diff --git a/agents/virt/common/log.c b/agents/virt/common/log.c index d81a66a5..61018ed4 100644 --- a/agents/virt/common/log.c +++ b/agents/virt/common/log.c @@ -1,200 +1,204 @@ /** * Syslog wrapper that does not block * * Lon Hohberger, 2009 */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include #include "list.h" struct log_entry { list_head(); char *message; int sev; int bufsz; }; #define MAX_QUEUE_LENGTH 10 #define LOGLEN 256 static struct log_entry *_log_entries = NULL; static pthread_mutex_t log_mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t log_cond = PTHREAD_COND_INITIALIZER; static int log_size = 0; static int dropped = 0; static pthread_t thread_id = 0; void __real_syslog(int severity, const char *fmt, ...); void __wrap_syslog(int severity, const char *fmt, ...); void __wrap_closelog(void); static void * _log_thread(void *arg) { struct timeval tv; struct timespec ts; struct log_entry *entry; do { gettimeofday(&tv, NULL); ts.tv_sec = tv.tv_sec + 10; ts.tv_nsec = tv.tv_usec; pthread_mutex_lock(&log_mutex); while (!(entry = _log_entries)) { if (pthread_cond_timedwait(&log_cond, &log_mutex, &ts) == ETIMEDOUT) goto out; } list_remove(&_log_entries, entry); --log_size; if (log_size < 0) raise(SIGSEGV); pthread_mutex_unlock(&log_mutex); __real_syslog(entry->sev, entry->message); free(entry->message); free(entry); } while (1); out: thread_id = (pthread_t)0; pthread_mutex_unlock(&log_mutex); return NULL; } static int insert_entry(int sev, char *buf, int bufsz) { struct log_entry *lent; pthread_attr_t attrs; lent = malloc(sizeof(*lent)); if (!lent) return -1; lent->sev = sev; lent->message = buf; lent->bufsz = bufsz; pthread_mutex_lock(&log_mutex); if (log_size >= MAX_QUEUE_LENGTH) { free(lent->message); free(lent); ++dropped; lent = (struct log_entry *)(le(_log_entries)->le_prev); lent->sev = LOG_WARNING; snprintf(lent->message, lent->bufsz, "%d message(s) lost due to syslog load\n", dropped + 1); /* Dropped +1 because we overwrote a message to * give the 'dropped' message */ } else { ++log_size; dropped = 0; list_insert(&_log_entries, lent); } if (!thread_id) { pthread_attr_init(&attrs); pthread_attr_setinheritsched(&attrs, PTHREAD_INHERIT_SCHED); if (pthread_create(&thread_id, &attrs, _log_thread, NULL) < 0) thread_id = 0; pthread_mutex_unlock(&log_mutex); } else { pthread_mutex_unlock(&log_mutex); pthread_cond_signal(&log_cond); } return 0; } __attribute__((__format__ (__printf__, 2, 0))) void __wrap_syslog(int severity, const char *fmt, ...) { va_list args; char *logmsg; logmsg = malloc(LOGLEN); if (!logmsg) return; memset(logmsg, 0, LOGLEN); va_start(args, fmt); vsnprintf(logmsg + strlen(logmsg), LOGLEN - strlen(logmsg), fmt, args); va_end(args); insert_entry(severity, logmsg, LOGLEN); return; } void __real_closelog(void); void __wrap_closelog(void) { struct log_entry *lent; +#ifdef DEBUG int lost = 0; +#endif if (thread_id != 0) { pthread_cancel(thread_id); pthread_join(thread_id, NULL); thread_id = 0; } __real_closelog(); while (_log_entries) { +#ifdef DEBUG ++lost; +#endif lent = _log_entries; list_remove(&_log_entries, lent); free(lent->message); free(lent); } #ifdef DEBUG printf("%d lost\n", lost); #endif } #ifdef STANDALONE int main(int argc, char**argv) { int x; for (x = 0; x < 100; x++) { syslog(1, "Yo %d\n", x); } sleep(1); closelog(); return 0; } #endif