/*
 *
 * 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.
 *
 */

#include "src/core/lib/iomgr/combiner.h"

#include <grpc/grpc.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/thd.h>
#include <grpc/support/useful.h>

#include "test/core/util/test_config.h"

static void test_no_op(void) {
  gpr_log(GPR_DEBUG, "test_no_op");
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  GRPC_COMBINER_UNREF(&exec_ctx, grpc_combiner_create(), "test_no_op");
  grpc_exec_ctx_finish(&exec_ctx);
}

static void set_event_to_true(grpc_exec_ctx *exec_ctx, void *value,
                              grpc_error *error) {
  gpr_event_set(value, (void *)1);
}

static void test_execute_one(void) {
  gpr_log(GPR_DEBUG, "test_execute_one");

  grpc_combiner *lock = grpc_combiner_create();
  gpr_event done;
  gpr_event_init(&done);
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  GRPC_CLOSURE_SCHED(&exec_ctx,
                     GRPC_CLOSURE_CREATE(set_event_to_true, &done,
                                         grpc_combiner_scheduler(lock)),
                     GRPC_ERROR_NONE);
  grpc_exec_ctx_flush(&exec_ctx);
  GPR_ASSERT(gpr_event_wait(&done, grpc_timeout_seconds_to_deadline(5)) !=
             NULL);
  GRPC_COMBINER_UNREF(&exec_ctx, lock, "test_execute_one");
  grpc_exec_ctx_finish(&exec_ctx);
}

typedef struct {
  size_t ctr;
  grpc_combiner *lock;
  gpr_event done;
} thd_args;

typedef struct {
  size_t *ctr;
  size_t value;
} ex_args;

static void check_one(grpc_exec_ctx *exec_ctx, void *a, grpc_error *error) {
  ex_args *args = a;
  GPR_ASSERT(*args->ctr == args->value - 1);
  *args->ctr = args->value;
  gpr_free(a);
}

static void execute_many_loop(void *a) {
  thd_args *args = a;
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  size_t n = 1;
  for (size_t i = 0; i < 10; i++) {
    for (size_t j = 0; j < 10000; j++) {
      ex_args *c = gpr_malloc(sizeof(*c));
      c->ctr = &args->ctr;
      c->value = n++;
      GRPC_CLOSURE_SCHED(&exec_ctx,
                         GRPC_CLOSURE_CREATE(
                             check_one, c, grpc_combiner_scheduler(args->lock)),
                         GRPC_ERROR_NONE);
      grpc_exec_ctx_flush(&exec_ctx);
    }
    // sleep for a little bit, to test a combiner draining and another thread
    // picking it up
    gpr_sleep_until(grpc_timeout_milliseconds_to_deadline(100));
  }
  GRPC_CLOSURE_SCHED(&exec_ctx,
                     GRPC_CLOSURE_CREATE(set_event_to_true, &args->done,
                                         grpc_combiner_scheduler(args->lock)),
                     GRPC_ERROR_NONE);
  grpc_exec_ctx_finish(&exec_ctx);
}

static void test_execute_many(void) {
  gpr_log(GPR_DEBUG, "test_execute_many");

  grpc_combiner *lock = grpc_combiner_create();
  gpr_thd_id thds[100];
  thd_args ta[GPR_ARRAY_SIZE(thds)];
  for (size_t i = 0; i < GPR_ARRAY_SIZE(thds); i++) {
    gpr_thd_options options = gpr_thd_options_default();
    gpr_thd_options_set_joinable(&options);
    ta[i].ctr = 0;
    ta[i].lock = lock;
    gpr_event_init(&ta[i].done);
    GPR_ASSERT(gpr_thd_new(&thds[i], execute_many_loop, &ta[i], &options));
  }
  for (size_t i = 0; i < GPR_ARRAY_SIZE(thds); i++) {
    GPR_ASSERT(gpr_event_wait(&ta[i].done,
                              gpr_inf_future(GPR_CLOCK_REALTIME)) != NULL);
    gpr_thd_join(thds[i]);
  }
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  GRPC_COMBINER_UNREF(&exec_ctx, lock, "test_execute_many");
  grpc_exec_ctx_finish(&exec_ctx);
}

static gpr_event got_in_finally;

static void in_finally(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
  gpr_event_set(&got_in_finally, (void *)1);
}

static void add_finally(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
  GRPC_CLOSURE_SCHED(exec_ctx,
                     GRPC_CLOSURE_CREATE(in_finally, arg,
                                         grpc_combiner_finally_scheduler(arg)),
                     GRPC_ERROR_NONE);
}

static void test_execute_finally(void) {
  gpr_log(GPR_DEBUG, "test_execute_finally");

  grpc_combiner *lock = grpc_combiner_create();
  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
  gpr_event_init(&got_in_finally);
  GRPC_CLOSURE_SCHED(
      &exec_ctx,
      GRPC_CLOSURE_CREATE(add_finally, lock, grpc_combiner_scheduler(lock)),
      GRPC_ERROR_NONE);
  grpc_exec_ctx_flush(&exec_ctx);
  GPR_ASSERT(gpr_event_wait(&got_in_finally,
                            grpc_timeout_seconds_to_deadline(5)) != NULL);
  GRPC_COMBINER_UNREF(&exec_ctx, lock, "test_execute_finally");
  grpc_exec_ctx_finish(&exec_ctx);
}

int main(int argc, char **argv) {
  grpc_test_init(argc, argv);
  grpc_init();
  test_no_op();
  test_execute_one();
  test_execute_finally();
  test_execute_many();
  grpc_shutdown();

  return 0;
}