diff options
Diffstat (limited to 'src/core/ext/transport/chttp2/transport')
-rw-r--r-- | src/core/ext/transport/chttp2/transport/chttp2_transport.cc | 27 | ||||
-rw-r--r-- | src/core/ext/transport/chttp2/transport/flow_control.cc | 17 |
2 files changed, 36 insertions, 8 deletions
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc index bc6fa0d0eb..027a57d606 100644 --- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc +++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc @@ -812,6 +812,12 @@ static void set_write_state(grpc_chttp2_transport* t, write_state_name(t->write_state), write_state_name(st), reason)); t->write_state = st; + /* If the state is being reset back to idle, it means a write was just + * finished. Make sure all the run_after_write closures are scheduled. + * + * This is also our chance to close the transport if the transport was marked + * to be closed after all writes finish (for example, if we received a go-away + * from peer while we had some pending writes) */ if (st == GRPC_CHTTP2_WRITE_STATE_IDLE) { GRPC_CLOSURE_LIST_SCHED(&t->run_after_write); if (t->close_transport_on_writes_finished != nullptr) { @@ -899,6 +905,22 @@ void grpc_chttp2_initiate_write(grpc_chttp2_transport* t, grpc_chttp2_initiate_write_reason_string(reason)); t->is_first_write_in_batch = true; GRPC_CHTTP2_REF_TRANSPORT(t, "writing"); + /* Note that the 'write_action_begin_locked' closure is being scheduled + * on the 'finally_scheduler' of t->combiner. This means that + * 'write_action_begin_locked' is called only *after* all the other + * closures (some of which are potentially initiating more writes on the + * transport) are executed on the t->combiner. + * + * The reason for scheduling on finally_scheduler is to make sure we batch + * as many writes as possible. 'write_action_begin_locked' is the function + * that gathers all the relevant bytes (which are at various places in the + * grpc_chttp2_transport structure) and append them to 'outbuf' field in + * grpc_chttp2_transport thereby batching what would have been potentially + * multiple write operations. + * + * Also, 'write_action_begin_locked' only gathers the bytes into outbuf. + * It does not call the endpoint to write the bytes. That is done by the + * 'write_action' (which is scheduled by 'write_action_begin_locked') */ GRPC_CLOSURE_SCHED( GRPC_CLOSURE_INIT(&t->write_action_begin_locked, write_action_begin_locked, t, @@ -1007,9 +1029,12 @@ static void write_action(void* gt, grpc_error* error) { grpc_endpoint_write( t->ep, &t->outbuf, GRPC_CLOSURE_INIT(&t->write_action_end_locked, write_action_end_locked, t, - grpc_combiner_scheduler(t->combiner))); + grpc_combiner_scheduler(t->combiner)), + nullptr); } +/* Callback from the grpc_endpoint after bytes have been written by calling + * sendmsg */ static void write_action_end_locked(void* tp, grpc_error* error) { GPR_TIMER_SCOPE("terminate_writing_with_lock", 0); grpc_chttp2_transport* t = static_cast<grpc_chttp2_transport*>(tp); diff --git a/src/core/ext/transport/chttp2/transport/flow_control.cc b/src/core/ext/transport/chttp2/transport/flow_control.cc index e89c363200..53932bcb7f 100644 --- a/src/core/ext/transport/chttp2/transport/flow_control.cc +++ b/src/core/ext/transport/chttp2/transport/flow_control.cc @@ -40,6 +40,7 @@ namespace chttp2 { namespace { static constexpr const int kTracePadding = 30; +static constexpr const uint32_t kMaxWindowUpdateSize = (1u << 31) - 1; static char* fmt_int64_diff_str(int64_t old_val, int64_t new_val) { char* str; @@ -55,7 +56,7 @@ static char* fmt_int64_diff_str(int64_t old_val, int64_t new_val) { static char* fmt_uint32_diff_str(uint32_t old_val, uint32_t new_val) { char* str; - if (new_val > 0 && old_val != new_val) { + if (old_val != new_val) { gpr_asprintf(&str, "%" PRIu32 " -> %" PRIu32 "", old_val, new_val); } else { gpr_asprintf(&str, "%" PRIu32 "", old_val); @@ -98,10 +99,12 @@ void FlowControlTrace::Finish() { if (sfc_ != nullptr) { srw_str = fmt_int64_diff_str(remote_window_delta_ + remote_window, sfc_->remote_window_delta() + remote_window); - slw_str = fmt_int64_diff_str(local_window_delta_ + acked_local_window, - local_window_delta_ + acked_local_window); - saw_str = fmt_int64_diff_str(announced_window_delta_ + acked_local_window, - announced_window_delta_ + acked_local_window); + slw_str = + fmt_int64_diff_str(local_window_delta_ + acked_local_window, + sfc_->local_window_delta() + acked_local_window); + saw_str = + fmt_int64_diff_str(announced_window_delta_ + acked_local_window, + sfc_->announced_window_delta() + acked_local_window); } else { srw_str = gpr_leftpad("", ' ', kTracePadding); slw_str = gpr_leftpad("", ' ', kTracePadding); @@ -191,7 +194,7 @@ uint32_t TransportFlowControl::MaybeSendUpdate(bool writing_anyway) { if ((writing_anyway || announced_window_ <= target_announced_window / 2) && announced_window_ != target_announced_window) { const uint32_t announce = static_cast<uint32_t> GPR_CLAMP( - target_announced_window - announced_window_, 0, UINT32_MAX); + target_announced_window - announced_window_, 0, kMaxWindowUpdateSize); announced_window_ += announce; return announce; } @@ -265,7 +268,7 @@ uint32_t StreamFlowControl::MaybeSendUpdate() { FlowControlTrace trace("s updt sent", tfc_, this); if (local_window_delta_ > announced_window_delta_) { uint32_t announce = static_cast<uint32_t> GPR_CLAMP( - local_window_delta_ - announced_window_delta_, 0, UINT32_MAX); + local_window_delta_ - announced_window_delta_, 0, kMaxWindowUpdateSize); UpdateAnnouncedWindowDelta(tfc_, announce); return announce; } |