commit 06a76d1db49d7c9c386368583928cde11b509519 Author: Andrea Shepard <andrea@torproject.org> Date: Mon Oct 8 21:16:59 2012 -0700 Refactor channel_write_cell()/channel_write_packed_cell()/channel_write_var_cell() to eliminate redundant code --- src/or/channel.c | 217 ++++++++++++++++++++++++++--------------------------- 1 files changed, 106 insertions(+), 111 deletions(-) diff --git a/src/or/channel.c b/src/or/channel.c index 9fbfecb..fac4017 100644 --- a/src/or/channel.c +++ b/src/or/channel.c @@ -74,6 +74,8 @@ static uint64_t n_channels_allocated = 0; */ static digestmap_t *channel_identity_map = NULL; +static int cell_queue_entry_is_padding(cell_queue_entry_t *q); + /* Functions to maintain the digest map */ static void channel_add_to_digest_map(channel_t *chan); static void channel_remove_from_digest_map(channel_t *chan); @@ -85,8 +87,9 @@ static void channel_remove_from_digest_map(channel_t *chan); static ssize_t channel_flush_some_cells_from_outgoing_queue(channel_t *chan, ssize_t num_cells); - static void channel_force_free(channel_t *chan); +static void +channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q); /*********************************** * Channel state utility functions * @@ -1308,39 +1311,56 @@ channel_set_remote_end(channel_t *chan, } /** - * Write a cell to a channel - * - * Write a fixed-length cell to a channel using the write_cell() method. - * This is equivalent to the pre-channels connection_or_write_cell_to_buf(). - * - * @param chan Channel to write a cell to - * @param cell Cell to write to chan + * Check whether a cell queue entry is padding; this is a helper function + * for channel_write_cell_queue_entry() */ -void -channel_write_cell(channel_t *chan, cell_t *cell) +static int +cell_queue_entry_is_padding(cell_queue_entry_t *q) { - cell_queue_entry_t *q; - int sent = 0; + tor_assert(q); + + if (q->type == CELL_QUEUE_FIXED) { + if (q->u.fixed.cell) { + if (q->u.fixed.cell->command == CELL_PADDING || + q->u.fixed.cell->command == CELL_VPADDING) { + return 1; + } + } + } else if (q->type == CELL_QUEUE_VAR) { + if (q->u.var.var_cell) { + if (q->u.var.var_cell->command == CELL_PADDING || + q->u.var.var_cell->command == CELL_VPADDING) { + return 1; + } + } + } + + return 0; +} + +/** + * Given a cell_queue_entry_t filled out by the caller, try to send the cell + * and queue it if we can't. + */ + +static void +channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q) +{ + int result = 0, sent = 0; + cell_queue_entry_t *tmp = NULL; tor_assert(chan); tor_assert(!(chan->is_listener)); - tor_assert(cell); - tor_assert(chan->u.cell_chan.write_cell); + tor_assert(q); /* Assert that the state makes sense for a cell write */ tor_assert(chan->state == CHANNEL_STATE_OPENING || chan->state == CHANNEL_STATE_OPEN || chan->state == CHANNEL_STATE_MAINT); - log_debug(LD_CHANNEL, - "Writing cell_t %p to channel %p with global ID " - U64_FORMAT, - cell, chan, U64_PRINTF_ARG(chan->global_identifier)); - /* Increment the timestamp unless it's padding */ - if (!(cell->command == CELL_PADDING || - cell->command == CELL_VPADDING)) { + if (!cell_queue_entry_is_padding(q)) { chan->u.cell_chan.timestamp_last_added_nonpadding = approx_time(); } @@ -1348,7 +1368,31 @@ channel_write_cell(channel_t *chan, cell_t *cell) if (!