Commit 21c861bf authored by Mike Perry's avatar Mike Perry
Browse files

Refactor stream blocking due to channel cell queues 

Streams can get blocked on a circuit in two ways:
  1. When the circuit package window is full
  2. When the channel's cell queue is too high

Conflux needs to decouple stream blocking from both of these conditions,
because streams can continue on another circuit, even if the primary circuit
is blocked for either of these cases.

However, both conflux and congestion control need to know if the channel's
cell queue hit the highwatermark and is still draining, because this condition
is used by those components, independent of stream state.

Therefore, this commit renames the 'streams_blocked_on_chan' variable to
signify that it refers to the cell queue state, and also refactors the actual
stream blocking bits out, so they can be handled separately if conflux is
present.
parent a4ee0c29

src/core/mainloop/mainloop.c

+1 −1
Original line number Diff line number Diff line
@@ -497,7 +497,7 @@ connection_watch_events(connection_t *conn, watchable_events_t events) 


/** Return true iff <b>conn</b> is listening for read events. */

int

connection_is_reading(connection_t *conn)

connection_is_reading(const connection_t *conn)

{

  tor_assert(conn);

src/core/mainloop/mainloop.h

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ typedef enum watchable_events { 
  WRITE_EVENT=0x04 /**< We want to know when a connection is writable */

} watchable_events_t;

void connection_watch_events(connection_t *conn, watchable_events_t events);

int connection_is_reading(connection_t *conn);

int connection_is_reading(const connection_t *conn);

MOCK_DECL(void,connection_stop_reading,(connection_t *conn));

MOCK_DECL(void,connection_start_reading,(connection_t *conn));

src/core/or/circuit_st.h

+4 −4
Original line number Diff line number Diff line
@@ -88,11 +88,11 @@ struct circuit_t { 
  extend_info_t *n_hop;



  /** True iff we are waiting for n_chan_cells to become less full before

   * allowing p_streams to add any more cells. (Origin circuit only.) */

  unsigned int streams_blocked_on_n_chan : 1;

   * allowing any more cells on this circuit. (Origin circuit only.) */

  unsigned int circuit_blocked_on_n_chan : 1;

  /** True iff we are waiting for p_chan_cells to become less full before

   * allowing n_streams to add any more cells. (OR circuit only.) */

  unsigned int streams_blocked_on_p_chan : 1;

   * allowing any more cells on this circuit. (OR circuit only.) */

  unsigned int circuit_blocked_on_p_chan : 1;



  /** True iff we have queued a delete backwards on this circuit, but not put

   * it on the output buffer. */

src/core/or/circuituse.c

+2 −1
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ 
#include "lib/math/fp.h"

#include "lib/time/tvdiff.h"

#include "lib/trace/events.h"

#include "src/core/mainloop/mainloop.h"



#include "core/or/cpath_build_state_st.h"

#include "feature/dircommon/dir_connection_st.h"
@@ -938,7 +939,7 @@ circuit_log_ancient_one_hop_circuits(int age) 
                 c->marked_for_close,

                 c->hold_open_until_flushed ? "" : "not ",

                 conn->edge_has_sent_end ? "" : "not ",

                 conn->edge_blocked_on_circ ? "Blocked" : "Not blocked");

                 connection_is_reading(c) ? "Not blocked" : "Blocked");

      if (! c->linked_conn)

        continue;

src/core/or/congestion_control_common.c

+2 −2
Original line number Diff line number Diff line
@@ -954,11 +954,11 @@ congestion_control_update_circuit_bdp(congestion_control_t *cc, 
  if (CIRCUIT_IS_ORIGIN(circ)) {

    /* origin circs use n_chan */

    chan_q = circ->n_chan_cells.n;

    blocked_on_chan = circ->streams_blocked_on_n_chan;

    blocked_on_chan = circ->circuit_blocked_on_n_chan;

  } else {

    /* Both onion services and exits use or_circuit and p_chan */

    chan_q = CONST_TO_OR_CIRCUIT(circ)->p_chan_cells.n;

    blocked_on_chan = circ->streams_blocked_on_p_chan;

    blocked_on_chan = circ->circuit_blocked_on_p_chan;

  }



  /* If we have no EWMA RTT, it is because monotime has been stalled