diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/sys/resource.rs | 186 |
1 files changed, 180 insertions, 6 deletions
diff --git a/src/sys/resource.rs b/src/sys/resource.rs index 76ceaf5b..e9a11d95 100644 --- a/src/sys/resource.rs +++ b/src/sys/resource.rs @@ -1,7 +1,9 @@ //! 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; use std::mem; @@ -19,7 +21,7 @@ cfg_if! { target_os = "dragonfly", all(target_os = "linux", not(target_env = "gnu")) ))]{ - use libc::{c_int, rlimit}; + use libc::rlimit; } } @@ -242,11 +244,7 @@ pub fn getrlimit(resource: Resource) -> Result<(rlim_t, rlim_t)> { /// [`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<()> { +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, @@ -261,3 +259,179 @@ pub fn setrlimit( 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"))] + #[cfg_attr(docsrs, doc(cfg(all())))] + /// 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, 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 +/// +/// * [getrusage(2)](https://pubs.opengroup.org/onlinepubs/009696699/functions/getrusage.html) +/// * [Linux](https://man7.org/linux/man-pages/man2/getrusage.2.html) +/// * [FreeBSD](https://www.freebsd.org/cgi/man.cgi?query=getrusage) +/// * [NetBSD](https://man.netbsd.org/getrusage.2) +/// * [MacOS](https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/getrusage.2.html) +/// +/// [`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())) + } +} + +#[cfg(test)] +mod test { + use super::{getrusage, UsageWho}; + + #[test] + pub fn test_self_cpu_time() { + // Make sure some CPU time is used. + let mut numbers: Vec<i32> = (1..1_000_000).collect(); + numbers.iter_mut().for_each(|item| *item *= 2); + + // FIXME: this is here to help ensure the compiler does not optimize the whole + // thing away. Replace the assert with test::black_box once stabilized. + assert_eq!(numbers[100..200].iter().sum::<i32>(), 30_100); + + let usage = getrusage(UsageWho::RUSAGE_SELF).expect("Failed to call getrusage for SELF"); + let rusage = usage.as_ref(); + + let user = usage.user_time(); + assert!(user.tv_sec() > 0 || user.tv_usec() > 0); + assert_eq!(user.tv_sec(), rusage.ru_utime.tv_sec); + assert_eq!(user.tv_usec(), rusage.ru_utime.tv_usec); + } +} |