Debug Console: the listener is checked and retried, and debug off <seconds> comes back by itself

The framework's server begin() fails without a word: the console's task now
asks whether it listens, says so, and tries again. `debug off <seconds>`
closes the console and reopens it after the pause, which is the only way to
test its closing and reopening from afar.

Checked on the device: 25 closings and reopenings, each back a second after
the pause. Free heap dips about 270 bytes for each connection the device
closes and is all back two minutes later (TCP keeps a closed connection that
long): not a leak.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

README.md

@@ -204,7 +204,7 @@ A note holds up to 16 KB while it's edited. A bigger text file opens read-only i
 | `coredump erase` | Forgets the core dump |
 | `loop spin on` / `loop spin off` | Make the main loop spin without resting, to compare load and radio noise |
 | `crash abort` / `crash wdt` | Crash on purpose, or hang the main loop until the watchdog fires |
-| `debug status` / `debug off` | The Debug Console: whether it's on, has a token and a client; switch it off |
+| `debug status` / `debug off [seconds]` | The Debug Console: whether it's on, has a token and a client; switch it off. With a number of seconds, it comes back by itself after that long |
 | `debug on` / `debug token <value>` / `debug token new` | USB serial only: switch it on (making a token if there's none), give it a token of 16 to 64 characters, or make a new one. The token is never printed |
 | `help` | Lists the commands |
 

docs/milestones/R1.md

@@ -147,6 +147,8 @@ The issue asked for a token that could be set, so that Debug Builds could be pub
 - **Two settings,** `DebugConsole` and `DebugToken`, with the others: validated, and invalid stored values count as missing.
 - **The console's task and ring come and go with the setting.** `Console::openRing` allocates the ring; switching off closes the socket, frees it and ends the task. `tick` follows the settings once a second, so a switch off and on again takes a second or two.
 - **Measured against the two builds it replaces:** 1,881,799 bytes of flash and 54,700 of static RAM. The release build was 1,851,387 and 54,612 (so 30 KB more flash and 88 bytes more RAM); the Debug Build was 1,874,887 and 58,780 (4 KB of RAM back: the ring is no longer a static array).
+- **The listener is asked whether it listens.** The framework's `begin()` returns nothing and fails without a word; the task now checks, says so on the console, and tries again every two seconds.
+- **`debug off <seconds>`** closes the console and brings it back by itself: the only way to try its closing and reopening from afar, since switching it on is for the device and the cable only.
 - **`scripts/rdbg.py`** answers the challenge, and fetches a release's ELF from Gitea when a crash names a version that isn't in `.pio/elves/`.
 
 ### Checks
@@ -164,6 +166,9 @@ The issue asked for a token that could be set, so that Debug Builds could be pub
 | Three `crash abort` in a row | **Safe Mode**, with the console reachable: `info` works, `ls /` says `not available in Safe Mode`. `rdbg.py crash` decodes the backtrace to `runCommand` at the `abort()` line. `reboot` leaves Safe Mode |
 | An update over Wi-Fi with the console on | The setting and the token survive: the console is back by itself after the restart |
 | `debug off` over the console | The client is dropped and port 2323 refuses connections; the update port still answers |
+| `debug off 2`, 10 times in a row, then 15 | It came back each time, a second after the pause. Free heap dips by about 270 bytes for each connection the device closes and **is all back two minutes later** (107.2 KB before, 103.2 right after 15, 107.0 at two minutes): TCP holds a closed connection that long. Not a leak, though it looked like one for an hour |
 | Memory, console on with a client | 108 KB free (the Debug Build it replaces: 104 KB). In Safe Mode: 178 KB free |
 
+**One false alarm:** after the tests the console "wouldn't come back on". It was off: the setting had been left off by `debug off`, and the page's "Switch it on?" dialog opens on **Cancel**, so Enter twice leaves it off. Nothing was lost.
+
 **Not checked:** `scripts/flash.sh --debug` over USB (no device on USB here); "New token" and "Type a token" from the page (the code paths are the ones `debug token` uses, which need the cable); the Toast itself on screen (the console is closed while it shows; its Notification is in the log); free memory with the console off, which only the serial port could say (the static figures above are the evidence); fetching a release's ELF, which needs a crash on a released version.

site/content/dev/debug/commands.md

@@ -37,7 +37,7 @@ irc start | irc stop | irc dump | irc say <buffer> <text>
 install <path.ota>   Update from SD
 update check | list | status | install <tag>   the project's releases on Gitea
 sd card | sd list | cat <path> | log <text> | burst | sound on|off | short | normal
-debug status | debug off   the Debug Console over Wi-Fi (Settings > Debug Console)
+debug status | debug off [seconds]   the Debug Console over Wi-Fi (Settings > Debug Console); with seconds, it comes back
 debug on | debug token <16 to 64 characters> | debug token new   (USB serial only) switch it on, set its token
 crash abort|wdt   crash on purpose (to test crash reports and Safe Mode)
 wifi ip ... try <seconds> | wifi ip keep   a trial IP setting: back to the previous one unless kept
@@ -105,7 +105,7 @@ In **Safe Mode** (see [Crashes and Safe Mode](/dev/debug/crashes/)) only a few r
 | `coredump erase` | Forgets the core dump |
 | `loop spin on` / `loop spin off` | Make the main loop spin without resting, to compare load and radio noise |
 | `crash abort` / `crash wdt` | Crash on purpose, or hang the main loop until the watchdog fires |
-| `debug status` / `debug off` | The Debug Console: whether it's on, has a token and a client; switch it off |
+| `debug status` / `debug off [seconds]` | The Debug Console: whether it's on, has a token and a client; switch it off. With a number of seconds, it comes back by itself after that long |
 | `debug on` / `debug token <value>` / `debug token new` | USB serial only: switch it on (making a token if there's none), give it a token of 16 to 64 characters, or make a new one. The token is never printed |
 | `help` | Lists the commands |
 

