Cleanup: ust-tracepoint-event.h: extract `__num_fields` in a variable

[lttng-ust.git] / liblttng-ust / lttng-context-procname.c

diff --git a/liblttng-ust/lttng-context-procname.c b/liblttng-ust/lttng-context-procname.c
index 95d5f28dbe20b9a2e21decd18e7b2db04ccb0efa..73f38878f872557283a13b171977ca245c2969a5 100644 (file)
--- a/liblttng-ust/lttng-context-procname.c
+++ b/liblttng-ust/lttng-context-procname.c
@@ -21,6 +21,7 @@
  */
 
 #define _LGPL_SOURCE
+#include <stddef.h>
 #include <lttng/ust-events.h>
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
@@ -49,34 +50,36 @@ static DEFINE_URCU_TLS(int, procname_nesting);
 static inline
 char *wrapper_getprocname(void)
 {
-       int nesting = URCU_TLS(procname_nesting);
+       int nesting = CMM_LOAD_SHARED(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);
+               /* Increment nesting before updating cache. */
+               cmm_barrier();
                lttng_ust_getprocname(URCU_TLS(cached_procname)[nesting]);
                URCU_TLS(cached_procname)[nesting][LTTNG_UST_PROCNAME_LEN - 1] = '\0';
+               /* Decrement nesting after updating cache. */
+               cmm_barrier();
                CMM_STORE_SHARED(URCU_TLS(procname_nesting), nesting);
        }
        return URCU_TLS(cached_procname)[nesting];
 }
 
+/* Reset should not be called from a signal handler. */
 void lttng_context_procname_reset(void)
 {
-       URCU_TLS(cached_procname)[1][0] = '\0';
+       CMM_STORE_SHARED(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(cached_procname)[0][0], '\0');
        CMM_STORE_SHARED(URCU_TLS(procname_nesting), 0);
 }
 
 static
 size_t procname_get_size(struct lttng_ctx_field *field, size_t offset)
 {
-       size_t size = 0;
-
-       size += LTTNG_UST_PROCNAME_LEN;
-       return size;
+       return LTTNG_UST_PROCNAME_LEN;
 }
 
 static
@@ -94,10 +97,7 @@ static
 void procname_get_value(struct lttng_ctx_field *field,
                struct lttng_ctx_value *value)
 {
-       char *procname;
-
-       procname = wrapper_getprocname();
-       value->u.str = procname;
+       value->u.str = wrapper_getprocname();
 }
 
 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx)