src/base/timestamp.c

/*
 * Copyright 2012 Google Inc.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
 */

#include <stdint.h>
#include <stdio.h>
#include <sysinfo.h>

#include "base/fwdb.h"
#include "base/init_funcs.h"
#include "base/time.h"
#include "base/timestamp.h"
#include "drivers/timer/timer.h"

static TimestampTable *timestamp_table;

static int timestamp_table_max_entries(TimestampTable *table, size_t size)
{
	size_t entries_size = size - offsetof(TimestampTable, entries);
	return entries_size / sizeof(TimestampEntry);
}

static void timestamp_table_init(TimestampTable *table, size_t size)
{
	table->base_time = 0;
	table->max_entries = timestamp_table_max_entries(table, size);
	table->num_entries = 0;
}

static int timestamp_table_install(void)
{
	if (timestamp_table) {
		printf("Timestamp table is already initialized.\n");
		return 1;
	}

	FwdbEntry default_entry = {
		.size = offsetof(TimestampTable, entries) +
			CONFIG_MAX_TIMESTAMPS * sizeof(TimestampEntry),
	};
	FwdbEntry entry;
	if (fwdb_access("timestamp table", &entry, &default_entry))
		return 1;
	TimestampTable *table = (TimestampTable *)entry.ptr;
	if (!table->max_entries)
		timestamp_table_init(table, entry.size);

	int max_entries = timestamp_table_max_entries(table, entry.size);
	if (table->max_entries > max_entries) {
		printf("Timestamp table max entries too high.\n");
		return 1;
	}

	if (table->num_entries > table->max_entries) {
		printf("Timestamp table over filled.\n");
		return 1;
	}

	timestamp_table = table;

	timestamp_add_now(TS_START);
	return 0;
}

INIT_FUNC_TIMESTAMP(timestamp_table_install)

void timestamp_add(TimestampId id, uint64_t time)
{
	TimestampEntry *tse;

	if (!timestamp_table ||
	    (timestamp_table->num_entries ==
	     timestamp_table->max_entries)) {
		return;
	}

	tse = &timestamp_table->entries[timestamp_table->num_entries++];
	tse->id = id;
	tse->stamp = time - timestamp_table->base_time;
}

void timestamp_add_now(TimestampId id)
{
	if (CONFIG_TIMESTAMP_RAW)
		timestamp_add(id, timer_raw_value());
	else
		timestamp_add(id, time_us(0));
}