| /* |
| * |
| * Copyright 2016, 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. |
| * |
| */ |
| |
| /** Implementation of the gRPC LB policy. |
| * |
| * This policy takes as input a set of resolved addresses {a1..an} for which the |
| * LB set was set (it's the resolver's responsibility to ensure this). That is |
| * to say, {a1..an} represent a collection of LB servers. |
| * |
| * An internal channel (\a glb_lb_policy.lb_channel) is created over {a1..an}. |
| * This channel behaves just like a regular channel. In particular, the |
| * constructed URI over the addresses a1..an will use the default pick first |
| * policy to select from this list of LB server backends. |
| * |
| * The first time the policy gets a request for a pick, a ping, or to exit the |
| * idle state, \a query_for_backends() is called. It creates an instance of \a |
| * lb_client_data, an internal struct meant to contain the data associated with |
| * the internal communication with the LB server. This instance is created via |
| * \a lb_client_data_create(). There, the call over lb_channel to pick-first |
| * from {a1..an} is created, the \a LoadBalancingRequest message is assembled |
| * and all necessary callbacks for the progress of the internal call configured. |
| * |
| * Back in \a query_for_backends(), the internal *streaming* call to the LB |
| * server (whichever address from {a1..an} pick-first chose) is kicked off. |
| * It'll progress over the callbacks configured in \a lb_client_data_create() |
| * (see the field docstrings of \a lb_client_data for more details). |
| * |
| * If the call fails with UNIMPLEMENTED, the original call will also fail. |
| * There's a misconfiguration somewhere: at least one of {a1..an} isn't a LB |
| * server, which contradicts the LB bit being set. If the internal call times |
| * out, the usual behavior of pick-first applies, continuing to pick from the |
| * list {a1..an}. |
| * |
| * Upon sucesss, a \a LoadBalancingResponse is expected in \a res_recv_cb. An |
| * invalid one results in the termination of the streaming call. A new streaming |
| * call should be created if possible, failing the original call otherwise. |
| * For a valid \a LoadBalancingResponse, the server list of actual backends is |
| * extracted. A Round Robin policy will be created from this list. There are two |
| * possible scenarios: |
| * |
| * 1. This is the first server list received. There was no previous instance of |
| * the Round Robin policy. \a rr_handover_locked() will instantiate the RR |
| * policy and perform all the pending operations over it. |
| * 2. There's already a RR policy instance active. We need to introduce the new |
| * one build from the new serverlist, but taking care not to disrupt the |
| * operations in progress over the old RR instance. This is done by |
| * decreasing the reference count on the old policy. The moment no more |
| * references are held on the old RR policy, it'll be destroyed and \a |
| * glb_rr_connectivity_changed notified with a \a GRPC_CHANNEL_SHUTDOWN |
| * state. At this point we can transition to a new RR instance safely, which |
| * is done once again via \a rr_handover_locked(). |
| * |
| * |
| * Once a RR policy instance is in place (and getting updated as described), |
| * calls to for a pick, a ping or a cancellation will be serviced right away by |
| * forwarding them to the RR instance. Any time there's no RR policy available |
| * (ie, right after the creation of the gRPCLB policy, if an empty serverlist |
| * is received, etc), pick/ping requests are added to a list of pending |
| * picks/pings to be flushed and serviced as part of \a rr_handover_locked() the |
| * moment the RR policy instance becomes available. |
| * |
| * \see https://github.com/grpc/grpc/blob/master/doc/load-balancing.md for the |
| * high level design and details. */ |
| |
| /* TODO(dgq): |
| * - Implement LB service forwarding (point 2c. in the doc's diagram). |
| */ |
| |
| /* With the addition of a libuv endpoint, sockaddr.h now includes uv.h when |
| using that endpoint. Because of various transitive includes in uv.h, |
| including windows.h on Windows, uv.h must be included before other system |
| headers. Therefore, sockaddr.h must always be included first */ |
| #include "src/core/lib/iomgr/sockaddr.h" |
| |
| #include <errno.h> |
| |
| #include <string.h> |
| |
| #include <grpc/byte_buffer_reader.h> |
| #include <grpc/grpc.h> |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/host_port.h> |
| #include <grpc/support/string_util.h> |
| #include <grpc/support/time.h> |
| |
| #include "src/core/ext/client_channel/client_channel_factory.h" |
| #include "src/core/ext/client_channel/lb_policy_factory.h" |
| #include "src/core/ext/client_channel/lb_policy_registry.h" |
| #include "src/core/ext/client_channel/parse_address.h" |
| #include "src/core/ext/lb_policy/grpclb/grpclb.h" |
| #include "src/core/ext/lb_policy/grpclb/load_balancer_api.h" |
| #include "src/core/lib/channel/channel_args.h" |
| #include "src/core/lib/iomgr/sockaddr_utils.h" |
| #include "src/core/lib/support/string.h" |
| #include "src/core/lib/surface/call.h" |
| #include "src/core/lib/surface/channel.h" |
| #include "src/core/lib/transport/static_metadata.h" |
| |
| int grpc_lb_glb_trace = 0; |
| |
| /* add lb_token of selected subchannel (address) to the call's initial |
| * metadata */ |
| static void initial_metadata_add_lb_token( |
| grpc_metadata_batch *initial_metadata, |
| grpc_linked_mdelem *lb_token_mdelem_storage, grpc_mdelem *lb_token) { |
| GPR_ASSERT(lb_token_mdelem_storage != NULL); |
| GPR_ASSERT(lb_token != NULL); |
| grpc_metadata_batch_add_tail(initial_metadata, lb_token_mdelem_storage, |
| lb_token); |
| } |
| |
| typedef struct wrapped_rr_closure_arg { |
| /* the closure instance using this struct as argument */ |
