/*

 * task_smpl.c - example of a task sampling another one using a randomized sampling period

 *

 * Copyright (c) 2003-2006 Hewlett-Packard Development Company, L.P.

 * Contributed by Stephane Eranian <eranian@hpl.hp.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

 * of the Software, and to permit persons to whom the Software is furnished to do so,

 * subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in all

 * copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE

 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 */

#include <sys/types.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <signal.h>

#include <stdarg.h>

#include <stdint.h>

#include <getopt.h>

#include <time.h>

#include <sys/ptrace.h>

#include <sys/wait.h>

#include <sys/mman.h>

#include <sys/time.h>

#include <sys/resource.h>

#include <perfmon/pfmlib.h>

#include <perfmon/perfmon.h>

#include <perfmon/perfmon_dfl_smpl.h>

#include "detect_pmcs.h"

#define SAMPLING_PERIOD	100000

typedef struct {

	int opt_no_show;

	int opt_block;

} options_t;

typedef pfm_dfl_smpl_arg_t		smpl_fmt_arg_t;

typedef pfm_dfl_smpl_hdr_t		smpl_hdr_t;

typedef pfm_dfl_smpl_entry_t		smpl_entry_t;

typedef pfm_dfl_smpl_arg_t		smpl_arg_t;

#define FMT_NAME			PFM_DFL_SMPL_NAME

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

static uint64_t collected_samples, collected_partial;

static options_t options;

static struct option the_options[]={

	{ "help", 0, 0,  1},

	{ "ovfl-block", 0, &options.opt_block, 1},

	{ "no-show", 0, &options.opt_no_show, 1},

	{ 0, 0, 0, 0}

};

static void fatal_error(char *fmt,...) __attribute__((noreturn));

#define BPL (sizeof(uint64_t)<<3)

#define LBPL	6

static inline void pfm_bv_set(uint64_t *bv, uint16_t rnum)

{

	bv[rnum>>LBPL] |= 1UL << (rnum&(BPL-1));

}

static inline int pfm_bv_isset(uint64_t *bv, uint16_t rnum)

{

	return bv[rnum>>LBPL] & (1UL <<(rnum&(BPL-1))) ? 1 : 0;

}

static inline void pfm_bv_copy(uint64_t *d, uint64_t *j, uint16_t n)

{

	if (n <= BPL)

		*d = *j;

	else {

		memcpy(d, j, (n>>LBPL)*sizeof(uint64_t));

	}

}

static void

warning(char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

}

static void

fatal_error(char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

	exit(1);

}

int

child(char **arg)

{

	/*

	 * force the task to stop before executing the first

	 * user level instruction

	 */

	ptrace(PTRACE_TRACEME, 0, NULL, NULL);

	execvp(arg[0], arg);

	/* not reached */

	exit(1);

}

void

show_task_rusage(const struct timeval *start, const struct timeval *end, const struct rusage *ru)

{

	long secs, suseconds, end_usec;

	 secs     =  end->tv_sec - start->tv_sec;

	 end_usec = end->tv_usec;

	if (end_usec < start->tv_usec) {

      		end_usec += 1000000;

      		secs--;

    	}

  	suseconds = end_usec - start->tv_usec;

	printf ("real %ldh%02ldm%02ld.%03lds user %ldh%02ldm%02ld.%03lds sys %ldh%02ldm%02ld.%03lds\n", 

		secs / 3600, 

		(secs % 3600) / 60, 

		secs % 60,

		suseconds / 1000,

		ru->ru_utime.tv_sec / 3600, 

		(ru->ru_utime.tv_sec % 3600) / 60, 

		ru->ru_utime.tv_sec% 60,

		(long)(ru->ru_utime.tv_usec / 1000),

		ru->ru_stime.tv_sec / 3600, 

		(ru->ru_stime.tv_sec % 3600) / 60, 

		ru->ru_stime.tv_sec% 60,

		(long)(ru->ru_stime.tv_usec / 1000)

		);

}

static void

process_smpl_buf(smpl_hdr_t *hdr, uint64_t *smpl_pmds, unsigned int num_smpl_pmds, size_t entry_size)

{

	static uint64_t last_overflow = ~0; /* initialize to biggest value possible */

	static uint64_t last_count;

	smpl_entry_t *ent;

	size_t pos, count;

	uint64_t entry, *reg;

	unsigned int j, n;

	if (hdr->hdr_overflows == last_overflow && hdr->hdr_count == last_count) {

		warning("skipping identical set of samples %"PRIu64" = %"PRIu64"\n",

			hdr->hdr_overflows, last_overflow);

		return;	

