#[cfg(linux_android)]
/// A ceiling on the real-time priority that may be set for this process
/// using sched_setscheduler and sched_set‐ param.
RLIMIT_RTPRIO,
#[cfg(any(target_os = "linux"))]
/// A limit (in microseconds) on the amount of CPU time that a process
/// scheduled under a real-time scheduling policy may con‐ sume without
/// making a blocking system call.
RLIMIT_RTTIME,
#[cfg(linux_android)]
/// A limit on the number of signals that may be queued for the real
/// user ID of the calling process.
RLIMIT_SIGPENDING,
#[cfg(freebsdlike)]
/// The maximum size (in bytes) of socket buffer usage for this user.
RLIMIT_SBSIZE,
#[cfg(target_os = "freebsd")]
/// The maximum size (in bytes) of the swap space that may be reserved
/// or used by all of this user id's processes.
RLIMIT_SWAP,
#[cfg(target_os = "freebsd")]
/// An alias for RLIMIT_AS.
RLIMIT_VMEM,
}
}
/// Get the current processes resource limits
///
/// The special value [`RLIM_INFINITY`] indicates that no limit will be
/// enforced.
///
/// # Parameters
///
/// * `resource`: The [`Resource`] that we want to get the limits of.
///
/// # Examples
///
/// ```
/// # use nix::sys::resource::{getrlimit, Resource};
///
/// let (soft_limit, hard_limit) = getrlimit(Resource::RLIMIT_NOFILE).unwrap();
/// println!("current soft_limit: {}", soft_limit);
/// println!("current hard_limit: {}", hard_limit);
/// ```
///
/// # References
///
///
/// [`Resource`]: enum.Resource.html
pub fn getrlimit(resource: Resource) -> Result<(rlim_t, rlim_t)> {
let mut old_rlim = mem::MaybeUninit::<rlimit>::uninit();
cfg_if! {
if #[cfg(any(
all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")),
target_os = "hurd"
))] {
let res = unsafe { libc::getrlimit(resource as __rlimit_resource_t, old_rlim.as_mut_ptr()) };
} else {
let res = unsafe { libc::getrlimit(resource as c_int, old_rlim.as_mut_ptr()) };
}
}
Errno::result(res).map(|_| {
let rlimit { rlim_cur, rlim_max } = unsafe { old_rlim.assume_init() };
(rlim_cur, rlim_max)
})
}
/// Set the current processes resource limits
///
/// # Parameters
///
/// * `resource`: The [`Resource`] that we want to set the limits of.
/// * `soft_limit`: The value that the kernel enforces for the corresponding
/// resource.
/// * `hard_limit`: The ceiling for the soft limit. Must be lower or equal to
/// the current hard limit for non-root users.
///
/// The special value [`RLIM_INFINITY`] indicates that no limit will be
/// enforced.
///
/// # Examples
///
/// ```
/// # use nix::sys::resource::{setrlimit, Resource};
///
/// let soft_limit = 512;
/// let hard_limit = 1024;
/// setrlimit(Resource::RLIMIT_NOFILE, soft_limit, hard_limit).unwrap();
/// ```
///
/// # References
///
///
/// [`Resource`]: enum.Resource.html
///
/// Note: `setrlimit` provides a safe wrapper to libc's `setrlimit`.
pub fn setrlimit(
resource: Resource,
soft_limit: rlim_t,
hard_limit: rlim_t,
) -> Result<()> {
let new_rlim = rlimit {
rlim_cur: soft_limit,
rlim_max: hard_limit,
};
cfg_if! {
if #[cfg(any(
all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")),
target_os = "hurd",
))]{
let res = unsafe { libc::setrlimit(resource as __rlimit_resource_t, &new_rlim as *const rlimit) };
}else{
let res = unsafe { libc::setrlimit(resource as c_int, &new_rlim as *const rlimit) };
}
}
Errno::result(res).map(drop)
}
libc_enum! {
/// Whose resource usage should be returned by [`getrusage`].
#[repr(i32)]
#[non_exhaustive]
pub enum UsageWho {
/// Resource usage for the current process.
