/* * * Copyright 2015 gRPC authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ #ifndef GRPC_CORE_LIB_TRANSPORT_TRANSPORT_H #define GRPC_CORE_LIB_TRANSPORT_TRANSPORT_H #include #include #include "src/core/lib/channel/context.h" #include "src/core/lib/gprpp/arena.h" #include "src/core/lib/iomgr/call_combiner.h" #include "src/core/lib/iomgr/endpoint.h" #include "src/core/lib/iomgr/polling_entity.h" #include "src/core/lib/iomgr/pollset.h" #include "src/core/lib/iomgr/pollset_set.h" #include "src/core/lib/slice/slice_internal.h" #include "src/core/lib/transport/byte_stream.h" #include "src/core/lib/transport/metadata_batch.h" /* Minimum and maximum protocol accepted versions. */ #define GRPC_PROTOCOL_VERSION_MAX_MAJOR 2 #define GRPC_PROTOCOL_VERSION_MAX_MINOR 1 #define GRPC_PROTOCOL_VERSION_MIN_MAJOR 2 #define GRPC_PROTOCOL_VERSION_MIN_MINOR 1 /* forward declarations */ typedef struct grpc_transport grpc_transport; /* grpc_stream doesn't actually exist. It's used as a typesafe opaque pointer for whatever data the transport wants to track for a stream. */ typedef struct grpc_stream grpc_stream; extern grpc_core::DebugOnlyTraceFlag grpc_trace_stream_refcount; typedef struct grpc_stream_refcount { grpc_core::RefCount refs; grpc_closure destroy; #ifndef NDEBUG const char* object_type; #endif grpc_slice_refcount slice_refcount; } grpc_stream_refcount; #ifndef NDEBUG void grpc_stream_ref_init(grpc_stream_refcount* refcount, int initial_refs, grpc_iomgr_cb_func cb, void* cb_arg, const char* object_type); #define GRPC_STREAM_REF_INIT(rc, ir, cb, cb_arg, objtype) \ grpc_stream_ref_init(rc, ir, cb, cb_arg, objtype) #else void grpc_stream_ref_init(grpc_stream_refcount* refcount, int initial_refs, grpc_iomgr_cb_func cb, void* cb_arg); #define GRPC_STREAM_REF_INIT(rc, ir, cb, cb_arg, objtype) \ grpc_stream_ref_init(rc, ir, cb, cb_arg) #endif #ifndef NDEBUG inline void grpc_stream_ref(grpc_stream_refcount* refcount, const char* reason) { if (grpc_trace_stream_refcount.enabled()) { gpr_log(GPR_DEBUG, "%s %p:%p REF %s", refcount->object_type, refcount, refcount->destroy.cb_arg, reason); } refcount->refs.RefNonZero(DEBUG_LOCATION, reason); } #else inline void grpc_stream_ref(grpc_stream_refcount* refcount) { refcount->refs.RefNonZero(); } #endif void grpc_stream_destroy(grpc_stream_refcount* refcount); #ifndef NDEBUG inline void grpc_stream_unref(grpc_stream_refcount* refcount, const char* reason) { if (grpc_trace_stream_refcount.enabled()) { gpr_log(GPR_DEBUG, "%s %p:%p UNREF %s", refcount->object_type, refcount, refcount->destroy.cb_arg, reason); } if (GPR_UNLIKELY(refcount->refs.Unref(DEBUG_LOCATION, reason))) { grpc_stream_destroy(refcount); } } #else inline void grpc_stream_unref(grpc_stream_refcount* refcount) { if (GPR_UNLIKELY(refcount->refs.Unref())) { grpc_stream_destroy(refcount); } } #endif /* Wrap a buffer that is owned by some stream object into a slice that shares the same refcount */ grpc_slice grpc_slice_from_stream_owned_buffer(grpc_stream_refcount* refcount, void* buffer, size_t length); struct grpc_transport_one_way_stats { uint64_t framing_bytes = 0; uint64_t data_bytes = 0; uint64_t header_bytes = 0; }; struct grpc_transport_stream_stats { grpc_transport_one_way_stats incoming; grpc_transport_one_way_stats outgoing; }; void grpc_transport_move_one_way_stats(grpc_transport_one_way_stats* from, grpc_transport_one_way_stats* to); void grpc_transport_move_stats(grpc_transport_stream_stats* from, grpc_transport_stream_stats* to); // This struct (which is present in both grpc_transport_stream_op_batch // and grpc_transport_op_batch) is a convenience to allow filters or // transports to schedule a closure related to a particular batch without // having to allocate memory. The general pattern is to initialize the // closure with the callback arg set to the batch and extra_arg set to // whatever state is associated with the handler (e.g., the call element // or the transport stream object). // // Note that this can only be used by the current handler of a given // batch on the way down the stack (i.e., whichever filter or transport is // currently handling the batch). Once a filter or transport passes control // of the batch to the next handler, it cannot depend on the contents of // this struct anymore, because the next handler may reuse it. struct grpc_handler_private_op_data { void* extra_arg = nullptr; grpc_closure closure; grpc_handler_private_op_data() { memset(&closure, 0, sizeof(closure)); } }; typedef struct grpc_transport_stream_op_batch_payload grpc_transport_stream_op_batch_payload; /* Transport stream op: a set of operations to perform on a transport against a single stream */ struct grpc_transport_stream_op_batch { grpc_transport_stream_op_batch() : send_initial_metadata(false), send_trailing_metadata(false), send_message(false), recv_initial_metadata(false), recv_message(false), recv_trailing_metadata(false), cancel_stream(false), is_traced(false) {} /** Should be scheduled when all of the non-recv operations in the batch are complete. The recv ops (recv_initial_metadata, recv_message, and recv_trailing_metadata) each have their own callbacks. If a batch contains both recv ops and non-recv ops, on_complete should be scheduled as soon as the non-recv ops are complete, regardless of whether or not the recv ops are complete. If a batch contains only recv ops, on_complete can be null. */ grpc_closure* on_complete = nullptr; /** Values for the stream op (fields set are determined by flags above) */ grpc_transport_stream_op_batch_payload* payload = nullptr; /** Send initial metadata to the peer, from the provided metadata batch. */ bool send_initial_metadata : 1; /** Send trailing metadata to the peer, from the provided metadata batch. */ bool send_trailing_metadata : 1; /** Send message data to the peer, from the provided byte stream. */ bool send_message : 1; /** Receive initial metadata from the stream, into provided metadata batch. */ bool recv_initial_metadata : 1; /** Receive message data from the stream, into provided byte stream. */ bool recv_message : 1; /** Receive trailing metadata from the stream, into provided metadata batch. */ bool recv_trailing_metadata : 1; /** Cancel this stream with the provided error */ bool cancel_stream : 1; /** Is this stream traced */ bool is_traced : 1; /*************************************************************************** * remaining fields are initialized and used at the discretion of the * current handler of the op */ grpc_handler_private_op_data handler_private; }; struct grpc_transport_stream_op_batch_payload { explicit grpc_transport_stream_op_batch_payload( grpc_call_context_element* context) : context(context) {} ~grpc_transport_stream_op_batch_payload() { // We don't really own `send_message`, so release ownership and let the // owner clean the data. send_message.send_message.release(); } struct { grpc_metadata_batch* send_initial_metadata = nullptr; /** Iff send_initial_metadata != NULL, flags associated with send_initial_metadata: a bitfield of GRPC_INITIAL_METADATA_xxx */ uint32_t send_initial_metadata_flags = 0; // If non-NULL, will be set by the transport to the peer string (a char*). // The transport retains ownership of the string. // Note: This pointer may be used by the transport after the // send_initial_metadata op is completed. It must remain valid // until the call is destroyed. gpr_atm* peer_string = nullptr; } send_initial_metadata; struct { grpc_metadata_batch* send_trailing_metadata = nullptr; } send_trailing_metadata; struct { // The transport (or a filter that decides to return a failure before // the op gets down to the transport) takes ownership. // The batch's on_complete will not be called until after the byte // stream is orphaned. grpc_core::OrphanablePtr send_message; // Set by the transport if the stream has been closed for writes. If this // is set and send message op is present, we set the operation to be a // failure without sending a cancel OP down the stack. This is so that the // status of the call does not get overwritten