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pq.cc
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pq.cc
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// pq - query process/thread attributes
//
// SPDX-License-Identifier: GPL-3.0-or-later
// SPDX-FileCopyrightText: © 2020 Georg Sauthoff <mail@gms.tf>
#include <algorithm> // search(), find()
#include <charconv> // to_chars(), from_chars()
#include <functional> // default_searcher
#include <vector>
#include <string>
#include <string_view>
#include <unordered_map>
#include <array>
#include <memory> // unique_ptr
#include <optional>
#include <regex> // requires GCC > 4.8
#include <ixxx/util.hh>
#include <ixxx/ansi.hh>
#include <ixxx/posix.hh>
#include <ixxx/linux.hh>
#include <ixxx/sys_error.hh>
#include <stdlib.h> // exit()
#include <string.h> // strlen(), memcmp(), memchr(), ...
#include <fcntl.h> // O_RDONLY
#include <unistd.h> // getopt()
#include <sys/epoll.h> // epoll_event
#include <sys/signalfd.h> // signalfd_siginfo
#include <assert.h>
#include "syscalls.hh"
using namespace std;
// cf. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88545
template <typename Itr, typename T>
inline Itr fast_find(Itr b, Itr e, const T &v)
{
auto t = memchr(&*b, v, e-b);
if (t)
return Itr(t);
else
return e;
}
template <typename Itr, typename T>
inline Itr fast_rfind(Itr b, Itr e, const T &v)
{
auto t = memrchr(&*b, v, e-b);
if (t)
return Itr(t);
else
return e;
}
inline string_view nth_col(const string_view &v, unsigned x)
{
auto p = v.begin();
for (unsigned i = 0; i < x; ++i) {
for ( ; p != v.end() && (*p != '\t' && *p != ' '); ++p)
;
for ( ; p != v.end() && (*p == '\t' || *p == ' '); ++p)
;
}
auto ws = { '\t', ' ', '\n' };
auto e = find_first_of(p, v.end(), begin(ws), end(ws));
return string_view(p, e - p);
}
enum class Column {
AFFINITY , // /proc/$pid/status::Cpus_allowed_list
CLS , // scheduling class, proc/$pid/stat
CMD , // /proc/$pid/commandline
COMM , // /proc/comm or /proc/$pid/status::Name or /proc/$pid/stat
CPU , // last run on this CPU, /proc/$pid/stat::processor
CWBYTE , // /proc/$pid/io::cancelled_write_bytes
CWD , //
ENV , //
EPOCH , // clock_gettime()
EXE , //
FDS , // ls /proc/$pid/fd | wc -l
FDSIZE , // /proc/$pid/status::FDSize
FLAGS , // process flags, /proc/$pid/stat
GID , // effective ...
HELP , // dummy, displays column help ...
HUGEPAGES , // /proc/$pid/status::HugetlbPages
LOGINUID , // /proc/$pid/loginuid
MAJFLT , // major page faults /proc/$pid/status
MINFLT , // minor page faults /proc/$pid/status
NICE , // /proc/$pid/stat
NS , // UNIX epoch time in ns
NUMAGID , // NUMA group ID, /proc/$pid/status::Ngid
NVCTX , // non-voluntary context switches /proc/$pid/status
PID , //
PPID , //
RBYTE , // /proc/$pid/io::read_bytes
RCHAR , // /proc/$pid/io::rchar
RSS , //
RTPRIO , // /proc/$pid/stat
SLACK , // /proc/$pid/timerslack_ns
STACK , //
STATE , // /proc/$pid/status or /proc/$pid/stat
STIME , // start time /proc/$pid/stat
SYSCALL , // /proc/$pid/syscall
SYSCR , // /proc/$pid/io::syscr
SYSCW , // /proc/$pid/io::syscw
THREADS , //
TID , //
UID , // effective ...