| grpc_closure wrapper_closure; |
| |
| /* the original closure. Usually a on_complete/notify cb for pick() and ping() |
| * calls against the internal RR instance, respectively. */ |
| grpc_closure *wrapped_closure; |
| |
| /* the pick's initial metadata, kept in order to append the LB token for the |
| * pick */ |
| grpc_metadata_batch *initial_metadata; |
| |
| /* the picked target, used to determine which LB token to add to the pick's |
| * initial metadata */ |
| grpc_connected_subchannel **target; |
| |
| /* the LB token associated with the pick */ |
| grpc_mdelem *lb_token; |
| |
| /* storage for the lb token initial metadata mdelem */ |
| grpc_linked_mdelem *lb_token_mdelem_storage; |
| |
| /* The RR instance related to the closure */ |
| grpc_lb_policy *rr_policy; |
| |
| /* heap memory to be freed upon closure execution. */ |
| void *free_when_done; |
| } wrapped_rr_closure_arg; |
| |
| /* The \a on_complete closure passed as part of the pick requires keeping a |
| * reference to its associated round robin instance. We wrap this closure in |
| * order to unref the round robin instance upon its invocation */ |
| static void wrapped_rr_closure(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| wrapped_rr_closure_arg *wc_arg = arg; |
| if (wc_arg->rr_policy != NULL) { |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")", |
| (intptr_t)wc_arg->rr_policy); |
| } |
| GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "wrapped_rr_closure"); |
| |
| /* if target is NULL, no pick has been made by the RR policy (eg, all |
| * addresses failed to connect). There won't be any user_data/token |
| * available */ |
| if (wc_arg->target != NULL) { |
| initial_metadata_add_lb_token(wc_arg->initial_metadata, |
| wc_arg->lb_token_mdelem_storage, |
| GRPC_MDELEM_REF(wc_arg->lb_token)); |
| } |
| } |
| GPR_ASSERT(wc_arg->wrapped_closure != NULL); |
| grpc_exec_ctx_sched(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_REF(error), |
| NULL); |
| GPR_ASSERT(wc_arg->free_when_done != NULL); |
| gpr_free(wc_arg->free_when_done); |
| } |
| |
| /* Linked list of pending pick requests. It stores all information needed to |
| * eventually call (Round Robin's) pick() on them. They mainly stay pending |
| * waiting for the RR policy to be created/updated. |
| * |
| * One particularity is the wrapping of the user-provided \a on_complete closure |
| * (in \a wrapped_on_complete and \a wrapped_on_complete_arg). This is needed in |
| * order to correctly unref the RR policy instance upon completion of the pick. |
| * See \a wrapped_rr_closure for details. */ |
| typedef struct pending_pick { |
| struct pending_pick *next; |
| |
| /* original pick()'s arguments */ |
| grpc_lb_policy_pick_args pick_args; |
| |
| /* output argument where to store the pick()ed connected subchannel, or NULL |
| * upon error. */ |
| grpc_connected_subchannel **target; |
| |
| /* args for wrapped_on_complete */ |
| wrapped_rr_closure_arg wrapped_on_complete_arg; |
| } pending_pick; |
| |
| static void add_pending_pick(pending_pick **root, |
| const grpc_lb_policy_pick_args *pick_args, |
| grpc_connected_subchannel **target, |
| grpc_closure *on_complete) { |
| pending_pick *pp = gpr_malloc(sizeof(*pp)); |
| memset(pp, 0, sizeof(pending_pick)); |
| memset(&pp->wrapped_on_complete_arg, 0, sizeof(wrapped_rr_closure_arg)); |
| pp->next = *root; |
| pp->pick_args = *pick_args; |
| pp->target = target; |
| pp->wrapped_on_complete_arg.wrapped_closure = on_complete; |
| pp->wrapped_on_complete_arg.target = target; |
| pp->wrapped_on_complete_arg.initial_metadata = pick_args->initial_metadata; |
| pp->wrapped_on_complete_arg.lb_token_mdelem_storage = |
| pick_args->lb_token_mdelem_storage; |
| pp->wrapped_on_complete_arg.free_when_done = pp; |
| grpc_closure_init(&pp->wrapped_on_complete_arg.wrapper_closure, |
| wrapped_rr_closure, &pp->wrapped_on_complete_arg); |
| *root = pp; |
| } |
| |
| /* Same as the \a pending_pick struct but for ping operations */ |
| typedef struct pending_ping { |
| struct pending_ping *next; |
| |
| /* args for wrapped_notify */ |
| wrapped_rr_closure_arg wrapped_notify_arg; |
| } pending_ping; |
| |
| static void add_pending_ping(pending_ping **root, grpc_closure *notify) { |
| pending_ping *pping = gpr_malloc(sizeof(*pping)); |
| memset(pping, 0, sizeof(pending_ping)); |
| memset(&pping->wrapped_notify_arg, 0, sizeof(wrapped_rr_closure_arg)); |
| pping->wrapped_notify_arg.wrapped_closure = notify; |
| pping->wrapped_notify_arg.free_when_done = pping; |
| pping->next = *root; |
| grpc_closure_init(&pping->wrapped_notify_arg.wrapper_closure, |
| wrapped_rr_closure, &pping->wrapped_notify_arg); |
| *root = pping; |
| } |
| |
| /* |
| * glb_lb_policy |
| */ |
| typedef struct rr_connectivity_data rr_connectivity_data; |
| struct lb_client_data; |
| static const grpc_lb_policy_vtable glb_lb_policy_vtable; |
| typedef struct glb_lb_policy { |
| /** base policy: must be first */ |
| grpc_lb_policy base; |
| |
| /** mutex protecting remaining members */ |
| gpr_mu mu; |
| |
| /** who the client is trying to communicate with */ |
| const char *server_name; |
| grpc_client_channel_factory *cc_factory; |
| grpc_channel_args *args; |
| |
| /** deadline for the LB's call */ |
| gpr_timespec deadline; |
| |
| /** for communicating with the LB server */ |
| grpc_channel *lb_channel; |
| |
| /** the RR policy to use of the backend servers returned by the LB server */ |
| grpc_lb_policy *rr_policy; |
| |
| bool started_picking; |
| |
| /** our connectivity state tracker */ |
| grpc_connectivity_state_tracker state_tracker; |
| |
| /** stores the deserialized response from the LB. May be NULL until one such |
| * response has arrived. */ |
| grpc_grpclb_serverlist *serverlist; |
| |
| /** addresses from \a serverlist */ |
| grpc_lb_addresses *addresses; |
| |