RUSAGE_SELF,
/// Resource usage for all the children that have terminated and been waited for.
RUSAGE_CHILDREN,
#[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "openbsd"))]
/// Resource usage for the calling thread.
RUSAGE_THREAD,
}
}
/// Output of `getrusage` with information about resource usage. Some of the fields
/// may be unused in some platforms, and will be always zeroed out. See their manuals
/// for details.
#[repr(transparent)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct Usage(rusage);
impl AsRef<rusage> for Usage {
fn as_ref(&self) -> &rusage {
&self.0
}
}
impl AsMut<rusage> for Usage {
fn as_mut(&mut self) -> &mut rusage {
&mut self.0
}
}
impl Usage {
/// Total amount of time spent executing in user mode.
pub fn user_time(&self) -> TimeVal {
TimeVal::from(self.0.ru_utime)
}
/// Total amount of time spent executing in kernel mode.
pub fn system_time(&self) -> TimeVal {
TimeVal::from(self.0.ru_stime)
}
/// The resident set size at its peak,
#[cfg_attr(apple_targets, doc = " in bytes.")]
#[cfg_attr(not(apple_targets), doc = " in kilobytes.")]
pub fn max_rss(&self) -> c_long {
self.0.ru_maxrss
}
/// Integral value expressed in kilobytes times ticks of execution indicating
/// the amount of text memory shared with other processes.
pub fn shared_integral(&self) -> c_long {
self.0.ru_ixrss
}
/// Integral value expressed in kilobytes times ticks of execution indicating
/// the amount of unshared memory used by data.
pub fn unshared_data_integral(&self) -> c_long {
self.0.ru_idrss
}
/// Integral value expressed in kilobytes times ticks of execution indicating
/// the amount of unshared memory used for stack space.
pub fn unshared_stack_integral(&self) -> c_long {
self.0.ru_isrss
}
/// Number of page faults that were served without resorting to I/O, with pages
/// that have been allocated previously by the kernel.
pub fn minor_page_faults(&self) -> c_long {
self.0.ru_minflt
}
/// Number of page faults that were served through I/O (i.e. swap).
pub fn major_page_faults(&self) -> c_long {
self.0.ru_majflt
}
/// Number of times all of the memory was fully swapped out.
pub fn full_swaps(&self) -> c_long {
self.0.ru_nswap
}
/// Number of times a read was done from a block device.
pub fn block_reads(&self) -> c_long {
self.0.ru_inblock
}
/// Number of times a write was done to a block device.
pub fn block_writes(&self) -> c_long {
self.0.ru_oublock
}
/// Number of IPC messages sent.
pub fn ipc_sends(&self) -> c_long {
self.0.ru_msgsnd
}
/// Number of IPC messages received.
pub fn ipc_receives(&self) -> c_long {
self.0.ru_msgrcv
}
/// Number of signals received.
pub fn signals(&self) -> c_long {
self.0.ru_nsignals
}
/// Number of times a context switch was voluntarily invoked.
pub fn voluntary_context_switches(&self) -> c_long {
self.0.ru_nvcsw
}
/// Number of times a context switch was imposed by the kernel (usually due to
/// time slice expiring or preemption by a higher priority process).
pub fn involuntary_context_switches(&self) -> c_long {
self.0.ru_nivcsw
}
}
/// Get usage information for a process, its children or the current thread
///
/// Real time information can be obtained for either the current process or (in some
/// systems) thread, but information about children processes is only provided for
/// those that have terminated and been waited for (see [`super::wait::wait`]).
///
/// Some information may be missing depending on the platform, and the way information
/// is provided for children may also vary. Check the manuals for details.
///
/// # References
///
///
/// [`UsageWho`]: enum.UsageWho.html
///
/// Note: `getrusage` provides a safe wrapper to libc's [`libc::getrusage`].
pub fn getrusage(who: UsageWho) -> Result<Usage> {
unsafe {
let mut rusage = mem::MaybeUninit::<rusage>::uninit();
let res = libc::getrusage(who as c_int, rusage.as_mut_ptr());
Errno::result(res).map(|_| Usage(rusage.assume_init()))
}
}