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fix(command): broken pipe when ignoring output.

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This commit is contained in:
Jérôme BOULMIER 2019-03-07 00:22:00 -05:00 committed by Patrick Ziegler
parent 92181fd237
commit 5e5d8faf04
9 changed files with 169 additions and 97 deletions
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3
include/components/controller.hpp
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@ -18,6 +18,7 @@ POLYBAR_NS
enum class alignment;
class bar;
template <output_policy>
class command;
class config;
class connection;
@ -80,7 +81,7 @@ class controller
unique_ptr<bar> m_bar;
unique_ptr<ipc> m_ipc;
unique_ptr<inotify_watch> m_confwatch;
unique_ptr<command> m_command;
unique_ptr<command<output_policy::IGNORED>> m_command;
array<unique_ptr<file_descriptor>, 2> m_queuefd{};

5
include/components/types.hpp
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@ -236,4 +236,9 @@ struct event_timer {
};
};
enum class output_policy {
REDIRECTED,
IGNORED,
};
POLYBAR_NS_END

2
include/modules/script.hpp
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@ -27,7 +27,7 @@ namespace modules {
mutex_wrapper<function<chrono::duration<double>()>> m_handler;
unique_ptr<command> m_command;
unique_ptr<command<output_policy::REDIRECTED>> m_command;
bool m_tail;

73
include/utils/command.hpp
View File

@ -4,6 +4,7 @@
#include "common.hpp"
#include "components/logger.hpp"
#include "components/types.hpp"
#include "errors.hpp"
#include "utils/factory.hpp"
#include "utils/functional.hpp"
@ -15,17 +16,22 @@ DEFINE_ERROR(command_error);
/**
* Wrapper used to execute command in a subprocess.
* In-/output streams are opened to enable ipc.
* If the command is created using command_util::make_command<output_policy::REDIRECTED>, the child streams are
* redirected and you can read the program output or write into the program input.
*
* If the command is created using command_util::make_command<output_policy::IGNORED>, the output is not redirected and
* you can't communicate with the child program.
*
* Example usage:
*
* \code cpp
* auto cmd = command_util::make_command("cat /etc/rc.local");
* auto cmd = command_util::make_command<output_policy::REDIRECTED>("cat /etc/rc.local");
* cmd->exec();
* cmd->tail([](string s) { std::cout << s << std::endl; });
* \endcode
*
* \code cpp
* auto cmd = command_util::make_command(
* auto cmd = command_util::make_command<output_policy::REDIRECTED>(
* "while read -r line; do echo data from parent process: $line; done");
* cmd->exec(false);
* cmd->writeline("Test");
@ -34,29 +40,34 @@ DEFINE_ERROR(command_error);
* \endcode
*
* \code cpp
* auto cmd = command_util::make_command("for i in 1 2 3; do echo $i; done");
* auto cmd = command_util::make_command<output_policy::REDIRECTED>("for i in 1 2 3; do echo $i; done");
* cmd->exec();
* cout << cmd->readline(); // 1
* cout << cmd->readline() << cmd->readline(); // 23
* \endcode
*
* \code cpp
* auto cmd = command_util::make_command<output_policy::IGNORED>("ping kernel.org");
* int status = cmd->exec();
* \endcode
*/
class command {
template <output_policy>
class command;
template <>
class command<output_policy::IGNORED> {
public:
explicit command(const logger& logger, string cmd);
command(const command&) = delete;
~command();
command& operator=(const command&) = delete;
int exec(bool wait_for_completion = true);
void terminate();
bool is_running();
int wait();
void tail(callback<string> cb);
int writeline(string data);
string readline();
int get_stdout(int c);
int get_stdin(int c);
pid_t get_pid();
int get_exit_status();
@ -65,20 +76,46 @@ class command {
string m_cmd;
int m_stdout[2]{};
int m_stdin[2]{};
pid_t m_forkpid{};
int m_forkstatus{};
};
template <>
class command<output_policy::REDIRECTED> : private command<output_policy::IGNORED> {
public:
explicit command(const logger& logger, string cmd);
command(const command&) = delete;
~command();
command& operator=(const command&) = delete;
int exec(bool wait_for_completion = true);
using command<output_policy::IGNORED>::terminate;
using command<output_policy::IGNORED>::is_running;
using command<output_policy::IGNORED>::wait;
using command<output_policy::IGNORED>::get_pid;
using command<output_policy::IGNORED>::get_exit_status;
void tail(callback<string> cb);
int writeline(string data);
string readline();
int get_stdout(int c);
int get_stdin(int c);
protected:
int m_stdout[2]{};
int m_stdin[2]{};
std::mutex m_pipelock{};
};
namespace command_util {
template <typename... Args>
unique_ptr<command> make_command(Args&&... args) {
return factory_util::unique<command>(logger::make(), forward<Args>(args)...);
}
template <output_policy OutputType, typename... Args>
unique_ptr<command<OutputType>> make_command(Args&&... args) {
return factory_util::unique<command<OutputType>>(logger::make(), forward<Args>(args)...);
}
} // namespace command_util
POLYBAR_NS_END

