text: /**
   * Copyright (C) ARM Limited 2013-2014. 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 version 2 as
   * published by the Free Software Foundation.
   */
  
  #include "KMod.h"
  
  #include <sys/types.h>
  #include <dirent.h>
  #include <unistd.h>
  
  #include "ConfigurationXML.h"
  #include "Counter.h"
  #include "DriverSource.h"
  #include "Logging.h"
  
  // Claim all the counters in /dev/gator/events
  bool KMod::claimCounter(const Counter &counter) const {
  	char text[128];
  	snprintf(text, sizeof(text), "/dev/gator/events/%s", counter.getType());
  	return access(text, F_OK) == 0;
  }
  
  void KMod::resetCounters() {
  	char base[128];
  	char text[128];
  
  	// Initialize all perf counters in the driver, i.e. set enabled to zero
  	struct dirent *ent;
  	DIR* dir = opendir("/dev/gator/events");
  	if (dir) {
  		while ((ent = readdir(dir)) != NULL) {
  			// skip hidden files, current dir, and parent dir
  			if (ent->d_name[0] == '.')
  				continue;
  			snprintf(base, sizeof(base), "/dev/gator/events/%s", ent->d_name);
  			snprintf(text, sizeof(text), "%s/enabled", base);
  			DriverSource::writeDriver(text, 0);
  			snprintf(text, sizeof(text), "%s/count", base);
  			DriverSource::writeDriver(text, 0);
  		}
  		closedir(dir);
  	}
  }
  
  void KMod::setupCounter(Counter &counter) {
  	char base[128];
  	char text[128];
  	snprintf(base, sizeof(base), "/dev/gator/events/%s", counter.getType());
  
  	snprintf(text, sizeof(text), "%s/enabled", base);
  	int enabled = true;
  	if (DriverSource::writeReadDriver(text, &enabled) || !enabled) {
  		counter.setEnabled(false);
  		return;
  	}
  
  	snprintf(text, sizeof(text), "%s/key", base);
  	int key = 0;
  	DriverSource::readIntDriver(text, &key);
  	counter.setKey(key);
  
  	snprintf(text, sizeof(text), "%s/event", base);
  	DriverSource::writeDriver(text, counter.getEvent());
  	snprintf(text, sizeof(text), "%s/count", base);
  	if (access(text, F_OK) == 0) {
  		int count = counter.getCount();
  		if (DriverSource::writeReadDriver(text, &count) && counter.getCount() > 0) {
  			logg->logError(__FILE__, __LINE__, "Cannot enable EBS for %s:%i with a count of %d\n", counter.getType(), counter.getEvent(), counter.getCount());
  			handleException();
  		}
  		counter.setCount(count);
  	} else if (counter.getCount() > 0) {
  		ConfigurationXML::remove();
  		logg->logError(__FILE__, __LINE__, "Event Based Sampling is only supported with kernel versions 3.0.0 and higher with CONFIG_PERF_EVENTS=y, and CONFIG_HW_PERF_EVENTS=y. The invalid configuration.xml has been removed.\n");
  		handleException();
  	}
  }
  
  int KMod::writeCounters(mxml_node_t *root) const {
  	struct dirent *ent;
  	mxml_node_t *counter;
  
  	// counters.xml is simply a file listing of /dev/gator/events
  	DIR* dir = opendir("/dev/gator/events");
  	if (dir == NULL) {
  		return 0;
  	}
  
  	int count = 0;
  	while ((ent = readdir(dir)) != NULL) {
  		// skip hidden files, current dir, and parent dir
  		if (ent->d_name[0] == '.')
  			continue;
  		counter = mxmlNewElement(root, "counter");
  		mxmlElementSetAttr(counter, "name", ent->d_name);
  		++count;
  	}
  	closedir(dir);
  
  	return count;
  }
  