(chan->u.cell_chan.outgoing_queue && (smartlist_len(chan->u.cell_chan.outgoing_queue) > 0)) && chan->state == CHANNEL_STATE_OPEN) { - if (chan->u.cell_chan.write_cell(chan, cell)) { + /* Pick the right write function for this cell type and save the result */ + switch (q->type) { + case CELL_QUEUE_FIXED: + tor_assert(chan->u.cell_chan.write_cell); + tor_assert(q->u.fixed.cell); + result = chan->u.cell_chan.write_cell(chan, q->u.fixed.cell); + break; + case CELL_QUEUE_PACKED: + tor_assert(chan->u.cell_chan.write_packed_cell); + tor_assert(q->u.packed.packed_cell); + result = chan-> + u.cell_chan.write_packed_cell(chan, + q->u.packed.packed_cell); + break; + case CELL_QUEUE_VAR: + tor_assert(chan->u.cell_chan.write_var_cell); + tor_assert(q->u.var.var_cell); + result = chan->u.cell_chan.write_var_cell(chan, q->u.var.var_cell); + break; + default: + tor_assert(1); + } + + /* Check if we got it out */ + if (result > 0) { sent = 1; /* Timestamp for transmission */ channel_timestamp_xmit(chan); @@ -1363,39 +1407,56 @@ channel_write_cell(channel_t *chan, cell_t *cell) /* Not sent, queue it */ if (!(chan->u.cell_chan.outgoing_queue)) chan->u.cell_chan.outgoing_queue = smartlist_new(); - q = tor_malloc(sizeof(*q)); - q->type = CELL_QUEUE_FIXED; - q->u.fixed.cell = cell; - smartlist_add(chan->u.cell_chan.outgoing_queue, q); + /* + * We have to copy the queue entry passed in, since the caller probably + * used the stack. + */ + tmp = tor_malloc(sizeof(*tmp)); + memcpy(tmp, q, sizeof(*tmp)); + smartlist_add(chan->u.cell_chan.outgoing_queue, tmp); /* Try to process the queue? */ if (chan->state == CHANNEL_STATE_OPEN) channel_flush_cells(chan); } } /** + * Write a cell to a channel + * + * Write a fixed-length cell to a channel using the write_cell() method. + * This is equivalent to the pre-channels connection_or_write_cell_to_buf(). + */ + +void +channel_write_cell(channel_t *chan, cell_t *cell) +{ + cell_queue_entry_t q; + + tor_assert(chan); + tor_assert(cell); + + log_debug(LD_CHANNEL, + "Writing cell_t %p to channel %p with global ID " + U64_FORMAT, + cell, chan, U64_PRINTF_ARG(chan->global_identifier)); + + q.type = CELL_QUEUE_FIXED; + q.u.fixed.cell = cell; + channel_write_cell_queue_entry(chan, &q); +} + +/** * Write a packed cell to a channel * * Write a packed cell to a channel using the write_cell() method. - * - * @param chan Channel to write a cell to - * @param packed_cell Cell to write to chan */ void channel_write_packed_cell(channel_t *chan, packed_cell_t *packed_cell) { - cell_queue_entry_t *q; - int sent = 0; + cell_queue_entry_t q; tor_assert(chan); - tor_assert(!(chan->is_listener)); tor_assert(packed_cell); - tor_assert(chan->u.cell_chan.write_packed_cell); - - /* Assert that the state makes sense for a cell write */ - tor_assert(chan->state == CHANNEL_STATE_OPENING || - chan->state == CHANNEL_STATE_OPEN || - chan->state == CHANNEL_STATE_MAINT); log_debug(LD_CHANNEL, "Writing packed_cell_t %p to channel %p with global ID " @@ -1403,35 +1464,9 @@ channel_write_packed_cell(channel_t *chan, packed_cell_t *packed_cell) packed_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); - /* Increment the timestamp */ - chan->u.cell_chan.timestamp_last_added_nonpadding = approx_time(); - - /* Can we send it right out? If so, try */ - if (!