by the Cancel OP, which would // be especially problematic if we had received a valid status from the // server. // For send_initial_metadata, it is fine for the status to be overwritten // because at that point, the client will not have received a status. // For send_trailing_metadata, we might overwrite the status if we have // non-zero metadata to send. This is fine because the API does not allow // the client to send trailing metadata. bool stream_write_closed = false; } send_message; struct { grpc_metadata_batch* recv_initial_metadata = nullptr; // Flags are used only on the server side. If non-null, will be set to // a bitfield of the GRPC_INITIAL_METADATA_xxx macros (e.g., to // indicate if the call is idempotent). uint32_t* recv_flags = nullptr; /** Should be enqueued when initial metadata is ready to be processed. */ grpc_closure* recv_initial_metadata_ready = nullptr; // If not NULL, will be set to true if trailing metadata is // immediately available. This may be a signal that we received a // Trailers-Only response. bool* trailing_metadata_available = nullptr; // If non-NULL, will be set by the transport to the peer string (a char*). // The transport retains ownership of the string. // Note: This pointer may be used by the transport after the // recv_initial_metadata op is completed. It must remain valid // until the call is destroyed. gpr_atm* peer_string = nullptr; } recv_initial_metadata; struct { // Will be set by the transport to point to the byte stream // containing a received message. // Will be NULL if trailing metadata is received instead of a message. grpc_core::OrphanablePtr* recv_message = nullptr; /** Should be enqueued when one message is ready to be processed. */ grpc_closure* recv_message_ready = nullptr; } recv_message; struct { grpc_metadata_batch* recv_trailing_metadata = nullptr; grpc_transport_stream_stats* collect_stats = nullptr; /** Should be enqueued when initial metadata is ready to be processed. */ grpc_closure* recv_trailing_metadata_ready = nullptr; } recv_trailing_metadata; /** Forcefully close this stream. The HTTP2 semantics should be: - server side: if cancel_error has GRPC_ERROR_INT_GRPC_STATUS, and trailing metadata has not been sent, send trailing metadata with status and message from cancel_error (use grpc_error_get_status) followed by a RST_STREAM with error=GRPC_CHTTP2_NO_ERROR to force a full close - at all other times: use grpc_error_get_status to get a status code, and convert to a HTTP2 error code using grpc_chttp2_grpc_status_to_http2_error. Send a RST_STREAM with this error. */ struct { // Error contract: the transport that gets this op must cause cancel_error // to be unref'ed after processing it grpc_error* cancel_error = GRPC_ERROR_NONE; } cancel_stream; /* Indexes correspond to grpc_context_index enum values */ grpc_call_context_element* context; }; /** Transport op: a set of operations to perform on a transport as a whole */ typedef struct grpc_transport_op { /** Called when processing of this op is done. */ grpc_closure* on_consumed = nullptr; /** connectivity monitoring - set connectivity_state to NULL to unsubscribe */ grpc_closure* on_connectivity_state_change = nullptr; grpc_connectivity_state* connectivity_state = nullptr; /** should the transport be disconnected * Error contract: the transport that gets this op must cause * disconnect_with_error to be unref'ed after processing it */ grpc_error* disconnect_with_error = nullptr; /** what should the goaway contain? * Error contract: the transport that gets this op must cause * goaway_error to be unref'ed after processing it */ grpc_error* goaway_error = nullptr; /** set the callback for accepting new streams; this is a permanent callback, unlike the other one-shot closures. If true, the callback is set to set_accept_stream_fn, with its user_data argument set to set_accept_stream_user_data */ bool set_accept_stream = false; void (*set_accept_stream_fn)(void* user_data, grpc_transport* transport, const void* server_data) = nullptr; void* set_accept_stream_user_data = nullptr; /** add this transport to a pollset */ grpc_pollset* bind_pollset = nullptr; /** add this transport to a pollset_set */ grpc_pollset_set* bind_pollset_set = nullptr; /** send a ping, if either on_initiate or on_ack is not NULL */ struct { /** Ping may be delayed by the transport, on_initiate callback will be called when the ping is actually being sent. */ grpc_closure* on_initiate = nullptr; /** Called when the ping ack is received */ grpc_closure* on_ack = nullptr; } send_ping; // If true, will reset the channel's connection backoff. bool reset_connect_backoff = false; /*************************************************************************** * remaining fields are initialized and used at the discretion of the * transport implementation */ grpc_handler_private_op_data handler_private; } grpc_transport_op; /* Returns the amount of memory required to store a grpc_stream for this transport */ size_t grpc_transport_stream_size(grpc_transport* transport); /* Initialize transport data for a stream. Returns 0 on success, any other (transport-defined) value for failure. May assume that stream contains all-zeros. Arguments: transport - the transport on which to create this stream stream - a pointer to uninitialized memory to initialize server_data - either NULL for a client initiated stream, or a pointer supplied from the accept_stream callback function */ int grpc_transport_init_stream(grpc_transport* transport, grpc_stream* stream, grpc_stream_refcount* refcount, const void* server_data, grpc_core::Arena* arena); void grpc_transport_set_pops(grpc_transport* transport, grpc_stream* stream, grpc_polling_entity* pollent); /* Destroy transport data for a stream. Requires: a recv_batch with final_state == GRPC_STREAM_CLOSED has been received by the up-layer. Must not be called in the same call stack as recv_frame. Arguments: transport - the transport on which to create this stream stream - the grpc_stream to destroy (memory is still owned by the caller, but any child memory must be cleaned up) */ void grpc_transport_destroy_stream(grpc_transport* transport, grpc_stream* stream, grpc_closure* then_schedule_closure); void grpc_transport_stream_op_batch_finish_with_failure( grpc_transport_stream_op_batch* op, grpc_error* error, grpc_core::CallCombiner* call_combiner); char* grpc_transport_stream_op_batch_string(grpc_transport_stream_op_batch* op); char* grpc_transport_op_string(grpc_transport_op* op); /* Send a batch of operations on a transport Takes ownership of any objects contained in ops. Arguments: transport - the transport on which to initiate the stream stream - the stream on which to send the operations. This must be non-NULL and previously initialized by the same transport. op - a grpc_transport_stream_op_batch specifying the op to perform */ void grpc_transport_perform_stream_op(grpc_transport* transport, grpc_stream* stream, grpc_transport_stream_op_batch* op); void grpc_transport_perform_op(grpc_transport* transport, grpc_transport_op* op); /* Send a ping on a transport Calls cb with user data when a response is received. */ void grpc_transport_ping(grpc_transport* transport, grpc_closure* cb); /* Advise peer of pending connection termination. */ void grpc_transport_goaway(grpc_transport* transport, grpc_status_code status, grpc_slice debug_data); /* Destroy the transport */ void grpc_transport_destroy(grpc_transport* transport); /* Get the endpoint used by \a transport */ grpc_endpoint* grpc_transport_get_endpoint(grpc_transport* transport); /* Allocate a grpc_transport_op, and preconfigure the on_consumed closure to \a on_consumed and then delete the returned transport op */ grpc_transport_op* grpc_make_transport_op(grpc_closure* on_consumed); /* Allocate a grpc_transport_stream_op_batch, and preconfigure the on_consumed closure to \a on_consumed and then delete the returned transport op */ grpc_transport_stream_op_batch* grpc_make_transport_stream_op( grpc_closure* on_consumed); #endif /* GRPC_CORE_LIB_TRANSPORT_TRANSPORT_H */