From 968ceac7f34bc084c59a7e7d470a5b99a7d0ee77 Mon Sep 17 00:00:00 2001
From: Utkarsh Verma <utkarshverma@protonmail.com>
Date: Sat, 17 Apr 2021 15:47:40 +0530
Subject: [PATCH] Execute blocks asynchronously
---
README.md | 9 +--
config.h | 15 +++--
main.c | 178 +++++++++++++++++++++++++-----------------------------
3 files changed, 99 insertions(+), 103 deletions(-)
diff --git a/README.md b/README.md
index 20c2503..6e01143 100644
--- a/README.md
+++ b/README.md
@@ -5,8 +5,9 @@ A modular statusbar for `dwm` written in C. You may think of it as `i3blocks`, b
- Modular
- Lightweight
- Suckless
-- Modules are clickable
-- Each module can be externally triggered to update itself
+- Blocks are clickable
+- Blocks are loaded asynchronously
+- Each block can be externally triggered to update itself
- Compatible with `i3blocks` scripts
> Apart from these features, this build of `dwmblocks` is more optimized and fixes the scroll issue due to which the statusbar flickers on scrolling.
@@ -68,7 +69,7 @@ Update signal | Signal to be used for triggering the block. Must be a positive i
The syntax for defining a block is:
```c
-static const Block blocks[] = {
+static Block blocks[] = {
...
{"date", 1800, 1},
...
@@ -80,7 +81,7 @@ Apart from that you can also modify the block delimiters and width of each block
// Maximum length of each block, expressed in number of characters.
#define CMDLENGTH 50
-#define delimiter " "
+#define DELIMITER " "
```
## Signalling changes
diff --git a/config.h b/config.h
index 16c61e9..a7c854d 100644
--- a/config.h
+++ b/config.h
@@ -1,7 +1,15 @@
#define CMDLENGTH 50
-#define delimiter " "
+#define DELIMITER " "
-const Block blocks[] = {
+typedef struct {
+ char* command;
+ unsigned int interval;
+ unsigned int signal;
+ char output[CMDLENGTH];
+ int pipe[2];
+} Block;
+
+static Block blocks[] = {
{"sb-mail", 1800, 1},
{"sb-music", 0, 2},
{"sb-disk", 1800, 4},
@@ -10,5 +18,4 @@ const Block blocks[] = {
{"sb-volume", 0, 5},
{"sb-battery", 5, 6},
{"sb-date", 20, 7},
- {"sb-network", 5, 8},
-};
+ {"sb-network", 5, 8}};
diff --git a/main.c b/main.c
index 3d4b961..aa7cbd5 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,6 @@
#include <X11/Xlib.h>
+#include <fcntl.h>
+#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
@@ -6,27 +8,17 @@
#include <time.h>
#include <unistd.h>
-#define len(arr) (sizeof(arr) / sizeof(arr[0]))
-
-typedef struct {
- char *command;
- unsigned int interval;
- unsigned int signal;
-} Block;
#include "config.h"
-void debug();
-void setRoot();
+#define LEN(arr) (sizeof(arr) / sizeof(arr[0]))
+#define MIN(x, y) (x > y ? y : x)
static Display *dpy;
static int screen;
static Window root;
-static char commands[len(blocks)][256];
-static char statusbar[len(blocks)][CMDLENGTH];
-static char statusStr[2][len(blocks) * CMDLENGTH +
- (len(delimiter) - 1) * (len(blocks) - 1) + 1];
+static char statusBar[2][LEN(blocks) * (CMDLENGTH + LEN(DELIMITER) - 1) + 1];
static int statusContinue = 1;
-static void (*writeStatus)() = setRoot;
+void (*writeStatus)();
int gcd(int a, int b) {
int temp;
