| Message ID | 20191120141535.5303-1-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] support: Add support_process_state_wait | expand |
Ping. On 20/11/2019 11:15, Adhemerval Zanella wrote: > It allows parent process to wait for children state using a polling > strategy over procfs on Linux. The polling is used over ptrace to > avoid the need to handle signals on the target pid and to handle some > system specific limitations (such as YAMA). > > The polling has some limitations, such as resource consumption due > the procfs read in a loop and the lack of synchronization after the > state is obtained. > > The interface idea is to simplify some sleep synchronization in waitid > tests. > --- > support/Makefile | 2 + > support/process_state.h | 41 +++++++++++ > support/support_process_state.c | 89 ++++++++++++++++++++++++ > support/tst-support-process_state.c | 101 ++++++++++++++++++++++++++++ > 4 files changed, 233 insertions(+) > create mode 100644 support/process_state.h > create mode 100644 support/support_process_state.c > create mode 100644 support/tst-support-process_state.c > > diff --git a/support/Makefile b/support/Makefile > index 23c6d74627..b0d28200af 100644 > --- a/support/Makefile > +++ b/support/Makefile > @@ -56,6 +56,7 @@ libsupport-routines = \ > support_format_hostent \ > support_format_netent \ > support_isolate_in_subprocess \ > + support_process_state \ > support_ptrace \ > support_openpty \ > support_paths \ > @@ -223,6 +224,7 @@ tests = \ > tst-support_capture_subprocess \ > tst-support_descriptors \ > tst-support_format_dns_packet \ > + tst-support-process_state \ > tst-support_quote_blob \ > tst-support_quote_string \ > tst-support_record_failure \ > diff --git a/support/process_state.h b/support/process_state.h > new file mode 100644 > index 0000000000..d616f0e3e6 > --- /dev/null > +++ b/support/process_state.h > @@ -0,0 +1,41 @@ > +/* Wait for process state. > + Copyright (C) 2019 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef SUPPORT_PROCESS_STATE_H > +#define SUPPORT_PROCESS_STATE_H > + > +#include <sys/types.h> > + > +enum process_state_t > +{ > + process_state_running = 0x01, /* R (running) */ > + process_state_sleeping = 0x02, /* S (sleeping) */ > + process_state_disk_sleep = 0x04, /* D (disk sleep) */ > + process_state_stopped = 0x08, /* T (stopped) */ > + process_state_tracing_stop = 0x10, /* t (tracing stop) */ > + process_state_dead = 0x20, /* X (dead) */ > + process_state_zombie = 0x40, /* Z (zombie) */ > + process_state_parked = 0x80, /* P (parked) */ > +}; > + > +/* Wait for process PID to reach state STATE. It can be a combination of > + multiple possible states ('process_state_running | process_state_sleeping') > + where the function return when any of these state are observed. */ > +void support_process_state_wait (pid_t pid, enum process_state_t state); > + > +#endif > diff --git a/support/support_process_state.c b/support/support_process_state.c > new file mode 100644 > index 0000000000..77c684c49c > --- /dev/null > +++ b/support/support_process_state.c > @@ -0,0 +1,89 @@ > +/* Wait for process state. > + Copyright (C) 2019 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include <stdio.h> > +#include <fcntl.h> > +#include <time.h> > + > +#include <array_length.h> > + > +#include <support/process_state.h> > +#include <support/xunistd.h> > +#include <support/check.h> > + > +void > +support_process_state_wait (pid_t pid, enum process_state_t state) > +{ > +#ifdef __linux__ > + /* For Linux it does a polling check on /proc/<pid>/status checking on > + third field. */ > + > + /* It mimics the kernel states from fs/proc/array.c */ > + static struct process_states_t > + { > + enum process_state_t s; > + char v; > + } process_states[] = { > + { process_state_running, 'R' }, > + { process_state_sleeping, 'S' }, > + { process_state_disk_sleep, 'D' }, > + { process_state_stopped, 'T' }, > + { process_state_tracing_stop, 't' }, > + { process_state_dead, 'X' }, > + { process_state_zombie, 'Z' }, > + { process_state_parked, 'P' }, > + }; > + > + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") > + + 1]; > + snprintf (proc_path, sizeof (proc_path), "/proc/%i/stat", pid); > + > + int fd = xopen (proc_path, O_RDONLY, 0600); > + > + char statbuf[3 * sizeof (pid_t) /* pid. */ > + + 2 /* ' (' */ > + + 64 /* task name. */ > + + 2 /* ' )' */ > + + 1 /* <state>, 1 char. */ > + + 1]; /* Final \0. */ > + for (;;) > + { > + ssize_t ret = read (fd, statbuf, sizeof (statbuf) - 1); > + TEST_VERIFY (ret >= 0); > + statbuf[ret] = '\0'; > + > + char cur_state; > + int sret = sscanf (statbuf, "%*i %*s %c", &cur_state); > + TEST_VERIFY (sret == 1); > + > + for (size_t i = 0; i < array_length (process_states); ++i) > + if (state & process_states[i].s && cur_state == process_states[i].v) > + { > + close (fd); > + return; > + } > + > + xlseek (fd, 0, SEEK_SET); > + nanosleep (&(struct timespec) { 0, 10000000 }, NULL); > + } > + > + close (fd); > +#else > + sleep (2); > +#endif > +} > diff --git a/support/tst-support-process_state.c b/support/tst-support-process_state.c > new file mode 100644 > index 0000000000..3482f12fa5 > --- /dev/null > +++ b/support/tst-support-process_state.c > @@ -0,0 +1,101 @@ > +/* Wait for process state tests. > + Copyright (C) 2019 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include <stdio.h> > +#include <sys/wait.h> > +#include <unistd.h> > +#include <errno.h> > + > +#include <support/test-driver.h> > +#include <support/process_state.h> > +#include <support/check.h> > +#include <support/xsignal.h> > +#include <support/xunistd.h> > + > +static void > +sigusr1_handler (int signo) > +{ > +} > + > +static void > +test_child (void) > +{ > + xsignal (SIGUSR1, sigusr1_handler); > + > + raise (SIGSTOP); > + > + TEST_COMPARE (pause (), -1); > + TEST_COMPARE (errno, EINTR); > + > + while (1) > + asm (""); > +} > + > +static int > +do_test (void) > +{ > + pid_t pid = xfork (); > + if (pid == 0) > + { > + test_child (); > + _exit (127); > + } > + > + /* Adding process_state_tracing_stop ('t') allows the test to work under > + trace programs such as ptrace. */ > + enum process_state_t stop_state = process_state_stopped > + | process_state_tracing_stop; > + > + if (test_verbose) > + printf ("info: waiting pid %d, state_stopped/state_tracing_stop\n", > + (int) pid); > + support_process_state_wait (pid, stop_state); > + > + if (kill (pid, SIGCONT) != 0) > + FAIL_RET ("kill (%d, SIGCONT): %m\n", pid); > + > + if (test_verbose) > + printf ("info: waiting pid %d, state_sleeping\n", (int) pid); > + support_process_state_wait (pid, process_state_sleeping); > + > + if (kill (pid, SIGUSR1) != 0) > + FAIL_RET ("kill (%d, SIGUSR1): %m\n", pid); > + > + if (test_verbose) > + printf ("info: waiting pid %d, state_running\n", (int) pid); > + support_process_state_wait (pid, process_state_running); > + > + if (kill (pid, SIGKILL) != 0) > + FAIL_RET ("kill (%d, SIGKILL): %m\n", pid); > + > + if (test_verbose) > + printf ("info: waiting pid %d, state_zombie\n", (int) pid); > + support_process_state_wait (pid, process_state_zombie); > + > + siginfo_t info; > + int r = waitid (P_PID, pid, &info, WEXITED); > + TEST_COMPARE (r, 0); > + TEST_COMPARE (info.si_signo, SIGCHLD); > + TEST_COMPARE (info.si_code, CLD_KILLED); > + TEST_COMPARE (info.si_status, SIGKILL); > + TEST_COMPARE (info.si_pid, pid); > + > + return 0; > +} > + > +#include <support/test-driver.c> >
* Adhemerval Zanella: > It allows parent process to wait for children state using a polling > strategy over procfs on Linux. The polling is used over ptrace to > avoid the need to handle signals on the target pid and to handle some > system specific limitations (such as YAMA). > > The polling has some limitations, such as resource consumption due > the procfs read in a loop and the lack of synchronization after the > state is obtained. > > The interface idea is to simplify some sleep synchronization in waitid > tests. The goal is to reduce timeouts, I assume, replacing arbitrary two-second waits. > diff --git a/support/process_state.h b/support/process_state.h > new file mode 100644 > index 0000000000..d616f0e3e6 > --- /dev/null > +++ b/support/process_state.h > @@ -0,0 +1,41 @@ > +enum process_state_t > +{ > + process_state_running = 0x01, /* R (running) */ > + process_state_sleeping = 0x02, /* S (sleeping) */ > + process_state_disk_sleep = 0x04, /* D (disk sleep) */ > + process_state_stopped = 0x08, /* T (stopped) */ > + process_state_tracing_stop = 0x10, /* t (tracing stop) */ > + process_state_dead = 0x20, /* X (dead) */ > + process_state_zombie = 0x40, /* Z (zombie) */ > + process_state_parked = 0x80, /* P (parked) */ > +}; Maybe drop the reversed _t suffix and add a support_ prefix? > + > +/* Wait for process PID to reach state STATE. It can be a combination of > + multiple possible states ('process_state_running | process_state_sleeping') > + where the function return when any of these state are observed. */ > +void support_process_state_wait (pid_t pid, enum process_state_t state); This interface does not allow to poll for a process not to have a specific state. I guess we can adjust it once the need arises, so you can leave it for now. > --- /dev/null > +++ b/support/support_process_state.c > @@ -0,0 +1,89 @@ > +void > +support_process_state_wait (pid_t pid, enum process_state_t state) > +{ > +#ifdef __linux__ > + /* For Linux it does a polling check on /proc/<pid>/status checking on > + third field. */ > + > + /* It mimics the kernel states from fs/proc/array.c */ > + static struct process_states_t > + { > + enum process_state_t s; > + char v; > + } process_states[] = { > + { process_state_running, 'R' }, > + { process_state_sleeping, 'S' }, > + { process_state_disk_sleep, 'D' }, > + { process_state_stopped, 'T' }, > + { process_state_tracing_stop, 't' }, > + { process_state_dead, 'X' }, > + { process_state_zombie, 'Z' }, > + { process_state_parked, 'P' }, > + }; Should be const. > + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") > + + 1]; > + snprintf (proc_path, sizeof (proc_path), "/proc/%i/stat", pid); > + > + int fd = xopen (proc_path, O_RDONLY, 0600); > + > + char statbuf[3 * sizeof (pid_t) /* pid. */ > + + 2 /* ' (' */ > + + 64 /* task name. */ > + + 2 /* ' )' */ > + + 1 /* <state>, 1 char. */ > + + 1]; /* Final \0. */ > + for (;;) > + { > + ssize_t ret = read (fd, statbuf, sizeof (statbuf) - 1); > + TEST_VERIFY (ret >= 0); > + statbuf[ret] = '\0'; > + > + char cur_state; > + int sret = sscanf (statbuf, "%*i %*s %c", &cur_state); > + TEST_VERIFY (sret == 1); Hmm. Does this work if COMM includes a space? I think it's safer to parse /proc/PID/status. > + for (size_t i = 0; i < array_length (process_states); ++i) > + if (state & process_states[i].s && cur_state == process_states[i].v) > + { > + close (fd); > + return; > + } > + > + xlseek (fd, 0, SEEK_SET); > + nanosleep (&(struct timespec) { 0, 10000000 }, NULL); > + } > + > + close (fd); Should this have a fallback timeout? The sleep should probably be usleep or nanosleep, to avoid interfering with laram. The test looks reasonable. Thanks, Florian
