Merge pull request #839 from mehlis/posix-sleep

posix: added sleep and usleep

Makefile.dep

@@ -20,6 +20,12 @@ ifneq (,$(filter posix,$(USEMODULE)))
 	ifeq (,$(filter uart0,$(USEMODULE)))
 		USEMODULE += uart0
 	endif
+	ifeq (,$(filter timex,$(USEMODULE)))
+		USEMODULE += timex
+	endif
+	ifeq (,$(filter vtimer,$(USEMODULE)))
+		USEMODULE += vtimer
+	endif
 endif
 
 ifneq (,$(filter uart0,$(USEMODULE)))

sys/posix/Makefile

@@ -1,3 +1,3 @@
-MODULE =posix
+MODULE = posix
 
 include $(RIOTBASE)/Makefile.base

sys/posix/include/unistd.h

@@ -24,6 +24,11 @@
 #ifndef _UNISTD_H
 #define _UNISTD_H
 
+#include <stdint.h>
+
+#include "timex.h"
+#include "vtimer.h"
+
 #define STDIN_FILENO    0   ///< stdin file descriptor
 #define STDOUT_FILENO   1   ///< stdout file descriptor
 #define STDERR_FILENO   2   ///< stderr file descriptor
@@ -47,6 +52,45 @@
  */
 int close(int fildes);
 
+typedef uint32_t useconds_t;
+
+/**
+ * @brief the caller will sleep for given amount of micro seconds
+ * @details The usleep() function will cause the calling thread to be
+ *          suspended from execution until either the number of real-time microseconds
+ *          specified by the argument useconds has elapsed or a signal is delivered to
+ *          the calling thread and its action is to invoke a signal-catching function
+ *          or to terminate the process. The suspension time may be longer than
+ *          requested due to the scheduling of other activity by the system.
+ *
+ * @see <a href="http://pubs.opengroup.org/onlinepubs/7908799/xsh/usleep.html">
+ *          The Open Group Base Specification Issue 2, usleep
+ *      </a>
+ *
+ * @param useconds   time to sleep in micro seconds
+ * @return           0 on success
+ */
+int usleep(useconds_t useconds);
+
+/**
+ * @brief the caller will sleep for given amount of seconds
+ * @details The sleep() function shall cause the calling thread to be suspended
+ *          from execution until either the number of realtime seconds
+ *          specified by the argument seconds has elapsed or a signal is
+ *          delivered to the calling thread and its action is to invoke a
+ *          signal-catching function or to terminate the process. The
+ *          suspension time may be longer than requested due to the scheduling
+ *          of other activity by the system.
+ *
+ * @see <a href="http://pubs.opengroup.org/onlinepubs/009695399/functions/sleep.html">
+ *          The Open Group Base Specification Issue 6, sleep
+ *      </a>
+ *
+ * @param seconds   time to sleep in seconds
+ * @return          0 on success
+ */
+unsigned int sleep(unsigned int seconds);
+
 /**
  * @}
  */

sys/posix/unistd.c

@@ -11,6 +11,7 @@
  * @file    fd.c
  * @brief   Providing implementation for close for fds defined in fd.h.
  * @author  Martin Lenders <mlenders@inf.fu-berlin.de>
+ * @author  Christian Mehlis <mehlis@inf.fu-berlin.de>
  */
 #include <errno.h>
 
@@ -36,6 +37,21 @@ int close(int fildes)
     return 0;
 }
 
+int usleep(useconds_t useconds)
+{
+    timex_t time = timex_set(0, useconds);
+    timex_normalize(&time);
+    vtimer_sleep(time);
+    return 0;
+}
+
+unsigned int sleep(unsigned int seconds)
+{
+    timex_t time = timex_set(seconds, 0);
+    vtimer_sleep(time);
+    return 0;
+}
+
 /**
  * @}
  */

tests/test_posix_sleep/Makefile

@@ -0,0 +1,6 @@
+export PROJECT = test_posix_sleep
+include ../Makefile.tests_common
+
+USEMODULE += posix
+
+include $(RIOTBASE)/Makefile.include

tests/test_posix_sleep/main.c

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2014 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup tests
+ * @{
+ *
+ * @file
+ * @brief Posix sleep test application
+ *
+ * @author Christian Mehlis <mehlis@inf.fu-berlin.de>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+
+int main(void)
+{
+    puts("usleep 1 x 1000*1000");
+    for (int i = 0; i < 10; i++) {
+        useconds_t us = i*1000*1000;
+        printf("calling usleep(%u)\n", (unsigned int) us);
+        usleep(us);
+        puts("wake up");
+    }
+
+    puts("sleep 1");
+    for (int i = 0; i < 10; i++) {
+        unsigned int s = i;
+        printf("calling sleep(%d)\n", s);
+        sleep(s);
+        puts("wake up");
+    }
+
+    puts("done");
+}