Added support for task sleeping in the scheduler.

2 files changed, 86 insertions, 0 deletions

diff --git a/src/rt/sync/timer.cpp b/src/rt/sync/timer.cpp
new file mode 100644
index 00000000..e45dd633
--- /dev/null
+++ b/src/rt/sync/timer.cpp
@@ -0,0 +1,61 @@
+#include "../globals.h"
+#include "timer.h"
+
+#if defined(__APPLE__)
+#include <mach/mach_time.h>
+#endif
+
+timer::timer() {
+    reset(0);
+#if __WIN32__
+    uint64_t ticks_per_second;
+    QueryPerformanceFrequency((LARGE_INTEGER *)&ticks_per_second);
+    _ticks_per_us = ticks_per_second / 1000000;
+#endif
+}
+
+void
+timer::reset(uint64_t timeout) {
+    _start = get_time();
+    _timeout = timeout;
+}
+
+uint64_t
+timer::get_elapsed_time() {
+    return get_time() - _start;
+}
+
+int64_t
+timer::get_timeout() {
+    return _timeout - get_elapsed_time();
+}
+
+bool
+timer::has_timed_out() {
+    return get_timeout() <= 0;
+}
+
+uint64_t
+timer::get_time() {
+#ifdef __APPLE__
+    uint64_t time = mach_absolute_time();
+    mach_timebase_info_data_t info = {0, 0};
+    if (info.denom == 0) {
+        mach_timebase_info(&info);
+    }
+    uint64_t time_nano = time * (info.numer / info.denom);
+    return time_nano / 1000;
+#elif __WIN32__
+    uint64_t ticks;
+    QueryPerformanceCounter((LARGE_INTEGER *)&ticks);
+    return ticks / _ticks_per_us;
+#else
+    timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return (ts.tv_sec * 1000000000LL + ts.tv_nsec) / 1000;
+#endif
+}
+
+timer::~timer() {
+    // Nop.
+}
diff --git a/src/rt/sync/timer.h b/src/rt/sync/timer.h
new file mode 100644
index 00000000..509fd22c
--- /dev/null
+++ b/src/rt/sync/timer.h
@@ -0,0 +1,25 @@
+/*
+ *  Utility class to measure time in a platform independent way.
+ */
+
+#ifndef TIMER_H
+#define TIMER_H
+
+class timer {
+private:
+    uint64_t _start;
+    uint64_t _timeout;
+    uint64_t get_time();
+#if __WIN32__
+    uint64_t _ticks_per_us;
+#endif
+public:
+    timer();
+    void reset(uint64_t timeout);
+    uint64_t get_elapsed_time();
+    int64_t get_timeout();
+    bool has_timed_out();
+    virtual ~timer();
+};
+
+#endif /* TIMER_H */