2
src/adapters/net.cpp
View File

@ -129,7 +129,7 @@ namespace net {
bool network::ping() const {
try {
auto exec = "ping -c 2 -W 2 -I " + m_interface + " " + string(CONNECTION_TEST_IP);
auto ping = command_util::make_command(exec);
auto ping = command_util::make_command<output_policy::IGNORED>(exec);
return ping && ping->exec(true) == EXIT_SUCCESS;
} catch (const std::exception& err) {
return false;

2
src/components/controller.cpp
View File

@ -408,7 +408,7 @@ void controller::process_inputdata() {
}
m_log.info("Executing shell command: %s", cmd);
m_command = command_util::make_command(move(cmd));
m_command = command_util::make_command<output_policy::IGNORED>(move(cmd));
m_command->exec();
m_command.reset();
process_update(true);

4
src/modules/ipc.cpp
View File

@ -60,7 +60,7 @@ namespace modules {
*/
void ipc_module::start() {
if (m_initial) {
auto command = command_util::make_command(m_hooks.at(m_initial - 1)->command);
auto command = command_util::make_command<output_policy::REDIRECTED>(m_hooks.at(m_initial - 1)->command);
command->exec(false);
command->tail([this](string line) { m_output = line; });
}
@ -114,7 +114,7 @@ namespace modules {
try {
// Clear the output in case the command produces no output
m_output.clear();
auto command = command_util::make_command(hook->command);
auto command = command_util::make_command<output_policy::REDIRECTED>(hook->command);
command->exec(false);
command->tail([this](string line) { m_output = line; });
} catch (const exception& err) {

6
src/modules/script.cpp
View File

@ -22,7 +22,7 @@ namespace modules {
if (!m_command || !m_command->is_running()) {
string exec{string_util::replace_all(m_exec, "%counter%", to_string(++m_counter))};
m_log.info("%s: Invoking shell command: \"%s\"", name(), exec);
m_command = command_util::make_command(exec);
m_command = command_util::make_command<output_policy::REDIRECTED>(exec);
try {
m_command->exec(false);
@ -59,7 +59,7 @@ namespace modules {
try {
auto exec = string_util::replace_all(m_exec, "%counter%", to_string(++m_counter));
m_log.info("%s: Invoking shell command: \"%s\"", name(), exec);
m_command = command_util::make_command(exec);
m_command = command_util::make_command<output_policy::REDIRECTED>(exec);
m_command->exec(true);
} catch (const exception& err) {
m_log.err("%s: %s", name(), err.what());
@ -143,7 +143,7 @@ namespace modules {
bool script_module::check_condition() {
if (m_exec_if.empty()) {
return true;
} else if (command_util::make_command(m_exec_if)->exec(true) == 0) {
} else if (command_util::make_command<output_policy::IGNORED>(m_exec_if)->exec(true) == 0) {
return true;
} else if (!m_output.empty()) {
broadcast();