On 20/12/2019 11:09, Florian Weimer wrote: > * Adhemerval Zanella: > >> It allows parent process to wait for children state using a polling >> strategy over procfs on Linux. The polling is used over ptrace to >> avoid the need to handle signals on the target pid and to handle some >> system specific limitations (such as YAMA). >> >> The polling has some limitations, such as resource consumption due >> the procfs read in a loop and the lack of synchronization after the >> state is obtained. >> >> The interface idea is to simplify some sleep synchronization in waitid >> tests. > > The goal is to reduce timeouts, I assume, replacing arbitrary two-second > waits. Indeed, I updated the commit message. > >> diff --git a/support/process_state.h b/support/process_state.h >> new file mode 100644 >> index 0000000000..d616f0e3e6 >> --- /dev/null >> +++ b/support/process_state.h >> @@ -0,0 +1,41 @@ > >> +enum process_state_t >> +{ >> + process_state_running = 0x01, /* R (running) */ >> + process_state_sleeping = 0x02, /* S (sleeping) */ >> + process_state_disk_sleep = 0x04, /* D (disk sleep) */ >> + process_state_stopped = 0x08, /* T (stopped) */ >> + process_state_tracing_stop = 0x10, /* t (tracing stop) */ >> + process_state_dead = 0x20, /* X (dead) */ >> + process_state_zombie = 0x40, /* Z (zombie) */ >> + process_state_parked = 0x80, /* P (parked) */ >> +}; > > Maybe drop the reversed _t suffix and add a support_ prefix? Ack. > >> + >> +/* Wait for process PID to reach state STATE. It can be a combination of >> + multiple possible states ('process_state_running | process_state_sleeping') >> + where the function return when any of these state are observed. */ >> +void support_process_state_wait (pid_t pid, enum process_state_t state); > > This interface does not allow to poll for a process not to have a > specific state. I guess we can adjust it once the need arises, so you > can leave it for now. Ok. > >> --- /dev/null >> +++ b/support/support_process_state.c >> @@ -0,0 +1,89 @@ > >> +void >> +support_process_state_wait (pid_t pid, enum process_state_t state) >> +{ >> +#ifdef __linux__ >> + /* For Linux it does a polling check on /proc/<pid>/status checking on >> + third field. */ >> + >> + /* It mimics the kernel states from fs/proc/array.c */ >> + static struct process_states_t >> + { >> + enum process_state_t s; >> + char v; >> + } process_states[] = { >> + { process_state_running, 'R' }, >> + { process_state_sleeping, 'S' }, >> + { process_state_disk_sleep, 'D' }, >> + { process_state_stopped, 'T' }, >> + { process_state_tracing_stop, 't' }, >> + { process_state_dead, 'X' }, >> + { process_state_zombie, 'Z' }, >> + { process_state_parked, 'P' }, >> + }; > > Should be const. Ack. > >> + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") >> + + 1]; >> + snprintf (proc_path, sizeof (proc_path), "/proc/%i/stat", pid); >> + >> + int fd = xopen (proc_path, O_RDONLY, 0600); >> + >> + char statbuf[3 * sizeof (pid_t) /* pid. */ >> + + 2 /* ' (' */ >> + + 64 /* task name. */ >> + + 2 /* ' )' */ >> + + 1 /* <state>, 1 char. */ >> + + 1]; /* Final \0. */ >> + for (;;) >> + { >> + ssize_t ret = read (fd, statbuf, sizeof (statbuf) - 1); >> + TEST_VERIFY (ret >= 0); >> + statbuf[ret] = '\0'; >> + >> + char cur_state; >> + int sret = sscanf (statbuf, "%*i %*s %c", &cur_state); >> + TEST_VERIFY (sret == 1); > > Hmm. Does this work if COMM includes a space? I think it's safer to > parse /proc/PID/status. It does not, I updated to parse /proc/PID/status. > >> + for (size_t i = 0; i < array_length (process_states); ++i) >> + if (state & process_states[i].s && cur_state == process_states[i].v) >> + { >> + close (fd); >> + return; >> + } >> + >> + xlseek (fd, 0, SEEK_SET); >> + nanosleep (&(struct timespec) { 0, 10000000 }, NULL); >> + } >> + >> + close (fd); > > Should this have a fallback timeout? Do you mean if it can not get the process state? Currently support_process_state_wait fails either if it can not open the status file or if it can't find 'State:' field. Should we add a fallback for each case? > > The sleep should probably be usleep or nanosleep, to avoid interfering > with laram. Ok. > > The test looks reasonable. Updated patch below: -- diff --git a/support/Makefile b/support/Makefile index 23c6d74627..b0d28200af 100644 --- a/support/Makefile +++ b/support/Makefile @@ -56,6 +56,7 @@ libsupport-routines = \ support_format_hostent \ support_format_netent \ support_isolate_in_subprocess \ + support_process_state \ support_ptrace \ support_openpty \ support_paths \ @@ -223,6 +224,7 @@ tests = \ tst-support_capture_subprocess \ tst-support_descriptors \ tst-support_format_dns_packet \ + tst-support-process_state \ tst-support_quote_blob \ tst-support_quote_string \ tst-support_record_failure \ diff --git a/support/process_state.h b/support/process_state.h new file mode 100644 index 0000000000..d983197247 --- /dev/null +++ b/support/process_state.h @@ -0,0 +1,45 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef SUPPORT_PROCESS_STATE_H +#define SUPPORT_PROCESS_STATE_H + +#include <sys/types.h> + +enum support_process_state +{ + support_process_state_running = 0x01, /* R (running). */ + support_process_state_sleeping = 0x02, /* S (sleeping). */ + support_process_state_disk_sleep = 0x04, /* D (disk sleep). */ + support_process_state_stopped = 0x08, /* T (stopped). */ + support_process_state_tracing_stop = 0x10, /* t (tracing stop). */ + support_process_state_dead = 0x20, /* X (dead). */ + support_process_state_zombie = 0x40, /* Z (zombie). */ + support_process_state_parked = 0x80, /* P (parked). */ +}; + +/* Wait for process PID to reach state STATE. It can be a combination of + multiple possible states ('process_state_running | process_state_sleeping') + where the function return when any of these state are observed. + The timeout POLL_TS might be used to wait before polling the PID status + information from the kernel. A NULL value will set to use a default + value (10000000 ns). */ +void support_process_state_wait (pid_t pid, enum support_process_state state, + struct timespec *poll_ts); + +#endif diff --git a/support/support_process_state.c b/support/support_process_state.c new file mode 100644 index 0000000000..16c2c3642e --- /dev/null +++ b/support/support_process_state.c @@ -0,0 +1,102 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <fcntl.h> +#include <time.h> +#include <string.h> + +#include <array_length.h> + +#include <support/process_state.h> +#include <support/xunistd.h> +#include <support/check.h> + +/* Returns the character representing the task state from FD. */ +static char find_state (int fd) +{ + char statusbuf[strlen ("Name:\t") + + 64 /* task name. */ + + strlen ("Umask:\t") /* optional. */ + + 4 /* umask size. */ + + strlen ("State:\t") + + 1 /* <state>, 1 char. */ + + 1]; /* Final \0. */ + + ssize_t ret = read (fd, statusbuf, sizeof (statusbuf) - 1); + TEST_VERIFY (ret >= 0); + statusbuf[ret] = '\0'; + + char *statestr = strstr (statusbuf, "State:\t"); + TEST_VERIFY (statestr != NULL); + char state; + int sret = sscanf (statestr, "%*s %c", &state); + TEST_VERIFY (sret == 1); + + return state; +} + +void +support_process_state_wait (pid_t pid, enum support_process_state state, + struct timespec *poll_ts) +{ +#ifdef __linux__ + /* For Linux it does a polling check on /proc/<pid>/status checking on + third field. */ + + /* It mimics the kernel states from fs/proc/array.c */ + static const struct process_states_t + { + enum support_process_state s; + char v; + } process_states[] = { + { support_process_state_running, 'R' }, + { support_process_state_sleeping, 'S' }, + { support_process_state_disk_sleep, 'D' }, + { support_process_state_stopped, 'T' }, + { support_process_state_tracing_stop, 't' }, + { support_process_state_dead, 'X' }, + { support_process_state_zombie, 'Z' }, + { support_process_state_parked, 'P' }, + }; + + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") + + 1]; + snprintf (proc_path, sizeof (proc_path), "/proc/%i/status", pid); + + int fd = xopen (proc_path, O_RDONLY, 0600); + + for (;;) + { + char cur_state = find_state (fd); + + for (size_t i = 0; i < array_length (process_states); ++i) + if (state & process_states[i].s && cur_state == process_states[i].v) + goto found; + + xlseek (fd, 0, SEEK_SET); + + nanosleep (poll_ts ? poll_ts : &(struct timespec) { 0, 10000000 }, NULL); + } + +found: + xclose (fd); +#else + nanosleep (&(struct timespec) { 2, 0 }, NULL); +#endif +} diff --git a/support/tst-support-process_state.c b/support/tst-support-process_state.c new file mode 100644 index 0000000000..d0aa142c76 --- /dev/null +++ b/support/tst-support-process_state.c @@ -0,0 +1,101 @@ +/* Wait for process state tests. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <sys/wait.h> +#include <unistd.h> +#include <errno.h> + +#include <support/test-driver.h> +#include <support/process_state.h> +#include <support/check.h> +#include <support/xsignal.h> +#include <support/xunistd.h> + +static void +sigusr1_handler (int signo) +{ +} + +static void +test_child (void) +{ + xsignal (SIGUSR1, sigusr1_handler); + + raise (SIGSTOP); + + TEST_COMPARE (pause (), -1); + TEST_COMPARE (errno, EINTR); + + while (1) + asm (""); +} + +static int +do_test (void) +{ + pid_t pid = xfork (); + if (pid == 0) + { + test_child (); + _exit (127); + } + + /* Adding process_state_tracing_stop ('t') allows the test to work under + trace programs such as ptrace. */ + enum support_process_state stop_state = support_process_state_stopped + | support_process_state_tracing_stop; + + if (test_verbose) + printf ("info: waiting pid %d, state_stopped/state_tracing_stop\n", + (int) pid); + support_process_state_wait (pid, stop_state, NULL); + + if (kill (pid, SIGCONT) != 0) + FAIL_RET ("kill (%d, SIGCONT): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_sleeping\n", (int) pid); + support_process_state_wait (pid, support_process_state_sleeping, NULL); + + if (kill (pid, SIGUSR1) != 0) + FAIL_RET ("kill (%d, SIGUSR1): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_running\n", (int) pid); + support_process_state_wait (pid, support_process_state_running, NULL); + + if (kill (pid, SIGKILL) != 0) + FAIL_RET ("kill (%d, SIGKILL): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_zombie\n", (int) pid); + support_process_state_wait (pid, support_process_state_zombie, NULL); + + siginfo_t info; + int r = waitid (P_PID, pid, &info, WEXITED); + TEST_COMPARE (r, 0); + TEST_COMPARE (info.si_signo, SIGCHLD); + TEST_COMPARE (info.si_code, CLD_KILLED); + TEST_COMPARE (info.si_status, SIGKILL); + TEST_COMPARE (info.si_pid, pid); + + return 0; +} + +#include <support/test-driver.c>
* Adhemerval Zanella: > diff --git a/support/process_state.h b/support/process_state.h > new file mode 100644 > index 0000000000..d983197247 > --- /dev/null > +++ b/support/process_state.h > @@ -0,0 +1,45 @@ > +#ifndef SUPPORT_PROCESS_STATE_H > +#define SUPPORT_PROCESS_STATE_H > + > +#include <sys/types.h> I think you also need to include <time.h> for struct timespec, strictly speaking. > diff --git a/support/support_process_state.c b/support/support_process_state.c > new file mode 100644 > index 0000000000..16c2c3642e > --- /dev/null > +++ b/support/support_process_state.c > +/* Returns the character representing the task state from FD. */ > +static char find_state (int fd) > +{ > + char statusbuf[strlen ("Name:\t") > + + 64 /* task name. */ > + + strlen ("Umask:\t") /* optional. */ > + + 4 /* umask size. */ > + + strlen ("State:\t") > + + 1 /* <state>, 1 char. */ > + + 1]; /* Final \0. */ > + > + ssize_t ret = read (fd, statusbuf, sizeof (statusbuf) - 1); > + TEST_VERIFY (ret >= 0); > + statusbuf[ret] = '\0'; > + > + char *statestr = strstr (statusbuf, "State:\t"); > + TEST_VERIFY (statestr != NULL); > + char state; > + int sret = sscanf (statestr, "%*s %c", &state); > + TEST_VERIFY (sret == 1); > + > + return state; > +} I think the expectation here is that more things will be inserted after Name:. As you note, Umask: is already a late arrival. So if simplicity is a concern, I would just read 4 KiB or so, and then use strstr with "\nState:\t" (note the \n). The sscanf seems superfluous in this context. Every else heads in the direction of getline … I think it also makes sense to return 0 in case the state cannot be determined, rather than an indeterminate value. > +void > +support_process_state_wait (pid_t pid, enum support_process_state state, > + struct timespec *poll_ts) > +{ > +#ifdef __linux__ > + /* For Linux it does a polling check on /proc/<pid>/status checking on > + third field. */ > + > + /* It mimics the kernel states from fs/proc/array.c */ > + static const struct process_states_t > + { > + enum support_process_state s; > + char v; > + } process_states[] = { > + { support_process_state_running, 'R' }, > + { support_process_state_sleeping, 'S' }, > + { support_process_state_disk_sleep, 'D' }, > + { support_process_state_stopped, 'T' }, > + { support_process_state_tracing_stop, 't' }, > + { support_process_state_dead, 'X' }, > + { support_process_state_zombie, 'Z' }, > + { support_process_state_parked, 'P' }, > + }; > + > + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") > + + 1]; > + snprintf (proc_path, sizeof (proc_path), "/proc/%i/status", pid); > + > + int fd = xopen (proc_path, O_RDONLY, 0600); > + > + for (;;) > + { > + char cur_state = find_state (fd); > + > + for (size_t i = 0; i < array_length (process_states); ++i) > + if (state & process_states[i].s && cur_state == process_states[i].v) > + goto found; I missed that before, I think we should error out if the state is completely unknown. Maybe use strchr on "RSDTtXZP" instead, and use that for the shift? 8-)
On 20/12/2019 17:32, Florian Weimer wrote: > * Adhemerval Zanella: > >> diff --git a/support/process_state.h b/support/process_state.h >> new file mode 100644 >> index 0000000000..d983197247 >> --- /dev/null >> +++ b/support/process_state.h >> @@ -0,0 +1,45 @@ > >> +#ifndef SUPPORT_PROCESS_STATE_H >> +#define SUPPORT_PROCESS_STATE_H >> + >> +#include <sys/types.h> > > I think you also need to include <time.h> for struct timespec, > strictly speaking. Ack. > >> diff --git a/support/support_process_state.c b/support/support_process_state.c >> new file mode 100644 >> index 0000000000..16c2c3642e >> --- /dev/null >> +++ b/support/support_process_state.c > >> +/* Returns the character representing the task state from FD. */ >> +static char find_state (int fd) >> +{ >> + char statusbuf[strlen ("Name:\t") >> + + 64 /* task name. */ >> + + strlen ("Umask:\t") /* optional. */ >> + + 4 /* umask size. */ >> + + strlen ("State:\t") >> + + 1 /* <state>, 1 char. */ >> + + 1]; /* Final \0. */ >> + >> + ssize_t ret = read (fd, statusbuf, sizeof (statusbuf) - 1); >> + TEST_VERIFY (ret >= 0); >> + statusbuf[ret] = '\0'; >> + >> + char *statestr = strstr (statusbuf, "State:\t"); >> + TEST_VERIFY (statestr != NULL); >> + char state; >> + int sret = sscanf (statestr, "%*s %c", &state); >> + TEST_VERIFY (sret == 1); >> + >> + return state; >> +} > > I think the expectation here is that more things will be inserted > after Name:. As you note, Umask: is already a late arrival. > > So if simplicity is a concern, I would just read 4 KiB or so, and then > use strstr with "\nState:\t" (note the \n). The sscanf seems > superfluous in this context. Every else heads in the direction of > getline … > > I think it also makes sense to return 0 in case the state cannot be > determined, rather than an indeterminate value. I was trying more to make support_process_state_wait not consume much resources, but it seems since /proc/pid/status does not have a stable format we will need to parse it in the end. I have adjusted to use getline. > >> +void >> +support_process_state_wait (pid_t pid, enum support_process_state state, >> + struct timespec *poll_ts) >> +{ >> +#ifdef __linux__ >> + /* For Linux it does a polling check on /proc/<pid>/status checking on >> + third field. */ >> + >> + /* It mimics the kernel states from fs/proc/array.c */ >> + static const struct process_states_t >> + { >> + enum support_process_state s; >> + char v; >> + } process_states[] = { >> + { support_process_state_running, 'R' }, >> + { support_process_state_sleeping, 'S' }, >> + { support_process_state_disk_sleep, 'D' }, >> + { support_process_state_stopped, 'T' }, >> + { support_process_state_tracing_stop, 't' }, >> + { support_process_state_dead, 'X' }, >> + { support_process_state_zombie, 'Z' }, >> + { support_process_state_parked, 'P' }, >> + }; >> + >> + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") >> + + 1]; >> + snprintf (proc_path, sizeof (proc_path), "/proc/%i/status", pid); >> + >> + int fd = xopen (proc_path, O_RDONLY, 0600); >> + >> + for (;;) >> + { >> + char cur_state = find_state (fd); >> + >> + for (size_t i = 0; i < array_length (process_states); ++i) >> + if (state & process_states[i].s && cur_state == process_states[i].v) >> + goto found; > > I missed that before, I think we should error out if the state is > completely unknown. Maybe use strchr on "RSDTtXZP" instead, and use > that for the shift? 8-) > What I did instead is to to fallback to nanosleep (2s) for such case (another possibility would be to just assert/abort). -- diff --git a/support/Makefile b/support/Makefile index 23c6d74627..5a3bdd8e9f 100644 --- a/support/Makefile +++ b/support/Makefile @@ -56,6 +56,7 @@ libsupport-routines = \ support_format_hostent \ support_format_netent \ support_isolate_in_subprocess \ + support_process_state \ support_ptrace \ support_openpty \ support_paths \ @@ -95,6 +96,7 @@ libsupport-routines = \ xfopen \ xfork \ xftruncate \ + xgetline \ xgetsockname \ xlisten \ xlseek \ @@ -223,6 +225,7 @@ tests = \ tst-support_capture_subprocess \ tst-support_descriptors \ tst-support_format_dns_packet \ + tst-support-process_state \ tst-support_quote_blob \ tst-support_quote_string \ tst-support_record_failure \ diff --git a/support/process_state.h b/support/process_state.h new file mode 100644 index 0000000000..4325909efd --- /dev/null +++ b/support/process_state.h @@ -0,0 +1,47 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef SUPPORT_PROCESS_STATE_H +#define SUPPORT_PROCESS_STATE_H + +#include <sys/types.h> + +enum support_process_state +{ + support_process_state_running = 0x01, /* R (running). */ + support_process_state_sleeping = 0x02, /* S (sleeping). */ + support_process_state_disk_sleep = 0x04, /* D (disk sleep). */ + support_process_state_stopped = 0x08, /* T (stopped). */ + support_process_state_tracing_stop = 0x10, /* t (tracing stop). */ + support_process_state_dead = 0x20, /* X (dead). */ + support_process_state_zombie = 0x40, /* Z (zombie). */ + support_process_state_parked = 0x80, /* P (parked). */ +}; + +/* Wait for process PID to reach state STATE. It can be a combination of + multiple possible states ('process_state_running | process_state_sleeping') + where the function return when any of these state are observed. + The timeout POLL_TS might be used to wait before polling the PID status + information from the kernel. A NULL value will set to use a default + value (10000000 ns). + For an invalid state not represented by SUPPORT_PROCESS_STATE, it fallbacks + to a 2 second sleep. */ +void support_process_state_wait (pid_t pid, enum support_process_state state, + struct timespec *poll_ts); + +#endif diff --git a/support/support_process_state.c b/support/support_process_state.c new file mode 100644 index 0000000000..6a6dbc6287 --- /dev/null +++ b/support/support_process_state.c @@ -0,0 +1,91 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdlib.h> +#include <time.h> +#include <string.h> + +#include <array_length.h> + +#include <support/process_state.h> +#include <support/xstdio.h> +#include <support/check.h> + +void +support_process_state_wait (pid_t pid, enum support_process_state state, + struct timespec *poll_ts) +{ +#ifdef __linux__ + /* For Linux it does a polling check on /proc/<pid>/status checking on + third field. */ + + /* It mimics the kernel states from fs/proc/array.c */ + static struct process_states + { + enum support_process_state s; + char v; + } process_states[] = { + { support_process_state_running, 'R' }, + { support_process_state_sleeping, 'S' }, + { support_process_state_disk_sleep, 'D' }, + { support_process_state_stopped, 'T' }, + { support_process_state_tracing_stop, 't' }, + { support_process_state_dead, 'X' }, + { support_process_state_zombie, 'Z' }, + { support_process_state_parked, 'P' }, + }; + + char spath[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/status") + 1]; + snprintf (spath, sizeof (spath), "/proc/%i/status", pid); + + FILE *fstatus = xfopen (spath, "r"); + char *line = NULL; + size_t linesiz = 0; + + for (;;) + { + char cur_state = -1; + while (xgetline (&line, &linesiz, fstatus) != -1) + if (strncmp (line, "State:", strlen ("State:")) == 0) + { + TEST_COMPARE (sscanf (line, "%*s %c", &cur_state), 1); + break; + } + if (cur_state == -1) + break; + + for (size_t i = 0; i < array_length (process_states); ++i) + if (state & process_states[i].s && cur_state == process_states[i].v) + { + free (line); + xfclose (fstatus); + return; + } + + rewind (fstatus); + fflush (fstatus); + + nanosleep (poll_ts ? poll_ts : &(struct timespec) { 0, 10000000 }, NULL); + } + + free (line); + xfclose (fstatus); + /* Fallback to nanosleep if an invalid state is found. */ +#endif + nanosleep (&(struct timespec) { 2, 0 }, NULL); +} diff --git a/support/tst-support-process_state.c b/support/tst-support-process_state.c new file mode 100644 index 0000000000..3615bbe192 --- /dev/null +++ b/support/tst-support-process_state.c @@ -0,0 +1,105 @@ +/* Wait for process state tests. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <sys/wait.h> +#include <unistd.h> +#include <errno.h> + +#include <support/test-driver.h> +#include <support/process_state.h> +#include <support/check.h> +#include <support/xsignal.h> +#include <support/xunistd.h> + +#ifndef WEXITED +# define WEXITED 0 +#endif + +static void +sigusr1_handler (int signo) +{ +} + +static void +test_child (void) +{ + xsignal (SIGUSR1, sigusr1_handler); + + raise (SIGSTOP); + + TEST_COMPARE (pause (), -1); + TEST_COMPARE (errno, EINTR); + + while (1) + asm (""); +} + +static int +do_test (void) +{ + pid_t pid = xfork (); + if (pid == 0) + { + test_child (); + _exit (127); + } + + /* Adding process_state_tracing_stop ('t') allows the test to work under + trace programs such as ptrace. */ + enum support_process_state stop_state = support_process_state_stopped + | support_process_state_tracing_stop; + + if (test_verbose) + printf ("info: waiting pid %d, state_stopped/state_tracing_stop\n", + (int) pid); + support_process_state_wait (pid, stop_state, NULL); + + if (kill (pid, SIGCONT) != 0) + FAIL_RET ("kill (%d, SIGCONT): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_sleeping\n", (int) pid); + support_process_state_wait (pid, support_process_state_sleeping, NULL); + + if (kill (pid, SIGUSR1) != 0) + FAIL_RET ("kill (%d, SIGUSR1): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_running\n", (int) pid); + support_process_state_wait (pid, support_process_state_running, NULL); + + if (kill (pid, SIGKILL) != 0) + FAIL_RET ("kill (%d, SIGKILL): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_zombie\n", (int) pid); + support_process_state_wait (pid, support_process_state_zombie, NULL); + + siginfo_t info; + int r = waitid (P_PID, pid, &info, WEXITED); + TEST_COMPARE (r, 0); + TEST_COMPARE (info.si_signo, SIGCHLD); + TEST_COMPARE (info.si_code, CLD_KILLED); + TEST_COMPARE (info.si_status, SIGKILL); + TEST_COMPARE (info.si_pid, pid); + + return 0; +} + +#include <support/test-driver.c> diff --git a/support/xgetline.c b/support/xgetline.c new file mode 100644 index 0000000000..5b010bcf56 --- /dev/null +++ b/support/xgetline.c @@ -0,0 +1,34 @@ +/* fopen with error checking. + Copyright (C) 2016-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <support/xstdio.h> + +#include <support/check.h> +#include <errno.h> + +ssize_t +xgetline (char **lineptr, size_t *n, FILE *stream) +{ + int old_errno = errno; + errno = 0; + ssize_t ret = getline (lineptr, n, stream); + if (ret == -1 && errno != 0) + FAIL_EXIT1 ("getline failed: %m"); + errno = old_errno; + return ret; +} diff --git a/support/xstdio.h b/support/xstdio.h index e4e52b4c7e..df6ee27711 100644 --- a/support/xstdio.h +++ b/support/xstdio.h @@ -27,6 +27,8 @@ __BEGIN_DECLS FILE *xfopen (const char *path, const char *mode); void xfclose (FILE *); +ssize_t xgetline (char **lineptr, size_t *n, FILE *stream); + __END_DECLS #endif /* SUPPORT_XSTDIO_H */
diff --git a/support/Makefile b/support/Makefile index 23c6d74627..b0d28200af 100644 --- a/support/Makefile +++ b/support/Makefile @@ -56,6 +56,7 @@ libsupport-routines = \ support_format_hostent \ support_format_netent \ support_isolate_in_subprocess \ + support_process_state \ support_ptrace \ support_openpty \ support_paths \ @@ -223,6 +224,7 @@ tests = \ tst-support_capture_subprocess \ tst-support_descriptors \ tst-support_format_dns_packet \ + tst-support-process_state \ tst-support_quote_blob \ tst-support_quote_string \ tst-support_record_failure \ diff --git a/support/process_state.h b/support/process_state.h new file mode 100644 index 0000000000..d616f0e3e6 --- /dev/null +++ b/support/process_state.h @@ -0,0 +1,41 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef SUPPORT_PROCESS_STATE_H +#define SUPPORT_PROCESS_STATE_H + +#include <sys/types.h> + +enum process_state_t +{ + process_state_running = 0x01, /* R (running) */ + process_state_sleeping = 0x02, /* S (sleeping) */ + process_state_disk_sleep = 0x04, /* D (disk sleep) */ + process_state_stopped = 0x08, /* T (stopped) */ + process_state_tracing_stop = 0x10, /* t (tracing stop) */ + process_state_dead = 0x20, /* X (dead) */ + process_state_zombie = 0x40, /* Z (zombie) */ + process_state_parked = 0x80, /* P (parked) */ +}; + +/* Wait for process PID to reach state STATE. It can be a combination of + multiple possible states ('process_state_running | process_state_sleeping') + where the function return when any of these state are observed. */ +void support_process_state_wait (pid_t pid, enum process_state_t state); + +#endif diff --git a/support/support_process_state.c b/support/support_process_state.c new file mode 100644 index 0000000000..77c684c49c --- /dev/null +++ b/support/support_process_state.c @@ -0,0 +1,89 @@ +/* Wait for process state. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <fcntl.h> +#include <time.h> + +#include <array_length.h> + +#include <support/process_state.h> +#include <support/xunistd.h> +#include <support/check.h> + +void +support_process_state_wait (pid_t pid, enum process_state_t state) +{ +#ifdef __linux__ + /* For Linux it does a polling check on /proc/<pid>/status checking on + third field. */ + + /* It mimics the kernel states from fs/proc/array.c */ + static struct process_states_t + { + enum process_state_t s; + char v; + } process_states[] = { + { process_state_running, 'R' }, + { process_state_sleeping, 'S' }, + { process_state_disk_sleep, 'D' }, + { process_state_stopped, 'T' }, + { process_state_tracing_stop, 't' }, + { process_state_dead, 'X' }, + { process_state_zombie, 'Z' }, + { process_state_parked, 'P' }, + }; + + char proc_path[sizeof ("/proc/" + 3) * sizeof (pid_t) + sizeof ("/stat") + + 1]; + snprintf (proc_path, sizeof (proc_path), "/proc/%i/stat", pid); + + int fd = xopen (proc_path, O_RDONLY, 0600); + + char statbuf[3 * sizeof (pid_t) /* pid. */ + + 2 /* ' (' */ + + 64 /* task name. */ + + 2 /* ' )' */ + + 1 /* <state>, 1 char. */ + + 1]; /* Final \0. */ + for (;;) + { + ssize_t ret = read (fd, statbuf, sizeof (statbuf) - 1); + TEST_VERIFY (ret >= 0); + statbuf[ret] = '\0'; + + char cur_state; + int sret = sscanf (statbuf, "%*i %*s %c", &cur_state); + TEST_VERIFY (sret == 1); + + for (size_t i = 0; i < array_length (process_states); ++i) + if (state & process_states[i].s && cur_state == process_states[i].v) + { + close (fd); + return; + } + + xlseek (fd, 0, SEEK_SET); + nanosleep (&(struct timespec) { 0, 10000000 }, NULL); + } + + close (fd); +#else + sleep (2); +#endif +} diff --git a/support/tst-support-process_state.c b/support/tst-support-process_state.c new file mode 100644 index 0000000000..3482f12fa5 --- /dev/null +++ b/support/tst-support-process_state.c @@ -0,0 +1,101 @@ +/* Wait for process state tests. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <sys/wait.h> +#include <unistd.h> +#include <errno.h> + +#include <support/test-driver.h> +#include <support/process_state.h> +#include <support/check.h> +#include <support/xsignal.h> +#include <support/xunistd.h> + +static void +sigusr1_handler (int signo) +{ +} + +static void +test_child (void) +{ + xsignal (SIGUSR1, sigusr1_handler); + + raise (SIGSTOP); + + TEST_COMPARE (pause (), -1); + TEST_COMPARE (errno, EINTR); + + while (1) + asm (""); +} + +static int +do_test (void) +{ + pid_t pid = xfork (); + if (pid == 0) + { + test_child (); + _exit (127); + } + + /* Adding process_state_tracing_stop ('t') allows the test to work under + trace programs such as ptrace. */ + enum process_state_t stop_state = process_state_stopped + | process_state_tracing_stop; + + if (test_verbose) + printf ("info: waiting pid %d, state_stopped/state_tracing_stop\n", + (int) pid); + support_process_state_wait (pid, stop_state); + + if (kill (pid, SIGCONT) != 0) + FAIL_RET ("kill (%d, SIGCONT): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_sleeping\n", (int) pid); + support_process_state_wait (pid, process_state_sleeping); + + if (kill (pid, SIGUSR1) != 0) + FAIL_RET ("kill (%d, SIGUSR1): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_running\n", (int) pid); + support_process_state_wait (pid, process_state_running); + + if (kill (pid, SIGKILL) != 0) + FAIL_RET ("kill (%d, SIGKILL): %m\n", pid); + + if (test_verbose) + printf ("info: waiting pid %d, state_zombie\n", (int) pid); + support_process_state_wait (pid, process_state_zombie); + + siginfo_t info; + int r = waitid (P_PID, pid, &info, WEXITED); + TEST_COMPARE (r, 0); + TEST_COMPARE (info.si_signo, SIGCHLD); + TEST_COMPARE (info.si_code, CLD_KILLED); + TEST_COMPARE (info.si_status, SIGKILL); + TEST_COMPARE (info.si_pid, pid); + + return 0; +} + +#include <support/test-driver.c>