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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2007-03-21 17:21:26 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2007-03-21 17:21:26 +0000 |
commit | 9539b686d25f82b5a9938725c6fe2c2ac862e632 (patch) | |
tree | 15bd94438dbb8fd1f655598700f34c79dd3af092 /nuttx/Documentation/NuttxUserGuide.html | |
parent | 7407828071d3d8f8d15f4e99e34114208e97bc33 (diff) | |
download | px4-nuttx-9539b686d25f82b5a9938725c6fe2c2ac862e632.tar.gz px4-nuttx-9539b686d25f82b5a9938725c6fe2c2ac862e632.tar.bz2 px4-nuttx-9539b686d25f82b5a9938725c6fe2c2ac862e632.zip |
Added support for POSIX timers
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@111 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/Documentation/NuttxUserGuide.html')
-rw-r--r-- | nuttx/Documentation/NuttxUserGuide.html | 74 |
1 files changed, 70 insertions, 4 deletions
diff --git a/nuttx/Documentation/NuttxUserGuide.html b/nuttx/Documentation/NuttxUserGuide.html index 134a46dbc..09bad280c 100644 --- a/nuttx/Documentation/NuttxUserGuide.html +++ b/nuttx/Documentation/NuttxUserGuide.html @@ -21,7 +21,7 @@ User's Manual <P> Gregory Nutt <P> -<SMALL>Last Update: January 28, 2007</SMALL> +<SMALL>Last Update: March 21, 2007</SMALL> </CENTER> <H1>1.0 <A NAME="Introduction">Introduction</A></H1> @@ -37,7 +37,7 @@ perspective of the firmware developer. This section is divided into several paragraphs that describe different groups of OS interfaces: <UL> <LI>Paragraph 2.1 <A HREF="#Task_Control">Task Control Interfaces</A> -8nnnnn<LI>Paragraph 2.2 <A HREF="#Task_Schedule">Task Scheduling Interfaces</A> +<LI>Paragraph 2.2 <A HREF="#Task_Schedule">Task Scheduling Interfaces</A> <LI>Paragraph 2.3 <A HREF="#Task_Switch">Task Switching Interfaces</A> <LI>Paragraph 2.4 <A HREF="#Message_Queue">Named Message Queue Interfaces</A> <LI>Paragraph 2.5 <A HREF="#Semaphores">Counting Semaphore Interfaces</A> @@ -1840,6 +1840,7 @@ interface of the same name. <li><a href="#wddelete">2.6.2 wd_delete</a></li> <li><a href="#wdstart">2.6.3 wd_start</a></li> <li><a href="#wdcancel">2.6.4 wd_cancel</a></li> + <li><a href="#wdgettime">2.6.5 wd_gettime</a></li> </ul> <H3><a name="wdcreate">2.6.1 wd_create</a></H3> @@ -2017,6 +2018,30 @@ VxWorks provides the following comparable interface: STATUS wdCancel (WDOG_ID wdog); </PRE> +<h3><a name="wdgettime">2.6.5 wd_gettime</a></h3> +<p> + <b>Function Prototype:</b> +</p> +<pre> + #include <wdog.h> + Sint wd_gettime(WDOG_ID wdog); +</pre> +<p> + <b>Description:</b> + This function returns the time remaining before the the specified watchdog expires. +</p> +<p> + <b>Input Parameters:</b> + <ul> + <li><code>wdog</code>. Identifies the watchdog that the request is for.</li> + </ul> +</p> +<p> + <b>Returned Value:</b> + The time in system ticks remaining until the watchdog time expires. Zero + means either that wdog is not valid or that the wdog has already expired. +</p> + <HR> <H2><A NAME="ClocksNTimers">2.7 Clocks and Timers</A></H2> @@ -2217,7 +2242,8 @@ VxWorks provides the following comparable interface: <b>Input Parameters:</b> </p> <ul> - <li><code>clockid</code>. Specifies the clock to use as the timing base.</li> + <li><code>clockid</code>. Specifies the clock to use as the timing base. + Must be <code>CLOCK_REALTIME</code>.</li> <li><code>evp</code>. Refers to a user allocated sigevent structure that defines the asynchronous notification. evp may be NULL (see above).</li> <li><code>timerid</code>. The pre-thread timer created by the call to timer_create().</li> @@ -2241,6 +2267,13 @@ VxWorks provides the following comparable interface: to the CPU-time clock that is specified by clock_id and associated with a thread different thread invoking timer_create().