X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-procname.c;h=95d5f28dbe20b9a2e21decd18e7b2db04ccb0efa;hb=74011e88983b12958dacd6621d60c18f6a84f59b;hp=4d41593e17cb503286e1355cbc3f03c0166b4c81;hpb=b2cc986adb1aa11116ace6129dc2ec7e5c9737b1;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-procname.c b/liblttng-ust/lttng-context-procname.c
index 4d41593e..95d5f28d 100644
--- a/liblttng-ust/lttng-context-procname.c
+++ b/liblttng-ust/lttng-context-procname.c
@@ -20,6 +20,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _LGPL_SOURCE
 #include <lttng/ust-events.h>
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
@@ -27,6 +28,9 @@
 #include <assert.h>
 #include "compat.h"
 
+/* Maximum number of nesting levels for the procname cache. */
+#define PROCNAME_NESTING_MAX	2
+
 /*
  * We cache the result to ensure we don't trigger a system call for
  * each event.
@@ -36,26 +40,38 @@
  * be set for a thread before the first event is logged within this
  * thread.
  */
-typedef char procname_array[17];
+typedef char procname_array[PROCNAME_NESTING_MAX][17];
+
 static DEFINE_URCU_TLS(procname_array, cached_procname);
 
+static DEFINE_URCU_TLS(int, procname_nesting);
+
 static inline
 char *wrapper_getprocname(void)
 {
-	if (caa_unlikely(!URCU_TLS(cached_procname)[0])) {
-		lttng_ust_getprocname(URCU_TLS(cached_procname));
-		URCU_TLS(cached_procname)[LTTNG_UST_PROCNAME_LEN - 1] = '\0';
+	int nesting = URCU_TLS(procname_nesting);
+
+	if (caa_unlikely(nesting >= PROCNAME_NESTING_MAX))
+		return "<unknown>";
+	if (caa_unlikely(!URCU_TLS(cached_procname)[nesting][0])) {
+		CMM_STORE_SHARED(URCU_TLS(procname_nesting), nesting + 1);
+		lttng_ust_getprocname(URCU_TLS(cached_procname)[nesting]);
+		URCU_TLS(cached_procname)[nesting][LTTNG_UST_PROCNAME_LEN - 1] = '\0';
+		CMM_STORE_SHARED(URCU_TLS(procname_nesting), nesting);
 	}
-	return URCU_TLS(cached_procname);
+	return URCU_TLS(cached_procname)[nesting];
 }
 
 void lttng_context_procname_reset(void)
 {
-	URCU_TLS(cached_procname)[0] = '\0';
+	URCU_TLS(cached_procname)[1][0] = '\0';
+	CMM_STORE_SHARED(URCU_TLS(procname_nesting), 1);
+	URCU_TLS(cached_procname)[0][0] = '\0';
+	CMM_STORE_SHARED(URCU_TLS(procname_nesting), 0);
 }
 
 static
-size_t procname_get_size(size_t offset)
+size_t procname_get_size(struct lttng_ctx_field *field, size_t offset)
 {
 	size_t size = 0;
 
@@ -76,12 +92,12 @@ void procname_record(struct lttng_ctx_field *field,
 
 static
 void procname_get_value(struct lttng_ctx_field *field,
-		union lttng_ctx_value *value)
+		struct lttng_ctx_value *value)
 {
 	char *procname;
 
 	procname = wrapper_getprocname();
-	value->str = procname;
+	value->u.str = procname;
 }
 
 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx)