Revive RFC: Change Process to use directory fd

.github/workflows/rust.yml

@@ -8,7 +8,7 @@ jobs:
   build:
     strategy:
       matrix:
-        toolchain: ["1.42.0", "stable", "beta", "nightly"]
+        toolchain: ["1.48.0", "stable", "beta", "nightly"]
     runs-on: ubuntu-latest
 
     steps:
@@ -19,12 +19,6 @@ jobs:
       with:
         toolchain: ${{ matrix.toolchain }}
 
-    - name: Pin bitflags
-      if: matrix.toolchain == '1.42.0'
-      run: |
-        cargo +${{ matrix.toolchain }} update
-        cargo +${{ matrix.toolchain }} update -p bitflags --precise 1.2.1
-
     - name: Build
       run: cargo +${{ matrix.toolchain }} build --verbose
     - name: Run tests
@@ -42,7 +36,7 @@ jobs:
   check:
     strategy:
       matrix:
-        toolchain: ["1.42.0", "stable", "beta", "nightly"]
+        toolchain: ["1.48.0", "stable", "beta", "nightly"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -58,13 +52,6 @@ jobs:
           toolchain: ${{ matrix.toolchain }}
           target: i686-unknown-linux-gnu
 
-      - name: Pin hex and bitflags
-        if:  matrix.toolchain == '1.42.0'
-        run: |
-          cargo +${{ matrix.toolchain }} update
-          cargo +${{ matrix.toolchain }} update -p hex --precise 0.4.2
-          cargo +${{ matrix.toolchain }} update -p bitflags --precise 1.2.1
-
       - name: cargo check (aarch64)
         run: cargo +${{ matrix.toolchain }} check --target aarch64-linux-android
       - name: cargo check (i686)

Cargo.toml

@@ -15,7 +15,7 @@ edition = "2018"
 default = ["chrono", "flate2"]
 
 [dependencies]
-libc = "0.2"
+rustix = "0.34.0"
 bitflags = "1.2"
 lazy_static = "1"
 chrono = {version = "0.4", optional = true }

README.md

@@ -3,7 +3,7 @@ procfs
 
 [![Crate](https://img.shields.io/crates/v/procfs.svg)](https://crates.io/crates/procfs)
 [![Docs](https://docs.rs/procfs/badge.svg)](https://docs.rs/procfs)
-[![Minimum rustc version](https://img.shields.io/badge/rustc-1.34+-lightgray.svg)](https://github.com/eminence/procfs#minimum-rust-version)
+[![Minimum rustc version](https://img.shields.io/badge/rustc-1.48+-lightgray.svg)](https://github.com/eminence/procfs#minimum-rust-version)
 
 
 This crate is an interface to the `proc` pseudo-filesystem on linux, which is normally mounted as `/proc`.
@@ -21,23 +21,27 @@ process.  This is very similar to what "ps" does in its default mode:
 ```rust
 fn main() {
     let me = procfs::process::Process::myself().unwrap();
+    let me_stat = me.stat().unwrap();
     let tps = procfs::ticks_per_second().unwrap();
 
     println!("{: >5} {: <8} {: >8} {}", "PID", "TTY", "TIME", "CMD");
 
-    let tty = format!("pty/{}", me.stat.tty_nr().1);
+    let tty = format!("pty/{}", me_stat.tty_nr().1);
     for prc in procfs::process::all_processes().unwrap() {
-        if prc.stat.tty_nr == me.stat.tty_nr {
+        let prc = prc.unwrap();
+        let stat = prc.stat().unwrap();
+        if stat.tty_nr == me_stat.tty_nr {
             // total_time is in seconds
             let total_time =
-                (prc.stat.utime + prc.stat.stime) as f32 / (tps as f32);
+                (stat.utime + stat.stime) as f32 / (tps as f32);
             println!(
                 "{: >5} {: <8} {: >8} {}",
-                prc.stat.pid, tty, total_time, prc.stat.comm
+                stat.pid, tty, total_time, stat.comm
             );
         }
     }
 }
+
 ```
 
 Here's another example that shows how to get the current memory usage of the current process:
@@ -47,15 +51,17 @@ use procfs::process::Process;
 
 fn main() {
     let me = Process::myself().unwrap();
+    let me_stat = me.stat().unwrap();
     println!("PID: {}", me.pid);
 
     let page_size = procfs::page_size().unwrap() as u64;
     println!("Memory page size: {}", page_size);
 
