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/*
*
* Copyright 2016 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.
*
*/
#include <grpc/support/port_platform.h>
#include <string.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/channel/handshaker.h"
#include "src/core/lib/iomgr/timer.h"
//
// grpc_handshaker
//
void grpc_handshaker_init(const grpc_handshaker_vtable* vtable,
grpc_handshaker* handshaker) {
handshaker->vtable = vtable;
}
void grpc_handshaker_destroy(grpc_handshaker* handshaker) {
handshaker->vtable->destroy(handshaker);
}
void grpc_handshaker_shutdown(grpc_handshaker* handshaker, grpc_error* why) {
handshaker->vtable->shutdown(handshaker, why);
}
void grpc_handshaker_do_handshake(grpc_handshaker* handshaker,
grpc_tcp_server_acceptor* acceptor,
grpc_closure* on_handshake_done,
grpc_handshaker_args* args) {
handshaker->vtable->do_handshake(handshaker, acceptor, on_handshake_done,
args);
}
//
// grpc_handshake_manager
//
struct grpc_handshake_manager {
gpr_mu mu;
gpr_refcount refs;
bool shutdown;
// An array of handshakers added via grpc_handshake_manager_add().
size_t count;
grpc_handshaker** handshakers;
// The index of the handshaker to invoke next and closure to invoke it.
size_t index;
grpc_closure call_next_handshaker;
// The acceptor to call the handshakers with.
grpc_tcp_server_acceptor* acceptor;
// Deadline timer across all handshakers.
grpc_timer deadline_timer;
grpc_closure on_timeout;
// The final callback and user_data to invoke after the last handshaker.
grpc_closure on_handshake_done;
void* user_data;
// Handshaker args.
grpc_handshaker_args args;
// Links to the previous and next managers in a list of all pending handshakes
// Used at server side only.
grpc_handshake_manager* prev;
grpc_handshake_manager* next;
};
grpc_handshake_manager* grpc_handshake_manager_create() {
grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>(
gpr_zalloc(sizeof(grpc_handshake_manager)));
gpr_mu_init(&mgr->mu);
gpr_ref_init(&mgr->refs, 1);
return mgr;
}
void grpc_handshake_manager_pending_list_add(grpc_handshake_manager** head,
grpc_handshake_manager* mgr) {
GPR_ASSERT(mgr->prev == nullptr);
GPR_ASSERT(mgr->next == nullptr);
mgr->next = *head;
if (*head) {
(*head)->prev = mgr;
}
*head = mgr;
}
void grpc_handshake_manager_pending_list_remove(grpc_handshake_manager** head,
grpc_handshake_manager* mgr) {
if (mgr->next != nullptr) {
mgr->next->prev = mgr->prev;
}
if (mgr->prev != nullptr) {
mgr->prev->next = mgr->next;
} else {
GPR_ASSERT(*head == mgr);
*head = mgr->next;
}
}
void grpc_handshake_manager_pending_list_shutdown_all(
grpc_handshake_manager* head, grpc_error* why) {
while (head != nullptr) {
grpc_handshake_manager_shutdown(head, GRPC_ERROR_REF(why));
head = head->next;
}
GRPC_ERROR_UNREF(why);
}
static bool is_power_of_2(size_t n) { return (n & (n - 1)) == 0; }
void grpc_handshake_manager_add(grpc_handshake_manager* mgr,
grpc_handshaker* handshaker) {
gpr_mu_lock(&mgr->mu);
// To avoid allocating memory for each handshaker we add, we double
// the number of elements every time we need more.
size_t realloc_count = 0;
if (mgr->count == 0) {
realloc_count = 2;
} else if (mgr->count >= 2 && is_power_of_2(mgr->count)) {
realloc_count = mgr->count * 2;
}
if (realloc_count > 0) {
mgr->handshakers = static_cast<grpc_handshaker**>(gpr_realloc(
mgr->handshakers, realloc_count * sizeof(grpc_handshaker*)));
}
mgr->handshakers[mgr->count++] = handshaker;
gpr_mu_unlock(&mgr->mu);
}
static void grpc_handshake_manager_unref(grpc_handshake_manager* mgr) {
if (gpr_unref(&mgr->refs)) {
for (size_t i = 0; i < mgr->count; ++i) {
grpc_handshaker_destroy(mgr->handshakers[i]);
}
gpr_free(mgr->handshakers);
gpr_mu_destroy(&mgr->mu);
gpr_free(mgr);
}
}
void grpc_handshake_manager_destroy(grpc_handshake_manager* mgr) {
grpc_handshake_manager_unref(mgr);
}
void grpc_handshake_manager_shutdown(grpc_handshake_manager* mgr,
grpc_error* why) {
gpr_mu_lock(&mgr->mu);
// Shutdown the handshaker that's currently in progress, if any.
if (!mgr->shutdown && mgr->index > 0) {
mgr->shutdown = true;
grpc_handshaker_shutdown(mgr->handshakers[mgr->index - 1],
GRPC_ERROR_REF(why));
}
gpr_mu_unlock(&mgr->mu);
GRPC_ERROR_UNREF(why);
}
// Helper function to call either the next handshaker or the
// on_handshake_done callback.