	}

	count = hdr->hdr_count;

	if (options.opt_no_show) {

		collected_samples += count;

		return;

	}

	ent   = (smpl_entry_t *)(hdr+1);

	pos   = (unsigned long)ent;

	entry = collected_samples;

	while(count--) {

		printf("entry %"PRIu64" PID:%d TID:%d CPU:%d LAST_VAL:%"PRIu64" IIP:0x%llx\n",

			entry,

			ent->tgid,

			ent->pid,

			ent->cpu,

			-ent->last_reset_val,

			(unsigned long long)ent->ip);

		/*

		 * print body: additional PMDs recorded

		 * PMD are recorded in increasing index order

		 */

		reg = (uint64_t *)(ent+1);

		n = num_smpl_pmds;

		for(j=0; n; j++) {	

			if (pfm_bv_isset(smpl_pmds, j)) {

				printf("PMD%-3d:0x%016"PRIx64"\n", j, *reg);

				reg++;

				n--;

			}

		}

		pos += entry_size;

		ent = (smpl_entry_t *)pos;

		entry++;

	}

	collected_samples = entry;

	last_overflow = hdr->hdr_overflows;

	if (last_count != hdr->hdr_count && (last_count || last_overflow == 0))

		collected_partial += hdr->hdr_count;

	last_count = hdr->hdr_count;

}

int

mainloop(char **arg)

{

	smpl_hdr_t *hdr;

	pfarg_ctx_t ctx;

	smpl_arg_t buf_arg;

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfarg_pmd_t pd[NUM_PMDS];

	pfarg_pmc_t pc[NUM_PMCS];

	pfarg_load_t load_args;

	struct timeval start_time, end_time;

	struct rusage rusage;

	pfarg_msg_t msg;

	uint64_t ovfl_count = 0;

	size_t entry_size;

	void *buf_addr;

	pid_t pid;

	int status, ret, fd;

	unsigned int i, num_counters;

	unsigned int max_pmd = 0, num_smpl_pmds = 0;

	/*

	 * intialize all locals

	 */

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

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

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

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

	memset(pd, 0, sizeof(pd));

	memset(pc, 0, sizeof(pc));

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

	pfm_get_num_counters(&num_counters);

	if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)

		fatal_error("cannot find cycle event\n");

	if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)

		fatal_error("cannot find inst retired event\n");

	i = 2;

	/*

	 * set the privilege mode:

	 * 	PFM_PLM3 : user level

	 * 	PFM_PLM0 : kernel level

	 */

	inp.pfp_dfl_plm   = PFM_PLM3;

	if (i > num_counters) {

		i = num_counters;

		printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);

	}

	/*

	 * how many counters we use

	 */

	inp.pfp_event_count = i;

	/*

	 * build the pfp_unavail_pmcs bitmask by looking

	 * at what perfmon has available. It is not always

	 * the case that all PMU registers are actually available

	 * to applications. For instance, on IA-32 platforms, some

	 * registers may be reserved for the NMI watchdog timer.

	 *

	 * With this bitmap, the library knows which registers NOT to

	 * use. Of source, it is possible that no valid assignement may

	 * be possible if certina PMU registers  are not available.

	 */

	detect_unavail_pmcs(-1, &inp.pfp_unavail_pmcs);

	/*

	 * let the library figure out the values for the PMCS

	 */

	if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS)

		fatal_error("cannot configure events: %s\n", pfm_strerror(ret));

	/*

	 * Now prepare the argument to initialize the PMDs and PMCS.

	 * We use pfp_pmc_count to determine the number of PMC to intialize.

	 * We use pfp_pmd_count to determine the number of PMD to initialize.

	 * Some events/features may cause extra PMCs to be used, leading to:

	 * 	- pfp_pmc_count may be >= pfp_event_count

	 * 	- pfp_pmd_count may be >= pfp_event_count

	 */

	for (i=0; i < outp.pfp_pmc_count; i++) {

		pc[i].reg_num   = outp.pfp_pmcs[i].reg_num;

		pc[i].reg_value = outp.pfp_pmcs[i].reg_value;

	}

	for (i=0; i < outp.pfp_pmd_count; i++) {

		pd[i].reg_num = outp.pfp_pmds[i].reg_num;

		/*

		 * skip first counter (sampling period)

		 * track highest PMD 

		 */

		if (i) {

			pfm_bv_set(pd[0].reg_smpl_pmds, pd[i].reg_num);

			if (pd[i].reg_num > max_pmd)

				max_pmd = pd[i].reg_num;

			num_smpl_pmds++;

		}

	}

	/*

	 * we our sampling counter overflow, we want to be notified.

