Changeset 3272be1 in mainline

Timestamp:

2026-04-16T13:09:35Z (17 hours ago)

Author:

Vojtech Horky <vojtech.horky@…>

Branches:

topic/fix-logger-deadlock

Parents:

5df2570

Message:

Fix deadlock in logger service

Location:

uspace/srv/logger

Files:

• initlvl.c (modified) (1 diff)
• logger.h (modified) (2 diffs)
• logs.c (modified) (7 diffs)

uspace/srv/logger/initlvl.c

@@ -67 +67 @@
 
         log->logged_level = level;
-        log->ref_counter++;
+        refcount_up(&log->ref_counter);
 
         log_unlock(log);

uspace/srv/logger/logger.h

@@ -41 +41 @@
 #include <async.h>
 #include <stdbool.h>
+#include <refcount.h>
 #include <fibril_synch.h>
 #include <stdio.h>
@@ -64 +65 @@
         link_t link;
 
-        size_t ref_counter;
+        atomic_refcount_t ref_counter;
 
         fibril_mutex_t guard;

uspace/srv/logger/logs.c

@@ -99 +99 @@
         fibril_mutex_initialize(&result->guard);
         link_initialize(&result->link);
+        refcount_init(&result->ref_counter);
+        refcount_up(&result->ref_counter);
         result->parent = parent;
 
@@ -125 +127 @@
                 list_append(&result->link, &log_list);
                 if (result->parent != NULL) {
-                        fibril_mutex_lock(&result->parent->guard);
-                        result->parent->ref_counter++;
-                        fibril_mutex_unlock(&result->parent->guard);
+                        refcount_up(&result->parent->ref_counter);
                 }
         }
@@ -209 +209 @@
 {
         assert(fibril_mutex_is_locked(&log->guard));
-        assert(log->ref_counter > 0);
-
-        /* We are definitely not the last ones. */
-        if (log->ref_counter > 1) {
-                log->ref_counter--;
+
+        if (!refcount_down(&log->ref_counter)) {
+                /* We are definitely not the last ones. */
                 fibril_mutex_unlock(&log->guard);
                 return;
         }
+
+
 
         /*
@@ -225 +225 @@
          *   LOCKED(list), wants to LOCK(log)
          */
+        refcount_up(&log->ref_counter);
         fibril_mutex_unlock(&log->guard);
 
@@ -234 +235 @@
          */
         fibril_mutex_lock(&log->guard);
-        assert(log->ref_counter > 0);
-        log->ref_counter--;
-
-        if (log->ref_counter > 0) {
+
+        if (!refcount_down(&log->ref_counter)) {
                 /*
                  * Meanwhile, someone else increased the ref counter.
@@ -255 +254 @@
          * - destroy dest (if top-level log)
          */
-        assert(log->ref_counter == 0);
-
         list_remove(&log->link);
         fibril_mutex_unlock(&log_list_guard);
@@ -314 +311 @@
 
         assert(fibril_mutex_is_locked(&new_log->guard));
-        new_log->ref_counter++;
+        refcount_up(&new_log->ref_counter);
 
         logs->logs[logs->logs_count] = new_log;