@@ -44,55 +36,45 @@ void replace(char *str, char old, char new) {
*ch = new;
}
-// Open process *command and store output in *output
-void getCommand(const Block *block, char *output) {
- // Leave signal in output for dwm
- if (block->signal) {
- output[0] = block->signal;
- output++;
- }
+void getCommand(int i, const char *button) {
+ Block *block = blocks + i;
- char *cmd = block->command;
- FILE *cmdFile = popen(cmd, "r");
- if (!cmdFile) return;
+ if (fork() == 0) {
+ dup2(block->pipe[1], STDOUT_FILENO);
+ close(block->pipe[0]);
+ close(block->pipe[1]);
- int fd = fileno(cmdFile);
- if (!read(fd, output, CMDLENGTH - 2))
- output[0] = '\0';
- else {
- output[CMDLENGTH - 2] = '\0';
- replace(output, '\n', '\0');
+ // Temporary hack
+ char cmd[1024];
+ sprintf(cmd, "echo \"_$(%s)\"", block->command);
+
+ char *command[] = {"/bin/sh", "-c", cmd, NULL};
+ if (button) setenv("BLOCK_BUTTON", button, 1);
+ setsid();
+ execvp(command[0], command);
}
- pclose(cmdFile);
}
void getCommands(int time) {
- const Block *current;
- for (int i = 0; i < len(blocks); i++) {
- current = blocks + i;
- if (time == -1 || (current->interval != 0 && time % current->interval == 0))
- getCommand(current, statusbar[i]);
- }
+ for (int i = 0; i < LEN(blocks); i++)
+ if (time == 0 || (blocks[i].interval != 0 && time % blocks[i].interval == 0))
+ getCommand(i, NULL);
}
-void getSignalCommands(int signal) {
- const Block *current;
- for (int i = 0; i < len(blocks); i++) {
- current = blocks + i;
- if (current->signal == signal)
- getCommand(current, statusbar[i]);
- }
+void getSignalCommand(int signal) {
+ for (int i = 0; i < LEN(blocks); i++)
+ if (blocks[i].signal == signal)
+ getCommand(i, NULL);
}
int getStatus(char *new, char *old) {
strcpy(old, new);
new[0] = '\0';
- strcat(new, delimiter);
- for (int i = 0; i < len(blocks); i++) {
- strcat(new, statusbar[i]);
- if (strlen(statusbar[i]) > (blocks[i].signal != 0) &&
- i != len(blocks) - 1)
- strcat(new, delimiter);
+ for (int i = 0; i < LEN(blocks); i++) {
+ Block *block = blocks + i;
+ if (strlen(block->output) > (block->signal != 0))
+ strcat(new, DELIMITER);
+ strcat(new, block->output);
}
new[strlen(new)] = '\0';
return strcmp(new, old);
@@ -100,63 +82,67 @@ int getStatus(char *new, char *old) {
void debug() {
// Only write out if text has changed
- if (!getStatus(statusStr[0], statusStr[1])) return;
+ if (!getStatus(statusBar[0], statusBar[1])) return;
- write(STDOUT_FILENO, statusStr[0], strlen(statusStr[0]));
+ write(STDOUT_FILENO, statusBar[0], strlen(statusBar[0]));
write(STDOUT_FILENO, "\n", 1);
}
void setRoot() {
// Only set root if text has changed
- if (!getStatus(statusStr[0], statusStr[1])) return;
+ if (!getStatus(statusBar[0], statusBar[1])) return;
Display *d = XOpenDisplay(NULL);
if (d) dpy = d;
screen = DefaultScreen(dpy);
root = RootWindow(dpy, screen);
- XStoreName(dpy, root, statusStr[0]);
+ XStoreName(dpy, root, statusBar[0]);
XCloseDisplay(dpy);
}
void buttonHandler(int sig, siginfo_t *si, void *ucontext) {
- char button[2] = {'0' + si->si_value.sival_int & 0xff, '\0'};
sig = si->si_value.sival_int >> 8;
- if (fork() == 0) {
