Have the OOM handler also count the age the data in a stream buffer

1 files changed, 41 insertions, 0 deletions

diff --git a/src/or/buffers.c b/src/or/buffers.c
index 9be0476f64..4b176a83e6 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -68,6 +68,8 @@ typedef struct chunk_t {
   size_t datalen; /**< The number of bytes stored in this chunk */
   size_t memlen; /**< The number of usable bytes of storage in <b>mem</b>. */
   char *data; /**< A pointer to the first byte of data stored in <b>mem</b>. */
+  uint32_t inserted_time; /**< Timestamp in truncated ms since epoch
+                           * when this chunk was inserted. */
   char mem[FLEXIBLE_ARRAY_MEMBER]; /**< The actual memory used for storage in
                 * this chunk. */
 } chunk_t;
@@ -139,6 +141,9 @@ static chunk_freelist_t freelists[] = {
  * could help with? */
 static uint64_t n_freelist_miss = 0;
 
+/** DOCDOC */
+static size_t total_bytes_allocated_in_chunks = 0;
+
 static void assert_freelist_ok(chunk_freelist_t *fl);
 
 /** Return the freelist to hold chunks of size <b>alloc</b>, or NULL if
@@ -172,6 +177,8 @@ chunk_free_unchecked(chunk_t *chunk)
   } else {
     if (freelist)
       ++freelist->n_free;
+    tor_assert(total_bytes_allocated_in_chunks >= alloc);
+    total_bytes_allocated_in_chunks -= alloc;
     tor_free(chunk);
   }
 }
@@ -200,6 +207,7 @@ chunk_new_with_alloc_size(size_t alloc)
     else
       ++n_freelist_miss;
     ch = tor_malloc(alloc);
+    total_bytes_allocated_in_chunks += alloc;
   }
   ch->next = NULL;
   ch->datalen = 0;
@@ -211,6 +219,10 @@ chunk_new_with_alloc_size(size_t alloc)
 static void
 chunk_free_unchecked(chunk_t *chunk)
 {
+  if (!chunk)
+    return;
+  tor_assert(total_bytes_allocated_in_chunks >= CHUNK_ALLOC_SIZE(chunk->memlen));
+  total_bytes_allocated_in_chunks -= CHUNK_ALLOC_SIZE(chunk->memlen);
   tor_free(chunk);
 }
 static INLINE chunk_t *
@@ -221,6 +233,7 @@ chunk_new_with_alloc_size(size_t alloc)
   ch->next = NULL;
   ch->datalen = 0;
   ch->memlen = CHUNK_SIZE_WITH_ALLOC(alloc);
+  total_bytes_allocated_in_chunks += alloc;
   ch->data = &ch->mem[0];
   return ch;
 }
@@ -237,6 +250,7 @@ chunk_grow(chunk_t *chunk, size_t sz)
   chunk = tor_realloc(chunk, CHUNK_ALLOC_SIZE(sz));
   chunk->memlen = sz;
   chunk->data = chunk->mem + offset;
+  total_bytes_allocated_in_chunks += (sz - chunk->memlen);
   return chunk;
 }
 
@@ -298,6 +312,8 @@ buf_shrink_freelists(int free_all)
       *chp = NULL;
       while (chunk) {
         chunk_t *next = chunk->next;
+        tor_assert(total_bytes_allocated_in_chunks >= CHUNK_ALLOC_SIZE(chunk->memlen));
+        total_bytes_allocated_in_chunks -= CHUNK_ALLOC_SIZE(chunk->memlen);
         tor_free(chunk);
         chunk = next;
         --n_to_free;
@@ -599,6 +615,7 @@ static chunk_t *
 buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped)
 {
   chunk_t *chunk;
+  struct timeval now;
   if (CHUNK_ALLOC_SIZE(capacity) < buf->default_chunk_size) {
     chunk = chunk_new_with_alloc_size(buf->default_chunk_size);
   } else if (capped && CHUNK_ALLOC_SIZE(capacity) > MAX_CHUNK_ALLOC) {
@@ -606,6 +623,10 @@ buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped)
   } else {
     chunk = chunk_new_with_alloc_size(preferred_chunk_size(capacity));
   }
+
+  tor_gettimeofday_cached(&now);
+  chunk->inserted_time = (uint32_t)tv_to_msec(&now);
+
   if (buf->tail) {
     tor_assert(buf->head);
     buf->tail->next = chunk;
@@ -618,6 +639,26 @@ buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped)
   return chunk;
 }
 
+/** Return the age of the oldest chunk in the buffer <b>buf</b>, in
+ * milliseconds.  Requires the current time, in truncated milliseconds since
+ * the epoch, as its input <b>now</b>.
+ */
+uint32_t
+buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now)
+{
+  if (buf->head) {
+    return now - buf->head->inserted_time;
+  } else {
+    return 0;
+  }
+}
+
+size_t
+buf_get_total_allocation(void)
+{
+  return total_bytes_allocated_in_chunks;
+}
+
 /** Read up to <b>at_most</b> bytes from the socket <b>fd</b> into
  * <b>chunk</b> (which must be on <b>buf</b>). If we get an EOF, set
  * *<b>reached_eof</b> to 1.  Return -1 on error, 0 on eof or blocking,