| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "src/core/channel/child_channel.h" |
| #include "src/core/iomgr/iomgr.h" |
| #include <grpc/support/alloc.h> |
| |
| /* Link back filter: passes up calls to the client channel, pushes down calls |
| down */ |
| |
| static void maybe_destroy_channel(grpc_child_channel *channel); |
| |
| typedef struct { |
| gpr_mu mu; |
| gpr_cv cv; |
| grpc_channel_element *back; |
| /* # of active calls on the channel */ |
| gpr_uint32 active_calls; |
| /* has grpc_child_channel_destroy been called? */ |
| gpr_uint8 destroyed; |
| /* has the transport reported itself disconnected? */ |
| gpr_uint8 disconnected; |
| /* are we calling 'back' - our parent channel */ |
| gpr_uint8 calling_back; |
| /* have we or our parent sent goaway yet? - dup suppression */ |
| gpr_uint8 sent_goaway; |
| /* are we currently sending farewell (in this file: goaway + disconnect) */ |
| gpr_uint8 sending_farewell; |
| /* have we sent farewell (goaway + disconnect) */ |
| gpr_uint8 sent_farewell; |
| } lb_channel_data; |
| |
| typedef struct { |
| grpc_child_channel *channel; |
| } lb_call_data; |
| |
| static void lb_start_transport_op(grpc_call_element *elem, grpc_transport_op *op) { |
| grpc_call_next_op(elem, op); |
| } |
| |
| /* Currently we assume all channel operations should just be pushed up. */ |
| static void lb_channel_op(grpc_channel_element *elem, |
| grpc_channel_element *from_elem, |
| grpc_channel_op *op) { |
| lb_channel_data *chand = elem->channel_data; |
| grpc_channel_element *back; |
| int calling_back = 0; |
| |
| switch (op->dir) { |
| case GRPC_CALL_UP: |
| gpr_mu_lock(&chand->mu); |
| back = chand->back; |
| if (back) { |
| chand->calling_back++; |
| calling_back = 1; |
| } |
| gpr_mu_unlock(&chand->mu); |
| if (back) { |
| back->filter->channel_op(chand->back, elem, op); |
| } else if (op->type == GRPC_TRANSPORT_GOAWAY) { |
| gpr_slice_unref(op->data.goaway.message); |
| } |
| break; |
| case GRPC_CALL_DOWN: |
| grpc_channel_next_op(elem, op); |
| break; |
| } |
| |
| gpr_mu_lock(&chand->mu); |
| switch (op->type) { |
| case GRPC_TRANSPORT_CLOSED: |
| chand->disconnected = 1; |
| maybe_destroy_channel(grpc_channel_stack_from_top_element(elem)); |
| break; |
| case GRPC_CHANNEL_GOAWAY: |
| chand->sent_goaway = 1; |
| break; |
| case GRPC_CHANNEL_DISCONNECT: |
| case GRPC_TRANSPORT_GOAWAY: |
| case GRPC_ACCEPT_CALL: |
| break; |
| } |
| |
| if (calling_back) { |
| chand->calling_back--; |
| gpr_cv_signal(&chand->cv); |
| maybe_destroy_channel(grpc_channel_stack_from_top_element(elem)); |
| } |
| gpr_mu_unlock(&chand->mu); |
| } |
| |
| /* Constructor for call_data */ |
| static void lb_init_call_elem(grpc_call_element *elem, |
| const void *server_transport_data, grpc_transport_op *initial_op) {} |
| |
| /* Destructor for call_data */ |
| static void lb_destroy_call_elem(grpc_call_element *elem) {} |
| |
| /* Constructor for channel_data */ |
| static void lb_init_channel_elem(grpc_channel_element *elem, |
| const grpc_channel_args *args, |
| grpc_mdctx *metadata_context, int is_first, |
| int is_last) { |
| lb_channel_data *chand = elem->channel_data; |
| GPR_ASSERT(is_first); |
| GPR_ASSERT(!is_last); |
| gpr_mu_init(&chand->mu); |
| gpr_cv_init(&chand->cv); |
| chand->back = NULL; |
| chand->destroyed = 0; |
| chand->disconnected = 0; |
| chand->active_calls = 0; |
| chand->sent_goaway = 0; |
| chand->calling_back = 0; |
| chand->sending_farewell = 0; |
| chand->sent_farewell = 0; |
| } |
| |
| /* Destructor for channel_data */ |
| static void lb_destroy_channel_elem(grpc_channel_element *elem) { |
| lb_channel_data *chand = elem->channel_data; |
| gpr_mu_destroy(&chand->mu); |
| gpr_cv_destroy(&chand->cv); |
| } |
| |
| const grpc_channel_filter grpc_child_channel_top_filter = { |
| lb_start_transport_op, lb_channel_op, sizeof(lb_call_data), |
| lb_init_call_elem, lb_destroy_call_elem, sizeof(lb_channel_data), |
| lb_init_channel_elem, lb_destroy_channel_elem, "child-channel", }; |
| |
| /* grpc_child_channel proper */ |
| |
| #define LINK_BACK_ELEM_FROM_CHANNEL(channel) \ |
| grpc_channel_stack_element((channel), 0) |
| |
| #define LINK_BACK_ELEM_FROM_CALL(call) grpc_call_stack_element((call), 0) |
| |
| static void finally_destroy_channel(void *c, int success) { |
| /* ignore success or not... this is a destruction callback and will only |
