static void *logwriter_thread(void *arg)
{
/* set name */
prctl(PR_SET_NAME, "sdlog2_writer", 0);
int log_fd = open_log_file();
if (log_fd < 0) {
return NULL;
}
struct logbuffer_s *logbuf = (struct logbuffer_s *)arg;
/* write log messages formats, version and parameters */
log_bytes_written += write_formats(log_fd);
log_bytes_written += write_version(log_fd);
log_bytes_written += write_parameters(log_fd);
fsync(log_fd);
int poll_count = 0;
void *read_ptr;
int n = 0;
bool should_wait = false;
bool is_part = false;
while (true) {
/* make sure threads are synchronized */
pthread_mutex_lock(&logbuffer_mutex);
/* update read pointer if needed */
if (n > 0) {
logbuffer_mark_read(&lb, n);
}
/* only wait if no data is available to process */
if (should_wait && !logwriter_should_exit) {
/* blocking wait for new data at this line */
pthread_cond_wait(&logbuffer_cond, &logbuffer_mutex);
}
/* only get pointer to thread-safe data, do heavy I/O a few lines down */
int available = logbuffer_get_ptr(logbuf, &read_ptr, &is_part);
/* continue */
pthread_mutex_unlock(&logbuffer_mutex);
if (available > 0) {
/* do heavy IO here */
if (available > MAX_WRITE_CHUNK) {
n = MAX_WRITE_CHUNK;
} else {
n = available;
}
n = write(log_fd, read_ptr, n);
should_wait = (n == available) && !is_part;
if (n < 0) {
main_thread_should_exit = true;
err(1, "error writing log file");
}
if (n > 0) {
log_bytes_written += n;
}
} else {
n = 0;
/* exit only with empty buffer */
if (main_thread_should_exit || logwriter_should_exit) {
break;
}
should_wait = true;
}
if (++poll_count == 10) {
fsync(log_fd);
poll_count = 0;
}
}
fsync(log_fd);
close(log_fd);
return NULL;
}
static void *logwriter_thread(void *arg)
{
/* set name */
prctl(PR_SET_NAME, "sdlog2_writer", 0);
struct logbuffer_s *logbuf = (struct logbuffer_s *)arg;
int log_file = open_logfile();
/* write log messages formats */
write_formats(log_file);
int poll_count = 0;
void *read_ptr;
int n = 0;
bool should_wait = false;
bool is_part = false;
while (true) {
/* make sure threads are synchronized */
pthread_mutex_lock(&logbuffer_mutex);
/* update read pointer if needed */
if (n > 0) {
logbuffer_mark_read(&lb, n);
}
/* only wait if no data is available to process */
if (should_wait && !logwriter_should_exit) {
/* blocking wait for new data at this line */
pthread_cond_wait(&logbuffer_cond, &logbuffer_mutex);
}
/* only get pointer to thread-safe data, do heavy I/O a few lines down */
int available = logbuffer_get_ptr(logbuf, &read_ptr, &is_part);
#ifdef SDLOG2_DEBUG
int rp = logbuf->read_ptr;
int wp = logbuf->write_ptr;
#endif
/* continue */
pthread_mutex_unlock(&logbuffer_mutex);
if (available > 0) {
/* do heavy IO here */
if (available > MAX_WRITE_CHUNK) {
n = MAX_WRITE_CHUNK;
} else {
n = available;
}
n = write(log_file, read_ptr, n);
should_wait = (n == available) && !is_part;
#ifdef SDLOG2_DEBUG
printf("write %i %i of %i rp=%i wp=%i, is_part=%i, should_wait=%i\n", log_bytes_written, n, available, rp, wp, (int)is_part, (int)should_wait);
#endif
if (n < 0) {
main_thread_should_exit = true;
err(1, "error writing log file");
}
if (n > 0) {
log_bytes_written += n;
}
} else {
n = 0;
#ifdef SDLOG2_DEBUG
printf("no data available, main_thread_should_exit=%i, logwriter_should_exit=%i\n", (int)main_thread_should_exit, (int)logwriter_should_exit);
#endif
/* exit only with empty buffer */
if (main_thread_should_exit || logwriter_should_exit) {
#ifdef SDLOG2_DEBUG
printf("break logwriter thread\n");
#endif
break;
}
should_wait = true;
}
if (++poll_count == 10) {
fsync(log_file);
poll_count = 0;
}
}
fsync(log_file);
close(log_file);
#ifdef SDLOG2_DEBUG
printf("logwriter thread exit\n");
#endif
return OK;
}
