/*

   * builtin-record.c
   *
   * Builtin record command: Record the profile of a workload
   * (or a CPU, or a PID) into the perf.data output file - for
   * later analysis via perf report.

   */

  #include "builtin.h"

  
  #include "perf.h"

  #include "util/util.h"

  #include "util/parse-options.h"

  #include "util/parse-events.h"

  #include "util/string.h"

  #include "util/header.h"

  #include "util/event.h"

  #include "util/debug.h"

  #include "util/trace-event.h"

  #include <unistd.h>

  #include <sched.h>

  #define ALIGN(x, a)		__ALIGN_MASK(x, (typeof(x))(a)-1)
  #define __ALIGN_MASK(x, mask)	(((x)+(mask))&~(mask))

  static int			fd[MAX_NR_CPUS][MAX_COUNTERS];

  
  static long			default_interval		= 100000;

  static int			nr_cpus				= 0;

  static unsigned int		page_size;

  static unsigned int		mmap_pages			= 128;

  static int			freq				= 0;

  static int			output;

  static const char		*output_name			= "perf.data";

  static int			group				= 0;

  static unsigned int		realtime_prio			= 0;

  static int			raw_samples			= 0;

  static int			system_wide			= 0;

  static int			profile_cpu			= -1;

  static pid_t			target_pid			= -1;

  static pid_t			child_pid			= -1;

  static int			inherit				= 1;

  static int			force				= 0;

  static int			append_file			= 0;

  static int			call_graph			= 0;

  static int			inherit_stat			= 0;
  static int			no_samples			= 0;

  static int			sample_address			= 0;

  static int			multiplex			= 0;

  static int			multiplex_fd			= -1;

  static long			samples;
  static struct timeval		last_read;
  static struct timeval		this_read;

  static u64			bytes_written;

  
  static struct pollfd		event_array[MAX_NR_CPUS * MAX_COUNTERS];
  
  static int			nr_poll;
  static int			nr_cpu;

  static int			file_new = 1;

  
  struct perf_header		*header;

  struct mmap_data {

  	int			counter;
  	void			*base;
  	unsigned int		mask;
  	unsigned int		prev;

  };

  static struct mmap_data		mmap_array[MAX_NR_CPUS][MAX_COUNTERS];

  static unsigned long mmap_read_head(struct mmap_data *md)

  {

  	struct perf_event_mmap_page *pc = md->base;

  	long head;

  
  	head = pc->data_head;
  	rmb();
  
  	return head;
  }

  static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
  {

  	struct perf_event_mmap_page *pc = md->base;

  
  	/*
  	 * ensure all reads are done before we write the tail out.
  	 */
  	/* mb(); */
  	pc->data_tail = tail;
  }

  static void write_output(void *buf, size_t size)
  {
  	while (size) {
  		int ret = write(output, buf, size);
  
  		if (ret < 0)
  			die("failed to write");
  
  		size -= ret;
  		buf += ret;
  
  		bytes_written += ret;
  	}
  }

  static void mmap_read(struct mmap_data *md)
  {
  	unsigned int head = mmap_read_head(md);
  	unsigned int old = md->prev;
  	unsigned char *data = md->base + page_size;
  	unsigned long size;
  	void *buf;
  	int diff;
  
  	gettimeofday(&this_read, NULL);
  
  	/*
  	 * If we're further behind than half the buffer, there's a chance

  	 * the writer will bite our tail and mess up the samples under us.

  	 *
  	 * If we somehow ended up ahead of the head, we got messed up.
  	 *
  	 * In either case, truncate and restart at head.
  	 */
  	diff = head - old;

  	if (diff < 0) {

  		struct timeval iv;
  		unsigned long msecs;
  
  		timersub(&this_read, &last_read, &iv);
  		msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
  
  		fprintf(stderr, "WARNING: failed to keep up with mmap data."
  				"  Last read %lu msecs ago.
  ", msecs);
  
  		/*
  		 * head points to a known good entry, start there.
  		 */
  		old = head;
  	}
  
  	last_read = this_read;
  
  	if (old != head)

  		samples++;

  
  	size = head - old;
  
  	if ((old & md->mask) + size != (head & md->mask)) {
  		buf = &data[old & md->mask];
  		size = md->mask + 1 - (old & md->mask);
  		old += size;

  		write_output(buf, size);

  	}
  
  	buf = &data[old & md->mask];
  	size = head - old;
  	old += size;

  	write_output(buf, size);

  
  	md->prev = old;

  	mmap_write_tail(md, old);

  }
  
  static volatile int done = 0;

  static volatile int signr = -1;

  static void sig_handler(int sig)

  {

  	done = 1;

  	signr = sig;
  }
  
  static void sig_atexit(void)
  {

  	if (child_pid != -1)
  		kill(child_pid, SIGTERM);

  	if (signr == -1)
  		return;
  
  	signal(signr, SIG_DFL);
  	kill(getpid(), signr);

  }

  static pid_t pid_synthesize_comm_event(pid_t pid, int full)

  {

  	struct comm_event comm_ev;

  	char filename[PATH_MAX];
  	char bf[BUFSIZ];

  	FILE *fp;
  	size_t size = 0;

  	DIR *tasks;
  	struct dirent dirent, *next;

  	pid_t tgid = 0;

  	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);

  	fp = fopen(filename, "r");

  	if (fp == NULL) {

  		/*
  		 * We raced with a task exiting - just return:
  		 */
  		if (verbose)
  			fprintf(stderr, "couldn't open %s
  ", filename);

  		return 0;

  	}

  	memset(&comm_ev, 0, sizeof(comm_ev));

  	while (!comm_ev.comm[0] || !comm_ev.pid) {
  		if (fgets(bf, sizeof(bf), fp) == NULL)
  			goto out_failure;
  
  		if (memcmp(bf, "Name:", 5) == 0) {
  			char *name = bf + 5;
  			while (*name && isspace(*name))
  				++name;
  			size = strlen(name) - 1;
  			memcpy(comm_ev.comm, name, size++);
  		} else if (memcmp(bf, "Tgid:", 5) == 0) {
  			char *tgids = bf + 5;
  			while (*tgids && isspace(*tgids))
  				++tgids;
  			tgid = comm_ev.pid = atoi(tgids);
  		}
  	}

  	comm_ev.header.type = PERF_RECORD_COMM;

  	size = ALIGN(size, sizeof(u64));

  	comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);

  	if (!full) {
  		comm_ev.tid = pid;

  		write_output(&comm_ev, comm_ev.header.size);

  		goto out_fclose;

  	}
  
  	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
  
  	tasks = opendir(filename);
  	while (!readdir_r(tasks, &dirent, &next) && next) {
  		char *end;
  		pid = strtol(dirent.d_name, &end, 10);
  		if (*end)
  			continue;
  
  		comm_ev.tid = pid;

  		write_output(&comm_ev, comm_ev.header.size);

  	}

  	closedir(tasks);

  
  out_fclose:
  	fclose(fp);
  	return tgid;

  out_failure:
  	fprintf(stderr, "couldn't get COMM and pgid, malformed %s
  ",
  		filename);
  	exit(EXIT_FAILURE);

  }

  static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)

  {
  	char filename[PATH_MAX];
  	FILE *fp;
  
  	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
  
  	fp = fopen(filename, "r");
  	if (fp == NULL) {

  		/*
  		 * We raced with a task exiting - just return:
  		 */
  		if (verbose)
  			fprintf(stderr, "couldn't open %s
  ", filename);
  		return;

  	}
  	while (1) {

  		char bf[BUFSIZ], *pbf = bf;

  		struct mmap_event mmap_ev = {

  			.header = { .type = PERF_RECORD_MMAP },

  		};

  		int n;

  		size_t size;
  		if (fgets(bf, sizeof(bf), fp) == NULL)
  			break;
  
  		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */

  		n = hex2u64(pbf, &mmap_ev.start);
  		if (n < 0)
  			continue;
  		pbf += n + 1;
  		n = hex2u64(pbf, &mmap_ev.len);
  		if (n < 0)
  			continue;
  		pbf += n + 3;
  		if (*pbf == 'x') { /* vm_exec */

  			char *execname = strchr(bf, '/');

