[dpdk-dev] [PATCH v2 1/6] eal: add internal API for current time

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

Many PMDs use POSIX gettimeofday(). Add rte_time_get_us() function
to obtain current time with microsecond precision on all platforms.

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---
 lib/librte_eal/include/rte_time.h    | 17 +++++++++++++++++
 lib/librte_eal/rte_eal_exports.def   |  1 +
 lib/librte_eal/unix/eal_unix_timer.c | 13 +++++++++++++
 lib/librte_eal/version.map           |  1 +
 lib/librte_eal/windows/eal_timer.c   | 21 ++++++++++++++++++++-
 5 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/include/rte_time.h b/lib/librte_eal/include/rte_time.h
index 5ad7c8841..50fa4f889 100644
--- a/lib/librte_eal/include/rte_time.h
+++ b/lib/librte_eal/include/rte_time.h
@@ -8,6 +8,8 @@
 #include <stdint.h>
 #include <time.h>
 
+#include <rte_compat.h>
+
 #define NSEC_PER_SEC             1000000000L
 
 /**
@@ -98,4 +100,19 @@ rte_ns_to_timespec(uint64_t nsec)
 	return ts;
 }
 
+/* Point of time with microsecond precision. */
+struct rte_time_us {
+	int64_t sec;  /**< Number of whole seconds. */
+	int64_t usec; /**< Fractional part of second in [0, 999999]. */
+};
+
+/**
+ * Get current system time.
+ *
+ * @param now
+ *  Receives current system time.
+ */
+__rte_internal
+void rte_time_get_us(struct rte_time_us *now);
+
 #endif /* _RTE_TIME_H_ */
diff --git a/lib/librte_eal/rte_eal_exports.def b/lib/librte_eal/rte_eal_exports.def
index 474cf123f..cb691f7bc 100644
--- a/lib/librte_eal/rte_eal_exports.def
+++ b/lib/librte_eal/rte_eal_exports.def
@@ -334,3 +334,4 @@ EXPORTS
 	rte_mem_map
 	rte_mem_page_size
 	rte_mem_unmap
+	rte_time_get_us
diff --git a/lib/librte_eal/unix/eal_unix_timer.c b/lib/librte_eal/unix/eal_unix_timer.c
index cc5015910..5612fdebe 100644
--- a/lib/librte_eal/unix/eal_unix_timer.c
+++ b/lib/librte_eal/unix/eal_unix_timer.c
@@ -4,7 +4,10 @@
 
 #include <time.h>
 
+#include <sys/time.h>
+
 #include <rte_cycles.h>
+#include <rte_time.h>
 
 void
 rte_delay_us_sleep(unsigned int us)
@@ -27,3 +30,13 @@ rte_delay_us_sleep(unsigned int us)
 		ind = 1 - ind;
 	}
 }
+
+void
+rte_time_get_us(struct rte_time_us *now)
+{
+	struct timeval sys;
+
+	gettimeofday(&sys, NULL);
+	now->sec = sys.tv_sec;
+	now->usec = sys.tv_usec;
+}
diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
index fce90a112..405bed766 100644
--- a/lib/librte_eal/version.map
+++ b/lib/librte_eal/version.map
@@ -421,4 +421,5 @@ INTERNAL {
 	rte_mem_map;
 	rte_mem_page_size;
 	rte_mem_unmap;
+	rte_time_get_us;
 };
diff --git a/lib/librte_eal/windows/eal_timer.c b/lib/librte_eal/windows/eal_timer.c
index b070cb775..a5c42106a 100644
--- a/lib/librte_eal/windows/eal_timer.c
+++ b/lib/librte_eal/windows/eal_timer.c
@@ -9,6 +9,7 @@
 #include <rte_cycles.h>
 #include <rte_eal.h>
 #include <rte_errno.h>
+#include <rte_time.h>
 #include "eal_private.h"
 
 #define US_PER_SEC 1E6
@@ -85,10 +86,28 @@ get_tsc_freq(void)
 	return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_10MHZ);
 }
 
-
 int
 rte_eal_timer_init(void)
 {
 	set_tsc_freq();
 	return 0;
 }
+
+void
+rte_time_get_us(struct rte_time_us *now)
+{
+	/* 100ns ticks from 1601-01-01 to 1970-01-01 */
+	static const uint64_t EPOCH = 116444736000000000ULL;
+	static const uint64_t TICKS_PER_USEC = 10;
+	static const uint64_t USEC_PER_SEC = 1000000;
+
+	FILETIME ft;
+	uint64_t ticks, sec;
+
+	GetSystemTimePreciseAsFileTime(&ft);
+	ticks = ((uint64_t)ft.dwHighDateTime << 32) | ft.dwLowDateTime;
+	ticks -= EPOCH;
+	sec = ticks / (TICKS_PER_USEC * USEC_PER_SEC);
+	now->sec = sec;
+	now->usec = ticks / TICKS_PER_USEC - sec * USEC_PER_SEC;
+}
-- 
2.29.2