UMASK , //
USER , //
VCTX , // voluntary context switches /proc/$pid/status
VSIZE , //
WBYTE , // /proc/$pid/io::write_bytes
WCHAN , // /proc/$pid/wchan
WCHAR , // /proc/$pid/io::wchar
END_OF_ENUM // just a sentinel for this enum ...
// TODO:
//
// /proc/$pid/status: THP_enabled, CoreDumping, VmSwap, ...
// /proc/$pid/limits
// /proc/$pid/cgroup
// /proc/$pid/auxv
// real uid/gid
};
static const string_view col2header[] = {
"aff" , // AFFINITY
"cls" , // CLS
"cmd" , // CMD
"comm" , // COMM
"cpu" , // CPU
"cwbyte" , // CWBYTE
"cwd" , // CWD
"env" , // ENV
"epoch" , // EPOCH
"exe" , // EXE
"fds" , // FDS
"fdsz" , // FDSIZE
"flags" , // FLAGS
"gid" , // GID
"XXXhelp" , // HELP
"hugepages" , // HUGEPAGES
"loginuid" , // LOGINUID
"majflt" , // MAJFLT
"minflt" , // MINFLT
"nice" , // NICE
"ns" , // NS
"nid" , // NUMAGID
"nvctx" , // NVCTX
"pid" , // PID
"ppid" , // PPID
"rbyte" , // RBYTE
"rchar" , // RCHAR
"rss" , // RSS
"pri" , // RTPRIO
"slack" , // SLACK
"stack" , // STACK
"state" , // STATE
"stime" , // STIME
"syscall" , // SYSCALL
"syscr" , // SYSCR
"syscw" , // SYSCW
"threads" , // THREADS
"tid" , // TID
"uid" , // UID
"umask" , // UMASK
"user" , // USER
"vctx" , // VCTX
"vsize" , // VSIZE
"wbyte" , // WBYTE
"wchan" , // WCHAN
"wchar" // WCHAR
};
static_assert(sizeof col2header / sizeof col2header[0] == static_cast<size_t>(Column::END_OF_ENUM));
static const char * const col2help[] = {
"CPU (core) affinity, i.e. task only runs on those cores" , // AFFINITY
"scheduling class", // CLS
"command line, i.e. the argument vector" , // CMD
"process/thread name" , // COMM
"last ran on that CPU (core)" , // CPU
"write bytes, cancelled" , // CWBYTE
"current wording directory" , // CWD
"display an environment variable, e.g. env:MYID" , // ENV
"unix time at traversal time, i.e. seconds since the epoch", // EPOCH
"process' executable" , // EXE
"number of open files" , // FDS
"number of allocated file descriptor slots" , // FDSIZE
"process flags (e.g. PF_KTHREAD, PF_WQ_WORKER or PF_NO_SETAFFINITY)", // FLAGS
"group ID" , // GID
"XXXhelp", // HELP
"#hugepages" , // HUGEPAGES
"login user ID or 2**32-1 if daemon etc." , // LOGINUID
"major page faults" , // MAJFLT
"minor page faults" , // MINFLT
"process niceness", // NICE
"nanoseconds since the epoch", // NS
"NUMA group ID" , // NUMAGID
"non-voluntary context switches" , // NVCTX
"process ID" , // PID
"parent process ID" , // PPID
"bytes read, actually", // RBYTE
"bytes read", // RCHAR
"resident size set in KiB" , // RSS
"realtime priority (1-99)", // RTPRIO
"current timer slack value of a thread in ns", // SLACK
"top of stack function the task is executing/blocked on (requires root)" , // STACK
"state the process is in, e.g. running, sleeping etc." , // STATE
"start time in ISO format" , // STIME
"current syscall the task is executing/blocked on, if any" , // SYSCALL
"number of read syscalls" , // SYSCR
"number of write syscalls" , // SYSCW
"number of threads of that process/the process the thread is part of" , // THREADS