(chan->u.cell_chan.outgoing_queue && - (smartlist_len(chan->u.cell_chan.outgoing_queue) > 0)) && - chan->state == CHANNEL_STATE_OPEN) { - if (chan->u.cell_chan.write_packed_cell(chan, packed_cell)) { - sent = 1; - /* Timestamp for transmission */ - channel_timestamp_xmit(chan); - /* If we're here the queue is empty, so it's drained too */ - channel_timestamp_drained(chan); - /* Update the counter */ - ++(chan->u.cell_chan.n_cells_xmitted); - } - } - - if (!sent) { - /* Not sent, queue it */ - if (!(chan->u.cell_chan.outgoing_queue)) - chan->u.cell_chan.outgoing_queue = smartlist_new(); - q = tor_malloc(sizeof(*q)); - q->type = CELL_QUEUE_PACKED; - q->u.packed.packed_cell = packed_cell; - smartlist_add(chan->u.cell_chan.outgoing_queue, q); - /* Try to process the queue? */ - if (chan->state == CHANNEL_STATE_OPEN) channel_flush_cells(chan); - } + q.type = CELL_QUEUE_PACKED; + q.u.packed.packed_cell = packed_cell; + channel_write_cell_queue_entry(chan, &q); } /** @@ -1440,26 +1475,15 @@ channel_write_packed_cell(channel_t *chan, packed_cell_t *packed_cell) * Write a variable-length cell to a channel using the write_cell() method. * This is equivalent to the pre-channels * connection_or_write_var_cell_to_buf(). - * - * @param chan Channel to write a cell to - * @param var_cell Cell to write to chan */ void channel_write_var_cell(channel_t *chan, var_cell_t *var_cell) { - cell_queue_entry_t *q; - int sent = 0; + cell_queue_entry_t q; tor_assert(chan); - tor_assert(!(chan->is_listener)); tor_assert(var_cell); - tor_assert(chan->u.cell_chan.write_var_cell); - - /* Assert that the state makes sense for a cell write */ - tor_assert(chan->state == CHANNEL_STATE_OPENING || - chan->state == CHANNEL_STATE_OPEN || - chan->state == CHANNEL_STATE_MAINT); log_debug(LD_CHANNEL, "Writing var_cell_t %p to channel %p with global ID " @@ -1467,38 +1491,9 @@ channel_write_var_cell(channel_t *chan, var_cell_t *var_cell) var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); - /* Increment the timestamp unless it's padding */ - if (!(var_cell->command == CELL_PADDING || - var_cell->command == CELL_VPADDING)) { - chan->u.cell_chan.timestamp_last_added_nonpadding = approx_time(); - } - - /* Can we send it right out? If so, then try */ - if (!(chan->u.cell_chan.outgoing_queue && - (smartlist_len(chan->u.cell_chan.outgoing_queue) > 0)) && - chan->state == CHANNEL_STATE_OPEN) { - if (chan->u.cell_chan.write_var_cell(chan, var_cell)) { - sent = 1; - /* Timestamp for transmission */ - channel_timestamp_xmit(chan); - /* If we're here the queue is empty, so it's drained too */ - channel_timestamp_drained(chan); - /* Update the counter */ - ++(chan->u.cell_chan.n_cells_xmitted); - } - } - - if (!sent) { - /* Not sent, queue it */ - if (!(chan->u.cell_chan.outgoing_queue)) - chan->u.cell_chan.outgoing_queue = smartlist_new(); - q = tor_malloc(sizeof(*q)); - q->type = CELL_QUEUE_VAR; - q->u.var.var_cell = var_cell; - smartlist_add(chan->u.cell_chan.outgoing_queue, q); - /* Try to process the queue? */ - if (chan->state == CHANNEL_STATE_OPEN) channel_flush_cells(chan); - } + q.type = CELL_QUEUE_VAR; + q.u.var.var_cell = var_cell; + channel_write_cell_queue_entry(chan, &q); } /**