fix auto version fetch, make it non-blocking

src/web/WebStatusService.cpp

@@ -359,6 +359,8 @@ void WebStatusService::getVersions(JsonObject root) {
         dev         = versions_dev_;
     }
 
+    versions_fetch_requested_ = true;
+
     if (!cache_valid) {
         // no successful fetch yet (no network, fetch pending, or parse error)
         return;
@@ -402,12 +404,12 @@ void WebStatusService::schedule_versions_refresh() {
     versions_next_fetch_ms_ = next;
 }
 
-// periodic refresh (1 hour) of the cached versions.json, only when auto_fw_check is enabled
+// refresh of the cached versions.json, at most once a day
-// runs on the main loop task so the blocking fetch never happens in an AsyncTCP callback
 void WebStatusService::loop() {
 #ifndef EMSESP_STANDALONE
-    // only reach out to emsesp.org if the user has asked us to
+    // with auto_fw_check off we only reach out to emsesp.org when the WebUI asks for version
-    if (!EMSESP::system_.auto_fw_check()) {
+    // information, so an unattended system never contacts it at all
+    if (!EMSESP::system_.auto_fw_check() && !versions_fetch_requested_) {
         return;
     }
 
@@ -426,6 +428,8 @@ void WebStatusService::loop() {
         return;
     }
 
+    versions_fetch_requested_ = false;
+
     uint32_t interval;
     if (refresh_versions_cache()) {
         versions_failures_ = 0;

src/web/WebStatusService.h

@@ -7,6 +7,7 @@
 #include "../core/firmwareVersion.h"
 #include "../emsesp_version.h"
 
+#include <atomic>
 #include <mutex>
 
 namespace emsesp {
@@ -23,6 +24,7 @@ class WebStatusService {
 
     // called from EMSESP::loop() to refresh the cached versions.json from emsesp.org
     // so that the web request handler never has to do blocking HTTPS on the small AsyncTCP stack
+    // fetches on a daily schedule when auto_fw_check is on, otherwise only when getVersions asks
     void loop();
 
     // true once we've had at least one successful versions.json fetch
@@ -71,6 +73,10 @@ class WebStatusService {
     uint32_t    versions_next_fetch_ms_ = 0;     // uuid::get_uptime() of the next attempt; 0 = idle
     uint8_t     versions_failures_      = 0;     // consecutive failed fetches, drives the retry backoff
 
+    // set by getVersions() on the AsyncTCP task, consumed by the loop task, so that the WebUI still
+    // gets version information when auto_fw_check is off
+    std::atomic<bool> versions_fetch_requested_{false};
+
     // the cache is written by the loop task in refresh_versions_cache() and read by the AsyncTCP
     // task in getVersions()/current_upgradeable(), so the std::strings need guarding - without it a
     // request landing mid-update reads a buffer that has just been freed
@@ -80,7 +86,7 @@ class WebStatusService {
 
     static constexpr const char * VERSIONS_URL = "http://emsesp.org/versions.json";
 
-    static constexpr uint32_t VERSIONS_REFRESH_INTERVAL_MS    = 60UL * 60UL * 1000UL; // 1 hour on success
+    static constexpr uint32_t VERSIONS_REFRESH_INTERVAL_MS    = 24UL * 60UL * 60UL * 1000UL; // once a day on success
     static constexpr uint32_t VERSIONS_RETRY_INTERVAL_MS      = 5UL * 60UL * 1000UL;         // 5 min after the first failure
     static constexpr uint32_t VERSIONS_INITIAL_FETCH_DELAY_MS = 5UL * 1000UL;                // 5 s after a link comes up