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/**
* Copyright (C) ARM Limited 2010-2013. 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.
*/
#define __STDC_FORMAT_MACROS
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/time.h>
#include <inttypes.h>
#include "Collector.h"
#include "SessionData.h"
#include "Logging.h"
#include "Sender.h"
// Driver initialization independent of session settings
Collector::Collector() {
mBufferFD = 0;
checkVersion();
int enable = -1;
if (readIntDriver("/dev/gator/enable", &enable) != 0 || enable != 0) {
logg->logError(__FILE__, __LINE__, "Driver already enabled, possibly a session is already in progress.");
handleException();
}
readIntDriver("/dev/gator/cpu_cores", &gSessionData->mCores);
if (gSessionData->mCores == 0) {
gSessionData->mCores = 1;
}
mBufferSize = 0;
if (readIntDriver("/dev/gator/buffer_size", &mBufferSize) || mBufferSize <= 0) {
logg->logError(__FILE__, __LINE__, "Unable to read the driver buffer size");
handleException();
}
}
Collector::~Collector() {
// Write zero for safety, as a zero should have already been written
writeDriver("/dev/gator/enable", "0");
// Calls event_buffer_release in the driver
if (mBufferFD) {
close(mBufferFD);
}
}
void Collector::checkVersion() {
int driver_version = 0;
if (readIntDriver("/dev/gator/version", &driver_version) == -1) {
logg->logError(__FILE__, __LINE__, "Error reading gator driver version");
handleException();
}
// Verify the driver version matches the daemon version
if (driver_version != PROTOCOL_VERSION) {
if ((driver_version > PROTOCOL_DEV) || (PROTOCOL_VERSION > PROTOCOL_DEV)) {
// One of the mismatched versions is development version
logg->logError(__FILE__, __LINE__,
"DEVELOPMENT BUILD MISMATCH: gator driver version \"%d\" is not in sync with gator daemon version \"%d\".\n"
">> The following must be synchronized from engineering repository:\n"
">> * gator driver\n"
">> * gator daemon\n"
">> * Streamline", driver_version, PROTOCOL_VERSION);
handleException();
} else {
// Release version mismatch
logg->logError(__FILE__, __LINE__,
"gator driver version \"%d\" is different than gator daemon version \"%d\".\n"
">> Please upgrade the driver and daemon to the latest versions.", driver_version, PROTOCOL_VERSION);
handleException();
}
}
}
void Collector::start() {
// Set the maximum backtrace depth
if (writeReadDriver("/dev/gator/backtrace_depth", &gSessionData->mBacktraceDepth)) {
logg->logError(__FILE__, __LINE__, "Unable to set the driver backtrace depth");
handleException();
}
// open the buffer which calls userspace_buffer_open() in the driver
mBufferFD = open("/dev/gator/buffer", O_RDONLY);
if (mBufferFD < 0) {
logg->logError(__FILE__, __LINE__, "The gator driver did not set up properly. Please view the linux console or dmesg log for more information on the failure.");
handleException();
}
// set the tick rate of the profiling timer
if (writeReadDriver("/dev/gator/tick", &gSessionData->mSampleRate) != 0) {
logg->logError(__FILE__, __LINE__, "Unable to set the driver tick");
handleException();
}
// notify the kernel of the response type
int response_type = gSessionData->mLocalCapture ? 0 : RESPONSE_APC_DATA;
if (writeDriver("/dev/gator/response_type", response_type)) {
logg->logError(__FILE__, __LINE__, "Unable to write the response type");
handleException();
}
// Set the live rate
if (writeReadDriver("/dev/gator/live_rate", &gSessionData->mLiveRate)) {
logg->logError(__FILE__, __LINE__, "Unable to set the driver live rate");
handleException();
}
logg->logMessage("Start the driver");
// This command makes the driver start profiling by calling gator_op_start() in the driver
if (writeDriver("/dev/gator/enable", "1") != 0) {
logg->logError(__FILE__, __LINE__, "The gator driver did not start properly. Please view the linux console or dmesg log for more information on the failure.");
handleException();
}
lseek(mBufferFD, 0, SEEK_SET);
}
// These commands should cause the read() function in collect() to return
void Collector::stop() {
// This will stop the driver from profiling
if (writeDriver("/dev/gator/enable", "0") != 0) {
logg->logMessage("Stopping kernel failed");
}
}
int Collector::collect(char* buffer) {
// Calls event_buffer_read in the driver
int bytesRead;
errno = 0;
bytesRead = read(mBufferFD, buffer, mBufferSize);
// If read() returned due to an interrupt signal, re-read to obtain the last bit of collected data
if (bytesRead == -1 && errno == EINTR) {
bytesRead = read(mBufferFD, buffer, mBufferSize);
}
// return the total bytes written
logg->logMessage("Driver read of %d bytes", bytesRead);
return bytesRead;
}
int Collector::readIntDriver(const char* fullpath, int* value) {
FILE* file = fopen(fullpath, "r");
if (file == NULL) {
return -1;
}
if (fscanf(file, "%u", value) != 1) {
fclose(file);
logg->logMessage("Invalid value in file %s", fullpath);
return -1;
}
fclose(file);
return 0;
}
int Collector::readInt64Driver(const char* fullpath, int64_t* value) {
FILE* file = fopen(fullpath, "r");
if (file == NULL) {
return -1;
}
if (fscanf(file, "%" SCNi64, value) != 1) {
fclose(file);
logg->logMessage("Invalid value in file %s", fullpath);
return -1;
}
fclose(file);
return 0;
}
int Collector::writeDriver(const char* path, int value) {
char data[40]; // Sufficiently large to hold any integer
snprintf(data, sizeof(data), "%d", value);
return writeDriver(path, data);
}
int Collector::writeDriver(const char* path, int64_t value) {
char data[40]; // Sufficiently large to hold any integer
snprintf(data, sizeof(data), "%" PRIi64, value);
return writeDriver(path, data);
}
int Collector::writeDriver(const char* fullpath, const char* data) {
int fd = open(fullpath, O_WRONLY);
if (fd < 0) {
return -1;
}
if (write(fd, data, strlen(data)) < 0) {
close(fd);
logg->logMessage("Opened but could not write to %s", fullpath);
return -1;
}
close(fd);
return 0;
}
int Collector::writeReadDriver(const char* path, int* value) {
if (writeDriver(path, *value) || readIntDriver(path, value)) {
return -1;
}
return 0;
}
int Collector::writeReadDriver(const char* path, int64_t* value) {
if (writeDriver(path, *value) || readInt64Driver(path, value)) {
return -1;
}
return 0;
}
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