diff options
Diffstat (limited to 'src/core/ext/transport/chttp2/transport/chttp2_transport.c')
-rw-r--r-- | src/core/ext/transport/chttp2/transport/chttp2_transport.c | 207 |
1 files changed, 106 insertions, 101 deletions
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c index 89659e7464..8676a3752e 100644 --- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c +++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c @@ -187,7 +187,8 @@ static void destruct_transport(grpc_exec_ctx *exec_ctx, GRPC_COMBINER_UNREF(exec_ctx, t->combiner, "chttp2_transport"); - cancel_pings(exec_ctx, t, GRPC_ERROR_CREATE("Transport destroyed")); + cancel_pings(exec_ctx, t, + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport destroyed")); while (t->write_cb_pool) { grpc_chttp2_write_cb *next = t->write_cb_pool->next; @@ -494,8 +495,9 @@ static void destroy_transport_locked(grpc_exec_ctx *exec_ctx, void *tp, t->destroying = 1; close_transport_locked( exec_ctx, t, - grpc_error_set_int(GRPC_ERROR_CREATE("Transport destroyed"), - GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state)); + grpc_error_set_int( + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport destroyed"), + GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state)); GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "destroy"); } @@ -518,7 +520,8 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx, if (t->write_state != GRPC_CHTTP2_WRITE_STATE_IDLE) { if (t->close_transport_on_writes_finished == NULL) { t->close_transport_on_writes_finished = - GRPC_ERROR_CREATE("Delayed close due to in-progress write"); + GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "Delayed close due to in-progress write"); } t->close_transport_on_writes_finished = grpc_error_add_child(t->close_transport_on_writes_finished, error); @@ -834,7 +837,8 @@ static void write_action_end_locked(grpc_exec_ctx *exec_ctx, void *tp, if (t->sent_goaway_state == GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED) { t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SENT; if (grpc_chttp2_stream_map_size(&t->stream_map) == 0) { - close_transport_locked(exec_ctx, t, GRPC_ERROR_CREATE("goaway sent")); + close_transport_locked( + exec_ctx, t, GRPC_ERROR_CREATE_FROM_STATIC_STRING("goaway sent")); } } @@ -898,22 +902,19 @@ void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, uint32_t goaway_error, grpc_slice goaway_text) { - char *msg = grpc_dump_slice(goaway_text, GPR_DUMP_HEX | GPR_DUMP_ASCII); - GRPC_CHTTP2_IF_TRACING( - gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg)); - grpc_slice_unref_internal(exec_ctx, goaway_text); + // GRPC_CHTTP2_IF_TRACING( + // gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg)); t->seen_goaway = 1; /* lie: use transient failure from the transport to indicate goaway has been * received */ connectivity_state_set( exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE, grpc_error_set_str( - grpc_error_set_int(GRPC_ERROR_CREATE("GOAWAY received"), - GRPC_ERROR_INT_HTTP2_ERROR, - (intptr_t)goaway_error), - GRPC_ERROR_STR_RAW_BYTES, msg), + grpc_error_set_int( + GRPC_ERROR_CREATE_FROM_STATIC_STRING("GOAWAY received"), + GRPC_ERROR_INT_HTTP2_ERROR, (intptr_t)goaway_error), + GRPC_ERROR_STR_RAW_BYTES, goaway_text), "got_goaway"); - gpr_free(msg); } static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx, @@ -936,9 +937,10 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx, t->next_stream_id += 2; if (t->next_stream_id >= MAX_CLIENT_STREAM_ID) { - connectivity_state_set(exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE, - GRPC_ERROR_CREATE("Stream IDs exhausted"), - "no_more_stream_ids"); + connectivity_state_set( + exec_ctx, t, GRPC_CHANNEL_TRANSIENT_FAILURE, + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Stream IDs exhausted"), + "no_more_stream_ids"); } grpc_chttp2_stream_map_add(&t->stream_map, s->id, s); @@ -952,9 +954,9 @@ static void maybe_start_some_streams(grpc_exec_ctx *exec_ctx, grpc_chttp2_list_pop_waiting_for_concurrency(t, &s)) { grpc_chttp2_cancel_stream( exec_ctx, t, s, - grpc_error_set_int(GRPC_ERROR_CREATE("Stream IDs exhausted"), - GRPC_ERROR_INT_GRPC_STATUS, - GRPC_STATUS_UNAVAILABLE)); + grpc_error_set_int( + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Stream IDs exhausted"), + GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE)); } } @@ -1003,11 +1005,11 @@ void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx, } if (error != GRPC_ERROR_NONE) { if (closure->error_data.error == GRPC_ERROR_NONE) { - closure->error_data.error = - GRPC_ERROR_CREATE("Error in HTTP transport completing operation"); - closure->error_data.error = - grpc_error_set_str(closure->error_data.error, - GRPC_ERROR_STR_TARGET_ADDRESS, t->peer_string); + closure->error_data.error = GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "Error in HTTP transport completing operation"); + closure->error_data.error = grpc_error_set_str( + closure->error_data.error, GRPC_ERROR_STR_TARGET_ADDRESS, + grpc_slice_from_copied_string(t->peer_string)); } closure->error_data.error = grpc_error_add_child(closure->error_data.error, error); @@ -1182,10 +1184,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, exec_ctx, t, s, grpc_error_set_int( grpc_error_set_int( - grpc_error_set_int( - GRPC_ERROR_CREATE("to-be-sent initial metadata size " - "exceeds peer limit"), - GRPC_ERROR_INT_SIZE, (intptr_t)metadata_size), + grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "to-be-sent initial metadata size " + "exceeds peer limit"), + GRPC_ERROR_INT_SIZE, + (intptr_t)metadata_size), GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit), GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED)); } else { @@ -1201,9 +1204,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, } else { grpc_chttp2_cancel_stream( exec_ctx, t, s, - grpc_error_set_int(GRPC_ERROR_CREATE("Transport closed"), - GRPC_ERROR_INT_GRPC_STATUS, - GRPC_STATUS_UNAVAILABLE)); + grpc_error_set_int( + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport closed"), + GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE)); } } else { GPR_ASSERT(s->id != 0); @@ -1215,7 +1218,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, s->send_initial_metadata = NULL; grpc_chttp2_complete_closure_step( exec_ctx, t, s, &s->send_initial_metadata_finished, - GRPC_ERROR_CREATE_REFERENCING( + GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( "Attempt to send initial metadata after stream was closed", &s->write_closed_error, 1), "send_initial_metadata_finished"); @@ -1229,7 +1232,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, if (s->write_closed) { grpc_chttp2_complete_closure_step( exec_ctx, t, s, &s->fetching_send_message_finished, - GRPC_ERROR_CREATE_REFERENCING( + GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( "Attempt to send message after stream was closed", &s->write_closed_error, 1), "fetching_send_message_finished"); @@ -1277,10 +1280,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, exec_ctx, t, s, grpc_error_set_int( grpc_error_set_int( - grpc_error_set_int( - GRPC_ERROR_CREATE("to-be-sent trailing metadata size " - "exceeds peer limit"), - GRPC_ERROR_INT_SIZE, (intptr_t)metadata_size), + grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "to-be-sent trailing metadata size " + "exceeds peer limit"), + GRPC_ERROR_INT_SIZE, + (intptr_t)metadata_size), GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit), GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED)); } else { @@ -1293,8 +1297,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op, exec_ctx, t, s, &s->send_trailing_metadata_finished, grpc_metadata_batch_is_empty(op->send_trailing_metadata) ? GRPC_ERROR_NONE - : GRPC_ERROR_CREATE("Attempt to send trailing metadata after " - "stream was closed"), + : GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "Attempt to send trailing metadata after " + "stream was closed"), "send_trailing_metadata_finished"); } else if (s->id != 0) { /* TODO(ctiller): check if there's flow control for any outstanding @@ -1409,11 +1414,11 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_error *error) { t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED; grpc_http2_error_code http_error; - const char *msg; - grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL, &msg, - &http_error); + grpc_slice slice; + grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL, + &slice, &http_error); grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error, - grpc_slice_from_copied_string(msg), &t->qbuf); + grpc_slice_ref_internal(slice), &t->qbuf); grpc_chttp2_initiate_write(exec_ctx, t, false, "goaway_sent"); GRPC_ERROR_UNREF(error); } @@ -1573,7 +1578,7 @@ static void remove_stream(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, if (t->sent_goaway_state == GRPC_CHTTP2_GOAWAY_SENT) { close_transport_locked( exec_ctx, t, - GRPC_ERROR_CREATE_REFERENCING( + GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( "Last stream closed after sending GOAWAY", &error, 1)); } } @@ -1614,8 +1619,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx, void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_chttp2_stream *s, grpc_error *error) { grpc_status_code status; - const char *msg; - grpc_error_get_status(error, s->deadline, &status, &msg, NULL); + grpc_slice slice; + grpc_error_get_status(error, s->deadline, &status, &slice, NULL); if (status != GRPC_STATUS_OK) { s->seen_error = true; @@ -1636,13 +1641,13 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_mdelem_from_slices( exec_ctx, GRPC_MDSTR_GRPC_STATUS, grpc_slice_from_copied_string(status_string)))); - if (msg != NULL) { + if (!GRPC_SLICE_IS_EMPTY(slice)) { GRPC_LOG_IF_ERROR( "add_status_message", grpc_chttp2_incoming_metadata_buffer_replace_or_add( exec_ctx, &s->metadata_buffer[1], grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_MESSAGE, - grpc_slice_from_copied_string(msg)))); + grpc_slice_ref_internal(slice)))); } s->published_metadata[1] = GRPC_METADATA_SYNTHESIZED_FROM_FAKE; grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s); @@ -1671,7 +1676,8 @@ static grpc_error *removal_error(grpc_error *extra_error, grpc_chttp2_stream *s, add_error(extra_error, refs, &nrefs); grpc_error *error = GRPC_ERROR_NONE; if (nrefs > 0) { - error = GRPC_ERROR_CREATE_REFERENCING(master_error_msg, refs, nrefs); + error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(master_error_msg, + refs, nrefs); } GRPC_ERROR_UNREF(extra_error); return error; @@ -1770,8 +1776,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, uint8_t *p; uint32_t len = 0; grpc_status_code grpc_status; - const char *msg; - grpc_error_get_status(error, s->deadline, &grpc_status, &msg, NULL); + grpc_slice slice; + grpc_error_get_status(error, s->deadline, &grpc_status, &slice, NULL); GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100); @@ -1827,32 +1833,30 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, GPR_ASSERT(p == GRPC_SLICE_END_PTR(status_hdr)); len += (uint32_t)GRPC_SLICE_LENGTH(status_hdr); - if (msg != NULL) { - size_t msg_len = strlen(msg); - GPR_ASSERT(msg_len <= UINT32_MAX); - uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 0); - message_pfx = grpc_slice_malloc(14 + msg_len_len); - p = GRPC_SLICE_START_PTR(message_pfx); - *p++ = 0x00; /* literal header, not indexed */ - *p++ = 12; /* len(grpc-message) */ - *p++ = 'g'; - *p++ = 'r'; - *p++ = 'p'; - *p++ = 'c'; - *p++ = '-'; - *p++ = 'm'; - *p++ = 'e'; - *p++ = 's'; - *p++ = 's'; - *p++ = 'a'; - *p++ = 'g'; - *p++ = 'e'; - GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 0, 0, p, (uint32_t)msg_len_len); - p += msg_len_len; - GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx)); - len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx); - len += (uint32_t)msg_len; - } + size_t msg_len = GRPC_SLICE_LENGTH(slice); + GPR_ASSERT(msg_len <= UINT32_MAX); + uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 1); + message_pfx = grpc_slice_malloc(14 + msg_len_len); + p = GRPC_SLICE_START_PTR(message_pfx); + *p++ = 0x00; /* literal header, not indexed */ + *p++ = 12; /* len(grpc-message) */ + *p++ = 'g'; + *p++ = 'r'; + *p++ = 'p'; + *p++ = 'c'; + *p++ = '-'; + *p++ = 'm'; + *p++ = 'e'; + *p++ = 's'; + *p++ = 's'; + *p++ = 'a'; + *p++ = 'g'; + *p++ = 'e'; + GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 1, 0, p, (uint32_t)msg_len_len); + p += msg_len_len; + GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx)); + len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx); + len += (uint32_t)msg_len; hdr = grpc_slice_malloc(9); p = GRPC_SLICE_START_PTR(hdr); @@ -1872,10 +1876,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t, grpc_slice_buffer_add(&t->qbuf, http_status_hdr); } grpc_slice_buffer_add(&t->qbuf, status_hdr); - if (msg != NULL) { - grpc_slice_buffer_add(&t->qbuf, message_pfx); - grpc_slice_buffer_add(&t->qbuf, grpc_slice_from_copied_string(msg)); - } + grpc_slice_buffer_add(&t->qbuf, message_pfx); + grpc_slice_buffer_add(&t->qbuf, grpc_slice_ref_internal(slice)); grpc_slice_buffer_add( &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR, &s->stats.outgoing)); @@ -1950,9 +1952,9 @@ static grpc_error *try_http_parsing(grpc_exec_ctx *exec_ctx, if (parse_error == GRPC_ERROR_NONE && (parse_error = grpc_http_parser_eof(&parser)) == GRPC_ERROR_NONE) { error = grpc_error_set_int( - grpc_error_set_int( - GRPC_ERROR_CREATE("Trying to connect an http1.x server"), - GRPC_ERROR_INT_HTTP_STATUS, response.status), + grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "Trying to connect an http1.x server"), + GRPC_ERROR_INT_HTTP_STATUS, response.status), GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE); } GRPC_ERROR_UNREF(parse_error); @@ -1973,9 +1975,10 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp, grpc_error *err = error; if (err != GRPC_ERROR_NONE) { - err = grpc_error_set_int( - GRPC_ERROR_CREATE_REFERENCING("Endpoint read failed", &err, 1), - GRPC_ERROR_INT_OCCURRED_DURING_WRITE, t->write_state); + err = grpc_error_set_int(GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( + "Endpoint read failed", &err, 1), + GRPC_ERROR_INT_OCCURRED_DURING_WRITE, + t->write_state); } GPR_SWAP(grpc_error *, err, error); GRPC_ERROR_UNREF(err); @@ -1996,8 +1999,8 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp, if (errors[1] != GRPC_ERROR_NONE) { errors[2] = try_http_parsing(exec_ctx, t); GRPC_ERROR_UNREF(error); - error = GRPC_ERROR_CREATE_REFERENCING("Failed parsing HTTP/2", errors, - GPR_ARRAY_SIZE(errors)); + error = GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( + "Failed parsing HTTP/2", errors, GPR_ARRAY_SIZE(errors)); } for (i = 0; i < GPR_ARRAY_SIZE(errors); i++) { GRPC_ERROR_UNREF(errors[i]); @@ -2022,7 +2025,7 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp, GPR_TIMER_BEGIN("post_reading_action_locked", 0); bool keep_reading = false; if (error == GRPC_ERROR_NONE && t->closed) { - error = GRPC_ERROR_CREATE("Transport closed"); + error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Transport closed"); } if (error != GRPC_ERROR_NONE) { close_transport_locked(exec_ctx, t, GRPC_ERROR_REF(error)); @@ -2157,8 +2160,8 @@ static void keepalive_watchdog_fired_locked(grpc_exec_ctx *exec_ctx, void *arg, if (t->keepalive_state == GRPC_CHTTP2_KEEPALIVE_STATE_PINGING) { if (error == GRPC_ERROR_NONE) { t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DYING; - close_transport_locked(exec_ctx, t, - GRPC_ERROR_CREATE("keepalive watchdog timeout")); + close_transport_locked(exec_ctx, t, GRPC_ERROR_CREATE_FROM_STATIC_STRING( + "keepalive watchdog timeout")); } } else { /** The watchdog timer should have been cancelled by @@ -2357,7 +2360,8 @@ void grpc_chttp2_incoming_byte_stream_push(grpc_exec_ctx *exec_ctx, gpr_mu_lock(&bs->slice_mu); if (bs->remaining_bytes < GRPC_SLICE_LENGTH(slice)) { incoming_byte_stream_publish_error( - exec_ctx, bs, GRPC_ERROR_CREATE("Too many bytes in stream")); + exec_ctx, bs, + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Too many bytes in stream")); } else { bs->remaining_bytes -= (uint32_t)GRPC_SLICE_LENGTH(slice); if (bs->on_next != NULL) { @@ -2377,7 +2381,7 @@ void grpc_chttp2_incoming_byte_stream_finished( if (error == GRPC_ERROR_NONE) { gpr_mu_lock(&bs->slice_mu); if (bs->remaining_bytes != 0) { - error = GRPC_ERROR_CREATE("Truncated message"); + error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Truncated message"); } gpr_mu_unlock(&bs->slice_mu); } @@ -2457,9 +2461,9 @@ static void benign_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg, t->peer_string); } send_goaway(exec_ctx, t, - grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"), - GRPC_ERROR_INT_HTTP2_ERROR, - GRPC_HTTP2_ENHANCE_YOUR_CALM)); + grpc_error_set_int( + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"), + GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_ENHANCE_YOUR_CALM)); } else if (error == GRPC_ERROR_NONE && grpc_resource_quota_trace) { gpr_log(GPR_DEBUG, "HTTP2: %s - skip benign reclamation, there are still %" PRIdPTR @@ -2486,9 +2490,10 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg, s->id); } grpc_chttp2_cancel_stream( - exec_ctx, t, s, grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"), - GRPC_ERROR_INT_HTTP2_ERROR, - GRPC_HTTP2_ENHANCE_YOUR_CALM)); + exec_ctx, t, s, + grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING("Buffers full"), + GRPC_ERROR_INT_HTTP2_ERROR, + GRPC_HTTP2_ENHANCE_YOUR_CALM)); if (n > 1) { /* Since we cancel one stream per destructive reclamation, if there are more streams left, we can immediately post a new |