Merge 47df912 into 31fbbf2

changes/bug25373

@@ -0,0 +1,7 @@
+  o Major features (main loop, CPU wakeup):
+    - The bandwidth-limitation logic has been refactored so that
+      bandwidth calculations are performed on-demand, rather than
+      every TokenBucketRefillInterval milliseconds.
+      This change should improve the granularity of our bandwidth
+      calculations, and limit the number of times that the Tor process needs
+      to wake up when it is idle. Closes ticket 25373.

changes/bug25828

@@ -0,0 +1,7 @@
+  o Minor bugfixes (bandwidth management):
+    - Consider ourselves "low on write bandwidth" if we have exhausted our
+      write bandwidth some time in the last second. This was the
+      documented behavior before, but the actual behavior was to change
+      this value every TokenBucketRefillInterval. Fixes bug 25828; bugfix on
+      0.2.3.5-alpha.
+

doc/tor.1.txt

@@ -1285,9 +1285,11 @@ The following options are useful only for clients (that is, if
     2 minutes)
 
 [[TokenBucketRefillInterval]] **TokenBucketRefillInterval** __NUM__ [**msec**|**second**]::
-    Set the refill interval of Tor's token bucket to NUM milliseconds.
-    NUM must be between 1 and 1000, inclusive.  Note that the configured
-    bandwidth limits are still expressed in bytes per second: this
+    Set the refill delay interval of Tor's token bucket to NUM milliseconds.
+    NUM must be between 1 and 1000, inclusive.  When Tor is out of bandwidth,
+    on a connection or globally, it will wait up to this long before it tries
+    to use that connection again.
+    Note that bandwidth limits are still expressed in bytes per second: this
     option only affects the frequency with which Tor checks to see whether
     previously exhausted connections may read again.
     Can not be changed while tor is running. (Default: 100 msec)

src/common/token_bucket.c

@@ -238,13 +238,18 @@ token_bucket_rw_dec_write(token_bucket_rw_t *bucket,
 
 /**
  * As token_bucket_rw_dec_read and token_bucket_rw_dec_write, in a single
- * operation.
+ * operation.  Return a bitmask of TB_READ and TB_WRITE to indicate
+ * which buckets became empty.
  */
-void
+int
 token_bucket_rw_dec(token_bucket_rw_t *bucket,
                     ssize_t n_read, ssize_t n_written)
 {
-  token_bucket_rw_dec_read(bucket, n_read);
-  token_bucket_rw_dec_write(bucket, n_written);
+  int flags = 0;
+  if (token_bucket_rw_dec_read(bucket, n_read))
+    flags |= TB_READ;
+  if (token_bucket_rw_dec_write(bucket, n_written))
+    flags |= TB_WRITE;
+  return flags;
 }
 

src/common/token_bucket.h

@@ -85,8 +85,8 @@ int token_bucket_rw_dec_read(token_bucket_rw_t *bucket,
 int token_bucket_rw_dec_write(token_bucket_rw_t *bucket,
                               ssize_t n);
 
-void token_bucket_rw_dec(token_bucket_rw_t *bucket,
-                         ssize_t n_read, ssize_t n_written);
+int token_bucket_rw_dec(token_bucket_rw_t *bucket,
+                        ssize_t n_read, ssize_t n_written);
 
 static inline size_t token_bucket_rw_get_read(const token_bucket_rw_t *bucket);
 static inline size_t