| happen once - the only purpose here is to release resources */ |
| grpc_child_channel *channel = c; |
| lb_channel_data *chand = LINK_BACK_ELEM_FROM_CHANNEL(channel)->channel_data; |
| /* wait for the initiator to leave the mutex */ |
| gpr_mu_lock(&chand->mu); |
| gpr_mu_unlock(&chand->mu); |
| grpc_channel_stack_destroy(channel); |
| gpr_free(channel); |
| } |
| |
| static void send_farewells(void *c, int success) { |
| grpc_child_channel *channel = c; |
| grpc_channel_element *lbelem = LINK_BACK_ELEM_FROM_CHANNEL(channel); |
| lb_channel_data *chand = lbelem->channel_data; |
| int send_goaway; |
| grpc_channel_op op; |
| |
| gpr_mu_lock(&chand->mu); |
| send_goaway = !chand->sent_goaway; |
| chand->sent_goaway = 1; |
| gpr_mu_unlock(&chand->mu); |
| |
| if (send_goaway) { |
| op.type = GRPC_CHANNEL_GOAWAY; |
| op.dir = GRPC_CALL_DOWN; |
| op.data.goaway.status = GRPC_STATUS_OK; |
| op.data.goaway.message = gpr_slice_from_copied_string("Client disconnect"); |
| grpc_channel_next_op(lbelem, &op); |
| } |
| |
| op.type = GRPC_CHANNEL_DISCONNECT; |
| op.dir = GRPC_CALL_DOWN; |
| grpc_channel_next_op(lbelem, &op); |
| |
| gpr_mu_lock(&chand->mu); |
| chand->sending_farewell = 0; |
| chand->sent_farewell = 1; |
| maybe_destroy_channel(channel); |
| gpr_mu_unlock(&chand->mu); |
| } |
| |
| static void maybe_destroy_channel(grpc_child_channel *channel) { |
| lb_channel_data *chand = LINK_BACK_ELEM_FROM_CHANNEL(channel)->channel_data; |
| if (chand->destroyed && chand->disconnected && chand->active_calls == 0 && |
| !chand->sending_farewell && !chand->calling_back) { |
| grpc_iomgr_add_callback(finally_destroy_channel, channel); |
| } else if (chand->destroyed && !chand->disconnected && |
| chand->active_calls == 0 && !chand->sending_farewell && |
| !chand->sent_farewell) { |
| chand->sending_farewell = 1; |
| grpc_iomgr_add_callback(send_farewells, channel); |
| } |
| } |
| |
| grpc_child_channel *grpc_child_channel_create( |
| grpc_channel_element *parent, const grpc_channel_filter **filters, |
| size_t filter_count, const grpc_channel_args *args, |
| grpc_mdctx *metadata_context) { |
| grpc_channel_stack *stk = |
| gpr_malloc(grpc_channel_stack_size(filters, filter_count)); |
| lb_channel_data *lb; |
| |
| grpc_channel_stack_init(filters, filter_count, args, metadata_context, stk); |
| |
| lb = LINK_BACK_ELEM_FROM_CHANNEL(stk)->channel_data; |
| gpr_mu_lock(&lb->mu); |
| lb->back = parent; |
| gpr_mu_unlock(&lb->mu); |
| |
| return stk; |
| } |
| |
| void grpc_child_channel_destroy(grpc_child_channel *channel, |
| int wait_for_callbacks) { |
| grpc_channel_element *lbelem = LINK_BACK_ELEM_FROM_CHANNEL(channel); |
| lb_channel_data *chand = lbelem->channel_data; |
| |
| gpr_mu_lock(&chand->mu); |
| while (wait_for_callbacks && chand->calling_back) { |
| gpr_cv_wait(&chand->cv, &chand->mu, gpr_inf_future); |
| } |
| |
| chand->back = NULL; |
| chand->destroyed = 1; |
| maybe_destroy_channel(channel); |
| gpr_mu_unlock(&chand->mu); |
| } |
| |
| void grpc_child_channel_handle_op(grpc_child_channel *channel, |
| grpc_channel_op *op) { |
| grpc_channel_next_op(LINK_BACK_ELEM_FROM_CHANNEL(channel), op); |
| } |
| |
| grpc_child_call *grpc_child_channel_create_call(grpc_child_channel *channel, |
| grpc_call_element *parent, grpc_transport_op *initial_op) { |
| grpc_call_stack *stk = gpr_malloc((channel)->call_stack_size); |
| grpc_call_element *lbelem; |
| lb_call_data *lbcalld; |
| lb_channel_data *lbchand; |
| |
| grpc_call_stack_init(channel, NULL, initial_op, stk); |
| lbelem = LINK_BACK_ELEM_FROM_CALL(stk); |
| lbchand = lbelem->channel_data; |
| lbcalld = lbelem->call_data; |
| lbcalld->channel = channel; |
| |
| gpr_mu_lock(&lbchand->mu); |
| lbchand->active_calls++; |
| gpr_mu_unlock(&lbchand->mu); |
| |
| return stk; |
| } |
| |
| void grpc_child_call_destroy(grpc_child_call *call) { |
| grpc_call_element *lbelem = LINK_BACK_ELEM_FROM_CALL(call); |
| lb_call_data *calld = lbelem->call_data; |
| lb_channel_data *chand = lbelem->channel_data; |
| grpc_child_channel *channel = calld->channel; |
| grpc_call_stack_destroy(call); |
| gpr_free(call); |
| gpr_mu_lock(&chand->mu); |
| chand->active_calls--; |
| maybe_destroy_channel(channel); |
| gpr_mu_unlock(&chand->mu); |
| } |
| |
| grpc_call_element *grpc_child_call_get_top_element(grpc_child_call *call) { |
| return LINK_BACK_ELEM_FROM_CALL(call); |
| } |