[ovs-dev] [PATCH 2/3] timeval: Coalesce backtraces with counts.

[Ethan Jackson]

Making stubs turned out to be cleanest.  Here's an incremental.

---
 lib/timeval.c |   28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/lib/timeval.c b/lib/timeval.c
index bd2a84d..b36203a 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -39,10 +39,6 @@
 #include "util.h"
 #include "vlog.h"
 
-#ifndef HAVE_EXECINFO_H
-#define HAVE_EXECINFO_H 0
-#endif
-
 VLOG_DEFINE_THIS_MODULE(timeval);
 
 /* The clock to use for measuring time intervals.  This is CLOCK_MONOTONIC by
@@ -98,6 +94,22 @@ static void timespec_add(struct timespec *sum,
                          const struct timespec *a, const struct timespec *b);
 static unixctl_cb_func backtrace_cb;
 
+#ifndef HAVE_EXECINFO_H
+#define HAVE_EXECINFO_H 0
+
+static int
+backtrace(void **buffer OVS_UNUSED, int size OVS_UNUSED)
+{
+    NOT_REACHED();
+}
+
+static char **
+backtrace_symbols(void *const *buffer OVS_UNUSED, int size OVS_UNUSED)
+{
+    NOT_REACHED();
+}
+#endif
+
 /* Initializes the timetracking module, if not already initialized. */
 static void
 time_init(void)
@@ -398,15 +410,13 @@ sigalrm_handler(int sig_nr OVS_UNUSED)
     wall_tick = true;
     monotonic_tick = true;
 
-#if HAVE_EXECINFO_H
-    if (CACHE_TIME) {
+    if (HAVE_EXECINFO_H && CACHE_TIME) {
         struct trace *trace = &traces[trace_head];
 
         trace->n_frames = backtrace(trace->backtrace,
                                     ARRAY_SIZE(trace->backtrace));
         trace_head = (trace_head + 1) % MAX_TRACES;
     }
-#endif
 }
 
 static void
@@ -611,8 +621,7 @@ format_backtraces(struct ds *ds)
 {
     time_init();
 
-#if HAVE_EXECINFO_H
-    if (CACHE_TIME) {
+    if (HAVE_EXECINFO_H && CACHE_TIME) {
         struct hmap trace_map = HMAP_INITIALIZER(&trace_map);
         struct trace *trace, *next;
         sigset_t oldsigs;
@@ -658,7 +667,6 @@ format_backtraces(struct ds *ds)
         ds_chomp(ds, '\n');
         unblock_sigalrm(&oldsigs);
     }
-#endif
 }
 
 /* Unixctl interface. */
-- 
1.7.9.5