| /** list of picks that are waiting on RR's policy connectivity */ |
| pending_pick *pending_picks; |
| |
| /** list of pings that are waiting on RR's policy connectivity */ |
| pending_ping *pending_pings; |
| |
| /** client data associated with the LB server communication */ |
| struct lb_client_data *lb_client; |
| |
| /** for tracking of the RR connectivity */ |
| rr_connectivity_data *rr_connectivity; |
| } glb_lb_policy; |
| |
| /* Keeps track and reacts to changes in connectivity of the RR instance */ |
| struct rr_connectivity_data { |
| grpc_closure on_change; |
| grpc_connectivity_state state; |
| glb_lb_policy *glb_policy; |
| }; |
| |
| static bool is_server_valid(const grpc_grpclb_server *server, size_t idx, |
| bool log) { |
| const grpc_grpclb_ip_address *ip = &server->ip_address; |
| if (server->port >> 16 != 0) { |
| if (log) { |
| gpr_log(GPR_ERROR, |
| "Invalid port '%d' at index %lu of serverlist. Ignoring.", |
| server->port, (unsigned long)idx); |
| } |
| return false; |
| } |
| |
| if (ip->size != 4 && ip->size != 16) { |
| if (log) { |
| gpr_log(GPR_ERROR, |
| "Expected IP to be 4 or 16 bytes, got %d at index %lu of " |
| "serverlist. Ignoring", |
| ip->size, (unsigned long)idx); |
| } |
| return false; |
| } |
| return true; |
| } |
| |
| /* vtable for LB tokens in grpc_lb_addresses. */ |
| static void *lb_token_copy(void *token) { |
| return token == NULL ? NULL : GRPC_MDELEM_REF(token); |
| } |
| static void lb_token_destroy(void *token) { |
| if (token != NULL) GRPC_MDELEM_UNREF(token); |
| } |
| static int lb_token_cmp(void *token1, void *token2) { |
| if (token1 > token2) return 1; |
| if (token1 < token2) return -1; |
| return 0; |
| } |
| static const grpc_lb_user_data_vtable lb_token_vtable = { |
| lb_token_copy, lb_token_destroy, lb_token_cmp}; |
| |
| /* Returns addresses extracted from \a serverlist. */ |
| static grpc_lb_addresses *process_serverlist( |
| const grpc_grpclb_serverlist *serverlist) { |
| size_t num_valid = 0; |
| /* first pass: count how many are valid in order to allocate the necessary |
| * memory in a single block */ |
| for (size_t i = 0; i < serverlist->num_servers; ++i) { |
| if (is_server_valid(serverlist->servers[i], i, true)) ++num_valid; |
| } |
| if (num_valid == 0) return NULL; |
| |
| grpc_lb_addresses *lb_addresses = |
| grpc_lb_addresses_create(num_valid, &lb_token_vtable); |
| |
| /* second pass: actually populate the addresses and LB tokens (aka user data |
| * to the outside world) to be read by the RR policy during its creation. |
| * Given that the validity tests are very cheap, they are performed again |
| * instead of marking the valid ones during the first pass, as this would |
| * incurr in an allocation due to the arbitrary number of server */ |
| size_t addr_idx = 0; |
| for (size_t sl_idx = 0; sl_idx < serverlist->num_servers; ++sl_idx) { |
| GPR_ASSERT(addr_idx < num_valid); |
| const grpc_grpclb_server *server = serverlist->servers[sl_idx]; |
| if (!is_server_valid(serverlist->servers[sl_idx], sl_idx, false)) continue; |
| |
| /* address processing */ |
| const uint16_t netorder_port = htons((uint16_t)server->port); |
| /* the addresses are given in binary format (a in(6)_addr struct) in |
| * server->ip_address.bytes. */ |
| const grpc_grpclb_ip_address *ip = &server->ip_address; |
| grpc_resolved_address addr; |
| memset(&addr, 0, sizeof(addr)); |
| if (ip->size == 4) { |
| addr.len = sizeof(struct sockaddr_in); |
| struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr.addr; |
| addr4->sin_family = AF_INET; |
| memcpy(&addr4->sin_addr, ip->bytes, ip->size); |
| addr4->sin_port = netorder_port; |
| } else if (ip->size == 16) { |
| addr.len = sizeof(struct sockaddr_in6); |
| struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr.addr; |
| addr6->sin6_family = AF_INET; |
| memcpy(&addr6->sin6_addr, ip->bytes, ip->size); |
| addr6->sin6_port = netorder_port; |
| } |
| |
| /* lb token processing */ |
| void *user_data; |
| if (server->has_load_balance_token) { |
| const size_t lb_token_size = |
| GPR_ARRAY_SIZE(server->load_balance_token) - 1; |
| grpc_mdstr *lb_token_mdstr = grpc_mdstr_from_buffer( |
| (uint8_t *)server->load_balance_token, lb_token_size); |
| user_data = grpc_mdelem_from_metadata_strings(GRPC_MDSTR_LB_TOKEN, |
| lb_token_mdstr); |
| } else { |
| gpr_log(GPR_ERROR, |
| "Missing LB token for backend address '%s'. The empty token will " |
| "be used instead", |
| grpc_sockaddr_to_uri(&addr)); |
| user_data = GRPC_MDELEM_LB_TOKEN_EMPTY; |
| } |
| |
| grpc_lb_addresses_set_address(lb_addresses, addr_idx, &addr.addr, addr.len, |
| false /* is_balancer */, |
| NULL /* balancer_name */, user_data); |
| ++addr_idx; |
| } |
| GPR_ASSERT(addr_idx == num_valid); |
| |
| return lb_addresses; |
| } |
| |
| /* perform a pick over \a rr_policy. Given that a pick can return immediately |
| * (ignoring its completion callback) we need to perform the cleanups this |
| * callback would be otherwise resposible for */ |
| static bool pick_from_internal_rr_locked( |
| grpc_exec_ctx *exec_ctx, grpc_lb_policy *rr_policy, |
| const grpc_lb_policy_pick_args *pick_args, |
| grpc_connected_subchannel **target, wrapped_rr_closure_arg *wc_arg) { |
| GPR_ASSERT(rr_policy != NULL); |
| const bool pick_done = |
| grpc_lb_policy_pick(exec_ctx, rr_policy, pick_args, target, |
| (void **)&wc_arg->lb_token, &wc_arg->wrapper_closure); |
| if (pick_done) { |
| /* synchronous grpc_lb_policy_pick call. Unref the RR policy. */ |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Unreffing RR (0x%" PRIxPTR ")", |
| (intptr_t)wc_arg->rr_policy); |
| } |
| GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick"); |
| |
| /* add the load reporting initial metadata */ |
| initial_metadata_add_lb_token(pick_args->initial_metadata, |
| pick_args->lb_token_mdelem_storage, |
