From 9f0f5947890c7899b7c9f1059989b97a2f2d37f0 Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Tue, 2 Aug 2016 14:15:45 +0200 Subject: [PATCH] grpc plugin: Switch to the synchronous interface. --- src/collectd.conf.in | 1 - src/collectd.conf.pod | 5 - src/grpc.cc | 280 ++++++++++-------------------------------- 3 files changed, 65 insertions(+), 221 deletions(-) diff --git a/src/collectd.conf.in b/src/collectd.conf.in index b678c425..9375202b 100644 --- a/src/collectd.conf.in +++ b/src/collectd.conf.in @@ -565,7 +565,6 @@ # # -# WorkerThreads 5 # # EnableSSL true # SSLRootCerts "/path/to/root.pem" diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod index ac06547f..381d6729 100644 --- a/src/collectd.conf.pod +++ b/src/collectd.conf.pod @@ -2669,11 +2669,6 @@ connections. =back -=item B I - -Number of threads to start for handling incoming connections. The default -value is B<5>. - =back =head2 Plugin C diff --git a/src/grpc.cc b/src/grpc.cc index aeb1c6d0..5a5899dd 100644 --- a/src/grpc.cc +++ b/src/grpc.cc @@ -258,95 +258,43 @@ static grpc::Status unmarshal_value_list(const collectd::types::ValueList &msg, return status; } /* unmarshal_value_list() */ -/* - * request call-backs and call objects - */ -static grpc::Status DispatchValue(grpc::ServerContext *ctx, DispatchValuesRequest request, DispatchValuesResponse *reply) -{ - value_list_t vl = VALUE_LIST_INIT; - auto status = unmarshal_value_list(request.value_list(), &vl); - if (!status.ok()) - return status; - - if (plugin_dispatch_values(&vl)) - status = grpc::Status(grpc::StatusCode::INTERNAL, - grpc::string("failed to enqueue values for writing")); - - reply->Clear(); - return status; -} /* grpc::Status DispatchValue */ - -// CallData is the abstract base class for asynchronous calls. -class CallData { -public: - virtual ~CallData() {} - virtual void process(bool ok) = 0; - -protected: - CallData() {} - -private: - CallData(const CallData&) = delete; - CallData& operator=(const CallData&) = delete; -}; - /* * Collectd service */ - -// QueryValuesCallData holds the state and implements the logic for QueryValues calls. -class QueryValuesCallData : public CallData { +class CollectdImpl : public collectd::Collectd::Service { public: - QueryValuesCallData(Collectd::AsyncService* service, grpc::ServerCompletionQueue* cq) - : cq_(cq), service_(service), writer_(&context_) { - process(true); - } + grpc::Status QueryValues(grpc::ServerContext *ctx, QueryValuesRequest const *req, grpc::ServerWriter *writer) override { + value_list_t match; + auto err = unmarshal_ident(req->identifier(), &match, false); + if (!err.ok()) { + return err; + } - void process(bool ok) final { - if (status_ == Status::INIT) { - status_ = Status::READ; - service_->RequestQueryValues(&context_, &request_, &writer_, cq_, cq_, this); - } else if (status_ == Status::READ) { - auto err = queryValues(); - if (!err.ok()) { - writer_.Finish(err, this); - status_ = Status::DONE; - return; - } - respond(); - } else if (status_ == Status::WRITE) { - respond(); - } else if (status_ == Status::DONE) { - new QueryValuesCallData(service_, cq_); - delete this; - } else { - throw std::logic_error("Unhandled state enum."); + std::queue value_lists; + err = this->read(&match, &value_lists); + if (err.ok()) { + err = this->write(ctx, writer, &value_lists); + } + + while (!value_lists.empty()) { + auto vl = value_lists.front(); + value_lists.pop(); + sfree(vl.values); } + + return err; } private: - enum class Status { - INIT, - READ, - WRITE, - DONE, - }; - - grpc::Status queryValues (void) { + grpc::Status read(value_list_t const *match, std::queue *value_lists) { uc_iter_t *iter; - char *name = NULL; - - value_list_t matcher; - auto status = unmarshal_ident(request_.identifier(), &matcher, false); - if (!status.ok()) - return status; - if ((iter = uc_get_iterator()) == NULL) { return grpc::Status(grpc::StatusCode::INTERNAL, grpc::string("failed to query values: cannot create iterator")); } - status = grpc::Status::OK; + grpc::Status status = grpc::Status::OK; + char *name = NULL; while (uc_iterator_next(iter, &name) == 0) { value_list_t vl; if (parse_identifier_vl(name, &vl) != 0) { @@ -355,7 +303,7 @@ private: break; } - if (!ident_matches(&vl, &matcher)) + if (!ident_matches(&vl, match)) continue; if (uc_iterator_get_time(iter, &vl.time) < 0) { @@ -374,97 +322,62 @@ private: break; } - value_lists_.push(vl); - } + value_lists->push(vl); + } // while (uc_iterator_next(iter, &name) == 0) uc_iterator_destroy(iter); return status; } - void respond() { - if (value_lists_.empty()) { - writer_.Finish(grpc::Status::OK, this); - status_ = Status::DONE; - return; - } + grpc::Status write(grpc::ServerContext *ctx, + grpc::ServerWriter *writer, + std::queue *value_lists) { + while (!value_lists->empty()) { + auto vl = value_lists->front(); + QueryValuesResponse res; + res.Clear(); + + auto err = marshal_value_list(&vl, res.mutable_value_list()); + if (!err.ok()) { + return err; + } - auto vl = value_lists_.front(); + if (!writer->Write(res)) { + return grpc::Status::CANCELLED; + } - response_.Clear(); - auto err = marshal_value_list(&vl, response_.mutable_value_list()); - if (!err.ok()) { - writer_.Finish(err, this); - status_ = Status::DONE; - return; + value_lists->pop(); + sfree(vl.values); } - value_lists_.pop(); - free(vl.values); - - writer_.Write(response_, this); - status_ = Status::WRITE; + return grpc::Status::OK; } - - Status status_ = Status::INIT; - grpc::ServerContext context_; - grpc::ServerCompletionQueue* cq_; - Collectd::AsyncService* service_; - QueryValuesRequest request_; - std::queue value_lists_; - QueryValuesResponse response_; - grpc::ServerAsyncWriter writer_; }; /* * Dispatch service */ -// DispatchValuesCallData holds the state and implements the logic for DispatchValues calls. -class DispatchValuesCallData : public CallData { +class DispatchImpl : public collectd::Dispatch::Service { public: - DispatchValuesCallData(Dispatch::AsyncService* service, grpc::ServerCompletionQueue* cq) - : cq_(cq), service_(service), reader_(&context_) { - process(true); - } - - void process(bool ok) final { - if (status == Status::INIT) { - service_->RequestDispatchValues(&context_, &reader_, cq_, cq_, this); - status = Status::CALL; - } else if (status == Status::CALL) { - reader_.Read(&request_, this); - status = Status::READ; - } else if (status == Status::READ && ok) { - (void) DispatchValue(&context_, request_, &response_); - - reader_.Read(&request_, this); - } else if (status == Status::READ) { - response_.Clear(); - - status = Status::DONE; - } else if (status == Status::DONE) { - new DispatchValuesCallData(service_, cq_); - delete this; - } else { - ERROR("grpc: DispatchValuesCallData: invalid state"); + grpc::Status DispatchValues(grpc::ServerContext *ctx, + grpc::ServerReader *reader, + DispatchValuesResponse *res) override { + DispatchValuesRequest req; + + while (reader->Read(&req)) { + value_list_t vl = VALUE_LIST_INIT; + auto status = unmarshal_value_list(req.value_list(), &vl); + if (!status.ok()) + return status; + + if (plugin_dispatch_values(&vl)) + return grpc::Status(grpc::StatusCode::INTERNAL, + grpc::string("failed to enqueue values for writing")); } - } -private: - enum class Status { - INIT, - CALL, - READ, - DONE, - }; - Status status = Status::INIT; - - grpc::ServerContext context_; - grpc::ServerCompletionQueue* cq_; - Dispatch::AsyncService* service_; - - DispatchValuesRequest request_; - DispatchValuesResponse response_; - grpc::ServerAsyncReader reader_; + res->Clear(); + return grpc::Status::OK; + } }; /* @@ -499,44 +412,22 @@ public: } } - cq_ = builder.AddCompletionQueue(); - builder.RegisterService(&collectd_service_); builder.RegisterService(&dispatch_service_); server_ = builder.BuildAndStart(); - new QueryValuesCallData(&collectd_service_, cq_.get()); - new DispatchValuesCallData(&dispatch_service_, cq_.get()); } /* Start() */ void Shutdown() { server_->Shutdown(); - cq_->Shutdown(); } /* Shutdown() */ - void Mainloop() - { - while (true) { - void *tag = NULL; - bool ok = false; - - // Block waiting to read the next event from the completion queue. - // The event is uniquely identified by its tag, which in this case - // is the memory address of a CallData instance. - if (!cq_->Next(&tag, &ok)) - break; // Queue shut down. - - static_cast(tag)->process(ok); - } - } /* Mainloop() */ - private: - Collectd::AsyncService collectd_service_; - Dispatch::AsyncService dispatch_service_; + CollectdImpl collectd_service_; + DispatchImpl dispatch_service_; std::unique_ptr server_; - std::unique_ptr cq_; }; /* class CollectdServer */ static CollectdServer *server = nullptr; @@ -545,16 +436,6 @@ static CollectdServer *server = nullptr; * collectd plugin interface */ extern "C" { - static pthread_t *workers; - static size_t workers_num = 5; - - static void *worker_thread(void *arg) - { - CollectdServer *s = (CollectdServer *)arg; - s->Mainloop(); - return NULL; - } /* worker_thread() */ - static int c_grpc_config_listen(oconfig_item_t *ci) { if ((ci->values_num != 2) @@ -638,12 +519,6 @@ extern "C" { if (c_grpc_config_listen(child)) return -1; } - else if (!strcasecmp("WorkerThreads", child->key)) { - int n; - if (cf_util_get_int(child, &n)) - return -1; - workers_num = (size_t)n; - } else { WARNING("grpc: Option `%s` not allowed here.", child->key); } @@ -655,47 +530,22 @@ extern "C" { static int c_grpc_init(void) { server = new CollectdServer(); - size_t i; - - if (! server) { + if (!server) { ERROR("grpc: Failed to create server"); return -1; } - workers = (pthread_t *)calloc(workers_num, sizeof(*workers)); - if (! workers) { - delete server; - server = nullptr; - - ERROR("grpc: Failed to allocate worker threads"); - return -1; - } - server->Start(); - for (i = 0; i < workers_num; i++) { - plugin_thread_create(&workers[i], /* attr = */ NULL, - worker_thread, server); - } - INFO("grpc: Started %zu workers", workers_num); return 0; } /* c_grpc_init() */ static int c_grpc_shutdown(void) { - size_t i; - if (!server) - return -1; + return 0; server->Shutdown(); - INFO("grpc: Waiting for %zu workers to terminate", workers_num); - for (i = 0; i < workers_num; i++) - pthread_join(workers[i], NULL); - free(workers); - workers = NULL; - workers_num = 0; - delete server; server = nullptr; -- 2.30.2