	 * The notification will come ONLY when the sampling buffer

	 * becomes full.

	 *

	 * We also activate randomization of the sampling period.

	 */

	pd[0].reg_flags	|= PFM_REGFL_OVFL_NOTIFY | PFM_REGFL_RANDOM;

	/*

	 * we also want to reset the other PMDs on

	 * every overflow. If we do not set

	 * this, the non-overflowed counters

	 * will be untouched.

	 */

	pfm_bv_copy(pd[0].reg_reset_pmds, pd[0].reg_smpl_pmds, max_pmd);

	pd[0].reg_value       = - SAMPLING_PERIOD;

	pd[0].reg_short_reset = - SAMPLING_PERIOD;

	pd[0].reg_long_reset  = - SAMPLING_PERIOD;

	/*

	 * setup randomization parameters, we allow a range of up to +256 here.

	 */

	pd[0].reg_random_seed = 5;

	pd[0].reg_random_mask = 0xff;

	/*

	 * in this example program, we use fixed-size entries, therefore we

	 * can compute the entry size in advance. Perfmon-2 supports variable

	 * size entries.

	 */

	entry_size = sizeof(smpl_entry_t)+(num_smpl_pmds<<3);

	printf("programming %u PMCS and %u PMDS\n", outp.pfp_pmc_count, inp.pfp_event_count);

	/*

	 * prepare context structure.

	 */

	/*

	 * We initialize the format specific information.

	 * The format is identified by its UUID which must be copied

	 * into the ctx_buf_fmt_id field.

	 */

	ctx.ctx_flags = options.opt_block ? PFM_FL_NOTIFY_BLOCK : 0;

	/*

	 * the size of the buffer is indicated in bytes (not entries).

	 *

	 * The kernel will record into the buffer up to a certain point.

	 * No partial samples are ever recorded.

	 */

	buf_arg.buf_size = 3*getpagesize()+512;

	/*

	 * now create our perfmon context.

	 */

	fd = pfm_create_context(&ctx, FMT_NAME, &buf_arg, sizeof(buf_arg));

	if (fd == -1) {

		if (errno == ENOSYS) {

			fatal_error("Your kernel does not have performance monitoring support!\n");

		}

		fatal_error("Can't create PFM context %s\n", strerror(errno));

	}

	/*

	 * retrieve the virtual address at which the sampling

	 * buffer has been mapped

	 */

	buf_addr = mmap(NULL, (size_t)buf_arg.buf_size, PROT_READ, MAP_PRIVATE, fd, 0);

	if (buf_addr == MAP_FAILED)

		fatal_error("cannot mmap sampling buffer: %s\n", strerror(errno));

	printf("buffer mapped @%p\n", buf_addr);

	hdr = (smpl_hdr_t *)buf_addr;

	printf("hdr_cur_offs=%llu version=%u.%u\n",

		(unsigned long long)hdr->hdr_cur_offs,

		PFM_VERSION_MAJOR(hdr->hdr_version),

		PFM_VERSION_MINOR(hdr->hdr_version));

	if (PFM_VERSION_MAJOR(hdr->hdr_version) < 1)

		fatal_error("invalid buffer format version\n");

	/*

	 * Now program the registers

	 */

	if (pfm_write_pmcs(fd, pc, outp.pfp_pmc_count))

		fatal_error("pfm_write_pmcs error errno %d\n",errno);

	/*

	 * initialize the PMDs

	 * To be read, each PMD must be either written or declared

	 * as being part of a sample (reg_smpl_pmds, reg_reset_pmds)

	 */

	if (pfm_write_pmds(fd, pd, outp.pfp_pmd_count))

		fatal_error("pfm_write_pmds error errno %d\n",errno);

	/*

	 * Create the child task

	 */

	if ((pid=fork()) == -1)

		fatal_error("Cannot fork process\n");

	/*

	 * In order to get the PFM_END_MSG message, it is important

	 * to ensure that the child task does not inherit the file

	 * descriptor of the context. By default, file descriptor

	 * are inherited during exec(). We explicitely close it

	 * here. We could have set it up through fcntl(FD_CLOEXEC)

	 * to achieve the same thing.

	 */

	if (pid == 0) {

		close(fd);

		child(arg);

	}

	/*

	 * wait for the child to exec

	 */

	waitpid(pid, &status, WUNTRACED);

	/*

	 * process is stopped at this point

	 */

	if (WIFEXITED(status)) {

		warning("task %s [%d] exited already status %d\n", arg[0], pid, WEXITSTATUS(status));

		goto terminate_session;

	}

	/*

	 * attach context to stopped task

	 */

	load_args.load_pid = pid;

	if (pfm_load_context (fd, &load_args))

		fatal_error("pfm_load_context error errno %d\n",errno);

	/*

	 * activate monitoring for stopped task.

