/*

 * set_notify.c - example of how to get notification at the end of a set chain

 *

 * Copyright (c) 2005-2006 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.

 *

 * This file is part of libpfm, a performance monitoring support library for

 * applications on Linux.

 */

#include <sys/types.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <signal.h>

#include <fcntl.h>

#include <perfmon/perfmon.h>

#include <perfmon/pfmlib.h>

#include "detect_pmcs.h"

#define NUM_SETS	3

#define THE_TIMEOUT	1

static volatile unsigned long notification_received;

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

static int ctx_fd;

static char *event1_name;

static pfarg_set_info_t setinfo[NUM_SETS];

static pfarg_pmd_attr_t pd[2];

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

static void

fatal_error(char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

	exit(1);

}

static void

warning(char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	vfprintf(stderr, fmt, ap);

	va_end(ap);

}

static void

sigio_handler(int n, struct siginfo *info, void *data)

{

	pfarg_msg_t msg;

	unsigned int k;

	int r;

retry:

	r = read(ctx_fd, &msg, sizeof(msg));

	if (r != sizeof(msg)) {

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

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

			goto retry;

		}

		fatal_error("cannot read overflow message: %s\n", strerror(errno));

	}

	if (msg.type != PFM_MSG_OVFL) {

		fatal_error("unexpected msg type: %d\n",msg.type);

	}

	if (pfm_getinfo_sets(ctx_fd, 0, setinfo, NUM_SETS * sizeof(*setinfo)) == -1) {

		fatal_error("pfm_getinfo_sets: %s", strerror(errno));

	}

	if (pfm_read(ctx_fd, 0, PFM_RW_PMD_ATTR, pd, 2 * sizeof(*pd)) == -1)

		fatal_error("pfm_read: %s", strerror(errno));

	/*

	 * XXX: risky to do printf() in signal handler!

	 */

	printf("Notification %lu: set%u pd[0]=%"PRIx64" pd[1]=%"PRIx64"\n",

		notification_received,

		pd[0].reg_set,

		pd[0].reg_value,

		pd[1].reg_value);

	for(k=0; k < NUM_SETS; k++)

		printf("set%u %"PRIu64" runs\n", setinfo[k].set_id, setinfo[k].set_runs);

	/*

	 * At this point, the counter used for the sampling period has already

	 * be reset by the kernel because we are in non-blocking mode, self-monitoring.

	 */

	/*

	 * increment our notification counter

	 */

	notification_received++;

	/*

	 * And resume monitoring

	 */

	if (pfm_set_state(ctx_fd, 0, PFM_ST_RESTART) == -1)

		fatal_error("pfm_set_state(restart): %s", strerror(errno));

}

/*

 * infinite loop waiting for notification to get out

 */

void

busyloop(void)

{

	/*

	 * busy loop to burn CPU cycles

	 */

	for(;notification_received < 3;) ;

}

#ifdef __ia64__

#define FUDGE 1

#else

#define FUDGE 0x100

#endif

/*

 * build end marker set

 */

void

setup_end_marker(int fd, pfarg_sinfo_t *sif, unsigned int set_id, uint64_t num_ovfls, int plm_mask)

{

	pfarg_set_desc_t setdesc;

	pfarg_pmr_t pc[8];

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	unsigned int i;

	int ret;

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

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

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

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

	/*

	 * we use the cycle event twice:

	 *   - first as sampling period to force switch to set 0

	 *   - second as sampling period to force notification

	 */

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

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

	inp.pfp_events[1] = inp.pfp_events[0];

	inp.pfp_dfl_plm     = plm_mask;

	inp.pfp_event_count = 2;

	/*

	 * 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_pmu_regs(sif, &inp.pfp_unavail_pmcs, NULL);

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

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

	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;

		pc[i].reg_set   = set_id;

	}

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

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

		pd[i].reg_set = set_id;

	}

	/*

	 * first cycle overflow: no notification, simply trigger a switch

	 */

	pd[0].reg_flags		  = 0;

	pd[0].reg_value           = -1;

	pd[0].reg_long_reset      = -1;

	pd[0].reg_short_reset     = -1;

	pd[0].reg_ovfl_swcnt      = 1;

	/*

	 * second cycle overflow: generate notification, switch on restart

	 */

	pd[1].reg_flags		  = PFM_REGFL_OVFL_NOTIFY;

	pd[1].reg_value           = -num_ovfls*FUDGE;

	pd[1].reg_long_reset      = -num_ovfls*FUDGE;

	pd[1].reg_short_reset     = -num_ovfls*FUDGE;

	pd[1].reg_ovfl_swcnt      =  1;