</li> </ul> +<p> + <b>POSIX Compatibility:</b> + Comparable to the POSIX interface of the same name. Differences from the full POSIX implementation include: +</p> +<ul> + <li>Only <code>CLOCK_REALTIME</code> is supported for the <code>clockid</code> argument.</li> +</ul> <H3><a name="timerdelete">2.7.8 timer_delete</A></H3> <p> @@ -2275,6 +2308,10 @@ VxWorks provides the following comparable interface: <ul> <li><code>EINVAL</code>. The timer specified timerid is not valid.</li> </ul> +<p> + <b>POSIX Compatibility:</b> + Comparable to the POSIX interface of the same name. +</p> <H3><a name="timersettime">2.7.9 timer_settime</A></H3> <p> @@ -2327,6 +2364,8 @@ VxWorks provides the following comparable interface: disarmed, together with the previous timer reload value. Timers will not expire before their scheduled time. </p> + <b>NOTE:</b>At present, the <code>ovalue</code> argument is ignored. +</p> <p> <b>Input Parameters:</b> </p> @@ -2334,7 +2373,7 @@ VxWorks provides the following comparable interface: <li><code>timerid</code>. The pre-thread timer, previously created by the call to timer_create(), to be be set.</li> <li><code>flags</code>. Specifie characteristics of the timer (see above)</li> <li><code>value</code>. Specifies the timer value to set</li> - <li><code>ovalue</code>. A location in which to return the time remaining from the previous timer setting.</li> + <li><code>ovalue</code>. A location in which to return the time remaining from the previous timer setting (ignored).</li> </ul> <p> <b>Returned Values:</b> @@ -2348,6 +2387,13 @@ VxWorks provides the following comparable interface: <li><code>EINVAL</code>. A value structure specified a nanosecond value less than zero or greater than or equal to 1000 million, and the it_value member of that structure did not specify zero seconds and nanoseconds.</li> </ul> +<p> + <b>POSIX Compatibility:</b> + Comparable to the POSIX interface of the same name. Differences from the full POSIX implementation include: +</p> +<ul> + <li>The <code>ovalue</code> argument is ignored.</li> +</ul> <H3><a name="timergettime">2.7.10 timer_gettime</A></H3> <p> @@ -2368,6 +2414,11 @@ VxWorks provides the following comparable interface: <code>value</code> will contain the reload value last set by <code>timer_settime()</code>. </p> <p> + Due to the asynchronous operation of this function, the time reported + by this function could be significantly more than that actual time + remaining on the timer at any time. +</p> +<p> <b>Input Parameters:</b> </p> <ul> @@ -2386,6 +2437,10 @@ VxWorks provides the following comparable interface: The <code>timerid</code> argument does not correspond to an ID returned by <code>timer_create()</code> but not yet deleted by <code>timer_delete()</code>.</li> </ul> +<p> + <b>POSIX Compatibility:</b> + Comparable to the POSIX interface of the same name. +</p> <H3><a name="timergetoverrun">2.7.11 timer_getoverrun</A></H3> <p> @@ -2415,6 +2470,9 @@ VxWorks provides the following comparable interface: return value of <code>timer_getoverrun()</code> is unspecified. </p> <p> + <b>NOTE:</b> This interface is not currently implemented in NuttX. +</p> +<p> <b>Input Parameters:</b> </p> <ul> @@ -2431,6 +2489,13 @@ VxWorks provides the following comparable interface: The <code>timerid</code> argument does not correspond to an ID returned by <code>timer_create()</code> but not yet deleted by <code>timer_delete()</code>.</li> </ul> +<p> + <b>POSIX Compatibility:</b> + Comparable to the POSIX interface of the same name. Differences from the full POSIX implementation include: +</p> +<ul> + <li>This interface is not currently implemented by NuttX.</li> +</ul> <B>Assumptions/Limitations:</B> <P> @@ -4925,6 +4990,7 @@ notify a task when a message is available on a queue. <li><a href="#wdcancel">wd_cancel</a></li> <li><a href="#wdcreate">wd_create</a></li> <li><a href="#wddelete">wd_delete</a></li> + <li><a href="#wdgettime">wd_gettime</a></li> <li><a href="#wdstart">wd_start</a></li> </ul> |