| GRPC_MDELEM_REF(wc_arg->lb_token)); |
| |
| gpr_free(wc_arg); |
| } |
| /* else, the pending pick will be registered and taken care of by the |
| * pending pick list inside the RR policy (glb_policy->rr_policy). |
| * Eventually, wrapped_on_complete will be called, which will -among other |
| * things- add the LB token to the call's initial metadata */ |
| |
| return pick_done; |
| } |
| |
| static grpc_lb_policy *create_rr_locked( |
| grpc_exec_ctx *exec_ctx, const grpc_grpclb_serverlist *serverlist, |
| glb_lb_policy *glb_policy) { |
| GPR_ASSERT(serverlist != NULL && serverlist->num_servers > 0); |
| |
| if (glb_policy->addresses != NULL) { |
| /* dispose of the previous version */ |
| grpc_lb_addresses_destroy(glb_policy->addresses); |
| } |
| glb_policy->addresses = process_serverlist(serverlist); |
| |
| grpc_lb_policy_args args; |
| memset(&args, 0, sizeof(args)); |
| args.client_channel_factory = glb_policy->cc_factory; |
| |
| // Replace the LB addresses in the channel args that we pass down to |
| // the subchannel. |
| static const char *keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES}; |
| const grpc_arg arg = |
| grpc_lb_addresses_create_channel_arg(glb_policy->addresses); |
| args.args = grpc_channel_args_copy_and_add_and_remove( |
| glb_policy->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg, |
| 1); |
| |
| grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args); |
| grpc_channel_args_destroy(args.args); |
| |
| return rr; |
| } |
| |
| static void rr_handover_locked(grpc_exec_ctx *exec_ctx, |
| glb_lb_policy *glb_policy, grpc_error *error) { |
| GPR_ASSERT(glb_policy->serverlist != NULL && |
| glb_policy->serverlist->num_servers > 0); |
| glb_policy->rr_policy = |
| create_rr_locked(exec_ctx, glb_policy->serverlist, glb_policy); |
| |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Created RR policy (0x%" PRIxPTR ")", |
| (intptr_t)glb_policy->rr_policy); |
| } |
| GPR_ASSERT(glb_policy->rr_policy != NULL); |
| grpc_pollset_set_add_pollset_set(exec_ctx, |
| glb_policy->rr_policy->interested_parties, |
| glb_policy->base.interested_parties); |
| glb_policy->rr_connectivity->state = grpc_lb_policy_check_connectivity( |
| exec_ctx, glb_policy->rr_policy, &error); |
| grpc_lb_policy_notify_on_state_change( |
| exec_ctx, glb_policy->rr_policy, &glb_policy->rr_connectivity->state, |
| &glb_policy->rr_connectivity->on_change); |
| grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker, |
| glb_policy->rr_connectivity->state, |
| GRPC_ERROR_REF(error), "rr_handover"); |
| grpc_lb_policy_exit_idle(exec_ctx, glb_policy->rr_policy); |
| |
| /* flush pending ops */ |
| pending_pick *pp; |
| while ((pp = glb_policy->pending_picks)) { |
| glb_policy->pending_picks = pp->next; |
| GRPC_LB_POLICY_REF(glb_policy->rr_policy, "rr_handover_pending_pick"); |
| pp->wrapped_on_complete_arg.rr_policy = glb_policy->rr_policy; |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Pending pick about to PICK from 0x%" PRIxPTR "", |
| (intptr_t)glb_policy->rr_policy); |
| } |
| pick_from_internal_rr_locked(exec_ctx, glb_policy->rr_policy, |
| &pp->pick_args, pp->target, |
| &pp->wrapped_on_complete_arg); |
| } |
| |
| pending_ping *pping; |
| while ((pping = glb_policy->pending_pings)) { |
| glb_policy->pending_pings = pping->next; |
| GRPC_LB_POLICY_REF(glb_policy->rr_policy, "rr_handover_pending_ping"); |
| pping->wrapped_notify_arg.rr_policy = glb_policy->rr_policy; |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Pending ping about to PING from 0x%" PRIxPTR "", |
| (intptr_t)glb_policy->rr_policy); |
| } |
| grpc_lb_policy_ping_one(exec_ctx, glb_policy->rr_policy, |
| &pping->wrapped_notify_arg.wrapper_closure); |
| } |
| } |
| |
| static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| rr_connectivity_data *rr_conn_data = arg; |
| glb_lb_policy *glb_policy = rr_conn_data->glb_policy; |
| |
| if (rr_conn_data->state == GRPC_CHANNEL_SHUTDOWN) { |
| if (glb_policy->serverlist != NULL) { |
| /* a RR policy is shutting down but there's a serverlist available -> |
| * perform a handover */ |
| gpr_mu_lock(&glb_policy->mu); |
| rr_handover_locked(exec_ctx, glb_policy, error); |
| gpr_mu_unlock(&glb_policy->mu); |
| } else { |
| /* shutting down and no new serverlist available. Bail out. */ |
| gpr_free(rr_conn_data); |
| } |
| } else { |
| if (error == GRPC_ERROR_NONE) { |
| gpr_mu_lock(&glb_policy->mu); |
| /* RR not shutting down. Mimic the RR's policy state */ |
| grpc_connectivity_state_set(exec_ctx, &glb_policy->state_tracker, |
| rr_conn_data->state, GRPC_ERROR_REF(error), |
| "glb_rr_connectivity_changed"); |
| /* resubscribe */ |
| grpc_lb_policy_notify_on_state_change(exec_ctx, glb_policy->rr_policy, |
| &rr_conn_data->state, |
| &rr_conn_data->on_change); |
| gpr_mu_unlock(&glb_policy->mu); |
| } else { /* error */ |
| gpr_free(rr_conn_data); |
| } |
| } |
| } |
| |
| static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx, |
| grpc_lb_policy_factory *factory, |
| grpc_lb_policy_args *args) { |
| /* Get server name. */ |
| const grpc_arg *arg = |
| grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME); |
| const char *server_name = |
| arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL; |
| |
| /* Count the number of gRPC-LB addresses. There must be at least one. |
| * TODO(roth): For now, we ignore non-balancer addresses, but in the |
| * future, we may change the behavior such that we fall back to using |
| * the non-balancer addresses if we cannot reach any balancers. At that |
| * time, this should be changed to allow a list with no balancer addresses, |
| * since the resolver might fail to return a balancer address even when |
| * this is the right LB policy to use. */ |
| arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES); |
| GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER); |