  			/* Catch VDSO */
  			if (execname == NULL)
  				execname = strstr(bf, "[vdso]");

  			if (execname == NULL)

  				continue;

  			size = strlen(execname);
  			execname[size - 1] = '\0'; /* Remove 
   */
  			memcpy(mmap_ev.filename, execname, size);

  			size = ALIGN(size, sizeof(u64));

  			mmap_ev.len -= mmap_ev.start;
  			mmap_ev.header.size = (sizeof(mmap_ev) -
  					       (sizeof(mmap_ev.filename) - size));

  			mmap_ev.pid = tgid;

  			mmap_ev.tid = pid;

  			write_output(&mmap_ev, mmap_ev.header.size);

  		}
  	}
  
  	fclose(fp);
  }

  static void synthesize_all(void)

  {
  	DIR *proc;
  	struct dirent dirent, *next;
  
  	proc = opendir("/proc");
  
  	while (!readdir_r(proc, &dirent, &next) && next) {
  		char *end;

  		pid_t pid, tgid;

  
  		pid = strtol(dirent.d_name, &end, 10);
  		if (*end) /* only interested in proper numerical dirents */
  			continue;

  		tgid = pid_synthesize_comm_event(pid, 1);
  		pid_synthesize_mmap_samples(pid, tgid);

  	}
  
  	closedir(proc);
  }

  static int group_fd;

  static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)

  {
  	struct perf_header_attr *h_attr;
  
  	if (nr < header->attrs) {
  		h_attr = header->attr[nr];
  	} else {
  		h_attr = perf_header_attr__new(a);
  		perf_header__add_attr(header, h_attr);
  	}
  
  	return h_attr;
  }

  static void create_counter(int counter, int cpu, pid_t pid)

  {

  	struct perf_event_attr *attr = attrs + counter;

  	struct perf_header_attr *h_attr;
  	int track = !counter; /* only the first counter needs these */
  	struct {
  		u64 count;
  		u64 time_enabled;
  		u64 time_running;
  		u64 id;
  	} read_data;
  
  	attr->read_format	= PERF_FORMAT_TOTAL_TIME_ENABLED |
  				  PERF_FORMAT_TOTAL_TIME_RUNNING |
  				  PERF_FORMAT_ID;

  	attr->sample_type	|= PERF_SAMPLE_IP | PERF_SAMPLE_TID;

  	if (freq) {

  		attr->sample_type	|= PERF_SAMPLE_PERIOD;

  		attr->freq		= 1;
  		attr->sample_freq	= freq;

  	}

  	if (no_samples)
  		attr->sample_freq = 0;
  
  	if (inherit_stat)
  		attr->inherit_stat = 1;

  	if (sample_address)
  		attr->sample_type	|= PERF_SAMPLE_ADDR;

  	if (call_graph)
  		attr->sample_type	|= PERF_SAMPLE_CALLCHAIN;

  	if (raw_samples) {

  		attr->sample_type	|= PERF_SAMPLE_TIME;

  		attr->sample_type	|= PERF_SAMPLE_RAW;

  		attr->sample_type	|= PERF_SAMPLE_CPU;
  	}

  	attr->mmap		= track;
  	attr->comm		= track;
  	attr->inherit		= (cpu < 0) && inherit;

  	attr->disabled		= 1;

  try_again:

  	fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);

  	if (fd[nr_cpu][counter] < 0) {
  		int err = errno;

  		if (err == EPERM || err == EACCES)

  			die("Permission error - are you root?
  ");

  		else if (err ==  ENODEV && profile_cpu != -1)
  			die("No such device - did you specify an out-of-range profile CPU?
  ");

  
  		/*
  		 * If it's cycles then fall back to hrtimer
  		 * based cpu-clock-tick sw counter, which
  		 * is always available even if no PMU support:
  		 */
  		if (attr->type == PERF_TYPE_HARDWARE