"thread ID" , // TID
"(effective) user ID" , // UID
"user file creation mask" , // UMASK
"(effective) user name", // USER
"number of voluntary context-switches" , // VCTX
"virtual memory usage in KiB" , // VSIZE
"bytes written, actually", // WBYTE
"kernel function the task waits for, cf. stack (some kernels doesn't support it - e.g. Fedora's doesn't)", // WCHAN
"bytes written" // WCHAR
};
static_assert(sizeof col2header / sizeof col2header[0] == sizeof col2help / sizeof col2help[0]);
static const unsigned col2width[] = {
5 , // AFFINITY
3 , // CLS
15 , // CMD
15 , // COMM
3 , // CPU
11 , // CWBYTE
15 , // CWD
8 , // ENV
10 , // EPOCH
10 , // EXE
3 , // FDS
3 , // FDSIZE
5 , // FLAGS
4 , // GID
0 , // HELP
10 , // HUGEPAGES
10 , // LOGINUID
10 , // MAJFLT
10 , // MINFLT
4 , // NICE
19 , // NS
3 , // NUMAGID
10 , // NVCTX
7 , // PID
7 , // PPID
11, // RBYTE
11, // RCHAR
8 , // RSS
3 , // RTPRIO
5 , // SLACK
10 , // STACK
10 , // STATE
10 , // STIME
10 , // SYSCALL
8 , // SYSCR
8 , // SYSCW
7 , // THREADS
7 , // TID
4 , // UID
4 , // UMASK
8 , // USER
10 , // VCTX
8 , // VSIZE
11 , // WBYTE
10 , // WCHAN
11 // WCHAR
};
static_assert(sizeof col2header / sizeof col2header[0] == sizeof col2width / sizeof col2width[0]);
static const unordered_map<string_view, Column> str2column = {
{ "pid" , Column::PID },
{ "tid" , Column::TID },
{ "comm" , Column::COMM },
{ "name" , Column::COMM },
{ "epoch" , Column::EPOCH },
{ "exe" , Column::EXE },
{ "affinity" , Column::AFFINITY },
{ "aff" , Column::AFFINITY },
{ "cores" , Column::AFFINITY },
{ "wchan" , Column::WCHAN },
{ "wchar" , Column::WCHAR },
{ "wbyte" , Column::WBYTE },
{ "syscall" , Column::SYSCALL },
{ "scall" , Column::SYSCALL },
{ "ecall" , Column::SYSCALL },
{ "syscr" , Column::SYSCR },
{ "syscw" , Column::SYSCW },
{ "state" , Column::STATE },
{ "cmd" , Column::CMD },
{ "cmdline" , Column::CMD },
{ "cmdline" , Column::CMD },
{ "cwd" , Column::CWD },
{ "cpu" , Column::CPU },
{ "psr" , Column::CPU },
{ "core" , Column::CPU },
{ "cwbyte" , Column::CWBYTE },
{ "gid" , Column::GID },
{ "egid" , Column::GID },
{ "uid" , Column::UID },
{ "euid" , Column::UID },
{ "help" , Column::HELP },
{ "hugepages" , Column::HUGEPAGES },
{ "hpages" , Column::HUGEPAGES },
{ "threads" , Column::THREADS },
{ "slack" , Column::SLACK },
{ "stack" , Column::STACK },
{ "ppid" , Column::PPID },
{ "rbyte" , Column::RBYTE },
{ "rchar" , Column::RCHAR },
{ "stime" , Column::STIME },
{ "start" , Column::STIME },
{ "nvctx" , Column::NVCTX },
{ "nctx" , Column::NVCTX },
{ "vctx" , Column::VCTX },
{ "minfault" , Column::MINFLT },
{ "minflt" , Column::MINFLT },
{ "majfault" , Column::MAJFLT },
{ "majflt" , Column::MAJFLT },
{ "umask" , Column::UMASK },
{ "loginuid" , Column::LOGINUID },
{ "luid" , Column::LOGINUID },
{ "rss" , Column::RSS },
{ "vsize" , Column::VSIZE },
{ "vmem" , Column::VSIZE },
{ "fds" , Column::FDS },
{ "fdsize" , Column::FDSIZE },
{ "numagid" , Column::NUMAGID },