- const Block *current;
- char *shCommand = NULL;
- for (int i = 0; i < len(blocks); i++) {
- current = blocks + i;
- if (current->signal == sig) {
- shCommand = commands[i];
- break;
- }
- }
- if (shCommand) {
- char *command[] = {"/bin/sh", "-c", shCommand, NULL};
- setenv("BLOCK_BUTTON", button, 1);
- setsid();
- execvp(command[0], command);
- }
- exit(EXIT_SUCCESS);
- }
+ int i = 0;
+ while (blocks[i].signal != sig) i++;
+ const char button[2] = {'0' + si->si_value.sival_int & 0xff, '\0'};
+ getCommand(i, button);
}
-void signalHandler(int signum) {
- getSignalCommands(signum - SIGRTMIN);
+void signalHandler(int signal) { getSignalCommand(signal - SIGRTMIN); }
+
+void termHandler(int signal) {
+ statusContinue = 0;
+ exit(EXIT_SUCCESS);
+}
+
+void childHandler() {
+ for (int i = 0; i < LEN(blocks); i++) {
+ Block *block = blocks + i;
+
+ int bytesToRead = CMDLENGTH;
+ char *output = block->output;
+ if (block->signal) output++, bytesToRead--;
+
+ char placebo;
+ if (read(block->pipe[0], &placebo, 1) == 1) {
+ char buffer[PIPE_BUF];
+ read(block->pipe[0], buffer, PIPE_BUF);
+ replace(buffer, '\n', '\0');
+ strncpy(output, buffer, bytesToRead);
+ break;
+ }
+ }
writeStatus();
}
-void termHandler(int sigNum) {
- statusContinue = 0;
- exit(0);
-}
-
void setupSignals() {
- struct sigaction sa;
+ signal(SIGTERM, termHandler);
+ signal(SIGINT, termHandler);
// Handle block update signals
- for (int i = 0; i < len(blocks); i++) {
+ struct sigaction sa;
+ for (int i = 0; i < LEN(blocks); i++) {
if (blocks[i].signal > 0) {
signal(SIGRTMIN + blocks[i].signal, signalHandler);
sigaddset(&sa.sa_mask, SIGRTMIN + blocks[i].signal);
@@ -167,20 +153,20 @@ void setupSignals() {
sa.sa_sigaction = buttonHandler;
sa.sa_flags = SA_SIGINFO;
sigaction(SIGUSR1, &sa, NULL);
+
+ // Handle exit of forks
struct sigaction sigchld_action = {
- .sa_handler = SIG_DFL,
+ .sa_handler = childHandler,
.sa_flags = SA_NOCLDWAIT,
};
sigaction(SIGCHLD, &sigchld_action, NULL);
}
void statusLoop() {
- setupSignals();
- getCommands(-1);
- writeStatus();
+ getCommands(0);
unsigned int sleepInterval = -1;
- for (int i = 0; i < len(blocks); i++)
+ for (int i = 0; i < LEN(blocks); i++)
if (blocks[i].interval)
sleepInterval = gcd(blocks[i].interval, sleepInterval);
@@ -194,7 +180,6 @@ void statusLoop() {
// Write to status after sleeping
getCommands(i);
- writeStatus();
// After sleep, reset timer and update counter
toSleep = sleepTime;
@@ -203,15 +188,18 @@ void statusLoop() {
}
int main(int argc, char **argv) {
- const int processID = getpid();
- for (int i = 0; i < len(blocks); i++)
- sprintf(commands[i], "%s && kill -%d %d", blocks[i].command,
- SIGRTMIN + blocks[i].signal, processID);
-
+ writeStatus = setRoot;
for (int i = 0; i < argc; i++)
if (!strcmp("-d", argv[i])) writeStatus = debug;
- signal(SIGTERM, termHandler);
- signal(SIGINT, termHandler);
+ for (int i = 0; i < LEN(blocks); i++) {
+ Block *block = blocks + i;
+ pipe(block->pipe);
+ fcntl(block->pipe[0], F_SETFL, O_NONBLOCK);
+
+ if (block->signal) block->output[0] = block->signal;
+ }
+
+ setupSignals();
statusLoop();
}