#include <errno.h>

  #include <inttypes.h>

  #include "builtin.h"
  #include "perf.h"

  #include "util/evlist.h"

  #include "util/evsel.h"

  #include "util/util.h"
  #include "util/cache.h"
  #include "util/symbol.h"
  #include "util/thread.h"
  #include "util/header.h"

  #include <subcmd/parse-options.h>

  #include "util/trace-event.h"
  
  #include "util/debug.h"
  #include "util/session.h"

  #include "util/tool.h"

  #include "util/data.h"

  
  #include <sys/types.h>
  #include <sys/prctl.h>
  #include <semaphore.h>
  #include <pthread.h>
  #include <math.h>
  #include <limits.h>
  
  #include <linux/list.h>
  #include <linux/hash.h>

  #include <linux/kernel.h>

  static struct perf_session *session;

  /* based on kernel/lockdep.c */
  #define LOCKHASH_BITS		12
  #define LOCKHASH_SIZE		(1UL << LOCKHASH_BITS)
  
  static struct list_head lockhash_table[LOCKHASH_SIZE];
  
  #define __lockhashfn(key)	hash_long((unsigned long)key, LOCKHASH_BITS)
  #define lockhashentry(key)	(lockhash_table + __lockhashfn((key)))

  struct lock_stat {

  	struct list_head	hash_entry;
  	struct rb_node		rb;		/* used for sorting */

  	/*

  	 * FIXME: perf_evsel__intval() returns u64,

  	 * so address of lockdep_map should be dealed as 64bit.

  	 * Is there more better solution?
  	 */
  	void			*addr;		/* address of lockdep_map, used as ID */
  	char			*name;		/* for strcpy(), we cannot use const */

  	unsigned int		nr_acquire;

  	unsigned int		nr_acquired;

  	unsigned int		nr_contended;
  	unsigned int		nr_release;

  	unsigned int		nr_readlock;
  	unsigned int		nr_trylock;

  	/* these times are in nano sec. */

  	u64                     avg_wait_time;

  	u64			wait_time_total;
  	u64			wait_time_min;
  	u64			wait_time_max;

  
  	int			discard; /* flag of blacklist */
  };
  
  /*
   * States of lock_seq_stat
   *
   * UNINITIALIZED is required for detecting first event of acquire.
   * As the nature of lock events, there is no guarantee
   * that the first event for the locks are acquire,
   * it can be acquired, contended or release.
   */
  #define SEQ_STATE_UNINITIALIZED      0	       /* initial state */
  #define SEQ_STATE_RELEASED	1
  #define SEQ_STATE_ACQUIRING	2
  #define SEQ_STATE_ACQUIRED	3
  #define SEQ_STATE_READ_ACQUIRED	4
  #define SEQ_STATE_CONTENDED	5
  
  /*
   * MAX_LOCK_DEPTH
   * Imported from include/linux/sched.h.
   * Should this be synchronized?
   */
  #define MAX_LOCK_DEPTH 48
  
  /*
   * struct lock_seq_stat:
   * Place to put on state of one lock sequence
   * 1) acquire -> acquired -> release
   * 2) acquire -> contended -> acquired -> release
   * 3) acquire (with read or try) -> release
   * 4) Are there other patterns?
   */
  struct lock_seq_stat {
  	struct list_head        list;
  	int			state;
  	u64			prev_event_time;
  	void                    *addr;
  
  	int                     read_count;

  };

  struct thread_stat {
  	struct rb_node		rb;
  
  	u32                     tid;
  	struct list_head        seq_list;
  };
  
  static struct rb_root		thread_stats;
  
  static struct thread_stat *thread_stat_find(u32 tid)
  {
  	struct rb_node *node;
  	struct thread_stat *st;
  
  	node = thread_stats.rb_node;
  	while (node) {
  		st = container_of(node, struct thread_stat, rb);
  		if (st->tid == tid)
  			return st;
  		else if (tid < st->tid)
  			node = node->rb_left;
  		else
  			node = node->rb_right;
  	}
  