| grpc_lb_addresses *addresses = arg->value.pointer.p; |
| size_t num_grpclb_addrs = 0; |
| for (size_t i = 0; i < addresses->num_addresses; ++i) { |
| if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs; |
| } |
| if (num_grpclb_addrs == 0) return NULL; |
| |
| glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy)); |
| memset(glb_policy, 0, sizeof(*glb_policy)); |
| |
| /* All input addresses in addresses come from a resolver that claims |
| * they are LB services. It's the resolver's responsibility to make sure |
| * this |
| * policy is only instantiated and used in that case. |
| * |
| * Create a client channel over them to communicate with a LB service */ |
| glb_policy->server_name = gpr_strdup(server_name); |
| glb_policy->cc_factory = args->client_channel_factory; |
| glb_policy->args = grpc_channel_args_copy(args->args); |
| GPR_ASSERT(glb_policy->cc_factory != NULL); |
| |
| /* construct a target from the addresses in args, given in the form |
| * ipvX://ip1:port1,ip2:port2,... |
| * TODO(dgq): support mixed ip version */ |
| char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs); |
| size_t addr_index = 0; |
| for (size_t i = 0; i < addresses->num_addresses; i++) { |
| if (addresses->addresses[i].user_data != NULL) { |
| gpr_log(GPR_ERROR, |
| "This LB policy doesn't support user data. It will be ignored"); |
| } |
| if (addresses->addresses[i].is_balancer) { |
| if (addr_index == 0) { |
| addr_strs[addr_index++] = |
| grpc_sockaddr_to_uri(&addresses->addresses[i].address); |
| } else { |
| GPR_ASSERT(grpc_sockaddr_to_string(&addr_strs[addr_index++], |
| &addresses->addresses[i].address, |
| true) > 0); |
| } |
| } |
| } |
| size_t uri_path_len; |
| char *target_uri_str = gpr_strjoin_sep((const char **)addr_strs, |
| num_grpclb_addrs, ",", &uri_path_len); |
| |
| /* Create a channel to talk to the LBs. |
| * |
| * We strip out the channel arg for the LB policy name, since we want |
| * to use the default (pick_first) in this case. |
| * |
| * We also strip out the channel arg for the resolved addresses, since |
| * that will be generated by the name resolver used in the LB channel. |
| * Note that the LB channel will use the sockaddr resolver, so this |
| * won't actually generate a query to DNS (or some other name service). |
| * However, the addresses returned by the sockaddr resolver will have |
| * is_balancer=false, whereas our own addresses have is_balancer=true. |
| * We need the LB channel to return addresses with is_balancer=false |
| * so that it does not wind up recursively using the grpclb LB policy, |
| * as per the special case logic in client_channel.c. |
| */ |
| static const char *keys_to_remove[] = {GRPC_ARG_LB_POLICY_NAME, |
| GRPC_ARG_LB_ADDRESSES}; |
| grpc_channel_args *new_args = grpc_channel_args_copy_and_remove( |
| args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove)); |
| glb_policy->lb_channel = grpc_client_channel_factory_create_channel( |
| exec_ctx, glb_policy->cc_factory, target_uri_str, |
| GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, new_args); |
| grpc_channel_args_destroy(new_args); |
| |
| gpr_free(target_uri_str); |
| for (size_t i = 0; i < num_grpclb_addrs; i++) { |
| gpr_free(addr_strs[i]); |
| } |
| gpr_free(addr_strs); |
| |
| if (glb_policy->lb_channel == NULL) { |
| gpr_free(glb_policy); |
| return NULL; |
| } |
| |
| rr_connectivity_data *rr_connectivity = |
| gpr_malloc(sizeof(rr_connectivity_data)); |
| memset(rr_connectivity, 0, sizeof(rr_connectivity_data)); |
| grpc_closure_init(&rr_connectivity->on_change, glb_rr_connectivity_changed, |
| rr_connectivity); |
| rr_connectivity->glb_policy = glb_policy; |
| glb_policy->rr_connectivity = rr_connectivity; |
| |
| grpc_lb_policy_init(&glb_policy->base, &glb_lb_policy_vtable); |
| gpr_mu_init(&glb_policy->mu); |
| grpc_connectivity_state_init(&glb_policy->state_tracker, GRPC_CHANNEL_IDLE, |
| "grpclb"); |
| return &glb_policy->base; |
| } |
| |
| static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| GPR_ASSERT(glb_policy->pending_picks == NULL); |
| GPR_ASSERT(glb_policy->pending_pings == NULL); |
| gpr_free((void *)glb_policy->server_name); |
| grpc_channel_args_destroy(glb_policy->args); |
| grpc_channel_destroy(glb_policy->lb_channel); |
| glb_policy->lb_channel = NULL; |
| grpc_connectivity_state_destroy(exec_ctx, &glb_policy->state_tracker); |
| if (glb_policy->serverlist != NULL) { |
| grpc_grpclb_destroy_serverlist(glb_policy->serverlist); |
| } |
| gpr_mu_destroy(&glb_policy->mu); |
| grpc_lb_addresses_destroy(glb_policy->addresses); |
| gpr_free(glb_policy); |
| } |
| |
| static void lb_client_data_destroy(struct lb_client_data *lb_client); |
| static void glb_shutdown(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| |
| pending_pick *pp = glb_policy->pending_picks; |
| glb_policy->pending_picks = NULL; |
| pending_ping *pping = glb_policy->pending_pings; |
| glb_policy->pending_pings = NULL; |
| gpr_mu_unlock(&glb_policy->mu); |
| |
| while (pp != NULL) { |
| pending_pick *next = pp->next; |
| *pp->target = NULL; |
| grpc_exec_ctx_sched(exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure, |
| GRPC_ERROR_NONE, NULL); |
| pp = next; |
| } |
| |
| while (pping != NULL) { |
| pending_ping *next = pping->next; |
| grpc_exec_ctx_sched(exec_ctx, &pping->wrapped_notify_arg.wrapper_closure, |
| GRPC_ERROR_NONE, NULL); |
| pping = next; |
| } |
| |
| if (glb_policy->rr_policy) { |
| /* unsubscribe */ |
| grpc_lb_policy_notify_on_state_change( |
| exec_ctx, glb_policy->rr_policy, NULL, |
| &glb_policy->rr_connectivity->on_change); |
| GRPC_LB_POLICY_UNREF(exec_ctx, glb_policy->rr_policy, "glb_shutdown"); |
| } |
| |
| lb_client_data_destroy(glb_policy->lb_client); |
| glb_policy->lb_client = NULL; |
| |
| grpc_connectivity_state_set( |
| exec_ctx, &glb_policy->state_tracker, GRPC_CHANNEL_SHUTDOWN, |