  			&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {

  
  			if (verbose)
  				warning(" ... trying to fall back to cpu-clock-ticks
  ");
  			attr->type = PERF_TYPE_SOFTWARE;

  			attr->config = PERF_COUNT_SW_CPU_CLOCK;

  			goto try_again;
  		}

  		printf("
  ");
  		error("perfcounter syscall returned with %d (%s)
  ",
  			fd[nr_cpu][counter], strerror(err));

  		die("No CONFIG_PERF_EVENTS=y kernel support configured?
  ");

  		exit(-1);
  	}

  	h_attr = get_header_attr(attr, counter);
  
  	if (!file_new) {
  		if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
  			fprintf(stderr, "incompatible append
  ");
  			exit(-1);
  		}
  	}

  	if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
  		perror("Unable to read perf file descriptor
  ");
  		exit(-1);
  	}

  
  	perf_header_attr__add_id(h_attr, read_data.id);

  	assert(fd[nr_cpu][counter] >= 0);
  	fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);

  	/*
  	 * First counter acts as the group leader:
  	 */
  	if (group && group_fd == -1)
  		group_fd = fd[nr_cpu][counter];

  	if (multiplex && multiplex_fd == -1)
  		multiplex_fd = fd[nr_cpu][counter];

  	if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
  		int ret;

  		ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);

  		assert(ret != -1);
  	} else {
  		event_array[nr_poll].fd = fd[nr_cpu][counter];
  		event_array[nr_poll].events = POLLIN;
  		nr_poll++;
  
  		mmap_array[nr_cpu][counter].counter = counter;
  		mmap_array[nr_cpu][counter].prev = 0;
  		mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
  		mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
  				PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
  		if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
  			error("failed to mmap with %d (%s)
  ", errno, strerror(errno));
  			exit(-1);
  		}
  	}

  	ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);

  }

  static void open_counters(int cpu, pid_t pid)
  {
  	int counter;

  	group_fd = -1;
  	for (counter = 0; counter < nr_counters; counter++)
  		create_counter(counter, cpu, pid);

  	nr_cpu++;
  }

  static void atexit_header(void)
  {

  	header->data_size += bytes_written;

  	perf_header__write(header, output);

  }

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

  {
  	int i, counter;

  	struct stat st;

  	pid_t pid = 0;

  	int flags;

  	int ret;

  	unsigned long waking = 0;

  
  	page_size = sysconf(_SC_PAGE_SIZE);

  	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
  	assert(nr_cpus <= MAX_NR_CPUS);
  	assert(nr_cpus >= 0);

  	atexit(sig_atexit);
  	signal(SIGCHLD, sig_handler);
  	signal(SIGINT, sig_handler);

  	if (!stat(output_name, &st) && st.st_size) {
  		if (!force && !append_file) {
  			fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.
  ",
  					output_name);
  			exit(-1);
  		}
  	} else {
  		append_file = 0;

  	}

  	flags = O_CREAT|O_RDWR;
  	if (append_file)

  		file_new = 0;

  	else
  		flags |= O_TRUNC;
  
  	output = open(output_name, flags, S_IRUSR|S_IWUSR);

  	if (output < 0) {
  		perror("failed to create output file");
  		exit(-1);
  	}

  	if (!file_new)
  		header = perf_header__read(output);
  	else
  		header = perf_header__new();

  
  	if (raw_samples) {

  		read_tracing_data(attrs, nr_counters);

  	} else {
  		for (i = 0; i < nr_counters; i++) {
  			if (attrs[i].sample_type & PERF_SAMPLE_RAW) {

  				read_tracing_data(attrs, nr_counters);

  				break;
  			}
  		}
  	}

  	atexit(atexit_header);

  	if (!system_wide) {

  		pid = target_pid;
  		if (pid == -1)
  			pid = getpid();

  		open_counters(profile_cpu, pid);
  	} else {
  		if (profile_cpu != -1) {
  			open_counters(profile_cpu, target_pid);
  		} else {
  			for (i = 0; i < nr_cpus; i++)
  				open_counters(i, target_pid);
  		}
  	}

  	if (file_new)
  		perf_header__write(header, output);
  
  	if (!system_wide) {

  		pid_t tgid = pid_synthesize_comm_event(pid, 0);
  		pid_synthesize_mmap_samples(pid, tgid);

  	} else
  		synthesize_all();

  	if (target_pid == -1 && argc) {

  		pid = fork();
  		if (pid < 0)
  			perror("failed to fork");

  		if (!pid) {

  			if (execvp(argv[0], (char **)argv)) {

  				perror(argv[0]);
  				exit(-1);
  			}

  		}

  
  		child_pid = pid;