{ "numa" , Column::NUMAGID },
{ "ngid" , Column::NUMAGID },
{ "nid" , Column::NUMAGID },
{ "user" , Column::USER },
{ "usr" , Column::USER },
{ "rtprio" , Column::RTPRIO },
{ "prio" , Column::RTPRIO },
{ "pri" , Column::RTPRIO },
{ "cls" , Column::CLS },
{ "class" , Column::CLS },
{ "policy" , Column::CLS },
{ "sched" , Column::CLS },
{ "nice" , Column::NICE },
{ "ns" , Column::NS },
{ "flags" , Column::FLAGS },
{ "pf" , Column::FLAGS }
};
enum Show_Tasks {
BOTH,
KERNEL,
USER
};
static time_t get_boot_time()
{
array<char, 64> buf;
ixxx::util::FD fd("/proc/uptime", O_RDONLY);
size_t n = ixxx::util::read_all(fd, buf);
char *b = buf.data();
char *e = b + n;
e = fast_find(b, e, '.');
struct timespec tp;
ixxx::posix::clock_gettime(CLOCK_REALTIME_COARSE, &tp);
size_t off = 0;
auto r = from_chars(b, e, off);
if (r.ptr != e)
throw runtime_error("uptime parse error");
time_t boot_time_s = tp.tv_sec - off;
return boot_time_s;
}
static size_t parse_uid(const char *s)
{
size_t uid = 0;
auto e = s + strlen(s);
if (e == s)
throw runtime_error("empty uid/user");
if (*s < '0' || *s > '9') {
struct passwd pass;
struct passwd *res;
array<char, 4 * 1024> buf;
ixxx::posix::getpwnam_r(s, &pass, buf.data(), buf.size(), &res);
if (!res)
throw runtime_error("user not found");
uid = pass.pw_uid;
} else {
auto r = from_chars(s, e, uid);
if (r.ptr != e)
throw runtime_error("uid parse error");
}
return uid;
}
struct Args {
vector<size_t> pids ;
bool all_pids {false} ;
optional<size_t> uid ;
string regex_str ;
Show_Tasks show_tasks {Show_Tasks::BOTH} ;
bool traverse_threads {false} ;
bool show_header {true} ;
vector<Column> columns ;
vector<string> env_vars ;
time_t boot_time_s {0} ;
unsigned clock_ticks {0} ;
unsigned interval_s {0} ;
unsigned count {0} ;
char delim {0} ;
void parse(int argc, char **argv);
private:
void init_default_columns();
};
static void help(FILE *o, const char *argv0)
{
fprintf(o, "%s - query process and thread attributes\n"
"Usage: %s [-o COL1 COL2..] [-p PID1 PID2..] [OPTS]\n"
"\n"
"Options:\n"
" -a list all processes\n"
" -c N repeat N times, if -i is set (default: unlimited)\n"
" -d CHAR delimit columns by character instead of whitespace\n"
" -e REGEX filter by regular expression (match against COMM)\n"
" -h display this help\n"
" -H omit header row\n"
" -i X repeat output after X seconds\n"
" -k only list kernel threads\n"
" -K only list user tasks\n"
" -o COL.. columns to display (use `-o help` to get a list)\n"
" -p PID.. only list the specified processes/threads\n"
" -t also list threads\n"
" -u USER filter by user/uid\n"
"\n"
"2020, Georg Sauthoff <mail@gms.tf>, GPLv3+\n"
,
argv0,
argv0);
}
static void help_col(FILE *o)
{
fprintf(o, "Available columns:\n"
"\n");
unordered_map<Column, vector<string>> aliases;
for (auto &x : str2column) {
auto &q = aliases[x.second];
q.reserve(10);
if (col2header[static_cast<unsigned>(x.second)] != x.first)
q.emplace_back(x.first);
}
for (unsigned i = 0; i < sizeof col2header / sizeof col2header[0]; ++i) {