  	return NULL;
  }
  
  static void thread_stat_insert(struct thread_stat *new)
  {
  	struct rb_node **rb = &thread_stats.rb_node;
  	struct rb_node *parent = NULL;
  	struct thread_stat *p;
  
  	while (*rb) {
  		p = container_of(*rb, struct thread_stat, rb);
  		parent = *rb;
  
  		if (new->tid < p->tid)
  			rb = &(*rb)->rb_left;
  		else if (new->tid > p->tid)
  			rb = &(*rb)->rb_right;
  		else
  			BUG_ON("inserting invalid thread_stat
  ");
  	}
  
  	rb_link_node(&new->rb, parent, rb);
  	rb_insert_color(&new->rb, &thread_stats);
  }
  
  static struct thread_stat *thread_stat_findnew_after_first(u32 tid)
  {
  	struct thread_stat *st;
  
  	st = thread_stat_find(tid);
  	if (st)
  		return st;
  
  	st = zalloc(sizeof(struct thread_stat));

  	if (!st) {
  		pr_err("memory allocation failed
  ");
  		return NULL;
  	}

  
  	st->tid = tid;
  	INIT_LIST_HEAD(&st->seq_list);
  
  	thread_stat_insert(st);
  
  	return st;
  }
  
  static struct thread_stat *thread_stat_findnew_first(u32 tid);
  static struct thread_stat *(*thread_stat_findnew)(u32 tid) =
  	thread_stat_findnew_first;
  
  static struct thread_stat *thread_stat_findnew_first(u32 tid)
  {
  	struct thread_stat *st;
  
  	st = zalloc(sizeof(struct thread_stat));

  	if (!st) {
  		pr_err("memory allocation failed
  ");
  		return NULL;
  	}

  	st->tid = tid;
  	INIT_LIST_HEAD(&st->seq_list);
  
  	rb_link_node(&st->rb, NULL, &thread_stats.rb_node);
  	rb_insert_color(&st->rb, &thread_stats);
  
  	thread_stat_findnew = thread_stat_findnew_after_first;
  	return st;
  }

  /* build simple key function one is bigger than two */

  #define SINGLE_KEY(member)						\

  	static int lock_stat_key_ ## member(struct lock_stat *one,	\
  					 struct lock_stat *two)		\
  	{								\
  		return one->member > two->member;			\
  	}
  
  SINGLE_KEY(nr_acquired)
  SINGLE_KEY(nr_contended)

  SINGLE_KEY(avg_wait_time)

  SINGLE_KEY(wait_time_total)

  SINGLE_KEY(wait_time_max)

  static int lock_stat_key_wait_time_min(struct lock_stat *one,
  					struct lock_stat *two)
  {
  	u64 s1 = one->wait_time_min;
  	u64 s2 = two->wait_time_min;
  	if (s1 == ULLONG_MAX)
  		s1 = 0;
  	if (s2 == ULLONG_MAX)
  		s2 = 0;
  	return s1 > s2;
  }

  struct lock_key {
  	/*
  	 * name: the value for specify by user
  	 * this should be simpler than raw name of member
  	 * e.g. nr_acquired -> acquired, wait_time_total -> wait_total
  	 */

  	const char		*name;
  	int			(*key)(struct lock_stat*, struct lock_stat*);

  };

  static const char		*sort_key = "acquired";
  
  static int			(*compare)(struct lock_stat *, struct lock_stat *);
  
  static struct rb_root		result;	/* place to store sorted data */

  
  #define DEF_KEY_LOCK(name, fn_suffix)	\
  	{ #name, lock_stat_key_ ## fn_suffix }
  struct lock_key keys[] = {
  	DEF_KEY_LOCK(acquired, nr_acquired),
  	DEF_KEY_LOCK(contended, nr_contended),

  	DEF_KEY_LOCK(avg_wait, avg_wait_time),

  	DEF_KEY_LOCK(wait_total, wait_time_total),
  	DEF_KEY_LOCK(wait_min, wait_time_min),
  	DEF_KEY_LOCK(wait_max, wait_time_max),
  