  	}
  
  	if (realtime_prio) {
  		struct sched_param param;
  
  		param.sched_priority = realtime_prio;
  		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
  			printf("Could not set realtime priority.
  ");
  			exit(-1);
  		}
  	}

  	for (;;) {

  		int hits = samples;

  		for (i = 0; i < nr_cpu; i++) {

  			for (counter = 0; counter < nr_counters; counter++) {
  				if (mmap_array[i][counter].base)
  					mmap_read(&mmap_array[i][counter]);
  			}

  		}

  		if (hits == samples) {
  			if (done)
  				break;

  			ret = poll(event_array, nr_poll, -1);
  			waking++;
  		}
  
  		if (done) {
  			for (i = 0; i < nr_cpu; i++) {
  				for (counter = 0; counter < nr_counters; counter++)

  					ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);

  			}

  		}

  	}

  	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]
  ", waking);

  	/*
  	 * Approximate RIP event size: 24 bytes.
  	 */
  	fprintf(stderr,

  		"[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]
  ",

  		(double)bytes_written / 1024.0 / 1024.0,
  		output_name,
  		bytes_written / 24);

  	return 0;
  }

  static const char * const record_usage[] = {

  	"perf record [<options>] [<command>]",
  	"perf record [<options>] -- <command> [<options>]",

  	NULL
  };

  static const struct option options[] = {

  	OPT_CALLBACK('e', "event", NULL, "event",

  		     "event selector. use 'perf list' to list available events",
  		     parse_events),

  	OPT_INTEGER('p', "pid", &target_pid,
  		    "record events on existing pid"),
  	OPT_INTEGER('r', "realtime", &realtime_prio,
  		    "collect data with this RT SCHED_FIFO priority"),

  	OPT_BOOLEAN('R', "raw-samples", &raw_samples,
  		    "collect raw sample records from all opened counters"),

  	OPT_BOOLEAN('a', "all-cpus", &system_wide,
  			    "system-wide collection from all CPUs"),

  	OPT_BOOLEAN('A', "append", &append_file,
  			    "append to the output file to do incremental profiling"),

  	OPT_INTEGER('C', "profile_cpu", &profile_cpu,
  			    "CPU to profile on"),

  	OPT_BOOLEAN('f', "force", &force,
  			"overwrite existing data file"),

  	OPT_LONG('c', "count", &default_interval,

  		    "event period to sample"),
  	OPT_STRING('o', "output", &output_name, "file",
  		    "output file name"),
  	OPT_BOOLEAN('i', "inherit", &inherit,
  		    "child tasks inherit counters"),

  	OPT_INTEGER('F', "freq", &freq,
  		    "profile at this frequency"),

  	OPT_INTEGER('m', "mmap-pages", &mmap_pages,
  		    "number of mmap data pages"),

  	OPT_BOOLEAN('g', "call-graph", &call_graph,
  		    "do call-graph (stack chain/backtrace) recording"),

  	OPT_BOOLEAN('v', "verbose", &verbose,
  		    "be more verbose (show counter open errors, etc)"),

  	OPT_BOOLEAN('s', "stat", &inherit_stat,
  		    "per thread counts"),

  	OPT_BOOLEAN('d', "data", &sample_address,
  		    "Sample addresses"),

  	OPT_BOOLEAN('n', "no-samples", &no_samples,
  		    "don't sample"),

  	OPT_BOOLEAN('M', "multiplex", &multiplex,
  		    "multiplex counter output in a single channel"),

  	OPT_END()
  };

  int cmd_record(int argc, const char **argv, const char *prefix __used)

  {
  	int counter;

  	argc = parse_options(argc, argv, options, record_usage,
  		PARSE_OPT_STOP_AT_NON_OPTION);

  	if (!argc && target_pid == -1 && !system_wide)

  		usage_with_options(record_usage, options);

  	if (!nr_counters) {
  		nr_counters	= 1;
  		attrs[0].type	= PERF_TYPE_HARDWARE;
  		attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
  	}

  
  	for (counter = 0; counter < nr_counters; counter++) {

  		if (attrs[counter].sample_period)

  			continue;

  		attrs[counter].sample_period = default_interval;

  	}
  
  	return __cmd_record(argc, argv);
  }