// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2008-2014 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

/**
 * @defgroup debug  Debug
 * @{
 */

/**
 * @file
 * @brief  Debug console functions.
 */

#include <debug.h>
#include <inttypes.h>
#include <lib/console.h>
#include <lib/zircon-internal/macros.h>
#include <platform.h>
#include <stdio.h>
#include <string.h>
#include <zircon/errors.h>
#include <zircon/time.h>
#include <zircon/types.h>

#include <kernel/cpu.h>
#include <kernel/mp.h>
#include <kernel/percpu.h>
#include <kernel/thread.h>
#include <kernel/thread_lock.h>
#include <vm/vm.h>

static int cmd_thread(int argc, const cmd_args* argv, uint32_t flags);
static int cmd_threadstats(int argc, const cmd_args* argv, uint32_t flags);
static int cmd_threadload(int argc, const cmd_args* argv, uint32_t flags);
static int cmd_threadq(int argc, const cmd_args* argv, uint32_t flags);

STATIC_COMMAND_START
STATIC_COMMAND_MASKED("thread", "manipulate kernel threads", &cmd_thread, CMD_AVAIL_ALWAYS)
STATIC_COMMAND("threadstats", "thread level statistics", &cmd_threadstats)
STATIC_COMMAND("threadload", "toggle thread load display", &cmd_threadload)
STATIC_COMMAND("threadq", "toggle thread queue display", &cmd_threadq)
STATIC_COMMAND_END(kernel)

static int cmd_thread(int argc, const cmd_args* argv, uint32_t flags) {
  if (argc < 2) {
  notenoughargs:
    printf("not enough arguments\n");
  usage:
    printf("%s bt <thread pointer or id>\n", argv[0].str);
    printf("%s dump <thread pointer or id>\n", argv[0].str);
    printf("%s list\n", argv[0].str);
    printf("%s list_full\n", argv[0].str);
    return -1;
  }

  if (!strcmp(argv[1].str, "bt")) {
    if (argc < 3) {
      goto notenoughargs;
    }

    Thread* t = NULL;
    if (is_kernel_address(argv[2].u)) {
      t = (Thread*)argv[2].u;
    } else {
      t = thread_id_to_thread_slow(argv[2].u);
    }
    if (t) {
      Backtrace bt;
      t->GetBacktrace(bt);
      bt.Print();
    }
  } else if (!strcmp(argv[1].str, "dump")) {
    if (argc < 3) {
      goto notenoughargs;
    }

    Thread* t = NULL;
    if (is_kernel_address(argv[2].u)) {
      t = (Thread*)argv[2].u;
      dump_thread(t, true);
    } else {
      if (flags & CMD_FLAG_PANIC) {
        dump_thread_tid_during_panic(argv[2].u, true);
      } else {
        dump_thread_tid(argv[2].u, true);
      }
    }
  } else if (!strcmp(argv[1].str, "list")) {
    printf("thread list:\n");
    if (flags & CMD_FLAG_PANIC) {
      dump_all_threads_during_panic(false);
    } else {
      dump_all_threads(false);
    }
  } else if (!strcmp(argv[1].str, "list_full")) {
    printf("thread list:\n");
    if (flags & CMD_FLAG_PANIC) {
      dump_all_threads_during_panic(true);
    } else {
      dump_all_threads(true);
    }
  } else {
    printf("invalid args\n");
    goto usage;
  }

  // reschedule to let debuglog potentially run
  if (!(flags & CMD_FLAG_PANIC)) {
    Thread::Current::Reschedule();
  }

  return 0;
}

static int cmd_threadstats(int argc, const cmd_args* argv, uint32_t flags) {
  for (cpu_num_t i = 0; i < percpu::processor_count(); i++) {
    if (!mp_is_cpu_active(i)) {
      continue;
    }
    const auto& percpu = percpu::Get(i);