site/content/dev/debug/switch-it-on.md

@@ -20,7 +20,7 @@ Before version 0.12 this was a separate *Debug Build* with a token compiled in f
 
 | Row | Does |
 |---|---|
-| **Debug Console** | The switch. Switching it **on** asks first, and makes a token if there is none |
+| **Debug Console** | The switch. Switching it **on** asks first (the question opens on *Cancel*: move to *Switch on*), and makes a token if there is none |
 | **Connect to** | The address and port: `10.39.39.12:2323` |
 | **New token** | Makes another one. The old one stops working, and whoever is connected is cut off |
 | **Type a token** | One of your own, of 16 to 64 characters |
@@ -63,6 +63,7 @@ debug token <value>      # give it this token: 16 to 64 characters
 debug token new          # make a new one
 debug status             # on or off, token set or not, a client or not (the token itself is never shown)
 debug off                # switch it off
+debug off 30             # ...for 30 seconds: it comes back by itself
 ```
 
 `debug on` and `debug token` work **over USB serial only**: the console cannot be used to open itself wider. `debug status` and `debug off` work from anywhere, and a screenshot taken over the console while this page is open shows the token, to someone who already had it. Your token file is made by the first build (`scripts/_docker.sh`), 32 hex digits, and is never committed.

site/content/dev/milestones/r1.md

@@ -155,6 +155,8 @@ The issue asked for a token that could be set, so that Debug Builds could be pub
 - **Two settings,** `DebugConsole` and `DebugToken`, with the others: validated, and invalid stored values count as missing.
 - **The console's task and ring come and go with the setting.** `Console::openRing` allocates the ring; switching off closes the socket, frees it and ends the task. `tick` follows the settings once a second, so a switch off and on again takes a second or two.
 - **Measured against the two builds it replaces:** 1,881,799 bytes of flash and 54,700 of static RAM. The release build was 1,851,387 and 54,612 (so 30 KB more flash and 88 bytes more RAM); the Debug Build was 1,874,887 and 58,780 (4 KB of RAM back: the ring is no longer a static array).
+- **The listener is asked whether it listens.** The framework's `begin()` returns nothing and fails without a word; the task now checks, says so on the console, and tries again every two seconds.
+- **`debug off <seconds>`** closes the console and brings it back by itself: the only way to try its closing and reopening from afar, since switching it on is for the device and the cable only.
 - **`scripts/rdbg.py`** answers the challenge, and fetches a release's ELF from Gitea when a crash names a version that isn't in `.pio/elves/`.
 
 ### Checks
@@ -172,6 +174,9 @@ The issue asked for a token that could be set, so that Debug Builds could be pub
 | Three `crash abort` in a row | **Safe Mode**, with the console reachable: `info` works, `ls /` says `not available in Safe Mode`. `rdbg.py crash` decodes the backtrace to `runCommand` at the `abort()` line. `reboot` leaves Safe Mode |
 | An update over Wi-Fi with the console on | The setting and the token survive: the console is back by itself after the restart |
 | `debug off` over the console | The client is dropped and port 2323 refuses connections; the update port still answers |
+| `debug off 2`, 10 times in a row, then 15 | It came back each time, a second after the pause. Free heap dips by about 270 bytes for each connection the device closes and **is all back two minutes later** (107.2 KB before, 103.2 right after 15, 107.0 at two minutes): TCP holds a closed connection that long. Not a leak, though it looked like one for an hour |
 | Memory, console on with a client | 108 KB free (the Debug Build it replaces: 104 KB). In Safe Mode: 178 KB free |
 
+**One false alarm:** after the tests the console "wouldn't come back on". It was off: the setting had been left off by `debug off`, and the page's "Switch it on?" dialog opens on **Cancel**, so Enter twice leaves it off. Nothing was lost.
+
 **Not checked:** `scripts/flash.sh --debug` over USB (no device on USB here); "New token" and "Type a token" from the page (the code paths are the ones `debug token` uses, which need the cable); the Toast itself on screen (the console is closed while it shows; its Notification is in the log); free memory with the console off, which only the serial port could say (the static figures above are the evidence); fetching a release's ELF, which needs a crash on a released version.

src/main.cpp

@@ -564,7 +564,7 @@ static const char* const kHelp =
     "install <path.ota>   Update from SD\n"
     "update check | list | status | install <tag>   the project's releases on Gitea\n"
     "sd card | sd list | cat <path> | log <text> | burst | sound on|off | short | normal\n"
-    "debug status | debug off   the Debug Console over Wi-Fi (Settings > Debug Console)\n"
+    "debug status | debug off [seconds]   the Debug Console over Wi-Fi (Settings > Debug Console); with seconds, it comes back\n"