| GRPC_ERROR_CREATE("Channel Shutdown"), "glb_shutdown"); |
| } |
| |
| static void glb_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, |
| grpc_connected_subchannel **target, |
| grpc_error *error) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| pending_pick *pp = glb_policy->pending_picks; |
| glb_policy->pending_picks = NULL; |
| while (pp != NULL) { |
| pending_pick *next = pp->next; |
| if (pp->target == target) { |
| *target = NULL; |
| grpc_exec_ctx_sched( |
| exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure, |
| GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1), NULL); |
| } else { |
| pp->next = glb_policy->pending_picks; |
| glb_policy->pending_picks = pp; |
| } |
| pp = next; |
| } |
| gpr_mu_unlock(&glb_policy->mu); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static grpc_call *lb_client_data_get_call(struct lb_client_data *lb_client); |
| static void glb_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, |
| uint32_t initial_metadata_flags_mask, |
| uint32_t initial_metadata_flags_eq, |
| grpc_error *error) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| if (glb_policy->lb_client != NULL) { |
| /* cancel the call to the load balancer service, if any */ |
| grpc_call_cancel(lb_client_data_get_call(glb_policy->lb_client), NULL); |
| } |
| pending_pick *pp = glb_policy->pending_picks; |
| glb_policy->pending_picks = NULL; |
| while (pp != NULL) { |
| pending_pick *next = pp->next; |
| if ((pp->pick_args.initial_metadata_flags & initial_metadata_flags_mask) == |
| initial_metadata_flags_eq) { |
| grpc_exec_ctx_sched( |
| exec_ctx, &pp->wrapped_on_complete_arg.wrapper_closure, |
| GRPC_ERROR_CREATE_REFERENCING("Pick Cancelled", &error, 1), NULL); |
| } else { |
| pp->next = glb_policy->pending_picks; |
| glb_policy->pending_picks = pp; |
| } |
| pp = next; |
| } |
| gpr_mu_unlock(&glb_policy->mu); |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void query_for_backends(grpc_exec_ctx *exec_ctx, |
| glb_lb_policy *glb_policy); |
| static void start_picking(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy) { |
| glb_policy->started_picking = true; |
| query_for_backends(exec_ctx, glb_policy); |
| } |
| |
| static void glb_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| if (!glb_policy->started_picking) { |
| start_picking(exec_ctx, glb_policy); |
| } |
| gpr_mu_unlock(&glb_policy->mu); |
| } |
| |
| static int glb_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, |
| const grpc_lb_policy_pick_args *pick_args, |
| grpc_connected_subchannel **target, void **user_data, |
| grpc_closure *on_complete) { |
| if (pick_args->lb_token_mdelem_storage == NULL) { |
| *target = NULL; |
| grpc_exec_ctx_sched( |
| exec_ctx, on_complete, |
| GRPC_ERROR_CREATE("No mdelem storage for the LB token. Load reporting " |
| "won't work without it. Failing"), |
| NULL); |
| return 0; |
| } |
| |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| glb_policy->deadline = pick_args->deadline; |
| bool pick_done; |
| |
| if (glb_policy->rr_policy != NULL) { |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "about to PICK from 0x%" PRIxPTR "", |
| (intptr_t)glb_policy->rr_policy); |
| } |
| GRPC_LB_POLICY_REF(glb_policy->rr_policy, "glb_pick"); |
| |
| wrapped_rr_closure_arg *wc_arg = gpr_malloc(sizeof(wrapped_rr_closure_arg)); |
| memset(wc_arg, 0, sizeof(wrapped_rr_closure_arg)); |
| |
| grpc_closure_init(&wc_arg->wrapper_closure, wrapped_rr_closure, wc_arg); |
| wc_arg->rr_policy = glb_policy->rr_policy; |
| wc_arg->target = target; |
| wc_arg->wrapped_closure = on_complete; |
| wc_arg->lb_token_mdelem_storage = pick_args->lb_token_mdelem_storage; |
| wc_arg->initial_metadata = pick_args->initial_metadata; |
| wc_arg->free_when_done = wc_arg; |
| pick_done = pick_from_internal_rr_locked(exec_ctx, glb_policy->rr_policy, |
| pick_args, target, wc_arg); |
| } else { |
| add_pending_pick(&glb_policy->pending_picks, pick_args, target, |
| on_complete); |
| |
| if (!glb_policy->started_picking) { |
| start_picking(exec_ctx, glb_policy); |
| } |
| pick_done = false; |
| } |
| gpr_mu_unlock(&glb_policy->mu); |
| return pick_done; |
| } |
| |
| static grpc_connectivity_state glb_check_connectivity( |
| grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, |
| grpc_error **connectivity_error) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| grpc_connectivity_state st; |
| gpr_mu_lock(&glb_policy->mu); |
| st = grpc_connectivity_state_check(&glb_policy->state_tracker, |
| connectivity_error); |
| gpr_mu_unlock(&glb_policy->mu); |
| return st; |
| } |
| |
| static void glb_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, |
| grpc_closure *closure) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| if (glb_policy->rr_policy) { |
| grpc_lb_policy_ping_one(exec_ctx, glb_policy->rr_policy, closure); |
| } else { |
| add_pending_ping(&glb_policy->pending_pings, closure); |
| if (!glb_policy->started_picking) { |
| start_picking(exec_ctx, glb_policy); |
| } |
| } |
| gpr_mu_unlock(&glb_policy->mu); |
| } |
| |
| static void glb_notify_on_state_change(grpc_exec_ctx *exec_ctx, |
| grpc_lb_policy *pol, |
| grpc_connectivity_state *current, |
| grpc_closure *notify) { |
| glb_lb_policy *glb_policy = (glb_lb_policy *)pol; |
| gpr_mu_lock(&glb_policy->mu); |
| grpc_connectivity_state_notify_on_state_change( |
| exec_ctx, &glb_policy->state_tracker, current, notify); |
| |
| gpr_mu_unlock(&glb_policy->mu); |
| } |
| |
| /* |
| * lb_client_data |
| * |
| * Used internally for the client call to the LB */ |
| typedef struct lb_client_data { |
| gpr_mu mu; |
| |
| /* called once initial metadata's been sent */ |
| grpc_closure md_sent; |
| |
| /* called once the LoadBalanceRequest has been sent to the LB server. See |
| * src/proto/grpc/.../load_balancer.proto */ |