if (i == static_cast<unsigned>(Column::HELP))
continue;
fprintf(o, " ");
fwrite(col2header[i].data(), 1, col2header[i].size(), o);
fprintf(o, " - %s", col2help[i]);
auto &v = aliases[Column(i)];
if (!v.empty()) {
if (v.size() == 1)
fprintf(o, " (Alias: ");
else
fprintf(o, " (Aliases: ");
auto a = v.begin();
auto b = v.end();
fprintf(o, "%s", (*a).c_str());
++a;
for (; a != b; ++a)
fprintf(o, ", %s", (*a).c_str());
fputc(')', o);
}
fputc('\n', o);
}
}
void Args::init_default_columns()
{
auto const default_columns = { Column::PID, Column::TID, Column::PPID,
Column::AFFINITY, Column::CPU, Column::CLS, Column::RTPRIO,
Column::NICE, Column::SYSCALL, Column::RSS, Column::COMM };
columns = default_columns;
env_vars.resize(columns.size());
}
// Not using Boost Program Options because of its atrocious API
// and slow compile times.
// Not using cxxopts because of its API being similar to Boost PO.
// Not using CLI11 because of its ultra slow compile times.
// (cf. https://github.com/CLIUtils/CLI11/issues/194)
void Args::parse(int argc, char **argv)
{
enum State { IN_PID_LIST, IN_COL_LIST };
char c = 0;
State state = IN_PID_LIST;
// '-' prefix: no reordering of arguments, non-option arguments are
// returned as argument to the 1 option
// ':': preceding opting takes a mandatory argument
while ((c = getopt(argc, argv, "-ae:c:d:Hhi:Kkoptu:")) != -1) {
switch (c) {
case '?':
fprintf(stderr, "unexpected option character: %c\n", optopt);
exit(1);
break;
case 'a':
all_pids = true;
break;
case 'c':
count = atoi(optarg);
if (!interval_s)
interval_s = 1;
break;
case 'd':
delim = *optarg;
break;
case 'e':
regex_str = optarg;
break;
case 'H':
show_header = false;
break;
case 'h':
help(stdout, argv[0]);
exit(0);
break;
case 'i':
interval_s = atoi(optarg);
break;
case 'K':
show_tasks = Show_Tasks::USER;
break;
case 'k':
show_tasks = Show_Tasks::KERNEL;
break;
case 'o':
state = IN_COL_LIST;
break;
case 'p':
state = IN_PID_LIST;
break;
case 't':
traverse_threads = true;
break;
case 'u':
all_pids = true;
uid = parse_uid(optarg);
break;
case 1:
switch (state) {
case IN_PID_LIST:
{
size_t pid;
auto e = optarg + strlen(optarg);
auto r = from_chars(optarg, e, pid);
if (r.ec != std::errc() || r.ptr != e) {
fprintf(stderr, "Invalid pid: %s\n", optarg);
exit(1);
}
pids.push_back(pid);
}
break;
case IN_COL_LIST:
if (strlen(optarg) > 4 && !memcmp(optarg, "env:", 4)) {
columns.push_back(Column::ENV);
env_vars.emplace_back(optarg + 4);
} else if (*optarg) {
if (*optarg == '+') {
++optarg;
init_default_columns();
if (!*optarg)
continue;
}
try {
columns.push_back(str2column.at(string_view(optarg)));
} catch (const out_of_range &) {
fprintf(stderr, "Unknown column: %s\n", optarg);
exit(1);
}
env_vars.emplace_back();
} else {
fprintf(stderr, "empty column\n");
exit(1);
}
if (columns.back() == Column::HELP) {
help_col(stdout);
exit(0);
}
if (columns.back() == Column::STIME) {
try {
boot_time_s = get_boot_time();
clock_ticks = ixxx::posix::sysconf(_SC_CLK_TCK);