	/*

	 * set uses overflow switch

	 */

	setdesc.set_id              = set_id;

	setdesc.set_flags           = PFM_SETFL_OVFL_SWITCH;

	setdesc.set_timeout	    = 0;

	if (pfm_create_sets(fd, 0, &setdesc, sizeof(setdesc)) == -1)

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

	if (pfm_write(fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)

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

	/*

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

	 * as being part of a sample (reg_smpl_pmds)

	 */

	if (pfm_write(fd, 0, PFM_RW_PMD_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)

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

}

int

main(int argc, char **argv)

{

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfarg_pmr_t pc[NUM_PMCS];

	pfarg_pmd_attr_t pd[NUM_PMDS];

	pfarg_sinfo_t sif;

	pfarg_set_desc_t setdesc;

	pfmlib_options_t pfmlib_options;

	struct sigaction act;

	uint64_t num_ovfls;

	unsigned int i, k;

	size_t len;

	int ret;

	/*

	 * 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));

	num_ovfls = argc > 1 ? strtoull(argv[1], NULL, 10) : 3;

	printf("chain contains %d sets, time switching every %u seconds\n"

	       "notification every %"PRIu64" times the end of the chain is reached\n",

		NUM_SETS,

		THE_TIMEOUT,

		num_ovfls);

	/*

	 * Install the signal handler (SIGIO)

	 *

	 * SA_SIGINFO required on some platforms

	 * to get siginfo passed to handler.

	 */

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

	act.sa_handler = (sig_t)sigio_handler;

	act.sa_flags   = SA_SIGINFO;

	sigaction (SIGIO, &act, 0);

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

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

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

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

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

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

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

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

	pfm_get_max_event_name_len(&len;;

	event1_name = malloc(len+1);

	if (event1_name == NULL)

		fatal_error("cannot allocate event name\n");

	pfm_get_full_event_name(&inp.pfp_events[1], event1_name, len+1);

	/*

	 * set the default privilege mode for all counters:

	 * 	PFM_PLM3 : user level only

	 */

	inp.pfp_dfl_plm = PFM_PLM3;

	/*

	 * how many counters we use

	 */

	inp.pfp_event_count = 1;

	/*

	 * now create the session

	 */

	ctx_fd = pfm_create(0, &sif;;

	if (ctx_fd == -1) {

		if (errno == ENOSYS)

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

		fatal_error("cannot create session %s\n", strerror(errno));

	}

	/*

	 * 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_pmu_regs(&sif, &inp.pfp_unavail_pmcs, NULL);

	/*

	 * 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 registers to

	 * setup. Note that this field can 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;

	pd[0].reg_value           = 0;

	pd[0].reg_long_reset      = 0;

	pd[0].reg_short_reset     = 0;

	pd[0].reg_ovfl_swcnt      = 0;

	for(k=0; k < NUM_SETS; k++) {

		setdesc.set_id              = setinfo[k].set_id = k;

		setdesc.set_flags           = PFM_SETFL_TIME_SWITCH;

		setdesc.set_timeout	    = THE_TIMEOUT * 1000000000; /* in nsecs */

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

			pc[i].reg_set = k;

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

			pd[i].reg_set = k;

		if (pfm_create_sets(ctx_fd, 0, &setdesc, sizeof(setdesc)) == -1)

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

		if (pfm_write(ctx_fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)

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

		/*

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

	 	 * as being part of a sample (reg_smpl_pmds)

	 	 */

		if (pfm_write(ctx_fd, 0, PFM_RW_PMD_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)

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

	}

	setup_end_marker(ctx_fd, &sif, k, num_ovfls, inp.pfp_dfl_plm);

	/*

	 * we want to monitor ourself

	 */ if (pfm_attach(ctx_fd, 0, getpid()) == -1)

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

	/*

	 * setup asynchronous notification on the file descriptor

	 */

	ret = fcntl(ctx_fd, F_SETFL, fcntl(ctx_fd, F_GETFL, 0) | O_ASYNC);

	if (ret == -1)

		fatal_error("cannot set ASYNC: %s\n", strerror(errno));

	/*

	 * get ownership of the descriptor

	 */

	ret = fcntl(ctx_fd, F_SETOWN, getpid());

	if (ret == -1)

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

	/*

	 * Let's roll now

	 */

	pfm_set_state(ctx_fd, 0, PFM_ST_START);

	busyloop();

	pfm_set_state(ctx_fd, 0, PFM_ST_STOP);

	close(ctx_fd);

	free(event1_name);

	return 0;

}