Merge remote-tracking branch 'andrea/cmux_refactor_configurable_threshold'

Conflicts:
	src/or/or.h
	src/test/Makefile.nmake

1 files changed, 82 insertions, 5 deletions

diff --git a/src/or/channel.h b/src/or/channel.h
index 4cd8f4391e..5c2a1a35e2 100644
--- a/src/or/channel.h
+++ b/src/or/channel.h
@@ -57,6 +57,32 @@ struct channel_s {
     CHANNEL_CLOSE_FOR_ERROR
   } reason_for_closing;
 
+  /** State variable for use by the scheduler */
+  enum {
+    /*
+     * The channel is not open, or it has a full output buffer but no queued
+     * cells.
+     */
+    SCHED_CHAN_IDLE = 0,
+    /*
+     * The channel has space on its output buffer to write, but no queued
+     * cells.
+     */
+    SCHED_CHAN_WAITING_FOR_CELLS,
+    /*
+     * The scheduler has queued cells but no output buffer space to write.
+     */
+    SCHED_CHAN_WAITING_TO_WRITE,
+    /*
+     * The scheduler has both queued cells and output buffer space, and is
+     * eligible for the scheduler loop.
+     */
+    SCHED_CHAN_PENDING
+  } scheduler_state;
+
+  /** Heap index for use by the scheduler */
+  int sched_heap_idx;
+
   /** Timestamps for both cell channels and listeners */
   time_t timestamp_created; /* Channel created */
   time_t timestamp_active; /* Any activity */
@@ -79,6 +105,11 @@ struct channel_s {
   /* Methods implemented by the lower layer */
 
   /**
+   * Ask the lower layer for an estimate of the average overhead for
+   * transmissions on this channel.
+   */
+  double (*get_overhead_estimate)(channel_t *);
+  /*
    * Ask the underlying transport what the remote endpoint address is, in
    * a tor_addr_t.  This is optional and subclasses may leave this NULL.
    * If they implement it, they should write the address out to the
@@ -110,7 +141,11 @@ struct channel_s {
   int (*matches_extend_info)(channel_t *, extend_info_t *);
   /** Check if this channel matches a target address when extending */
   int (*matches_target)(channel_t *, const tor_addr_t *);
-  /** Write a cell to an open channel */
+  /* Ask the lower layer how many bytes it has queued but not yet sent */
+  size_t (*num_bytes_queued)(channel_t *);
+  /* Ask the lower layer how many cells can be written */
+  int (*num_cells_writeable)(channel_t *);
+  /* Write a cell to an open channel */
   int (*write_cell)(channel_t *, cell_t *);
   /** Write a packed cell to an open channel */
   int (*write_packed_cell)(channel_t *, packed_cell_t *);
@@ -198,8 +233,16 @@ struct channel_s {
   uint64_t dirreq_id;
 
   /** Channel counters for cell channels */
-  uint64_t n_cells_recved;
-  uint64_t n_cells_xmitted;
+  uint64_t n_cells_recved, n_bytes_recved;
+  uint64_t n_cells_xmitted, n_bytes_xmitted;
+
+  /** Our current contribution to the scheduler's total xmit queue */
+  uint64_t bytes_queued_for_xmit;
+
+  /** Number of bytes in this channel's cell queue; does not include
+   * lower-layer queueing.
+   */
+  uint64_t bytes_in_queue;
 };
 
 struct channel_listener_s {
@@ -311,6 +354,34 @@ void channel_set_cmux_policy_everywhere(circuitmux_policy_t *pol);
 
 #ifdef TOR_CHANNEL_INTERNAL_
 
+#ifdef CHANNEL_PRIVATE_
+/* Cell queue structure (here rather than channel.c for test suite use) */
+
+typedef struct cell_queue_entry_s cell_queue_entry_t;
+struct cell_queue_entry_s {
+  TOR_SIMPLEQ_ENTRY(cell_queue_entry_s) next;
+  enum {
+    CELL_QUEUE_FIXED,
+    CELL_QUEUE_VAR,
+    CELL_QUEUE_PACKED
+  } type;
+  union {
+    struct {
+      cell_t *cell;
+    } fixed;
+    struct {
+      var_cell_t *var_cell;
+    } var;
+    struct {
+      packed_cell_t *packed_cell;
+    } packed;
+  } u;
+};
+
+/* Cell queue functions for benefit of test suite */
+STATIC int chan_cell_queue_len(const chan_cell_queue_t *queue);
+#endif
+
 /* Channel operations for subclasses and internal use only */
 
 /* Initialize a newly allocated channel - do this first in subclass
@@ -384,7 +455,8 @@ void channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell);
 void channel_flush_cells(channel_t *chan);
 
 /* Request from lower layer for more cells if available */
-ssize_t channel_flush_some_cells(channel_t *chan, ssize_t num_cells);
+MOCK_DECL(ssize_t, channel_flush_some_cells,
+          (channel_t *chan, ssize_t num_cells));
 
 /* Query if data available on this channel */
 int channel_more_to_flush(channel_t *chan);
@@ -435,7 +507,7 @@ channel_t * channel_next_with_digest(channel_t *chan);
  */
 
 const char * channel_describe_transport(channel_t *chan);
-void channel_dump_statistics(channel_t *chan, int severity);
+MOCK_DECL(void, channel_dump_statistics, (channel_t *chan, int severity));
 void channel_dump_transport_statistics(channel_t *chan, int severity);
 const char * channel_get_actual_remote_descr(channel_t *chan);
 const char * channel_get_actual_remote_address(channel_t *chan);
@@ -458,6 +530,7 @@ unsigned int channel_num_circuits(channel_t *chan);
 void channel_set_circid_type(channel_t *chan, crypto_pk_t *identity_rcvd,
                              int consider_identity);
 void channel_timestamp_client(channel_t *chan);
+void channel_update_xmit_queue_size(channel_t *chan);
 
 const char * channel_listener_describe_transport(channel_listener_t *chan_l);
 void channel_listener_dump_statistics(channel_listener_t *chan_l,
@@ -465,6 +538,10 @@ void channel_listener_dump_statistics(channel_listener_t *chan_l,
 void channel_listener_dump_transport_statistics(channel_listener_t *chan_l,
                                                 int severity);
 
+/* Flow control queries */
+uint64_t channel_get_global_queue_estimate(void);
+int channel_num_cells_writeable(channel_t *chan);
+
 /* Timestamp queries */
 time_t channel_when_created(channel_t *chan);
 time_t channel_when_last_active(channel_t *chan);