     "debug on | debug token <16 to 64 characters> | debug token new   (USB serial only) switch it on, set its token\n"
     "crash abort|wdt   crash on purpose (to test crash reports and Safe Mode)\n"
     "wifi ip ... try <seconds> | wifi ip keep   a trial IP setting: back to the previous one unless kept\n"
@@ -585,6 +585,16 @@ static bool safeModeCommand(const String& line) {
            line == "wifi status" || line.startsWith("wifi add ") || line.startsWith("debug ");
 }
 
+// `debug off <seconds>`: the console closes and comes back by itself. It can't open itself wider
+// that way (it was on, with the same token), and it's how its closing and reopening is tested from afar.
+static bool debugResumes = false;
+static uint32_t debugResumeMs = 0;
+static void debugResumeStep() {
+    if (!debugResumes || static_cast<int32_t>(millis() - debugResumeMs) < 0) return;
+    debugResumes = false;
+    settings.setBool(Setting::DebugConsole, true);
+}
+
 // `debug ...`: the Debug Console's switch and token (ADR 0010). Switching it on and setting its token
 // are for USB serial only (Q192): whoever holds the cable holds the device anyway, and the console
 // can't be used to open itself wider. The token is never printed.
@@ -595,6 +605,13 @@ static void debugCommand(const String& args, bool fromSerial) {
     } else if (args == "off") {
         settings.setBool(Setting::DebugConsole, false);
         console.println("debug: off");
+    } else if (args.startsWith("off ")) {  // debug off <seconds>: a pause, then on again as it was
+        uint32_t seconds = constrain(args.substring(4).toInt(), 1, 600);
+        if (!settings.getBool(Setting::DebugConsole)) return (void)console.println("debug: it is off");
+        settings.setBool(Setting::DebugConsole, false);
+        debugResumeMs = millis() + seconds * 1000;
+        debugResumes = true;
+        console.printf("debug: off for %lu s\n", (unsigned long)seconds);
     } else if (!fromSerial) {
         console.println("debug: over USB serial only (or Settings > Debug Console)");
     } else if (args == "on") {
@@ -607,7 +624,7 @@ static void debugCommand(const String& args, bool fromSerial) {
         std::string token = debug::tidyToken(args.substring(6).c_str());
         bool ok = debug::validToken(token) && settings.setString(Setting::DebugToken, token);
         console.println(ok ? "debug: token set" : "debug: a token is 16 to 64 characters");
-    } else console.println("debug: status | off | on | token <16 to 64 characters> | token new");
+    } else console.println("debug: status | off [seconds] | on | token <16 to 64 characters> | token new");
 }
 
 static void runCommand(String line, bool fromSerial = false) {
@@ -1004,6 +1021,7 @@ static void remoteCommands() {
         console.printf("> %s\n", remote.c_str());  // so the transcript reads the same on both ends
         runCommand(remote.c_str());
     }
+    debugResumeStep();
     for (std::string alert; debugConsole->takeAlert(alert);)
         bus.publish(Event::withText(EventType::Notification, alert.c_str(), static_cast<int32_t>(NotificationLevel::Warning)));
 }

src/services/debug_console.cpp

@@ -130,12 +130,23 @@ void DebugConsole::taskEntry(void* self) { static_cast<DebugConsole*>(self)->lis
 void DebugConsole::listen() {
     {
         NetworkServer server(kPort);
-        bool listening = false;
+        bool listening = false, complained = false;
         while (wanted_) {
             bool up = wifi_.state() == WifiController::State::Connected;
             if (up && !listening) {
+                // begin() gives up without a word (no socket, the port taken): ask whether it
+                // listens, and try again rather than believe it.
                 server.begin();
-                listening = true;
+                listening = static_cast<bool>(server);
+                if (!listening) {
+                    if (!complained) console.printf("debug: can't listen on port %u (errno %d), trying again\n", kPort, errno);
+                    complained = true;
+                    server.end();  // closes the socket a failed begin() leaves open
+                    vTaskDelay(pdMS_TO_TICKS(2000));
+                } else if (complained) {
+                    console.printf("debug: listening on port %u\n", kPort);
+                    complained = false;
+                }
             } else if (!up && listening) {
                 server.end();
                 listening = false;
@@ -152,7 +163,9 @@ void DebugConsole::listen() {
         }
         if (listening) server.end();
     }
-    // Switched off: nothing is left behind (Q189). The commands a client queued die with it.
+    // Switched off: nothing is left behind (Q189). The commands a client queued die with it. (Free
+    // heap dips by about 270 bytes for each connection the device closed, for two minutes: TCP keeps
+    // them that long. Measured over 15 switches: all of it comes back.)
     xSemaphoreTake(lock_, portMAX_DELAY);
     commands_.clear();
     xSemaphoreGive(lock_);