| grpc_closure req_sent; |
| |
| /* A response from the LB server has been received (or error). Process it */ |
| grpc_closure res_rcvd; |
| |
| /* After the client has sent a close to the LB server */ |
| grpc_closure close_sent; |
| |
| /* ... and the status from the LB server has been received */ |
| grpc_closure srv_status_rcvd; |
| |
| grpc_call *lb_call; /* streaming call to the LB server, */ |
| gpr_timespec deadline; /* for the streaming call to the LB server */ |
| |
| grpc_metadata_array initial_metadata_recv; /* initial MD from LB server */ |
| grpc_metadata_array trailing_metadata_recv; /* trailing MD from LB server */ |
| |
| /* what's being sent to the LB server. Note that its value may vary if the LB |
| * server indicates a redirect. */ |
| grpc_byte_buffer *request_payload; |
| |
| /* response from the LB server, if any. Processed in res_recv_cb() */ |
| grpc_byte_buffer *response_payload; |
| |
| /* the call's status and status detailset in srv_status_rcvd_cb() */ |
| grpc_status_code status; |
| char *status_details; |
| size_t status_details_capacity; |
| |
| /* pointer back to the enclosing policy */ |
| glb_lb_policy *glb_policy; |
| } lb_client_data; |
| |
| static void md_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error); |
| static void req_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error); |
| static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error); |
| static void close_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error); |
| static void srv_status_rcvd_cb(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error); |
| |
| static lb_client_data *lb_client_data_create(glb_lb_policy *glb_policy) { |
| GPR_ASSERT(glb_policy->server_name != NULL); |
| GPR_ASSERT(glb_policy->server_name[0] != '\0'); |
| |
| lb_client_data *lb_client = gpr_malloc(sizeof(lb_client_data)); |
| memset(lb_client, 0, sizeof(lb_client_data)); |
| |
| gpr_mu_init(&lb_client->mu); |
| grpc_closure_init(&lb_client->md_sent, md_sent_cb, lb_client); |
| |
| grpc_closure_init(&lb_client->req_sent, req_sent_cb, lb_client); |
| grpc_closure_init(&lb_client->res_rcvd, res_recv_cb, lb_client); |
| grpc_closure_init(&lb_client->close_sent, close_sent_cb, lb_client); |
| grpc_closure_init(&lb_client->srv_status_rcvd, srv_status_rcvd_cb, lb_client); |
| |
| lb_client->deadline = glb_policy->deadline; |
| |
| /* Note the following LB call progresses every time there's activity in \a |
| * glb_policy->base.interested_parties, which is comprised of the polling |
| * entities from \a client_channel. */ |
| lb_client->lb_call = grpc_channel_create_pollset_set_call( |
| glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS, |
| glb_policy->base.interested_parties, |
| "/grpc.lb.v1.LoadBalancer/BalanceLoad", glb_policy->server_name, |
| lb_client->deadline, NULL); |
| |
| grpc_metadata_array_init(&lb_client->initial_metadata_recv); |
| grpc_metadata_array_init(&lb_client->trailing_metadata_recv); |
| |
| grpc_grpclb_request *request = |
| grpc_grpclb_request_create(glb_policy->server_name); |
| gpr_slice request_payload_slice = grpc_grpclb_request_encode(request); |
| lb_client->request_payload = |
| grpc_raw_byte_buffer_create(&request_payload_slice, 1); |
| gpr_slice_unref(request_payload_slice); |
| grpc_grpclb_request_destroy(request); |
| |
| lb_client->status_details = NULL; |
| lb_client->status_details_capacity = 0; |
| lb_client->glb_policy = glb_policy; |
| return lb_client; |
| } |
| |
| static void lb_client_data_destroy(lb_client_data *lb_client) { |
| grpc_call_destroy(lb_client->lb_call); |
| grpc_metadata_array_destroy(&lb_client->initial_metadata_recv); |
| grpc_metadata_array_destroy(&lb_client->trailing_metadata_recv); |
| |
| grpc_byte_buffer_destroy(lb_client->request_payload); |
| |
| gpr_free(lb_client->status_details); |
| gpr_mu_destroy(&lb_client->mu); |
| gpr_free(lb_client); |
| } |
| static grpc_call *lb_client_data_get_call(lb_client_data *lb_client) { |
| return lb_client->lb_call; |
| } |
| |
| /* |
| * Auxiliary functions and LB client callbacks. |
| */ |
| static void query_for_backends(grpc_exec_ctx *exec_ctx, |
| glb_lb_policy *glb_policy) { |
| GPR_ASSERT(glb_policy->lb_channel != NULL); |
| |
| glb_policy->lb_client = lb_client_data_create(glb_policy); |
| grpc_call_error call_error; |
| grpc_op ops[1]; |
| memset(ops, 0, sizeof(ops)); |
| grpc_op *op = ops; |
| op->op = GRPC_OP_SEND_INITIAL_METADATA; |
| op->data.send_initial_metadata.count = 0; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, glb_policy->lb_client->lb_call, ops, (size_t)(op - ops), |
| &glb_policy->lb_client->md_sent); |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| |
| op = ops; |
| op->op = GRPC_OP_RECV_STATUS_ON_CLIENT; |
| op->data.recv_status_on_client.trailing_metadata = |
| &glb_policy->lb_client->trailing_metadata_recv; |
| op->data.recv_status_on_client.status = &glb_policy->lb_client->status; |
| op->data.recv_status_on_client.status_details = |
| &glb_policy->lb_client->status_details; |
| op->data.recv_status_on_client.status_details_capacity = |
| &glb_policy->lb_client->status_details_capacity; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, glb_policy->lb_client->lb_call, ops, (size_t)(op - ops), |
| &glb_policy->lb_client->srv_status_rcvd); |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| } |
| |
| static void md_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { |
| lb_client_data *lb_client = arg; |
| GPR_ASSERT(lb_client->lb_call); |
| grpc_op ops[1]; |
| memset(ops, 0, sizeof(ops)); |
| grpc_op *op = ops; |
| |
| op->op = GRPC_OP_SEND_MESSAGE; |
| op->data.send_message = lb_client->request_payload; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| grpc_call_error call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops), |