     println!("== Data from /proc/self/stat:");
-    println!("Total virtual memory used: {} bytes", me.stat.vsize);
-    println!("Total resident set: {} pages ({} bytes)", me.stat.rss, me.stat.rss as u64 * page_size);
+    println!("Total virtual memory used: {} bytes", me_stat.vsize);
+    println!("Total resident set: {} pages ({} bytes)", me_stat.rss, me_stat.rss as u64 * page_size);
 }
+
 ```
 
 There are a few ways to get this data, so also checkout the longer
@@ -72,11 +78,7 @@ The following cargo features are available:
 
 ## Minimum Rust Version
 
-This crate requires a minimum rust version of rust 1.42.0 (2020-03-12).  However, one dependency of this
-crate (`bitflags`) require a newer version of rust, and must be manually pinned to an older version in
-order to use rust 1.42.  You can do this by running:
-
-    cargo update -p bitflags --precise 1.2.1
+This crate requires a minimum rust version of 1.48.0 (2020-11-19).
 
 ## License
 

examples/dump.rs

@@ -11,6 +11,7 @@ fn main() {
     };
     println!("{:#?}", prc);
 
-    println!("State: {:?}", prc.stat.state());
-    println!("RSS:   {} bytes", prc.stat.rss_bytes().unwrap());
+    let stat = prc.stat().unwrap();
+    println!("State: {:?}", stat.state());
+    println!("RSS:   {} bytes", stat.rss_bytes().unwrap());
 }

examples/lslocks.rs

@@ -1,6 +1,6 @@
 use procfs::process::{FDTarget, Process};
+use rustix::fs::AtFlags;
 use std::path::Path;
-use std::{ffi::CString, os::unix::ffi::OsStrExt};
 
 fn main() {
     let myself = Process::myself().unwrap();
@@ -33,15 +33,15 @@ fn main() {
         let mut found = false;
         if let Some(pid) = lock.pid {
             if let Ok(fds) = Process::new(pid).and_then(|p| p.fd()) {
-                for fd in fds {
+                for f in fds {
+                    let fd = f.unwrap();
                     if let FDTarget::Path(p) = fd.target {
-                        let cstr = CString::new(p.as_os_str().as_bytes()).unwrap();
-
-                        let mut stat = unsafe { std::mem::zeroed() };
-                        if unsafe { libc::stat(cstr.as_ptr(), &mut stat) } == 0 && stat.st_ino as u64 == lock.inode {
-                            print!("{}", p.display());
-                            found = true;
-                            break;
+                        if let Ok(stat) = rustix::fs::statat(&rustix::fs::cwd(), &p, AtFlags::empty()) {
+                            if stat.st_ino as u64 == lock.inode {
+                                print!("{}", p.display());
+                                found = true;
+                                break;
+                            }
                         }
                     }
                 }

examples/netstat.rs

@@ -2,7 +2,7 @@
 
 extern crate procfs;
 
-use procfs::process::{FDTarget, Process};
+use procfs::process::{FDTarget, Stat};
 
 use std::collections::HashMap;
 
@@ -11,12 +11,13 @@ fn main() {
     let all_procs = procfs::process::all_processes().unwrap();
 
     // build up a map between socket inodes and processes:
-    let mut map: HashMap<u64, &Process> = HashMap::new();
-    for process in &all_procs {
-        if let Ok(fds) = process.fd() {
+    let mut map: HashMap<u64, Stat> = HashMap::new();
+    for p in all_procs {
+        let process = p.unwrap();
+        if let (Ok(stat), Ok(fds)) = (process.stat(), process.fd()) {
             for fd in fds {
-                if let FDTarget::Socket(inode) = fd.target {
-                    map.insert(inode, process);
+                if let FDTarget::Socket(inode) = fd.unwrap().target {
+                    map.insert(inode, stat.clone());
                 }
             }
         }
@@ -36,10 +37,10 @@ fn main() {
         let local_address = format!("{}", entry.local_address);
         let remote_addr = format!("{}", entry.remote_address);
         let state = format!("{:?}", entry.state);
-        if let Some(process) = map.get(&entry.inode) {
+        if let Some(stat) = map.get(&entry.inode) {
             println!(
                 "{:<26} {:<26} {:<15} {:<12} {}/{}",
-                local_address, remote_addr, state, entry.inode, process.stat.pid, process.stat.comm
+                local_address, remote_addr, state, entry.inode, stat.pid, stat.comm
             );
         } else {
             // We might not always be able to find the process assocated with this socket

examples/process_hierarchy.rs

@@ -1,17 +1,30 @@
-use procfs::process::{all_processes, Process};
+use procfs::process::{all_processes, Stat};
+
+struct ProcessEntry {
+    stat: Stat,
+    cmdline: Option<Vec<String>>,
+}
 
 /// Print all processes as a tree.
 /// The tree reflects the hierarchical relationship between parent and child processes.
 fn main() {
     // Get all processes
-    let processes = match all_processes() {
