From fd8c59b1a984eeb288c5ecbfad7fe6dda6235140 Mon Sep 17 00:00:00 2001
From: Radek Krejci <rkrejci@cesnet.cz>
Date: Fri, 5 Feb 2016 15:40:20 +0100
Subject: [PATCH] HACK "memory leak" of ly_errno in main thread
It wasn't actually a real memory leak, there was just still reachable
dynamically allocated memory on process exit, because the destructor
registered by pthread_key_create() in the main thread isn't executed
on process termination but only on thread termination (i.e. on
pthread_exit()).
So, on Linux, we are going to use static memory for the main thread's
ly_errno.
Fixes #15
---
src/common.c | 52 ++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 38 insertions(+), 14 deletions(-)
diff --git a/src/common.c b/src/common.c
index 043aeaf92..979efec2a 100644
--- a/src/common.c
+++ b/src/common.c
@@ -22,10 +22,14 @@
#define _GNU_SOURCE
#include <assert.h>
+#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <pthread.h>
+#include <sys/types.h>
+#include <syscall.h>
+#include <unistd.h>
#include "common.h"
#include "tree_internal.h"
@@ -35,12 +39,42 @@
LY_ERR ly_errno_int = LY_EINT;
static pthread_once_t ly_errno_once = PTHREAD_ONCE_INIT;
static pthread_key_t ly_errno_key;
+#ifdef __linux__
+LY_ERR ly_errno_main = LY_SUCCESS;
+#endif
+
static void
ly_errno_createkey(void)
{
- if (pthread_key_create(&ly_errno_key, free)) {
+ LY_ERR *value;
+ int r;
+ void (*destr) (void *);
+
+ /* prepare ly_errno storage */
+#ifdef __linux__
+ if (getpid() == syscall(SYS_gettid)) {
+ /* main thread - use global variable instead of thread-specific variable.
+ * This is mainly for valgrind, because in case of the main thread the
+ * destructor registered by pthread_key_create() is not called since
+ * the main thread is terminated rather by return or exit than by
+ * pthread_exit(). */
+ value = &ly_errno_main;
+ destr = NULL;
+ } else {
+#else
+ {
+#endif /* __linux__ */
+ destr = free;
+ value = calloc(1, sizeof *value);
+ }
+
+ /* initiate */
+ while ((r = pthread_key_create(&ly_errno_key, destr)) == EAGAIN);
+ if (r) {
LOGMEM;
+ return;
}
+ pthread_setspecific(ly_errno_key, value);
}
API LY_ERR *
@@ -48,21 +82,11 @@ ly_errno_location(void)
{
LY_ERR *retval;
- if (pthread_once(&ly_errno_once, ly_errno_createkey)) {
- return &ly_errno_int;
- }
-
+ pthread_once(&ly_errno_once, ly_errno_createkey);
retval = pthread_getspecific(ly_errno_key);
if (!retval) {
- /* first call */
- retval = calloc(1, sizeof *retval);
- if (!retval) {
- return &ly_errno_int;
- }
-
- if (pthread_setspecific(ly_errno_key, retval)) {
- return &ly_errno_int;
- }
+ /* error */
+ return &ly_errno_int;
}
return retval;