    printf("thread stats (cpu %u):\n", i);
    printf("\ttotal idle time: %" PRIi64 "\n", percpu.stats.idle_time);
    printf("\ttotal busy time: %" PRIi64 "\n",
           zx_time_sub_duration(current_time(), percpu.stats.idle_time));
    printf("\treschedules: %lu\n", percpu.stats.reschedules);
    printf("\treschedule_ipis: %lu\n", percpu.stats.reschedule_ipis);
    printf("\tcontext_switches: %lu\n", percpu.stats.context_switches);
    printf("\tpreempts: %lu\n", percpu.stats.preempts);
    printf("\tyields: %lu\n", percpu.stats.yields);
    printf("\ttimer interrupts: %lu\n", percpu.stats.timer_ints);
    printf("\ttimers: %lu\n", percpu.stats.timers);
  }

  return 0;
}

namespace {

RecurringCallback g_threadload_callback([]() {
  static struct cpu_stats old_stats[SMP_MAX_CPUS];
  static zx_duration_t last_idle_time[SMP_MAX_CPUS];

  printf(
      "cpu    load"
      " sched (cs ylds pmpts irq_pmpts)"
      "  sysc"
      " ints (hw  tmr tmr_cb)"
      " ipi (rs  gen)\n");
  for (cpu_num_t i = 0; i < percpu::processor_count(); i++) {
    Guard<MonitoredSpinLock, NoIrqSave> thread_lock_guard{ThreadLock::Get(), SOURCE_TAG};

    // dont display time for inactive cpus
    if (!mp_is_cpu_active(i)) {
      continue;
    }
    const auto& percpu = percpu::Get(i);

    zx_duration_t idle_time = percpu.stats.idle_time;

    // if the cpu is currently idle, add the time since it went idle up until now to the idle
    // counter
    bool is_idle = !!mp_is_cpu_idle(i);
    if (is_idle) {
      zx_duration_t recent_idle_time = zx_time_sub_time(
          current_time(), percpu.idle_thread.scheduler_state().last_started_running());
      idle_time = zx_duration_add_duration(idle_time, recent_idle_time);
    }

    zx_duration_t delta_time = zx_duration_sub_duration(idle_time, last_idle_time[i]);
    zx_duration_t busy_time;
    if (ZX_SEC(1) > delta_time) {
      busy_time = zx_duration_sub_duration(ZX_SEC(1), delta_time);
    } else {
      busy_time = 0;
    }
    zx_duration_t busypercent = zx_duration_mul_int64(busy_time, 10000) / ZX_SEC(1);

    printf(
        "%3u"
        " %3u.%02u%%"
        " %9lu %4lu %5lu %9lu"
        " %5lu"
        " %8lu %4lu %6lu"
        " %8lu %4lu"
        "\n",
        i, static_cast<uint>(busypercent / 100), static_cast<uint>(busypercent % 100),
        percpu.stats.context_switches - old_stats[i].context_switches,
        percpu.stats.yields - old_stats[i].yields, percpu.stats.preempts - old_stats[i].preempts,
        percpu.stats.irq_preempts - old_stats[i].irq_preempts,
        percpu.stats.syscalls - old_stats[i].syscalls,
        percpu.stats.interrupts - old_stats[i].interrupts,
        percpu.stats.timer_ints - old_stats[i].timer_ints,
        percpu.stats.timers - old_stats[i].timers,
        percpu.stats.reschedule_ipis - old_stats[i].reschedule_ipis,
        percpu.stats.generic_ipis - old_stats[i].generic_ipis);

    old_stats[i] = percpu.stats;
    last_idle_time[i] = idle_time;
  }
});

RecurringCallback g_threadq_callback([]() {
  printf("----------------------------------------------------\n");
  for (cpu_num_t i = 0; i < percpu::processor_count(); i++) {
    Guard<MonitoredSpinLock, NoIrqSave> thread_lock_guard{ThreadLock::Get(), SOURCE_TAG};

    if (!mp_is_cpu_active(i)) {
      continue;
    }

    printf("thread queue cpu %2u:\n", i);
    percpu::Get(i).scheduler.Dump();
  }
  printf("\n");
});

}  // anonymous namespace

static int cmd_threadload(int argc, const cmd_args* argv, uint32_t flags) {
  g_threadload_callback.Toggle();
  return 0;
}

static int cmd_threadq(int argc, const cmd_args* argv, uint32_t flags) {
  g_threadq_callback.Toggle();
  return 0;
}