talloc: use a library destructor instead of atexit() if available

[samba.git] / lib / talloc / talloc.c

diff --git a/lib/talloc/talloc.c b/lib/talloc/talloc.c
index 430ebc70f54cd38fc264bbed2b79cbe9cfc3423e..ce3bda45ece57ca0422c5984b70eff1c88cfcef1 100644 (file)
--- a/lib/talloc/talloc.c
+++ b/lib/talloc/talloc.c
@@ -121,8 +121,12 @@ static unsigned int talloc_magic = TALLOC_MAGIC_NON_RANDOM;
    NULL
 */
 static void *null_context;
+static bool talloc_report_null;
+static bool talloc_report_null_full;
 static void *autofree_context;
 
+static void talloc_setup_atexit(void);
+
 /* used to enable fill of memory on free, which can be useful for
  * catching use after free errors when valgrind is too slow
  */
@@ -426,6 +430,41 @@ void talloc_lib_init(void)
 #warning "No __attribute__((constructor)) support found on this platform, additional talloc security measures not available"
 #endif
 
+#ifdef HAVE_DESTRUCTOR_ATTRIBUTE
+void talloc_lib_fini(void) __attribute__((destructor));
+void talloc_lib_fini(void)
+#else /* ! HAVE_DESTRUCTOR_ATTRIBUTE */
+static void talloc_lib_fini(void)
+#endif /* ! HAVE_DESTRUCTOR_ATTRIBUTE */
+{
+       TALLOC_FREE(autofree_context);
+
+       if (talloc_total_size(null_context) == 0) {
+               return;
+       }
+
+       if (talloc_report_null_full) {
+               talloc_report_full(null_context, stderr);
+       } else if (talloc_report_null) {
+               talloc_report(null_context, stderr);
+       }
+}
+
+static void talloc_setup_atexit(void)
+{
+#ifndef HAVE_DESTRUCTOR_ATTRIBUTE
+       static bool done;
+
+       if (done) {
+               return;
+       }
+
+#warning "No __attribute__((destructor)) support found on this platform, using atexit"
+       atexit(talloc_lib_fini);
+       done = true;
+#endif /* ! HAVE_DESTRUCTOR_ATTRIBUTE */
+}
+
 static void talloc_log(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
 static void talloc_log(const char *fmt, ...)
 {
@@ -2294,26 +2333,6 @@ _PUBLIC_ void talloc_report(const void *ptr, FILE *f)
        talloc_report_depth_file(ptr, 0, 1, f);
 }
 
-/*
-  report on any memory hanging off the null context
-*/
-static void talloc_report_null(void)
-{
-       if (talloc_total_size(null_context) != 0) {
-               talloc_report(null_context, stderr);
-       }
-}
-
-/*
-  report on any memory hanging off the null context
-*/
-static void talloc_report_null_full(void)
-{
-       if (talloc_total_size(null_context) != 0) {
-               talloc_report_full(null_context, stderr);
-       }
-}
-
 /*
   enable tracking of the NULL context
 */
@@ -2369,7 +2388,8 @@ _PUBLIC_ void talloc_disable_null_tracking(void)
 _PUBLIC_ void talloc_enable_leak_report(void)
 {
        talloc_enable_null_tracking();
-       atexit(talloc_report_null);
+       talloc_report_null = true;
+       talloc_setup_atexit();
 }
 
 /*
@@ -2378,7 +2398,8 @@ _PUBLIC_ void talloc_enable_leak_report(void)
 _PUBLIC_ void talloc_enable_leak_report_full(void)
 {
        talloc_enable_null_tracking();
-       atexit(talloc_report_null_full);
+       talloc_report_null_full = true;
+       talloc_setup_atexit();
 }
 
 /*
@@ -2765,11 +2786,6 @@ static int talloc_autofree_destructor(void *ptr)
        return 0;
 }
 
-static void talloc_autofree(void)
-{
-       talloc_free(autofree_context);
-}
-
 /*
   return a context which will be auto-freed on exit
   this is useful for reducing the noise in leak reports
@@ -2779,7 +2795,7 @@ _PUBLIC_ void *talloc_autofree_context(void)
        if (autofree_context == NULL) {
                autofree_context = _talloc_named_const(NULL, 0, "autofree_context");
                talloc_set_destructor(autofree_context, talloc_autofree_destructor);
-               atexit(talloc_autofree);
+               talloc_setup_atexit();
        }
        return autofree_context;
 }