1 files changed, 32 insertions, 6 deletions

diff --git a/ext/clogger_ext/clogger.c b/ext/clogger_ext/clogger.c
index 7e01e6d..604b9b6 100644
--- a/ext/clogger_ext/clogger.c
+++ b/ext/clogger_ext/clogger.c
@@ -13,11 +13,38 @@
 #ifdef HAVE_FCNTL_H
 #  include <fcntl.h>
 #endif
-#define _POSIX_C_SOURCE 200112L
+#ifndef _POSIX_C_SOURCE
+#  define _POSIX_C_SOURCE 200112L
+#endif
 #include <time.h>
 #include "ruby_1_9_compat.h"
 #include "broken_system_compat.h"
 
+/*
+ * Availability of a monotonic clock needs to be detected at runtime
+ * since we could've been built on a different system than we're run
+ * under.
+ */
+static clockid_t hopefully_CLOCK_MONOTONIC = CLOCK_MONOTONIC;
+
+static void check_clock(void)
+{
+        struct timespec now;
+
+        /* we can't check this reliably at compile time */
+        if (clock_gettime(CLOCK_MONOTONIC, &now) == 0)
+                return;
+
+        if (clock_gettime(CLOCK_REALTIME, &now) == 0) {
+                hopefully_CLOCK_MONOTONIC = CLOCK_REALTIME;
+                rb_warn("CLOCK_MONOTONIC not available, "
+                        "falling back to CLOCK_REALTIME");
+        }
+        rb_warn("clock_gettime() totally broken, " \
+                "falling back to pure Ruby Clogger");
+        rb_raise(rb_eLoadError, "clock_gettime() broken");
+}
+
 static void clock_diff(struct timespec *a, const struct timespec *b)
 {
         a->tv_sec -= b->tv_sec;
@@ -346,11 +373,8 @@ static void append_ts(struct clogger *c, const VALUE *op, struct timespec *ts)
 static void append_request_time_fmt(struct clogger *c, const VALUE *op)
 {
         struct timespec now;
-        int r = clock_gettime(CLOCK_MONOTONIC, &now);
-
-        if (unlikely(r != 0))
-                rb_sys_fail("clock_gettime(CLOCK_MONONTONIC)");
 
+        clock_gettime(hopefully_CLOCK_MONOTONIC, &now);
         clock_diff(&now, &c->ts_start);
         append_ts(c, op, &now);
 }
@@ -724,7 +748,7 @@ static VALUE ccall(struct clogger *c, VALUE env)
 {
         VALUE rv;
 
-        clock_gettime(CLOCK_MONOTONIC, &c->ts_start);
+        clock_gettime(hopefully_CLOCK_MONOTONIC, &c->ts_start);
         c->env = env;
         c->cookies = Qfalse;
         rv = rb_funcall(c->app, call_id, 1, env);
@@ -859,6 +883,8 @@ void Init_clogger_ext(void)
 {
         VALUE tmp;
 
+        check_clock();
+
         ltlt_id = rb_intern("<<");
         call_id = rb_intern("call");
         each_id = rb_intern("each");