  	/* extra comparisons much complicated should be here */
  
  	{ NULL, NULL }
  };

  static int select_key(void)

  {
  	int i;
  
  	for (i = 0; keys[i].name; i++) {
  		if (!strcmp(keys[i].name, sort_key)) {
  			compare = keys[i].key;

  			return 0;

  		}
  	}

  	pr_err("Unknown compare key: %s
  ", sort_key);
  
  	return -1;

  }

  static void insert_to_result(struct lock_stat *st,

  			     int (*bigger)(struct lock_stat *, struct lock_stat *))

  {
  	struct rb_node **rb = &result.rb_node;
  	struct rb_node *parent = NULL;
  	struct lock_stat *p;
  
  	while (*rb) {
  		p = container_of(*rb, struct lock_stat, rb);
  		parent = *rb;
  
  		if (bigger(st, p))
  			rb = &(*rb)->rb_left;
  		else
  			rb = &(*rb)->rb_right;
  	}
  
  	rb_link_node(&st->rb, parent, rb);
  	rb_insert_color(&st->rb, &result);
  }
  
  /* returns left most element of result, and erase it */
  static struct lock_stat *pop_from_result(void)
  {
  	struct rb_node *node = result.rb_node;
  
  	if (!node)
  		return NULL;
  
  	while (node->rb_left)
  		node = node->rb_left;
  
  	rb_erase(node, &result);
  	return container_of(node, struct lock_stat, rb);
  }

  static struct lock_stat *lock_stat_findnew(void *addr, const char *name)

  {
  	struct list_head *entry = lockhashentry(addr);
  	struct lock_stat *ret, *new;
  
  	list_for_each_entry(ret, entry, hash_entry) {
  		if (ret->addr == addr)
  			return ret;
  	}
  
  	new = zalloc(sizeof(struct lock_stat));
  	if (!new)
  		goto alloc_failed;
  
  	new->addr = addr;
  	new->name = zalloc(sizeof(char) * strlen(name) + 1);

  	if (!new->name) {
  		free(new);

  		goto alloc_failed;

  	}

  	strcpy(new->name, name);

  	new->wait_time_min = ULLONG_MAX;
  
  	list_add(&new->hash_entry, entry);
  	return new;
  
  alloc_failed:

  	pr_err("memory allocation failed
  ");
  	return NULL;

  }

  struct trace_lock_handler {

  	int (*acquire_event)(struct perf_evsel *evsel,
  			     struct perf_sample *sample);

  	int (*acquired_event)(struct perf_evsel *evsel,
  			      struct perf_sample *sample);

  	int (*contended_event)(struct perf_evsel *evsel,
  			       struct perf_sample *sample);

  	int (*release_event)(struct perf_evsel *evsel,
  			     struct perf_sample *sample);

  };

  static struct lock_seq_stat *get_seq(struct thread_stat *ts, void *addr)
  {
  	struct lock_seq_stat *seq;
  
  	list_for_each_entry(seq, &ts->seq_list, list) {
  		if (seq->addr == addr)
  			return seq;
  	}
  
  	seq = zalloc(sizeof(struct lock_seq_stat));

  	if (!seq) {
  		pr_err("memory allocation failed
  ");
  		return NULL;
  	}

  	seq->state = SEQ_STATE_UNINITIALIZED;
  	seq->addr = addr;
  
  	list_add(&seq->list, &ts->seq_list);
  	return seq;
  }

  enum broken_state {
  	BROKEN_ACQUIRE,
  	BROKEN_ACQUIRED,
  	BROKEN_CONTENDED,
  	BROKEN_RELEASE,
  	BROKEN_MAX,
  };
  
  static int bad_hist[BROKEN_MAX];

  enum acquire_flags {
  	TRY_LOCK = 1,
  	READ_LOCK = 2,
  };

  static int report_lock_acquire_event(struct perf_evsel *evsel,
  				     struct perf_sample *sample)

