Fix atexit() function being called twice

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4644 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/Documentation/NuttX.html

@@ -8,7 +8,7 @@
   <tr align="center" bgcolor="#e4e4e4">
     <td>
       <h1><big><font color="#3c34ec"><i>NuttX RTOS</i></font></big></h1>
-      <p>Last Updated: April 14, 2012</p>
+      <p>Last Updated: April 23, 2012</p>
     </td>
   </tr>
 </table>
@@ -2228,10 +2228,13 @@
   <td>
     <p>
       <b>PIC32MX795F512L</b>.
-        This port uses the Microchip PIC32 Ethernet Starter Kit (DM320004) with the Expansion I/O board.
-        See the <a href="http://ww.microchip.com">Microchip website</a> for further information.
+        There one two board ports using this chip:
     </p>
     <ul>
+      <li><b>Microchip PIC32 Ethernet Starter Kit</b>.
+         This port uses the Microchip PIC32 Ethernet Starter Kit (DM320004) with the Expansion I/O board.
+         See the <a href="http://ww.microchip.com">Microchip website</a> for further information.
+      </li>
       <p>
        <b>STATUS:</b>
          This port was started and then shelved for some time until I received the Expansion I/O board.
@@ -2243,6 +2246,14 @@
          Also included are a a verified Ethernet driver, a partially verified USB device controller driver, and an unverifed SPI driver.
          Stay tuned for updates.
       </p>
+     <li><b>Mikroelektronika PIC32MX7 Mulitmedia Board (MMB)</b>.
+        A port has begun for the  Mikroelektronika PIC32MX7 Multimedia Board (MMB).
+        See http://www.mikroe.com/ for further information.
+      </li>
+      <p>
+       <b>STATUS:</b>
+         A configuration exists for this board, but has not been verfied as of this writing.
+      </p>
     </ul>
   </td>
 </tr>

nuttx/Documentation/NuttxUserGuide.html

@@ -522,6 +522,12 @@ And the UNIX interface:
 The task is first terminated and then reinitialized with same
 ID, priority, original entry point, stack size, and parameters
 it had when it was first started.
+</p>
+<p>
+NOTE: The normal task exit clean up is not performed.
+For example, file descriptors are not closed;
+any files opened prior to the restart will remain opened after the task is restarted.
+</p>
 <p>
 <b>Input Parameters:</b> 
 <ul>

nuttx/arch/arm/src/stm32/Kconfig

@@ -1467,6 +1467,13 @@ config USART1_2STOP
 	---help---
 		Two stop bits
 
+config USART1_RXDMA
+	bool "USART1 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA2
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "USART2 Configuration"
@@ -1516,6 +1523,13 @@ config USART2_2STOP
 	---help---
 		Two stop bits
 
+config USART2_RXDMA
+	bool "USART2 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA1
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "USART3 Configuration"
@@ -1565,6 +1579,13 @@ config USART3_2STOP
 	---help---
 		Two stop bits
 
+config USART3_RXDMA
+	bool "USART3 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA1
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "UART4 Configuration"
@@ -1614,6 +1635,13 @@ config USART4_2STOP
 	---help---
 		Two stop bits
 
+config USART4_RXDMA
+	bool "USART4 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA1
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "UART5 Configuration"
@@ -1663,6 +1691,13 @@ config USART5_2STOP
 	---help---
 		Two stop bits
 
+config USART5_RXDMA
+	bool "USART5 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA1
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "USART6 Configuration"
@@ -1712,6 +1747,13 @@ config USART6_2STOP
 	---help---
 		Two stop bits
 
+config USART6_RXDMA
+	bool "USART6 Rx DMA"
+	default n
+	depends on STM32_STM32F40XX && ARCH_DMA && STM32_DMA2
+	---help---
+		In high data rate usage, Rx DMA may eliminate Rx overrun errors
+
 endmenu
 
 menu "SPI Configuration"

nuttx/configs/README.txt

@@ -1496,9 +1496,6 @@ configs/pic32mx7mmb
   Mikroelektronika PIC32MX7 Multimedia Board (MMB).  See
   http://www.mikroe.com/ for further information.
 
-  On initial check-in, this directory is just a clone of the PIC32 starter
-  kit port with the appropriate naming changes.  More to come.
-
 configs/pjrc-8051
   8051 Microcontroller.  This port uses the PJRC 87C52 development system
   and the SDCC toolchain.   This port is not quite ready for prime time.

nuttx/configs/pic32mx7mmb/README.txt

@@ -2,7 +2,7 @@ configs/pic32mx7mmb README
 ===============================
 
 This README file discusses the port of NuttX to the  Mikroelektronika PIC32MX7
-Multimedia Board (MMB)
+Multimedia Board (MMB).  See http://www.mikroe.com/ for further information.
 
 Contents
 ========

nuttx/sched/task_delete.c

@@ -83,6 +83,21 @@
  *   This function causes a specified task to cease to exist. Its  stack and
  *   TCB will be deallocated.  This function is the companion to task_create().
  *
+ *   The logic in this function only deletes non-running tasks.  If the 'pid'
+ *   parameter refers to to the currently runing task, then processing is
+ *   redirected to exit().
+ *
+ *   Control will still be returned to task_delete() after the exit() logic
+ *   finishes.  In fact, this function is the final function called all task
+ *   termination sequences.  Here are all possible exit scenarios:
+ *
+ *   - pthread_exit().  Calls exit()
+ *   - exit(). Calls _exit()
+ *   - _exit().  Calls task_deletecurrent() making the currently running task
+ *     non-running then calls task_delete() to terminate the non-running
+ *     task.
+ *   - task_delete()
+ *
  * Inputs:
  *   pid - The task ID of the task to delete.  A pid of zero
  *         signifies the calling task.
@@ -145,6 +160,9 @@ int task_delete(pid_t pid)
    * this as early as possible so that higher level clean-up logic
    * can run in a healthy tasking environment.
    *
+   * In the case where the task exits via exit(), task_exithook()
+   * may be called twice.
+   *
    * I suppose EXIT_SUCCESS is an appropriate return value???
    */
 

nuttx/sched/task_exithook.c

@@ -114,14 +114,32 @@ void task_exithook(FAR _TCB *tcb, int status)
 #ifdef CONFIG_SCHED_ATEXIT
   if (tcb->atexitfunc)
     {
+      /* Call the atexit function */
+
       (*tcb->atexitfunc)();
+
+      /* Nullify the atexit function.  task_exithook may be called more then
+       * once in most task exit scenarios.  Nullifying the atext function
+       * pointer will assure that the callback is performed only once.
+       */
+
+      tcb->atexitfunc = NULL;
     }
 #endif
 
 #ifdef CONFIG_SCHED_ONEXIT
   if (tcb->onexitfunc)
     {
+      /* Call the on_exit function */
+
       (*tcb->onexitfunc)(status, tcb->onexitarg);
+
+      /* Nullify the on_exit function.  task_exithook may be called more then
+       * once in most task exit scenarios.  Nullifying the on_exit function
+       * pointer will assure that the callback is performed only once.
+       */
+
+      tcb->onexitfunc = NULL;
     }
 #endif