// Returns true if we've scheduled the on_handshake_done callback.
static bool call_next_handshaker_locked(grpc_handshake_manager* mgr,
grpc_error* error) {
GPR_ASSERT(mgr->index <= mgr->count);
// If we got an error or we've been shut down or we're exiting early or
// we've finished the last handshaker, invoke the on_handshake_done
// callback. Otherwise, call the next handshaker.
if (error != GRPC_ERROR_NONE || mgr->shutdown || mgr->args.exit_early ||
mgr->index == mgr->count) {
// Cancel deadline timer, since we're invoking the on_handshake_done
// callback now.
grpc_timer_cancel(&mgr->deadline_timer);
GRPC_CLOSURE_SCHED(&mgr->on_handshake_done, error);
mgr->shutdown = true;
} else {
grpc_handshaker_do_handshake(mgr->handshakers[mgr->index], mgr->acceptor,
&mgr->call_next_handshaker, &mgr->args);
}
++mgr->index;
return mgr->shutdown;
}
// A function used as the handshaker-done callback when chaining
// handshakers together.
static void call_next_handshaker(void* arg, grpc_error* error) {
grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>(arg);
gpr_mu_lock(&mgr->mu);
bool done = call_next_handshaker_locked(mgr, GRPC_ERROR_REF(error));
gpr_mu_unlock(&mgr->mu);
// If we're invoked the final callback, we won't be coming back
// to this function, so we can release our reference to the
// handshake manager.
if (done) {
grpc_handshake_manager_unref(mgr);
}
}
// Callback invoked when deadline is exceeded.
static void on_timeout(void* arg, grpc_error* error) {
grpc_handshake_manager* mgr = static_cast<grpc_handshake_manager*>(arg);
if (error == GRPC_ERROR_NONE) { // Timer fired, rather than being cancelled.
grpc_handshake_manager_shutdown(
mgr, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Handshake timed out"));
}
grpc_handshake_manager_unref(mgr);
}
void grpc_handshake_manager_do_handshake(
grpc_handshake_manager* mgr, grpc_pollset_set* interested_parties,
grpc_endpoint* endpoint, const grpc_channel_args* channel_args,
grpc_millis deadline, grpc_tcp_server_acceptor* acceptor,
grpc_iomgr_cb_func on_handshake_done, void* user_data) {
gpr_mu_lock(&mgr->mu);
GPR_ASSERT(mgr->index == 0);
GPR_ASSERT(!mgr->shutdown);
// Construct handshaker args. These will be passed through all
// handshakers and eventually be freed by the on_handshake_done callback.
mgr->args.interested_parties = interested_parties;
mgr->args.endpoint = endpoint;
mgr->args.args = grpc_channel_args_copy(channel_args);
mgr->args.user_data = user_data;
mgr->args.read_buffer = static_cast<grpc_slice_buffer*>(
gpr_malloc(sizeof(*mgr->args.read_buffer)));
grpc_slice_buffer_init(mgr->args.read_buffer);
// Initialize state needed for calling handshakers.
mgr->acceptor = acceptor;
GRPC_CLOSURE_INIT(&mgr->call_next_handshaker, call_next_handshaker, mgr,
grpc_schedule_on_exec_ctx);
GRPC_CLOSURE_INIT(&mgr->on_handshake_done, on_handshake_done, &mgr->args,
grpc_schedule_on_exec_ctx);
// Start deadline timer, which owns a ref.
gpr_ref(&mgr->refs);
GRPC_CLOSURE_INIT(&mgr->on_timeout, on_timeout, mgr,
grpc_schedule_on_exec_ctx);
grpc_timer_init(&mgr->deadline_timer, deadline, &mgr->on_timeout);
// Start first handshaker, which also owns a ref.
gpr_ref(&mgr->refs);
bool done = call_next_handshaker_locked(mgr, GRPC_ERROR_NONE);
gpr_mu_unlock(&mgr->mu);
if (done) {
grpc_handshake_manager_unref(mgr);
}
}
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