sway/swaybar/status_line.c
Charmander 66b7ac6a82 swaybar: allow status line cleanup to proceed when hidden
`determine_bar_visibility` stops and starts the status command process according to the bar’s visibility. If the bar was hidden during teardown, teardown would stall while waiting for the stopped status command process to exit.

This resumes a stopped status command during teardown and allows, for example, sway to reload or quit without leaving a swaybar instance behind each time.

Fixes #5536.

CONT before TERM as requested in review.
2020-07-22 09:40:37 +02:00

202 lines
5.9 KiB
C

#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <json.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "log.h"
#include "loop.h"
#include "swaybar/bar.h"
#include "swaybar/config.h"
#include "swaybar/i3bar.h"
#include "swaybar/status_line.h"
static void status_line_close_fds(struct status_line *status) {
if (status->read_fd != -1) {
loop_remove_fd(status->bar->eventloop, status->read_fd);
close(status->read_fd);
status->read_fd = -1;
}
if (status->write_fd != -1) {
close(status->write_fd);
status->write_fd = -1;
}
}
void status_error(struct status_line *status, const char *text) {
status_line_close_fds(status);
status->protocol = PROTOCOL_ERROR;
status->text = text;
}
bool status_handle_readable(struct status_line *status) {
ssize_t read_bytes = 1;
switch (status->protocol) {
case PROTOCOL_UNDEF:
errno = 0;
int available_bytes;
if (ioctl(status->read_fd, FIONREAD, &available_bytes) == -1) {
sway_log(SWAY_ERROR, "Unable to read status command output size");
status_error(status, "[error reading from status command]");
return true;
}
if ((size_t)available_bytes + 1 > status->buffer_size) {
// need room for leading '\0' too
status->buffer_size = available_bytes + 1;
status->buffer = realloc(status->buffer, status->buffer_size);
}
if (status->buffer == NULL) {
sway_log_errno(SWAY_ERROR, "Unable to read status line");
status_error(status, "[error reading from status command]");
return true;
}
read_bytes = read(status->read_fd, status->buffer, available_bytes);
if (read_bytes != available_bytes) {
status_error(status, "[error reading from status command]");
return true;
}
status->buffer[available_bytes] = 0;
// the header must be sent completely the first time round
char *newline = strchr(status->buffer, '\n');
json_object *header, *version;
if (newline != NULL
&& (header = json_tokener_parse(status->buffer))
&& json_object_object_get_ex(header, "version", &version)
&& json_object_get_int(version) == 1) {
sway_log(SWAY_DEBUG, "Using i3bar protocol.");
status->protocol = PROTOCOL_I3BAR;
json_object *click_events;
if (json_object_object_get_ex(header, "click_events", &click_events)
&& json_object_get_boolean(click_events)) {
sway_log(SWAY_DEBUG, "Enabling click events.");
status->click_events = true;
if (write(status->write_fd, "[\n", 2) != 2) {
status_error(status, "[failed to write to status command]");
json_object_put(header);
return true;
}
}
json_object *float_event_coords;
if (json_object_object_get_ex(header, "float_event_coords", &float_event_coords)
&& json_object_get_boolean(float_event_coords)) {
sway_log(SWAY_DEBUG, "Enabling floating-point coordinates.");
status->float_event_coords = true;
}
json_object *signal;
if (json_object_object_get_ex(header, "stop_signal", &signal)) {
status->stop_signal = json_object_get_int(signal);
sway_log(SWAY_DEBUG, "Setting stop signal to %d", status->stop_signal);
}
if (json_object_object_get_ex(header, "cont_signal", &signal)) {
status->cont_signal = json_object_get_int(signal);
sway_log(SWAY_DEBUG, "Setting cont signal to %d", status->cont_signal);
}
json_object_put(header);
wl_list_init(&status->blocks);
status->tokener = json_tokener_new();
status->buffer_index = strlen(newline + 1);
memmove(status->buffer, newline + 1, status->buffer_index + 1);
return i3bar_handle_readable(status);
}
sway_log(SWAY_DEBUG, "Using text protocol.");
status->protocol = PROTOCOL_TEXT;
status->text = status->buffer;
// intentional fall-through
case PROTOCOL_TEXT:
errno = 0;
while (true) {
if (status->buffer[read_bytes - 1] == '\n') {
status->buffer[read_bytes - 1] = '\0';
}
read_bytes = getline(&status->buffer,
&status->buffer_size, status->read);
if (errno == EAGAIN) {
clearerr(status->read);
return true;
} else if (errno) {
status_error(status, "[error reading from status command]");
return true;
}
}
case PROTOCOL_I3BAR:
return i3bar_handle_readable(status);
default:
return false;
}
}
struct status_line *status_line_init(char *cmd) {
struct status_line *status = calloc(1, sizeof(struct status_line));
status->stop_signal = SIGSTOP;
status->cont_signal = SIGCONT;
status->buffer_size = 8192;
status->buffer = malloc(status->buffer_size);
int pipe_read_fd[2];
int pipe_write_fd[2];
if (pipe(pipe_read_fd) != 0 || pipe(pipe_write_fd) != 0) {
sway_log(SWAY_ERROR, "Unable to create pipes for status_command fork");
exit(1);
}
assert(!getenv("WAYLAND_SOCKET") && "display must be initialized before "
" starting `status-command`; WAYLAND_SOCKET should not be set");
status->pid = fork();
if (status->pid == 0) {
dup2(pipe_read_fd[1], STDOUT_FILENO);
close(pipe_read_fd[0]);
close(pipe_read_fd[1]);
dup2(pipe_write_fd[0], STDIN_FILENO);
close(pipe_write_fd[0]);
close(pipe_write_fd[1]);
char *const _cmd[] = { "sh", "-c", cmd, NULL, };
execvp(_cmd[0], _cmd);
exit(1);
}
close(pipe_read_fd[1]);
status->read_fd = pipe_read_fd[0];
fcntl(status->read_fd, F_SETFL, O_NONBLOCK);
close(pipe_write_fd[0]);
status->write_fd = pipe_write_fd[1];
fcntl(status->write_fd, F_SETFL, O_NONBLOCK);
status->read = fdopen(status->read_fd, "r");
status->write = fdopen(status->write_fd, "w");
return status;
}
void status_line_free(struct status_line *status) {
status_line_close_fds(status);
kill(status->pid, status->cont_signal);
kill(status->pid, SIGTERM);
waitpid(status->pid, NULL, 0);
if (status->protocol == PROTOCOL_I3BAR) {
struct i3bar_block *block, *tmp;
wl_list_for_each_safe(block, tmp, &status->blocks, link) {
wl_list_remove(&block->link);
i3bar_block_unref(block);
}
json_tokener_free(status->tokener);
}
free(status->buffer);
free(status);
}