From ca4dc259d4055f5cce40567c60876ef8dcf65b58 Mon Sep 17 00:00:00 2001
From: Jeffy Chen <jeffy.chen@rock-chips.com>
Date: Fri, 29 Jul 2022 16:13:56 +0800
Subject: [PATCH 7/7] Support hotplug when listening all devices

Tested with:
Run: input-event-daemon -v -D
Hotplug:
input-event-daemon: read(/dev/input/event7): No such device
input-event-daemon: Adding device: /dev/input/event7...

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
 input-event-daemon.c | 78 +++++++++++++++++++++++++++++++-------------
 input-event-daemon.h |  1 +
 2 files changed, 56 insertions(+), 23 deletions(-)

diff --git a/input-event-daemon.c b/input-event-daemon.c
index f67bf17..9ba6dfd 100644
--- a/input-event-daemon.c
+++ b/input-event-daemon.c
@@ -298,7 +298,7 @@ static switch_event_t
 }
 
 void input_open_all_listener() {
-    int i, listen_len = 0;
+    int i;
     char filename[32];
 
     for(i=0; i<MAX_LISTENER; i++) {
@@ -310,17 +310,22 @@ void input_open_all_listener() {
             }
             continue;
         }
-        conf.listen[listen_len++] = strdup(filename);
+        conf.listen[i] = strdup(filename);
     }
+
+    conf.dynamic = 1;
 }
 
 void input_list_devices() {
     int fd, i, e;
     unsigned char evmask[EV_MAX/8 + 1];
 
-    for(i=0; i < MAX_LISTENER && conf.listen[i] != NULL; i++) {
+    for(i=0; i < MAX_LISTENER; i++) {
         char phys[64] = "no physical path", name[256] = "Unknown Device";
 
+        if (!conf.listen[i])
+            continue;
+
         fd = open(conf.listen[i], O_RDONLY);
         if(fd < 0) {
             fprintf(stderr, PROGRAM": open(%s): %s\n",
@@ -703,41 +708,50 @@ void daemon_init() {
     }
 }
 
-void daemon_start_listener() {
-    int i, select_r, fd_len;
-    unsigned long tms_start, tms_end, idle_time = 0;
-    fd_set fdset, initial_fdset;
-    struct input_event event;
-    struct timeval tv, tv_start, tv_end;
+static int update_fds(fd_set *fdset) {
+    int i, fd_len;
 
-    /* ignored forked processes */
-    signal(SIGCHLD, SIG_IGN);
+    for(i=0, fd_len=0; i < MAX_LISTENER; i++) {
+        if (!conf.listen[i] || conf.listen_fd[i])
+            continue;
 
-    FD_ZERO(&initial_fdset);
-    fd_len = 0;
-    for(i=0; i < MAX_LISTENER && conf.listen[i] != NULL; i++) {
         conf.listen_fd[i] = open(conf.listen[i], O_RDONLY);
 
         if(conf.listen_fd[i] < 0) {
-            fprintf(stderr, PROGRAM": open(%s): %s\n",
-                conf.listen[i], strerror(errno));
             conf.listen_fd[i] = 0;
             continue;
         }
         if(conf.verbose) {
             fprintf(stderr, PROGRAM": Adding device: %s...\n", conf.listen[i]);
         }
-        FD_SET(conf.listen_fd[i], &initial_fdset);
+        FD_SET(conf.listen_fd[i], fdset);
         fd_len++;
     }
 
+    return fd_len;
+}
+
+void daemon_start_listener() {
+    int i, select_r, fd_len, timeout, interval;
+    unsigned long tms_start, tms_end, idle_time = 0;
+    fd_set fdset, initial_fdset;
+    struct input_event event;
+    struct timeval tv, tv_start, tv_end;
+
+    /* ignored forked processes */
+    signal(SIGCHLD, SIG_IGN);
+
+    FD_ZERO(&initial_fdset);
+    fd_len = update_fds(&initial_fdset);
+
     if(fd_len == 0) {
         fprintf(stderr, PROGRAM": no listener found!\n");
         return;
     }
 
     if(conf.verbose) {
-        fprintf(stderr, PROGRAM": Start listening on %d devices...\n", fd_len);
+        fprintf(stderr, PROGRAM": Start listening on %d devices...%s\n",
+                fd_len, conf.dynamic ? "dynamically" : "");
     }
 
     if(conf.monitor) {
@@ -749,9 +763,18 @@ void daemon_start_listener() {
         }
     }
 
+    if (conf.dynamic)
+        interval = 1;
+    else
+        interval = conf.min_timeout;
+
+    timeout = 0;
     while(1) {
+        if (conf.dynamic)
+            fd_len += update_fds(&initial_fdset);
+
         fdset = initial_fdset;
-        tv.tv_sec = conf.min_timeout;
+        tv.tv_sec = interval;
         tv.tv_usec = 0;
 
         gettimeofday(&tv_start, NULL);
@@ -764,7 +787,13 @@ void daemon_start_listener() {
             perror(PROGRAM": select()");
             break;
         } else if(select_r == 0) {
-            idle_time += conf.min_timeout;
+            timeout += interval;
+            if (timeout < conf.min_timeout)
+                continue;
+
+            idle_time += timeout;
+            timeout = 0;
+
             idle_event_parse(idle_time);
             continue;
         }
@@ -775,6 +804,7 @@ void daemon_start_listener() {
         if(tms_end - tms_start > 750 || idle_time > 0) {
             idle_event_parse(IDLE_RESET);
             idle_time = 0;
+            timeout = 0;
         }
 
         for(i=0; i<MAX_LISTENER; i++) {
@@ -858,9 +888,11 @@ void daemon_clean() {
     }
     switch_event_n = 0;
 
-    for(i=0; i < MAX_LISTENER && conf.listen[i] != NULL; i++) {
-        free((void*) conf.listen[i]);
-        conf.listen[i] = NULL;
+    for(i=0; i < MAX_LISTENER; i++) {
+        if (conf.listen[i]) {
+            free((void*) conf.listen[i]);
+            conf.listen[i] = NULL;
+        }
         if(conf.listen_fd[i]) {
             close(conf.listen_fd[i]);
         }
diff --git a/input-event-daemon.h b/input-event-daemon.h
index 4a6944b..7d3eacf 100644
--- a/input-event-daemon.h
+++ b/input-event-daemon.h
@@ -23,6 +23,7 @@ struct {
     unsigned char   monitor;
     unsigned char   verbose;
     unsigned char   daemon;
+    unsigned char   dynamic;
 
     unsigned long   min_timeout;
 
-- 
2.20.1