refactor(log): replace the tag uncached list with standard SLIST.

NOTE: split the header modify outside.

diff --git a/components/log/log.c b/components/log/log.c
index 6a9756a24e16adbaa7473eb9389ff2d5f84d1452..07f8135a41b84680a25c1dcdd82d7d5c06bdab21 100644 (file)
--- a/components/log/log.c
+++ b/components/log/log.c
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 /*
- * Log library â\80\94 implementation notes.
+ * Log library â\80implementation notes.
  *
  * Log library stores all tags provided to esp_log_level_set as a linked
  * list. See uncached_tag_entry_t structure.
@@ -53,6 +53,7 @@
 #include <stdio.h>
 #include <assert.h>
 #include "esp_log.h"
+#include "rom/queue.h"
 
 //print number of bytes per line for esp_log_buffer_char and esp_log_buffer_hex
 #define BYTES_PER_LINE 16
@@ -76,14 +77,13 @@ typedef struct {
 } cached_tag_entry_t;
 
 typedef struct uncached_tag_entry_{
-    struct uncached_tag_entry_* next;
+    SLIST_ENTRY(uncached_tag_entry_) entries; 
     uint8_t level;  // esp_log_level_t as uint8_t
     char tag[0];    // beginning of a zero-terminated string
 } uncached_tag_entry_t;
 
 static esp_log_level_t s_log_default_level = ESP_LOG_VERBOSE;
-static uncached_tag_entry_t* s_log_tags_head = NULL;
-static uncached_tag_entry_t* s_log_tags_tail = NULL;
+static SLIST_HEAD(log_tags_head , uncached_tag_entry_) s_log_tags = SLIST_HEAD_INITIALIZER(s_log_tags);
 static cached_tag_entry_t s_log_cache[TAG_CACHE_SIZE];
 static uint32_t s_log_cache_max_generation = 0;
 static uint32_t s_log_cache_entry_count = 0;
@@ -122,41 +122,29 @@ void esp_log_level_set(const char* tag, esp_log_level_t level)
         return;
     }
 
-    // allocate new linked list entry and append it to the endo of the list
+    // allocate new linked list entry and append it to the head of the list
     size_t entry_size = offsetof(uncached_tag_entry_t, tag) + strlen(tag) + 1;
     uncached_tag_entry_t* new_entry = (uncached_tag_entry_t*) malloc(entry_size);
     if (!new_entry) {
         xSemaphoreGive(s_log_mutex);
         return;
     }
-    new_entry->next = NULL;
     new_entry->level = (uint8_t) level;
     strcpy(new_entry->tag, tag);
-    if (s_log_tags_tail) {
-        s_log_tags_tail->next = new_entry;
-    }
-    s_log_tags_tail = new_entry;
-    if (!s_log_tags_head) {
-        s_log_tags_head = new_entry;
-    }
+    SLIST_INSERT_HEAD( &s_log_tags, new_entry, entries );
     xSemaphoreGive(s_log_mutex);
 }
 
 void clear_log_level_list()
 {
-    for (uncached_tag_entry_t* it = s_log_tags_head; it != NULL; ) {
-        uncached_tag_entry_t* next = it->next;
-        free(it);
-        it = next;
+    while( !SLIST_EMPTY(&s_log_tags)) {
+        SLIST_REMOVE_HEAD(&s_log_tags, entries );
     }
-    s_log_tags_tail = NULL;
-    s_log_tags_head = NULL;
     s_log_cache_entry_count = 0;
     s_log_cache_max_generation = 0;
 #ifdef LOG_BUILTIN_CHECKS
     s_log_cache_misses = 0;
 #endif
-
 }
 
 void IRAM_ATTR esp_log_write(esp_log_level_t level,
@@ -253,7 +241,8 @@ static inline bool get_uncached_log_level(const char* tag, esp_log_level_t* leve
 {
     // Walk the linked list of all tags and see if given tag is present in the list.
     // This is slow because tags are compared as strings.
-    for (uncached_tag_entry_t* it = s_log_tags_head; it != NULL; it = it->next) {
+    uncached_tag_entry_t *it;
+    SLIST_FOREACH( it, &s_log_tags, entries ) {
         if (strcmp(tag, it->tag) == 0) {
             *level = it->level;
             return true;