169
src/utils/command.cpp
View File

@ -3,6 +3,7 @@
#include <csignal>
#include <cstdlib>
#include <utility>
#include <utils/string.hpp>
#include "errors.hpp"
#include "utils/command.hpp"
@ -18,7 +19,95 @@
POLYBAR_NS
command::command(const logger& logger, string cmd) : m_log(logger), m_cmd(move(cmd)) {
command<output_policy::IGNORED>::command(const logger& logger, string cmd) : m_log(logger), m_cmd(move(cmd)) {}
command<output_policy::IGNORED>::~command() {
if (is_running()) {
terminate();
}
}
/**
* Execute the command
*/
int command<output_policy::IGNORED>::exec(bool wait_for_completion) {
if ((m_forkpid = fork()) == -1) {
throw system_error("Failed to fork process");
}
if (process_util::in_forked_process(m_forkpid)) {
setpgid(m_forkpid, 0);
process_util::exec_sh(m_cmd.c_str());
} else {
if (wait_for_completion) {
auto status = wait();
m_forkpid = -1;
return status;
}
}
return EXIT_SUCCESS;
}
void command<output_policy::IGNORED>::terminate() {
if (is_running()) {
m_log.trace("command: Sending SIGTERM to running child process (%d)", m_forkpid);
killpg(m_forkpid, SIGTERM);
wait();
}
m_forkpid = -1;
}
/**
* Check if command is running
*/
bool command<output_policy::IGNORED>::is_running() {
return m_forkpid > 0 && process_util::wait_for_completion_nohang(m_forkpid, &m_forkstatus) > -1;
}
/**
* Wait for the child processs to finish
*/
int command<output_policy::IGNORED>::wait() {
do {
m_log.trace("command: Waiting for pid %d to finish...", m_forkpid);
process_util::wait_for_completion(m_forkpid, &m_forkstatus, WCONTINUED | WUNTRACED);
if (WIFEXITED(m_forkstatus) && m_forkstatus > 0) {
m_log.trace("command: Exited with failed status %d", WEXITSTATUS(m_forkstatus));
} else if (WIFEXITED(m_forkstatus)) {
m_log.trace("command: Exited with status %d", WEXITSTATUS(m_forkstatus));
} else if (WIFSIGNALED(m_forkstatus)) {
m_log.trace("command: killed by signal %d", WTERMSIG(m_forkstatus));
} else if (WIFSTOPPED(m_forkstatus)) {
m_log.trace("command: Stopped by signal %d", WSTOPSIG(m_forkstatus));
} else if (WIFCONTINUED(m_forkstatus)) {
m_log.trace("command: Continued");
} else {
break;
}
} while (!WIFEXITED(m_forkstatus) && !WIFSIGNALED(m_forkstatus));
return m_forkstatus;
}
/**
* Get command pid
*/
pid_t command<output_policy::IGNORED>::get_pid() {
return m_forkpid;
}
/**
* Get command exit status
*/
int command<output_policy::IGNORED>::get_exit_status() {
return m_forkstatus;
}
command<output_policy::REDIRECTED>::command(const polybar::logger& logger, std::string cmd)
: command<output_policy::IGNORED>(logger, move(cmd)) {
if (pipe(m_stdin) != 0) {
throw command_error("Failed to allocate input stream");
}
@ -27,10 +116,7 @@ command::command(const logger& logger, string cmd) : m_log(logger), m_cmd(move(c
}
}
command::~command() {
if (is_running()) {
terminate();
}
command<output_policy::REDIRECTED>::~command() {
if (m_stdin[PIPE_READ] > 0) {
close(m_stdin[PIPE_READ]);
}
@ -48,7 +134,7 @@ command::~command() {
/**
* Execute the command
*/
int command::exec(bool wait_for_completion) {
int command<output_policy::REDIRECTED>::exec(bool wait_for_completion) {
if ((m_forkpid = fork()) == -1) {
throw system_error("Failed to fork process");
}
@ -99,71 +185,28 @@ int command::exec(bool wait_for_completion) {
return EXIT_SUCCESS;
}
void command::terminate() {
if (is_running()) {
m_log.trace("command: Sending SIGTERM to running child process (%d)", m_forkpid);
killpg(m_forkpid, SIGTERM);
wait();
}
m_forkpid = -1;
}
/**
* Check if command is running
*/
bool command::is_running() {
return m_forkpid > 0 && process_util::wait_for_completion_nohang(m_forkpid, &m_forkstatus) > -1;
}
/**
* Wait for the child processs to finish
*/
int command::wait() {
do {
m_log.trace("command: Waiting for pid %d to finish...", m_forkpid);
process_util::wait_for_completion(m_forkpid, &m_forkstatus, WCONTINUED | WUNTRACED);
if (WIFEXITED(m_forkstatus) && m_forkstatus > 0) {
m_log.trace("command: Exited with failed status %d", WEXITSTATUS(m_forkstatus));
} else if (WIFEXITED(m_forkstatus)) {
m_log.trace("command: Exited with status %d", WEXITSTATUS(m_forkstatus));
} else if (WIFSIGNALED(m_forkstatus)) {
m_log.trace("command: killed by signal %d", WTERMSIG(m_forkstatus));
} else if (WIFSTOPPED(m_forkstatus)) {
m_log.trace("command: Stopped by signal %d", WSTOPSIG(m_forkstatus));
} else if (WIFCONTINUED(m_forkstatus)) {
m_log.trace("command: Continued");
} else {
break;
}
} while (!WIFEXITED(m_forkstatus) && !WIFSIGNALED(m_forkstatus));
return m_forkstatus;
}
/**
* Tail command output
*
* \note: This is a blocking call and will not
* end until the stream is closed
*/
void command::tail(callback<string> cb) {
io_util::tail(m_stdout[PIPE_READ], move(cb));
void command<output_policy::REDIRECTED>::tail(callback<string> cb) {
io_util::tail(m_stdout[PIPE_READ], cb);
}
/**
* Write line to command input channel
*/
int command::writeline(string data) {
int command<output_policy::REDIRECTED>::writeline(string data) {
std::lock_guard<std::mutex> lck(m_pipelock);
return io_util::writeline(m_stdin[PIPE_WRITE], move(data));
return static_cast<int>(io_util::writeline(m_stdin[PIPE_WRITE], data));
}
/**
* Read a line from the commands output stream
*/
string command::readline() {
string command<output_policy::REDIRECTED>::readline() {
std::lock_guard<std::mutex> lck(m_pipelock);
return io_util::readline(m_stdout[PIPE_READ]);
}
@ -171,29 +214,15 @@ string command::readline() {
/**
* Get command output channel
*/
int command::get_stdout(int c) {
int command<output_policy::REDIRECTED>::get_stdout(int c) {
return m_stdout[c];
}
/**
* Get command input channel
*/
int command::get_stdin(int c) {
int command<output_policy::REDIRECTED>::get_stdin(int c) {
return m_stdin[c];
}
/**
* Get command pid
*/
pid_t command::get_pid() {
return m_forkpid;
}
/**
* Get command exit status
*/
int command::get_exit_status() {
return m_forkstatus;
}
POLYBAR_NS_END