| &lb_client->req_sent); |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| } |
| |
| static void req_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { |
| lb_client_data *lb_client = arg; |
| GPR_ASSERT(lb_client->lb_call); |
| |
| grpc_op ops[2]; |
| memset(ops, 0, sizeof(ops)); |
| grpc_op *op = ops; |
| |
| op->op = GRPC_OP_RECV_INITIAL_METADATA; |
| op->data.recv_initial_metadata = &lb_client->initial_metadata_recv; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| |
| op->op = GRPC_OP_RECV_MESSAGE; |
| op->data.recv_message = &lb_client->response_payload; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| grpc_call_error call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops), |
| &lb_client->res_rcvd); |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| } |
| |
| static void res_recv_cb(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { |
| lb_client_data *lb_client = arg; |
| grpc_op ops[2]; |
| memset(ops, 0, sizeof(ops)); |
| grpc_op *op = ops; |
| if (lb_client->response_payload != NULL) { |
| /* Received data from the LB server. Look inside |
| * lb_client->response_payload, for a serverlist. */ |
| grpc_byte_buffer_reader bbr; |
| grpc_byte_buffer_reader_init(&bbr, lb_client->response_payload); |
| gpr_slice response_slice = grpc_byte_buffer_reader_readall(&bbr); |
| grpc_byte_buffer_destroy(lb_client->response_payload); |
| grpc_grpclb_serverlist *serverlist = |
| grpc_grpclb_response_parse_serverlist(response_slice); |
| if (serverlist != NULL) { |
| gpr_slice_unref(response_slice); |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, "Serverlist with %lu servers received", |
| (unsigned long)serverlist->num_servers); |
| } |
| |
| /* update serverlist */ |
| if (serverlist->num_servers > 0) { |
| gpr_mu_lock(&lb_client->glb_policy->mu); |
| if (grpc_grpclb_serverlist_equals(lb_client->glb_policy->serverlist, |
| serverlist)) { |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, |
| "Incoming server list identical to current, ignoring."); |
| } |
| } else { /* new serverlist */ |
| if (lb_client->glb_policy->serverlist != NULL) { |
| /* dispose of the old serverlist */ |
| grpc_grpclb_destroy_serverlist(lb_client->glb_policy->serverlist); |
| } |
| /* and update the copy in the glb_lb_policy instance */ |
| lb_client->glb_policy->serverlist = serverlist; |
| } |
| if (lb_client->glb_policy->rr_policy == NULL) { |
| /* initial "handover", in this case from a null RR policy, meaning |
| * it'll just create the first RR policy instance */ |
| rr_handover_locked(exec_ctx, lb_client->glb_policy, error); |
| } else { |
| /* unref the RR policy, eventually leading to its substitution with a |
| * new one constructed from the received serverlist (see |
| * glb_rr_connectivity_changed) */ |
| GRPC_LB_POLICY_UNREF(exec_ctx, lb_client->glb_policy->rr_policy, |
| "serverlist_received"); |
| } |
| gpr_mu_unlock(&lb_client->glb_policy->mu); |
| } else { |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, |
| "Received empty server list. Picks will stay pending until a " |
| "response with > 0 servers is received"); |
| } |
| } |
| |
| /* keep listening for serverlist updates */ |
| op->op = GRPC_OP_RECV_MESSAGE; |
| op->data.recv_message = &lb_client->response_payload; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| const grpc_call_error call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops), |
| &lb_client->res_rcvd); /* loop */ |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| return; |
| } |
| |
| GPR_ASSERT(serverlist == NULL); |
| gpr_log(GPR_ERROR, "Invalid LB response received: '%s'", |
| gpr_dump_slice(response_slice, GPR_DUMP_ASCII)); |
| gpr_slice_unref(response_slice); |
| |
| /* Disconnect from server returning invalid response. */ |
| op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT; |
| op->flags = 0; |
| op->reserved = NULL; |
| op++; |
| grpc_call_error call_error = grpc_call_start_batch_and_execute( |
| exec_ctx, lb_client->lb_call, ops, (size_t)(op - ops), |
| &lb_client->close_sent); |
| GPR_ASSERT(GRPC_CALL_OK == call_error); |
| } |
| /* empty payload: call cancelled by server. Cleanups happening in |
| * srv_status_rcvd_cb */ |
| } |
| |
| static void close_sent_cb(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, |
| "Close from LB client sent. Waiting from server status now"); |
| } |
| } |
| |
| static void srv_status_rcvd_cb(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error) { |
| lb_client_data *lb_client = arg; |
| if (grpc_lb_glb_trace) { |
| gpr_log(GPR_INFO, |
| "status from lb server received. Status = %d, Details = '%s', " |
| "Capacity " |
| "= %lu", |
| lb_client->status, lb_client->status_details, |
| (unsigned long)lb_client->status_details_capacity); |
| } |
| /* TODO(dgq): deal with stream termination properly (fire up another one? |
| * fail the original call?) */ |
| } |
| |
| /* Code wiring the policy with the rest of the core */ |
| static const grpc_lb_policy_vtable glb_lb_policy_vtable = { |
| glb_destroy, glb_shutdown, glb_pick, |
| glb_cancel_pick, glb_cancel_picks, glb_ping_one, |
| glb_exit_idle, glb_check_connectivity, glb_notify_on_state_change}; |
| |
| static void glb_factory_ref(grpc_lb_policy_factory *factory) {} |
| |
| static void glb_factory_unref(grpc_lb_policy_factory *factory) {} |
| |
| static const grpc_lb_policy_factory_vtable glb_factory_vtable = { |
| glb_factory_ref, glb_factory_unref, glb_create, "grpclb"}; |
| |
| static grpc_lb_policy_factory glb_lb_policy_factory = {&glb_factory_vtable}; |
| |
| grpc_lb_policy_factory *grpc_glb_lb_factory_create() { |
| return &glb_lb_policy_factory; |
| } |
| |
| /* Plugin registration */ |
| void grpc_lb_policy_grpclb_init() { |
| grpc_register_lb_policy(grpc_glb_lb_factory_create()); |
| grpc_register_tracer("glb", &grpc_lb_glb_trace); |
| } |
| |
| void grpc_lb_policy_grpclb_shutdown() {} |