} catch (...) {
fprintf(stderr, "Can't read /proc/uptime\n");
exit(1);
}
}
break;
default:
fprintf(stderr, "spurious positional argument: %s\n", optarg);
exit(1);
}
break;
}
}
if (pids.empty() && !all_pids) {
if (regex_str.empty()) {
fprintf(stderr, "Either specify one or more PIDs or -a or -e\n");
exit(1);
} else {
all_pids = true;
}
}
if (columns.empty())
init_default_columns();
}
struct Process;
typedef string_view (Process::*Process_Attr)();
struct Process {
public:
size_t pid {0} ;
size_t tid {0} ;
time_t boot_time_s ;
unsigned clock_ticks {0} ;
private:
string fn { "/proc/" } ;
size_t fn_stem {6} ;
char epsilon[1] {0} ;
// we could also use std::vector, however we would need
// to switch it from value to default initialization
// to eliminate superfluous initializations
// (such as in: https://github.com/gsauthof/libxfsx/blob/91979ec5f2bc56f3d0dd06ac0b8ff6658d889cfb/xfsx/raw_vector.hh#L7)
// as a bonus we save some overheads in memory management
array<char, 4*1024> environ_arr ;
array<char, 4*1024> stat_arr ;
array<char, 4*1024> status_arr ;
array<char, 4*1024> misc_arr ;
array<char, 4*1024> io_arr ;
string_view environ ;
string_view stat ;
string_view status ;
string_view misc ;
string_view io ;
array<char, 1024> buffer ;
unordered_map<size_t, string> username_cache ;
public:
Process() =default;
Process(const Process &) =delete;
Process &operator=(const Process &) =delete;
void set_pid(size_t pid, size_t tid);
const char *getenv(const string &s);
unsigned flags();
string_view comm();
string_view epoch();
string_view ns();
string_view exe();
string_view wchan();
string_view wchar();
string_view wbyte();
string_view cwbyte();
string_view affinity();
string_view syscall();
string_view syscr();
string_view syscw();
string_view loginuid();
string_view state();
string_view cls();
string_view cmd();
string_view cpu();
string_view cwd();
string_view gid();
string_view uid();
string_view hugepages();
string_view threads();
string_view slack();
string_view stack();
string_view ppid();
string_view rchar();
string_view rbyte();
string_view stime();
string_view nvctx();
string_view vctx();
string_view minflt();
string_view majflt();
string_view umask();
string_view user();
string_view rss();
string_view rtprio();
string_view vsize();
string_view fds();
string_view fdsize();
string_view numagid();
string_view nice();
string_view pflags();
string_view column(Column c);
private:
template <size_t N>
void read_proc(const char *q, array<char, N> &src,
string_view &dst, bool prefix = false);
string_view read_key_value(const string_view &status, const string_view &q);
string_view read_status(const string_view &q);
string_view read_io(const string_view &q);
string_view read_stat(unsigned i);
string_view read_link(const char *q);
};
Process_Attr process_attrs[] = {
&Process::affinity , // AFFINITY
&Process::cls , // CLS
&Process::cmd , // CMD
&Process::comm , // COMM
&Process::cpu , // CPU
&Process::cwbyte , // CWBYTE
&Process::cwd , // CWD
