1 files changed, 91 insertions, 0 deletions
diff --git a/deps/jemalloc/include/jemalloc/internal/ticker.h b/deps/jemalloc/include/jemalloc/internal/ticker.h
new file mode 100644
index 000000000..52d0db4c8
--- /dev/null
+++ b/deps/jemalloc/include/jemalloc/internal/ticker.h
@@ -0,0 +1,91 @@
+#ifndef JEMALLOC_INTERNAL_TICKER_H
+#define JEMALLOC_INTERNAL_TICKER_H
+
+#include "jemalloc/internal/util.h"
+
+/**
+ * A ticker makes it easy to count-down events until some limit.  You
+ * ticker_init the ticker to trigger every nticks events.  You then notify it
+ * that an event has occurred with calls to ticker_tick (or that nticks events
+ * have occurred with a call to ticker_ticks), which will return true (and reset
+ * the counter) if the countdown hit zero.
+ */
+
+typedef struct {
+	int32_t tick;
+	int32_t nticks;
+} ticker_t;
+
+static inline void
+ticker_init(ticker_t *ticker, int32_t nticks) {
+	ticker->tick = nticks;
+	ticker->nticks = nticks;
+}
+
+static inline void
+ticker_copy(ticker_t *ticker, const ticker_t *other) {
+	*ticker = *other;
+}
+
+static inline int32_t
+ticker_read(const ticker_t *ticker) {
+	return ticker->tick;
+}
+
+/*
+ * Not intended to be a public API.  Unfortunately, on x86, neither gcc nor
+ * clang seems smart enough to turn
+ *   ticker->tick -= nticks;
+ *   if (unlikely(ticker->tick < 0)) {
+ *     fixup ticker
+ *     return true;
+ *   }
+ *   return false;
+ * into
+ *   subq %nticks_reg, (%ticker_reg)
+ *   js fixup ticker
+ *
+ * unless we force "fixup ticker" out of line.  In that case, gcc gets it right,
+ * but clang now does worse than before.  So, on x86 with gcc, we force it out
+ * of line, but otherwise let the inlining occur.  Ordinarily this wouldn't be
+ * worth the hassle, but this is on the fast path of both malloc and free (via
+ * tcache_event).
+ */
+#if defined(__GNUC__) && !defined(__clang__)				\
+    && (defined(__x86_64__) || defined(__i386__))
+JEMALLOC_NOINLINE
+#endif
+static bool
+ticker_fixup(ticker_t *ticker) {
+	ticker->tick = ticker->nticks;
+	return true;
+}
+
+static inline bool
+ticker_ticks(ticker_t *ticker, int32_t nticks) {
+	ticker->tick -= nticks;
+	if (unlikely(ticker->tick < 0)) {
+		return ticker_fixup(ticker);
+	}
+	return false;
+}
+
+static inline bool
+ticker_tick(ticker_t *ticker) {
+	return ticker_ticks(ticker, 1);
+}
+
+/* 
+ * Try to tick.  If ticker would fire, return true, but rely on
+ * slowpath to reset ticker.
+ */
+static inline bool
+ticker_trytick(ticker_t *ticker) {
+	--ticker->tick;
+	if (unlikely(ticker->tick < 0)) {
+		return true;
+	}
+	return false;
+}
+
+#endif /* JEMALLOC_INTERNAL_TICKER_H */