  {

  	void *addr;

  	struct lock_stat *ls;
  	struct thread_stat *ts;
  	struct lock_seq_stat *seq;

  	const char *name = perf_evsel__strval(evsel, sample, "name");
  	u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");
  	int flag = perf_evsel__intval(evsel, sample, "flag");

  	memcpy(&addr, &tmp, sizeof(void *));
  
  	ls = lock_stat_findnew(addr, name);

  	if (!ls)

  		return -ENOMEM;

  	if (ls->discard)

  		return 0;

  	ts = thread_stat_findnew(sample->tid);

  	if (!ts)

  		return -ENOMEM;

  	seq = get_seq(ts, addr);

  	if (!seq)

  		return -ENOMEM;

  	switch (seq->state) {
  	case SEQ_STATE_UNINITIALIZED:
  	case SEQ_STATE_RELEASED:

  		if (!flag) {

  			seq->state = SEQ_STATE_ACQUIRING;
  		} else {

  			if (flag & TRY_LOCK)

  				ls->nr_trylock++;

  			if (flag & READ_LOCK)

  				ls->nr_readlock++;
  			seq->state = SEQ_STATE_READ_ACQUIRED;
  			seq->read_count = 1;
  			ls->nr_acquired++;
  		}
  		break;
  	case SEQ_STATE_READ_ACQUIRED:

  		if (flag & READ_LOCK) {

  			seq->read_count++;
  			ls->nr_acquired++;
  			goto end;
  		} else {
  			goto broken;
  		}

  		break;

  	case SEQ_STATE_ACQUIRED:
  	case SEQ_STATE_ACQUIRING:
  	case SEQ_STATE_CONTENDED:
  broken:
  		/* broken lock sequence, discard it */
  		ls->discard = 1;

  		bad_hist[BROKEN_ACQUIRE]++;

  		list_del(&seq->list);
  		free(seq);
  		goto end;

  	default:

  		BUG_ON("Unknown state of lock sequence found!
  ");

  		break;
  	}

  	ls->nr_acquire++;

  	seq->prev_event_time = sample->time;

  end:

  	return 0;

  }

  static int report_lock_acquired_event(struct perf_evsel *evsel,
  				      struct perf_sample *sample)

  {

  	void *addr;

  	struct lock_stat *ls;
  	struct thread_stat *ts;
  	struct lock_seq_stat *seq;
  	u64 contended_term;

  	const char *name = perf_evsel__strval(evsel, sample, "name");
  	u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");
  
  	memcpy(&addr, &tmp, sizeof(void *));

  	ls = lock_stat_findnew(addr, name);

  	if (!ls)

  		return -ENOMEM;

  	if (ls->discard)

  		return 0;

  	ts = thread_stat_findnew(sample->tid);

  	if (!ts)

  		return -ENOMEM;

  	seq = get_seq(ts, addr);

  	if (!seq)

  		return -ENOMEM;

  	switch (seq->state) {
  	case SEQ_STATE_UNINITIALIZED:
  		/* orphan event, do nothing */

  		return 0;

  	case SEQ_STATE_ACQUIRING:

  		break;

  	case SEQ_STATE_CONTENDED:

  		contended_term = sample->time - seq->prev_event_time;

  		ls->wait_time_total += contended_term;

  		if (contended_term < ls->wait_time_min)
  			ls->wait_time_min = contended_term;

  		if (ls->wait_time_max < contended_term)

  			ls->wait_time_max = contended_term;

  		break;

  	case SEQ_STATE_RELEASED:
  	case SEQ_STATE_ACQUIRED:
  	case SEQ_STATE_READ_ACQUIRED:
  		/* broken lock sequence, discard it */
  		ls->discard = 1;

  		bad_hist[BROKEN_ACQUIRED]++;

  		list_del(&seq->list);
  		free(seq);
  		goto end;

  	default:

  		BUG_ON("Unknown state of lock sequence found!
  ");

  		break;
  	}

  	seq->state = SEQ_STATE_ACQUIRED;
  	ls->nr_acquired++;

  	ls->avg_wait_time = ls->nr_contended ? ls->wait_time_total/ls->nr_contended : 0;

  	seq->prev_event_time = sample->time;

  end:

  	return 0;