	 * (nothing will be measured at this point

	 */

	if (pfm_start(fd, NULL))

		fatal_error("pfm_start error errno %d\n",errno);

	/*

	 * detach child. Side effect includes

	 * activation of monitoring.

	 */

	ptrace(PTRACE_DETACH, pid, NULL, 0);

	gettimeofday(&start_time, NULL);

	/*

	 * core loop

	 */

	for(;;) {

		/*

		 * wait for overflow/end notification messages

		 */

		ret = read(fd, &msg, sizeof(msg));

		if (ret == -1) {

			if(ret == -1 && errno == EINTR) {

				warning("read interrupted, retrying\n");

				continue;

			}

			fatal_error("cannot read perfmon msg: %s\n", strerror(errno));

		}

		switch(msg.type) {

			case PFM_MSG_OVFL: /* the sampling buffer is full */

				process_smpl_buf(hdr, pd[0].reg_smpl_pmds, num_smpl_pmds, entry_size);

				ovfl_count++;

				/*

				 * reactivate monitoring once we are done with the samples

				 *

				 * Note that this call can fail with EBUSY in non-blocking mode

				 * as the task may have disappeared while we were processing

				 * the samples.

				 */

				if (pfm_restart(fd)) {

					if (errno != EBUSY)

						fatal_error("pfm_restart error errno %d\n",errno);

					else

						warning("pfm_restart: task probably terminated \n");

				}

				break;

			case PFM_MSG_END: /* monitored task terminated */

				printf("task terminated\n");

				goto terminate_session;

			default: fatal_error("unknown message type %d\n", msg.type);

		}

	}

terminate_session:

	/*

	 * cleanup child

	 */

	wait4(pid, &status, 0, &rusage);

	gettimeofday(&end_time, NULL);

	/*

	 * check for any leftover samples

	 */

	process_smpl_buf(hdr, pd[0].reg_smpl_pmds, num_smpl_pmds, entry_size);

	/*

	 * close file descritor. Because of mmap() the number of reference to the

	 * "file" is 2, thus the context is only freed when the last reference is closed

	 * either by closed or munmap() depending on the order in which those calls are

	 * made:

	 * 	- close() -> munmap(): context and buffer destroyed after munmap().

	 * 			       buffer remains accessible after close().

	 * 	- munmap() -> close(): buffer unaccessible after munmap(), context and

	 * 			       buffer destroyed after close().

	 *

	 * It is important to free the resources cleanly, especially because the sampling

	 * buffer reserves locked memory.

	 */

	close(fd);

	/*

	 * unmap buffer, actually free the buffer and context because placed after

	 * the close(), i.e. is the last reference. See comments about close() above.

	 */

	ret = munmap(hdr, (size_t)buf_arg.buf_size);

	if (ret)

		fatal_error("cannot unmap buffer: %s\n", strerror(errno));

	printf("%"PRIu64" samples (%"PRIu64" in partial buffer) collected in %"PRIu64" buffer overflows\n",

		collected_samples,

		collected_partial,

		ovfl_count);

	show_task_rusage(&start_time, &end_time, &rusage);

	return 0;

}

static void

usage(void)

{

	printf("usage: task_smpl [-h] [--help] [--no-show] [--ovfl-block] cmd\n");

}

int

main(int argc, char **argv)

{

	pfmlib_options_t pfmlib_options;

	int c, ret;

	while ((c=getopt_long(argc, argv,"h", the_options, 0)) != -1) {

		switch(c) {

			case 0: continue;

			case 1:

			case 'h':

				usage();

				exit(0);

			default:

				fatal_error("");

		}

	}

	if (argv[optind] == NULL) {

		fatal_error("You must specify a command to execute\n");

	}

	/*

	 * pass options to library (optional)

	 */

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

	pfmlib_options.pfm_debug   = 0; /* set to 1 for debug */

	pfmlib_options.pfm_verbose = 1; /* set to 1 for verbose */

	pfm_set_options(&pfmlib_options);

	/*

	 * Initialize pfm library (required before we can use it)

	 */

	ret = pfm_initialize();

	if (ret != PFMLIB_SUCCESS)

		fatal_error("Cannot initialize library: %s\n", pfm_strerror(ret));

	return mainloop(argv+optind);

}