nullptr , // ENV
&Process::epoch , // EXE
&Process::exe , // EXE
&Process::fds , // FDS
&Process::fdsize , // FDSIZE
&Process::pflags , // FLAGS
&Process::gid , // GID
nullptr , // HELP - dummy - never called
&Process::hugepages , // HUGEPAGES
&Process::loginuid , // LOGINUID
&Process::majflt , // MAJFLT
&Process::minflt , // MINFLT
&Process::nice , // NICE
&Process::ns , // NS
&Process::numagid , // NUMAGID
&Process::nvctx , // NVCTX
nullptr , // PID
&Process::ppid , // PPID
&Process::rbyte , // RBYTE
&Process::rchar , // RCHAR
&Process::rss , // RSS
&Process::rtprio , // RTPRIO
&Process::slack , // SLACK
&Process::stack , // STACK
&Process::state , // STATE
&Process::stime , // STIME
&Process::syscall , // SYSCALL
&Process::syscr , // SYSCR
&Process::syscw , // SYSCW
&Process::threads , // THREADS
nullptr , // TID
&Process::uid , // UID
&Process::umask , // UMASK
&Process::user , // USER
&Process::vctx , // VCTX
&Process::vsize , // VSIZE
&Process::wbyte , // WBYTE
&Process::wchan , // WCHAN
&Process::wchar // WCHAR
};
string_view Process::column(Column c)
{
Process_Attr fn = process_attrs[static_cast<unsigned>(c)];
return (this->*fn)();
}
void Process::set_pid(size_t pid, size_t tid)
{
this->pid = pid;
this->tid = tid;
fn.resize(fn_stem);
array<char, 20> buf;
to_chars_result r = to_chars(buf.begin(), buf.end(), pid == tid ? pid : tid);
fn.append(buf.begin(), r.ptr);
fn.push_back('/');
environ = string_view(environ_arr.begin(), 0);
stat = string_view(stat_arr.begin() , 0);
status = string_view(status_arr.begin() , 0);
io = string_view(io_arr.begin() , 0);
}
template <size_t N>
void Process::read_proc(const char *q, array<char, N> &src,
string_view &dst, bool prefix)
{
if (!dst.empty())
return;
size_t l = fn.size();
fn.append(q);
size_t n = 0;
if (prefix) {
++n;
src[0] = '\n';
}
try {
ixxx::util::FD fd(fn, O_RDONLY);
n += ixxx::util::read_all(fd, src.begin() + n, src.size() - n);
} catch (...) {
src[0] = ' ';
n = 1;
}
dst = string_view(src.begin(), n);
fn.resize(l);
}
string_view Process::read_key_value(const string_view &status, const string_view &q)
{
auto p = search(status.begin(), status.end(),
std::default_searcher(q.begin(), q.end()));
if (p == status.end())
return string_view();
p += q.size();
auto e = fast_find(p, status.end(), '\n');
for ( ; p != e && (*p == ' ' || *p == '\t'); ++p)
;
return string_view(&*p, e-p);
}
string_view Process::read_status(const string_view &q)
{
read_proc("status", status_arr, status, true);
return read_key_value(status, q);
}
string_view Process::read_io(const string_view &q)
{
read_proc("io", io_arr, io, true);
return read_key_value(io, q);
}
// NB: The stat fields are space delimited. However, the 2nd field (comm)
// is enclosed by parentheses because comm itself may contain spaces
// and parantheses. Since none of the following fields might contain a ')'
// it's sufficient to handle the 2nd field in a special way by
// scanning for the terminating ')' by searching from the right.