  }

  static int report_lock_contended_event(struct perf_evsel *evsel,
  				       struct perf_sample *sample)

  {

  	void *addr;

  	struct lock_stat *ls;
  	struct thread_stat *ts;
  	struct lock_seq_stat *seq;

  	const char *name = perf_evsel__strval(evsel, sample, "name");
  	u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");
  
  	memcpy(&addr, &tmp, sizeof(void *));

  	ls = lock_stat_findnew(addr, name);

  	if (!ls)

  		return -ENOMEM;

  	if (ls->discard)

  		return 0;

  	ts = thread_stat_findnew(sample->tid);

  	if (!ts)

  		return -ENOMEM;

  	seq = get_seq(ts, addr);

  	if (!seq)

  		return -ENOMEM;

  	switch (seq->state) {
  	case SEQ_STATE_UNINITIALIZED:
  		/* orphan event, do nothing */

  		return 0;

  	case SEQ_STATE_ACQUIRING:

  		break;

  	case SEQ_STATE_RELEASED:
  	case SEQ_STATE_ACQUIRED:
  	case SEQ_STATE_READ_ACQUIRED:
  	case SEQ_STATE_CONTENDED:
  		/* broken lock sequence, discard it */
  		ls->discard = 1;

  		bad_hist[BROKEN_CONTENDED]++;

  		list_del(&seq->list);
  		free(seq);
  		goto end;

  	default:

  		BUG_ON("Unknown state of lock sequence found!
  ");

  		break;
  	}

  	seq->state = SEQ_STATE_CONTENDED;
  	ls->nr_contended++;

  	ls->avg_wait_time = ls->wait_time_total/ls->nr_contended;

  	seq->prev_event_time = sample->time;

  end:

  	return 0;

  }

  static int report_lock_release_event(struct perf_evsel *evsel,
  				     struct perf_sample *sample)

  {

  	void *addr;

  	struct lock_stat *ls;
  	struct thread_stat *ts;
  	struct lock_seq_stat *seq;

  	const char *name = perf_evsel__strval(evsel, sample, "name");
  	u64 tmp = perf_evsel__intval(evsel, sample, "lockdep_addr");

  	memcpy(&addr, &tmp, sizeof(void *));
  
  	ls = lock_stat_findnew(addr, name);

  	if (!ls)

  		return -ENOMEM;

  	if (ls->discard)

  		return 0;

  	ts = thread_stat_findnew(sample->tid);

  	if (!ts)

  		return -ENOMEM;

  	seq = get_seq(ts, addr);

  	if (!seq)

  		return -ENOMEM;

  	switch (seq->state) {
  	case SEQ_STATE_UNINITIALIZED:
  		goto end;

  	case SEQ_STATE_ACQUIRED:
  		break;
  	case SEQ_STATE_READ_ACQUIRED:
  		seq->read_count--;
  		BUG_ON(seq->read_count < 0);
  		if (!seq->read_count) {
  			ls->nr_release++;

  			goto end;
  		}

  		break;
  	case SEQ_STATE_ACQUIRING:
  	case SEQ_STATE_CONTENDED:
  	case SEQ_STATE_RELEASED:
  		/* broken lock sequence, discard it */
  		ls->discard = 1;

  		bad_hist[BROKEN_RELEASE]++;

  		goto free_seq;

  	default:

  		BUG_ON("Unknown state of lock sequence found!
  ");

  		break;
  	}

  	ls->nr_release++;
  free_seq:
  	list_del(&seq->list);
  	free(seq);

  end:

  	return 0;

  }
  
  /* lock oriented handlers */
  /* TODO: handlers for CPU oriented, thread oriented */

  static struct trace_lock_handler report_lock_ops  = {
  	.acquire_event		= report_lock_acquire_event,
  	.acquired_event		= report_lock_acquired_event,
  	.contended_event	= report_lock_contended_event,
  	.release_event		= report_lock_release_event,

