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/*
*
* Copyright 2015-2016, 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.
*
*/
#include "src/core/channel/client_uchannel.h"
#include <string.h>
#include "src/core/census/grpc_filter.h"
#include "src/core/channel/channel_args.h"
#include "src/core/channel/client_channel.h"
#include "src/core/channel/compress_filter.h"
#include "src/core/channel/subchannel_call_holder.h"
#include "src/core/iomgr/iomgr.h"
#include "src/core/support/string.h"
#include "src/core/surface/channel.h"
#include "src/core/transport/connectivity_state.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/sync.h>
#include <grpc/support/useful.h>
/** Microchannel (uchannel) implementation: a lightweight channel without any
* load-balancing mechanisms meant for communication from within the core. */
typedef struct client_uchannel_channel_data {
/** master channel - the grpc_channel instance that ultimately owns
this channel_data via its channel stack.
We occasionally use this to bump the refcount on the master channel
to keep ourselves alive through an asynchronous operation. */
grpc_channel_stack *owning_stack;
/** connectivity state being tracked */
grpc_connectivity_state_tracker state_tracker;
/** the subchannel wrapped by the microchannel */
grpc_connected_subchannel *connected_subchannel;
/** the callback used to stay subscribed to subchannel connectivity
* notifications */
grpc_closure connectivity_cb;
/** the current connectivity state of the wrapped subchannel */
grpc_connectivity_state subchannel_connectivity;
gpr_mu mu_state;
} channel_data;
typedef grpc_subchannel_call_holder call_data;
static void monitor_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
bool iomgr_success) {
channel_data *chand = arg;
grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
chand->subchannel_connectivity,
"uchannel_monitor_subchannel");
grpc_connected_subchannel_notify_on_state_change(
exec_ctx, chand->connected_subchannel, NULL,
&chand->subchannel_connectivity, &chand->connectivity_cb);
}
static char *cuc_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
return grpc_subchannel_call_holder_get_peer(exec_ctx, elem->call_data);
}
static void cuc_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
grpc_call_element *elem,
grpc_transport_stream_op *op) {
GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
grpc_subchannel_call_holder_perform_op(exec_ctx, elem->call_data, op);
}
static void cuc_start_transport_op(grpc_exec_ctx *exec_ctx,
grpc_channel_element *elem,
grpc_transport_op *op) {
channel_data *chand = elem->channel_data;
grpc_exec_ctx_enqueue(exec_ctx, op->on_consumed, true, NULL);
GPR_ASSERT(op->set_accept_stream == NULL);
GPR_ASSERT(op->bind_pollset == NULL);
if (op->on_connectivity_state_change != NULL) {
grpc_connectivity_state_notify_on_state_change(
exec_ctx, &chand->state_tracker, op->connectivity_state,
op->on_connectivity_state_change);
op->on_connectivity_state_change = NULL;
op->connectivity_state = NULL;
}
if (op->disconnect) {
grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
GRPC_CHANNEL_FATAL_FAILURE, "disconnect");
}
}
static int cuc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg,
grpc_metadata_batch *initial_metadata,
grpc_connected_subchannel **connected_subchannel,
grpc_closure *on_ready) {
channel_data *chand = arg;
GPR_ASSERT(initial_metadata != NULL);
*connected_subchannel = chand->connected_subchannel;
return 1;
}
/* Constructor for call_data */
static void cuc_init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
grpc_call_element_args *args) {
grpc_subchannel_call_holder_init(elem->call_data, cuc_pick_subchannel,
elem->channel_data, args->call_stack);
}
/* Destructor for call_data */
static void cuc_destroy_call_elem(grpc_exec_ctx *exec_ctx,
grpc_call_element *elem) {
grpc_subchannel_call_holder_destroy(exec_ctx, elem->call_data);
}
/* Constructor for channel_data */
static void cuc_init_channel_elem(grpc_exec_ctx *exec_ctx,
grpc_channel_element *elem,
grpc_channel_element_args *args) {
channel_data *chand = elem->channel_data;
memset(chand, 0, sizeof(*chand));
grpc_closure_init(&chand->connectivity_cb, monitor_subchannel, chand);
GPR_ASSERT(args->is_last);
GPR_ASSERT(elem->filter == &grpc_client_uchannel_filter);
chand->owning_stack = args->channel_stack;
grpc_connectivity_state_init(&chand->state_tracker, GRPC_CHANNEL_IDLE,
"client_uchannel");
gpr_mu_init(&chand->mu_state);
}
/* Destructor for channel_data */
static void cuc_destroy_channel_elem(grpc_exec_ctx *exec_ctx,
grpc_channel_element *elem) {
channel_data *chand = elem->channel_data;
/* cancel subscription */
grpc_connected_subchannel_notify_on_state_change(
exec_ctx, chand->connected_subchannel, NULL, NULL,
&chand->connectivity_cb);
grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
gpr_mu_destroy(&chand->mu_state);
GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, chand->connected_subchannel,
"uchannel");
}
static void cuc_set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
grpc_pollset *pollset) {
call_data *calld = elem->call_data;
calld->pollset = pollset;
}
const grpc_channel_filter grpc_client_uchannel_filter = {
cuc_start_transport_stream_op, cuc_start_transport_op, sizeof(call_data),
cuc_init_call_elem, cuc_set_pollset, cuc_destroy_call_elem,
sizeof(channel_data), cuc_init_channel_elem, cuc_destroy_channel_elem,
cuc_get_peer, "client-uchannel",
};
grpc_connectivity_state grpc_client_uchannel_check_connectivity_state(
grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect) {
channel_data *chand = elem->channel_data;
grpc_connectivity_state out;
gpr_mu_lock(&chand->mu_state);
out = grpc_connectivity_state_check(&chand->state_tracker);
gpr_mu_unlock(&chand->mu_state);
return out;
}
void grpc_client_uchannel_watch_connectivity_state(
grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, grpc_pollset *pollset,
grpc_connectivity_state *state, grpc_closure *on_complete) {
channel_data *chand = elem->channel_data;
gpr_mu_lock(&chand->mu_state);
grpc_connectivity_state_notify_on_state_change(
exec_ctx, &chand->state_tracker, state, on_complete);
gpr_mu_unlock(&chand->mu_state);
}
grpc_channel *grpc_client_uchannel_create(grpc_subchannel *subchannel,
grpc_channel_args *args) {
grpc_channel *channel = NULL;
#define MAX_FILTERS 3
const grpc_channel_filter *filters[MAX_FILTERS];
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
size_t n = 0;
if (grpc_channel_args_is_census_enabled(args)) {
filters[n++] = &grpc_client_census_filter;
}
filters[n++] = &grpc_compress_filter;
filters[n++] = &grpc_client_uchannel_filter;
GPR_ASSERT(n <= MAX_FILTERS);
channel =
grpc_channel_create_from_filters(&exec_ctx, NULL, filters, n, args, 1);
return channel;
}
void grpc_client_uchannel_set_connected_subchannel(
grpc_channel *uchannel, grpc_connected_subchannel *connected_subchannel) {
grpc_channel_element *elem =
grpc_channel_stack_last_element(grpc_channel_get_channel_stack(uchannel));
channel_data *chand = elem->channel_data;
GPR_ASSERT(elem->filter == &grpc_client_uchannel_filter);
gpr_mu_lock(&chand->mu_state);
chand->connected_subchannel = connected_subchannel;
GRPC_CONNECTED_SUBCHANNEL_REF(connected_subchannel, "uchannel");
gpr_mu_unlock(&chand->mu_state);
}
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