1 files changed, 130 insertions, 0 deletions
diff --git a/src/util/os_time.h b/src/util/os_time.h
new file mode 100644
index 00000000000..049ab118db2
--- /dev/null
+++ b/src/util/os_time.h
@@ -0,0 +1,130 @@
+/**************************************************************************
+ *
+ * Copyright 2008-2010 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/**
+ * @file
+ * OS independent time-manipulation functions.
+ * 
+ * @author Jose Fonseca <[email protected]>
+ */
+
+#ifndef _OS_TIME_H_
+#define _OS_TIME_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* must be equal to PIPE_TIMEOUT_INFINITE */
+#define OS_TIMEOUT_INFINITE 0xffffffffffffffffull
+
+/*
+ * Get the current time in nanoseconds from an unknown base.
+ */
+int64_t
+os_time_get_nano(void);
+
+
+/*
+ * Get the current time in microseconds from an unknown base.
+ */
+static inline int64_t
+os_time_get(void)
+{
+   return os_time_get_nano() / 1000;
+}
+
+
+/*
+ * Sleep.
+ */
+void
+os_time_sleep(int64_t usecs);
+
+
+/*
+ * Helper function for detecting time outs, taking in account overflow.
+ *
+ * Returns true if the current time has elapsed beyond the specified interval.
+ */
+static inline bool
+os_time_timeout(int64_t start,
+                int64_t end,
+                int64_t curr)
+{
+   if (start <= end)
+      return !(start <= curr && curr < end);
+   else
+      return !((start <= curr) || (curr < end));
+}
+
+
+/**
+ * Convert a relative timeout in nanoseconds into an absolute timeout,
+ * in other words, it returns current time + timeout.
+ * os_time_get_nano() must be monotonic.
+ * OS_TIMEOUT_INFINITE is passed through unchanged. If the calculation
+ * overflows, OS_TIMEOUT_INFINITE is returned.
+ */
+int64_t
+os_time_get_absolute_timeout(uint64_t timeout);
+
+
+/**
+ * Wait until the variable at the given memory location is zero.
+ *
+ * \param var           variable
+ * \param timeout       timeout in ns, can be anything from 0 (no wait) to
+ *                      OS_TIMEOUT_INFINITE (wait forever)
+ * \return     true if the variable is zero
+ */
+bool
+os_wait_until_zero(volatile int *var, uint64_t timeout);
+
+
+/**
+ * Wait until the variable at the given memory location is zero.
+ * The timeout is the absolute time when the waiting should stop. If it is
+ * less than or equal to the current time, it only returns the status and
+ * doesn't wait. OS_TIMEOUT_INFINITE waits forever. This requires that
+ * os_time_get_nano is monotonic.
+ *
+ * \param var       variable
+ * \param timeout   the time in ns when the waiting should stop
+ * \return     true if the variable is zero
+ */
+bool
+os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _OS_TIME_H_ */