  };
  
  static struct trace_lock_handler *trace_handler;

  static int perf_evsel__process_lock_acquire(struct perf_evsel *evsel,

  					     struct perf_sample *sample)

  {

  	if (trace_handler->acquire_event)

  		return trace_handler->acquire_event(evsel, sample);
  	return 0;

  }

  static int perf_evsel__process_lock_acquired(struct perf_evsel *evsel,

  					      struct perf_sample *sample)

  {

  	if (trace_handler->acquired_event)

  		return trace_handler->acquired_event(evsel, sample);
  	return 0;

  }

  static int perf_evsel__process_lock_contended(struct perf_evsel *evsel,

  					      struct perf_sample *sample)

  {

  	if (trace_handler->contended_event)

  		return trace_handler->contended_event(evsel, sample);
  	return 0;

  }

  static int perf_evsel__process_lock_release(struct perf_evsel *evsel,

  					    struct perf_sample *sample)

  {

  	if (trace_handler->release_event)

  		return trace_handler->release_event(evsel, sample);
  	return 0;

  }

  static void print_bad_events(int bad, int total)
  {
  	/* Output for debug, this have to be removed */
  	int i;
  	const char *name[4] =
  		{ "acquire", "acquired", "contended", "release" };
  
  	pr_info("
  === output for debug===
  
  ");

  	pr_info("bad: %d, total: %d
  ", bad, total);

  	pr_info("bad rate: %.2f %%
  ", (double)bad / (double)total * 100);

  	pr_info("histogram of events caused bad sequence
  ");
  	for (i = 0; i < BROKEN_MAX; i++)
  		pr_info(" %10s: %d
  ", name[i], bad_hist[i]);
  }

  /* TODO: various way to print, coloring, nano or milli sec */
  static void print_result(void)
  {
  	struct lock_stat *st;
  	char cut_name[20];

  	int bad, total;

  	pr_info("%20s ", "Name");
  	pr_info("%10s ", "acquired");
  	pr_info("%10s ", "contended");

  	pr_info("%15s ", "avg wait (ns)");

  	pr_info("%15s ", "total wait (ns)");
  	pr_info("%15s ", "max wait (ns)");
  	pr_info("%15s ", "min wait (ns)");

  	pr_info("
  
  ");

  	bad = total = 0;

  	while ((st = pop_from_result())) {

  		total++;
  		if (st->discard) {
  			bad++;
  			continue;
  		}

  		bzero(cut_name, 20);

  		if (strlen(st->name) < 16) {
  			/* output raw name */

  			pr_info("%20s ", st->name);

  		} else {
  			strncpy(cut_name, st->name, 16);
  			cut_name[16] = '.';
  			cut_name[17] = '.';
  			cut_name[18] = '.';
  			cut_name[19] = '\0';
  			/* cut off name for saving output style */

  			pr_info("%20s ", cut_name);

  		}

  		pr_info("%10u ", st->nr_acquired);
  		pr_info("%10u ", st->nr_contended);

  		pr_info("%15" PRIu64 " ", st->avg_wait_time);

  		pr_info("%15" PRIu64 " ", st->wait_time_total);
  		pr_info("%15" PRIu64 " ", st->wait_time_max);
  		pr_info("%15" PRIu64 " ", st->wait_time_min == ULLONG_MAX ?

  		       0 : st->wait_time_min);

  		pr_info("
  ");

  	}

  	print_bad_events(bad, total);

  }

  static bool info_threads, info_map;

  
  static void dump_threads(void)
  {
  	struct thread_stat *st;
  	struct rb_node *node;
  	struct thread *t;
  
  	pr_info("%10s: comm
  ", "Thread ID");
  
  	node = rb_first(&thread_stats);
  	while (node) {
  		st = container_of(node, struct thread_stat, rb);
  		t = perf_session__findnew(session, st->tid);

  		pr_info("%10d: %s
  ", st->tid, thread__comm_str(t));

  		node = rb_next(node);

  		thread__put(t);

  	};
  }

  static void dump_map(void)
  {
  	unsigned int i;
  	struct lock_stat *st;

  	pr_info("Address of instance: name of class
  ");

  	for (i = 0; i < LOCKHASH_SIZE; i++) {
  		list_for_each_entry(st, &lockhash_table[i], hash_entry) {

  			pr_info(" %p: %s
  ", st->addr, st->name);

  		}
  	}
  }

  static int dump_info(void)

  {

  	int rc = 0;

  	if (info_threads)
  		dump_threads();
  	else if (info_map)
  		dump_map();

  	else {
  		rc = -1;
  		pr_err("Unknown type of information
  ");
  	}
  
  	return rc;

  }

  typedef int (*tracepoint_handler)(struct perf_evsel *evsel,
  				  struct perf_sample *sample);

  static int process_sample_event(struct perf_tool *tool __maybe_unused,

  				union perf_event *event,

  				struct perf_sample *sample,

  				struct perf_evsel *evsel,

  				struct machine *machine)

  {

  	int err = 0;

  	struct thread *thread = machine__findnew_thread(machine, sample->pid,
  							sample->tid);

  	if (thread == NULL) {
  		pr_debug("problem processing %d event, skipping it.
  ",

  			event->header.type);

  		return -1;
  	}

  	if (evsel->handler != NULL) {
  		tracepoint_handler f = evsel->handler;

  		err = f(evsel, sample);

  	}

  	thread__put(thread);
  
  	return err;

  }

  static void sort_result(void)
  {
  	unsigned int i;
  	struct lock_stat *st;
  
  	for (i = 0; i < LOCKHASH_SIZE; i++) {
  		list_for_each_entry(st, &lockhash_table[i], hash_entry) {
  			insert_to_result(st, compare);
  		}
  	}
  }

  static const struct perf_evsel_str_handler lock_tracepoints[] = {
  	{ "lock:lock_acquire",	 perf_evsel__process_lock_acquire,   }, /* CONFIG_LOCKDEP */
  	{ "lock:lock_acquired",	 perf_evsel__process_lock_acquired,  }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */
  	{ "lock:lock_contended", perf_evsel__process_lock_contended, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */
  	{ "lock:lock_release",	 perf_evsel__process_lock_release,   }, /* CONFIG_LOCKDEP */
  };

  static bool force;

  static int __cmd_report(bool display_info)

  {

  	int err = -EINVAL;

  	struct perf_tool eops = {
  		.sample		 = process_sample_event,
  		.comm		 = perf_event__process_comm,

  		.namespaces	 = perf_event__process_namespaces,

  		.ordered_events	 = true,

  	};

  	struct perf_data_file file = {
  		.path = input_name,
  		.mode = PERF_DATA_MODE_READ,

  		.force = force,

  	};

  	session = perf_session__new(&file, false, &eops);

  	if (!session) {
  		pr_err("Initializing perf session failed
  ");

  		return -1;

  	}

  	symbol__init(&session->header.env);

  	if (!perf_session__has_traces(session, "lock record"))
  		goto out_delete;

  	if (perf_session__set_tracepoints_handlers(session, lock_tracepoints)) {
  		pr_err("Initializing perf session tracepoint handlers failed
  ");

  		goto out_delete;

  	}

  	if (select_key())
  		goto out_delete;

  	err = perf_session__process_events(session);

  	if (err)
  		goto out_delete;

  	setup_pager();

  	if (display_info) /* used for info subcommand */
  		err = dump_info();
  	else {
  		sort_result();
  		print_result();
  	}

  out_delete:
  	perf_session__delete(session);
  	return err;

  }

  static int __cmd_record(int argc, const char **argv)
  {

  	const char *record_args[] = {

  		"record", "-R", "-m", "1024", "-c", "1",

  	};

  	unsigned int rec_argc, i, j, ret;

  	const char **rec_argv;

  	for (i = 0; i < ARRAY_SIZE(lock_tracepoints); i++) {

  		if (!is_valid_tracepoint(lock_tracepoints[i].name)) {

  				pr_err("tracepoint %s is not enabled. "
  				       "Are CONFIG_LOCKDEP and CONFIG_LOCK_STAT enabled?
  ",

  				       lock_tracepoints[i].name);

  				return 1;
  		}
  	}

  	rec_argc = ARRAY_SIZE(record_args) + argc - 1;

  	/* factor of 2 is for -e in front of each tracepoint */
  	rec_argc += 2 * ARRAY_SIZE(lock_tracepoints);

  	rec_argv = calloc(rec_argc + 1, sizeof(char *));

  	if (!rec_argv)

  		return -ENOMEM;

  	for (i = 0; i < ARRAY_SIZE(record_args); i++)
  		rec_argv[i] = strdup(record_args[i]);

  	for (j = 0; j < ARRAY_SIZE(lock_tracepoints); j++) {
  		rec_argv[i++] = "-e";

  		rec_argv[i++] = strdup(lock_tracepoints[j].name);

  	}

  	for (j = 1; j < (unsigned int)argc; j++, i++)
  		rec_argv[i] = argv[j];
  
  	BUG_ON(i != rec_argc);

  	ret = cmd_record(i, rec_argv);

  	free(rec_argv);
  	return ret;

  }

  int cmd_lock(int argc, const char **argv)

  {

  	const struct option lock_options[] = {
  	OPT_STRING('i', "input", &input_name, "file", "input file name"),
  	OPT_INCR('v', "verbose", &verbose, "be more verbose (show symbol address, etc)"),
  	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace, "dump raw trace in ASCII"),

  	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),

  	OPT_END()
  	};

  	const struct option info_options[] = {
  	OPT_BOOLEAN('t', "threads", &info_threads,
  		    "dump thread list in perf.data"),
  	OPT_BOOLEAN('m', "map", &info_map,
  		    "map of lock instances (address:name table)"),

  	OPT_PARENT(lock_options)

  	};

  	const struct option report_options[] = {
  	OPT_STRING('k', "key", &sort_key, "acquired",

  		    "key for sorting (acquired / contended / avg_wait / wait_total / wait_max / wait_min)"),

  	/* TODO: type */

  	OPT_PARENT(lock_options)

  	};

  	const char * const info_usage[] = {
  		"perf lock info [<options>]",
  		NULL
  	};

  	const char *const lock_subcommands[] = { "record", "report", "script",
  						 "info", NULL };
  	const char *lock_usage[] = {
  		NULL,

  		NULL
  	};
  	const char * const report_usage[] = {
  		"perf lock report [<options>]",
  		NULL
  	};

  	unsigned int i;

  	int rc = 0;

  	for (i = 0; i < LOCKHASH_SIZE; i++)
  		INIT_LIST_HEAD(lockhash_table + i);

  	argc = parse_options_subcommand(argc, argv, lock_options, lock_subcommands,
  					lock_usage, PARSE_OPT_STOP_AT_NON_OPTION);

  	if (!argc)
  		usage_with_options(lock_usage, lock_options);
  
  	if (!strncmp(argv[0], "rec", 3)) {
  		return __cmd_record(argc, argv);

  	} else if (!strncmp(argv[0], "report", 6)) {
  		trace_handler = &report_lock_ops;

  		if (argc) {
  			argc = parse_options(argc, argv,

  					     report_options, report_usage, 0);

  			if (argc)

  				usage_with_options(report_usage, report_options);

  		}

  		rc = __cmd_report(false);

  	} else if (!strcmp(argv[0], "script")) {
  		/* Aliased to 'perf script' */

  		return cmd_script(argc, argv);

  	} else if (!strcmp(argv[0], "info")) {
  		if (argc) {
  			argc = parse_options(argc, argv,
  					     info_options, info_usage, 0);
  			if (argc)
  				usage_with_options(info_usage, info_options);
  		}

  		/* recycling report_lock_ops */
  		trace_handler = &report_lock_ops;

  		rc = __cmd_report(true);

  	} else {
  		usage_with_options(lock_usage, lock_options);
  	}

  	return rc;

  }