string_view Process::read_stat(unsigned k)
{
read_proc("stat", stat_arr, stat);
auto p = stat.begin();
unsigned i = 0;
if (i < k) {
p = fast_find(p, stat.end(), '(');
if (p != stat.end())
++p;
++i;
if (i < k) {
p = fast_rfind(p, stat.end(), ')');
if (p != stat.end())
++p;
for (; i < k; ++i) {
p = fast_find(p, stat.end(), ' ');
if (p != stat.end())
++p;
}
} else {
auto e = fast_rfind(p, stat.end(), ')');
return string_view(p, e-p);
}
}
auto e = fast_find(p, stat.end(), ' ');
return string_view(p, e-p);
}
const char *Process::getenv(const string &s)
{
read_proc("environ", environ_arr, environ);
auto p = search(environ.begin(), environ.end(),
std::default_searcher(s.begin(), s.end()));
if (p == environ.end())
return epsilon;
auto m = p + s.size();
if (m == environ.end() || *m != '=')
return epsilon;
++m;
return &*m;
}
string_view Process::read_link(const char *q)
{
size_t l = fn.size();
fn.append(q);
size_t n = 0;
try {
n = ixxx::posix::readlink(fn, buffer);
} catch (const ixxx::readlink_error &e) {
// ignore
}
fn.resize(l);
return string_view(buffer.data(), n);
}
// cf. https://elixir.bootlin.com/linux/v5.8.9/source/include/linux/sched.h#L1506
enum Process_Flags {
PF_KTHREAD = 0x00200000
};
// cf. https://elixir.bootlin.com/linux/v5.8.9/source/include/linux/sched.h#L1483
static const string_view pf2str[] = {
"0x0" ,
"PF_IDLE" , // 0x00000002 /* I am an IDLE thread */
"PF_EXITING" , // 0x00000004 /* Getting shut down */
"0x8" ,
"PF_VCPU" , // 0x00000010 /* I'm a virtual CPU */
"PF_WQ_WORKER" , // 0x00000020 /* I'm a workqueue worker */
"PF_FORKNOEXEC" , // 0x00000040 /* Forked but didn't exec */
"PF_MCE_PROCESS" , // 0x00000080 /* Process policy on mce errors */
"PF_SUPERPRIV" , // 0x00000100 /* Used super-user privileges */
"PF_DUMPCORE" , // 0x00000200 /* Dumped core */
"PF_SIGNALED" , // 0x00000400 /* Killed by a signal */
"PF_MEMALLOC" , // 0x00000800 /* Allocating memory */
"PF_NPROC_EXCEEDED" , // 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
"PF_USED_MATH" , // 0x00002000 /* If unset the fpu must be initialized before use */
"PF_USED_ASYNC" , // 0x00004000 /* Used async_schedule*(), used by module init */
"PF_NOFREEZE" , // 0x00008000 /* This thread should not be frozen */
"PF_FROZEN" , // 0x00010000 /* Frozen for system suspend */
"PF_KSWAPD" , // 0x00020000 /* I am kswapd */
"PF_MEMALLOC_NOFS" , // 0x00040000 /* All allocation requests will inherit GFP_NOFS */
"PF_MEMALLOC_NOIO" , // 0x00080000 /* All allocation requests will inherit GFP_NOIO */
"PF_LOCAL_THROTTLE" , // 0x00100000 /* Throttle writes only against the bdi I write to, I am cleaning dirty pages from some other bdi. */
"PF_KTHREAD" , // 0x00200000 /* I am a kernel thread */
"PF_RANDOMIZE" , // 0x00400000 /* Randomize virtual address space */
"PF_SWAPWRITE" , // 0x00800000 /* Allowed to write to swap */
"0x1000000" ,
"PF_UMH" , // 0x02000000 /* I'm an Usermodehelper process */
"PF_NO_SETAFFINITY" , // 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
"PF_MCE_EARLY" , // 0x08000000 /* Early kill for mce process policy */
"PF_MEMALLOC_NOCMA" , // 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
"PF_IO_WORKER" , // 0x20000000 /* Task is an IO worker */
"PF_FREEZER_SKIP" , // 0x40000000 /* Freezer should not count it as freezable */
"PF_SUSPEND_TASK" // 0x80000000 /* This thread called freeze_processes() and should not be frozen */
};
unsigned Process::flags()
{
auto x = read_stat(8);
unsigned r = 0;
from_chars(x.begin(), x.end(), r);
return r;
}
string_view Process::pflags()
{
unsigned f = flags();
unsigned m = 1;
char *p = misc_arr.data();
for (unsigned i = 0; i < 32; ++i, m<<=1) {
if (m & f) {
if (p != misc_arr.data()) {
*p++ = '|';