+    let processes: Vec<ProcessEntry> = match all_processes() {
         Err(err) => {
             println!("Failed to read all processes: {}", err);
             return;
         }
         Ok(processes) => processes,
-    };
-
+    }
+    .filter_map(|v| {
+        v.and_then(|p| {
+            let stat = p.stat()?;
+            let cmdline = p.cmdline().ok();
+            Ok(ProcessEntry { stat, cmdline })
+        })
+        .ok()
+    })
+    .collect();
     // Iterate through all processes and start with top-level processes.
     // Those can be identified by checking if their parent PID is zero.
     for process in &processes {
@@ -26,10 +39,10 @@ fn main() {
 /// It's a depth-first tree exploration.
 ///
 /// depth: The hierarchical depth of the process
-fn print_process(process: &Process, all_processes: &[Process], depth: usize) {
-    let cmdline = match process.cmdline() {
-        Ok(cmdline) => cmdline.join(" "),
-        Err(_) => "zombie process".into(),
+fn print_process(process: &ProcessEntry, all_processes: &Vec<ProcessEntry>, depth: usize) {
+    let cmdline = match &process.cmdline {
+        Some(cmdline) => cmdline.join(" "),
+        None => "zombie process".into(),
     };
 
     // Some processes seem to have an empty cmdline.
@@ -39,21 +52,21 @@ fn print_process(process: &Process, all_processes: &[Process], depth: usize) {
 
     // 10 characters width for the pid
     let pid_length = 8;
-    let mut pid = process.pid.to_string();
+    let mut pid = process.stat.pid.to_string();
     pid.push_str(&" ".repeat(pid_length - pid.len()));
 
     let padding = " ".repeat(4 * depth);
     println!("{}{}{}", pid, padding, cmdline);
 
-    let children = get_children(process.pid, all_processes);
+    let children = get_children(process.stat.pid, all_processes);
     for child in &children {
         print_process(child, all_processes, depth + 1);
     }
 }
 
 /// Get all children of a specific process, by iterating through all processes and
 /// checking their parent pid.
-pub fn get_children(pid: i32, all_processes: &[Process]) -> Vec<&Process> {
+fn get_children(pid: i32, all_processes: &Vec<ProcessEntry>) -> Vec<&ProcessEntry> {
     all_processes
         .iter()
         .filter(|process| process.stat.ppid == pid)

examples/ps.rs

@@ -6,17 +6,20 @@ extern crate procfs;
 /// It shows all the processes that share the same tty as our self
 
 fn main() {
-    let me = procfs::process::Process::myself().unwrap();
+    let mestat = procfs::process::Process::myself().unwrap().stat().unwrap();
     let tps = procfs::ticks_per_second().unwrap();
 
-    println!("{: >5} {: <8} {: >8} {}", "PID", "TTY", "TIME", "CMD");
+    println!("{: >10} {: <8} {: >8} {}", "PID", "TTY", "TIME", "CMD");
 
-    let tty = format!("pty/{}", me.stat.tty_nr().1);
-    for prc in procfs::process::all_processes().unwrap() {
-        if prc.stat.tty_nr == me.stat.tty_nr {
-            // total_time is in seconds
-            let total_time = (prc.stat.utime + prc.stat.stime) as f32 / (tps as f32);
-            println!("{: >5} {: <8} {: >8} {}", prc.stat.pid, tty, total_time, prc.stat.comm);
+    let tty = format!("pty/{}", mestat.tty_nr().1);
+    for p in procfs::process::all_processes().unwrap() {
+        let prc = p.unwrap();
+        if let Ok(stat) = prc.stat() {
+            if stat.tty_nr == mestat.tty_nr {
+                // total_time is in seconds
+                let total_time = (stat.utime + stat.stime) as f32 / (tps as f32);
+                println!("{: >10} {: <8} {: >8} {}", stat.pid, tty, total_time, stat.comm);
+            }
         }
     }
 }

examples/self_memory.rs

@@ -10,14 +10,16 @@ fn main() {
     // Note: when comparing the below values to what "top" will display, note that "top" will use
     // base-2 units (kibibytes), not base-10 units (kilobytes).
 
-    println!("== Data from /proc/self/stat:");
-    println!("Total virtual memory used: {} bytes", me.stat.vsize);
-    println!(
-        "Total resident set: {} pages ({} bytes)",
-        me.stat.rss,
-        me.stat.rss as u64 * page_size
-    );
-    println!();
+    if let Ok(stat) = me.stat() {
+        println!("== Data from /proc/self/stat:");
+        println!("Total virtual memory used: {} bytes", stat.vsize);
+        println!(
+            "Total resident set: {} pages ({} bytes)",
+            stat.rss,
+            stat.rss as u64 * page_size
+        );
+        println!();
+    }
 
     if let Ok(statm) = me.statm() {
         println!("== Data from /proc/self/statm:");

examples/shm.rs

@@ -10,6 +10,7 @@ fn main() {
         println!("============");
 
         for prc in procfs::process::all_processes().unwrap() {
+            let prc = prc.unwrap();
             match prc.smaps() {
                 Ok(memory_maps) => {
                     for (memory_map, _memory_map_data) in &memory_maps {