]> git.sur5r.net Git - freertos/blobdiff - FreeRTOS/Source/portable/MSVC-MingW/port.c
Fix spelling issues.
[freertos] / FreeRTOS / Source / portable / MSVC-MingW / port.c
index 6ae4ae9bac0b8d13984352bd2ca4f351b691b993..ec2341748b8539e909cabb25ec0c1c69153941b2 100644 (file)
@@ -1,97 +1,29 @@
 /*\r
-    FreeRTOS V8.2.0rc1 - Copyright (C) 2014 Real Time Engineers Ltd.\r
-    All rights reserved\r
-\r
-    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.\r
-\r
-    This file is part of the FreeRTOS distribution.\r
-\r
-    FreeRTOS is free software; you can redistribute it and/or modify it under\r
-    the terms of the GNU General Public License (version 2) as published by the\r
-    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.\r
-\r
-    >>!   NOTE: The modification to the GPL is included to allow you to     !<<\r
-    >>!   distribute a combined work that includes FreeRTOS without being   !<<\r
-    >>!   obliged to provide the source code for proprietary components     !<<\r
-    >>!   outside of the FreeRTOS kernel.                                   !<<\r
-\r
-    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY\r
-    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
-    FOR A PARTICULAR PURPOSE.  Full license text is available on the following\r
-    link: http://www.freertos.org/a00114.html\r
-\r
-    1 tab == 4 spaces!\r
-\r
-    ***************************************************************************\r
-     *                                                                       *\r
-     *    Having a problem?  Start by reading the FAQ "My application does   *\r
-     *    not run, what could be wrong?".  Have you defined configASSERT()?  *\r
-     *                                                                       *\r
-     *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
-     *                                                                       *\r
-    ***************************************************************************\r
-\r
-    ***************************************************************************\r
-     *                                                                       *\r
-     *    FreeRTOS provides completely free yet professionally developed,    *\r
-     *    robust, strictly quality controlled, supported, and cross          *\r
-     *    platform software that is more than just the market leader, it     *\r
-     *    is the industry's de facto standard.                               *\r
-     *                                                                       *\r
-     *    Help yourself get started quickly while simultaneously helping     *\r
-     *    to support the FreeRTOS project by purchasing a FreeRTOS           *\r
-     *    tutorial book, reference manual, or both:                          *\r
-     *    http://www.FreeRTOS.org/Documentation                              *\r
-     *                                                                       *\r
-    ***************************************************************************\r
-\r
-    ***************************************************************************\r
-     *                                                                       *\r
-     *   Investing in training allows your team to be as productive as       *\r
-     *   possible as early as possible, lowering your overall development    *\r
-     *   cost, and enabling you to bring a more robust product to market     *\r
-     *   earlier than would otherwise be possible.  Richard Barry is both    *\r
-     *   the architect and key author of FreeRTOS, and so also the world's   *\r
-     *   leading authority on what is the world's most popular real time     *\r
-     *   kernel for deeply embedded MCU designs.  Obtaining your training    *\r
-     *   from Richard ensures your team will gain directly from his in-depth *\r
-     *   product knowledge and years of usage experience.  Contact Real Time *\r
-     *   Engineers Ltd to enquire about the FreeRTOS Masterclass, presented  *\r
-     *   by Richard Barry:  http://www.FreeRTOS.org/contact\r
-     *                                                                       *\r
-    ***************************************************************************\r
-\r
-    ***************************************************************************\r
-     *                                                                       *\r
-     *    You are receiving this top quality software for free.  Please play *\r
-     *    fair and reciprocate by reporting any suspected issues and         *\r
-     *    participating in the community forum:                              *\r
-     *    http://www.FreeRTOS.org/support                                    *\r
-     *                                                                       *\r
-     *    Thank you!                                                         *\r
-     *                                                                       *\r
-    ***************************************************************************\r
-\r
-    http://www.FreeRTOS.org - Documentation, books, training, latest versions,\r
-    license and Real Time Engineers Ltd. contact details.\r
-\r
-    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
-    including FreeRTOS+Trace - an indispensable productivity tool, a DOS\r
-    compatible FAT file system, and our tiny thread aware UDP/IP stack.\r
-\r
-    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.\r
-    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.\r
-\r
-    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High\r
-    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS\r
-    licenses offer ticketed support, indemnification and commercial middleware.\r
-\r
-    http://www.SafeRTOS.com - High Integrity Systems also provide a safety\r
-    engineered and independently SIL3 certified version for use in safety and\r
-    mission critical applications that require provable dependability.\r
-\r
-    1 tab == 4 spaces!\r
-*/\r
+ * FreeRTOS Kernel V10.2.1\r
+ * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
+ *\r
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
+ * this software and associated documentation files (the "Software"), to deal in\r
+ * the Software without restriction, including without limitation the rights to\r
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
+ * the Software, and to permit persons to whom the Software is furnished to do so,\r
+ * subject to the following conditions:\r
+ *\r
+ * The above copyright notice and this permission notice shall be included in all\r
+ * copies or substantial portions of the Software.\r
+ *\r
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
+ *\r
+ * http://www.FreeRTOS.org\r
+ * http://aws.amazon.com/freertos\r
+ *\r
+ * 1 tab == 4 spaces!\r
+ */\r
 \r
 /* Standard includes. */\r
 #include <stdio.h>\r
 #define portMAX_INTERRUPTS                             ( ( uint32_t ) sizeof( uint32_t ) * 8UL ) /* The number of bits in an uint32_t. */\r
 #define portNO_CRITICAL_NESTING                ( ( uint32_t ) 0 )\r
 \r
+/* The priorities at which the various components of the simulation execute. */\r
+#define portDELETE_SELF_THREAD_PRIORITY                         THREAD_PRIORITY_TIME_CRITICAL /* Must be highest. */\r
+#define portSIMULATED_INTERRUPTS_THREAD_PRIORITY THREAD_PRIORITY_TIME_CRITICAL\r
+#define portSIMULATED_TIMER_THREAD_PRIORITY             THREAD_PRIORITY_HIGHEST\r
+#define portTASK_THREAD_PRIORITY                                THREAD_PRIORITY_ABOVE_NORMAL\r
+\r
 /*\r
  * Created as a high priority thread, this function uses a timer to simulate\r
  * a tick interrupt being generated on an embedded target.  In this Windows\r
@@ -130,6 +68,15 @@ static void prvProcessSimulatedInterrupts( void );
 static uint32_t prvProcessYieldInterrupt( void );\r
 static uint32_t prvProcessTickInterrupt( void );\r
 \r
+/*\r
+ * Exiting a critical section will cause the calling task to block on yield\r
+ * event to wait for an interrupt to process if an interrupt was pended while\r
+ * inside the critical section.  This variable protects against a recursive\r
+ * attempt to obtain pvInterruptEventMutex if a critical section is used inside\r
+ * an interrupt handler itself.\r
+ */\r
+volatile BaseType_t xInsideInterrupt = pdFALSE;\r
+\r
 /*\r
  * Called when the process exits to let Windows know the high timer resolution\r
  * is no longer required.\r
@@ -148,7 +95,11 @@ typedef struct
        /* Handle of the thread that executes the task. */\r
        void *pvThread;\r
 \r
-} xThreadState;\r
+       /* Event used to make sure the thread does not execute past a yield point\r
+       between the call to SuspendThread() to suspend the thread and the\r
+       asynchronous SuspendThread() operation actually being performed. */\r
+       void *pvYieldEvent;\r
+} ThreadState_t;\r
 \r
 /* Simulated interrupts waiting to be processed.  This is a bit mask where each\r
 bit represents one interrupt, so a maximum of 32 interrupts can be simulated. */\r
@@ -170,7 +121,7 @@ ulCriticalNesting will get set to zero when the first task runs.  This
 initialisation is probably not critical in this simulated environment as the\r
 simulated interrupt handlers do not get created until the FreeRTOS scheduler is\r
 started anyway. */\r
-static uint32_t ulCriticalNesting = 9999UL;\r
+static volatile uint32_t ulCriticalNesting = 9999UL;\r
 \r
 /* Handlers for all the simulated software interrupts.  The first two positions\r
 are used for the Yield and Tick interrupts so are handled slightly differently,\r
@@ -178,7 +129,7 @@ all the other interrupts can be user defined. */
 static uint32_t (*ulIsrHandler[ portMAX_INTERRUPTS ])( void ) = { 0 };\r
 \r
 /* Pointer to the TCB of the currently executing task. */\r
-extern void *pxCurrentTCB;\r
+extern void * volatile pxCurrentTCB;\r
 \r
 /* Used to ensure nothing is processed during the startup sequence. */\r
 static BaseType_t xPortRunning = pdFALSE;\r
@@ -227,20 +178,22 @@ TIMECAPS xTimeCaps;
 \r
                configASSERT( xPortRunning );\r
 \r
+               /* Can't proceed if in a critical section as pvInterruptEventMutex won't\r
+               be available. */\r
                WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
 \r
                /* The timer has expired, generate the simulated tick event. */\r
                ulPendingInterrupts |= ( 1 << portINTERRUPT_TICK );\r
 \r
                /* The interrupt is now pending - notify the simulated interrupt\r
-               handler thread. */\r
-               if( ulCriticalNesting == 0 )\r
-               {\r
-                       SetEvent( pvInterruptEvent );\r
-               }\r
+               handler thread.  Must be outside of a critical section to get here so\r
+               the handler thread can execute immediately pvInterruptEventMutex is\r
+               released. */\r
+               configASSERT( ulCriticalNesting == 0UL );\r
+               SetEvent( pvInterruptEvent );\r
 \r
                /* Give back the mutex so the simulated interrupt handler unblocks\r
-               and can access the interrupt handler variables. */\r
+               and can access the interrupt handler variables. */\r
                ReleaseMutex( pvInterruptEventMutex );\r
        }\r
 \r
@@ -265,29 +218,38 @@ TIMECAPS xTimeCaps;
                timeEndPeriod( xTimeCaps.wPeriodMin );\r
        }\r
 \r
-       return pdPASS;\r
+       return pdFALSE;\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )\r
 {\r
-xThreadState *pxThreadState = NULL;\r
+ThreadState_t *pxThreadState = NULL;\r
 int8_t *pcTopOfStack = ( int8_t * ) pxTopOfStack;\r
+const SIZE_T xStackSize = 1024; /* Set the size to a small number which will get rounded up to the minimum possible. */\r
 \r
        /* In this simulated case a stack is not initialised, but instead a thread\r
        is created that will execute the task being created.  The thread handles\r
-       the context switching itself.  The xThreadState object is placed onto\r
+       the context switching itself.  The ThreadState_t object is placed onto\r
        the stack that was created for the task - so the stack buffer is still\r
        used, just not in the conventional way.  It will not be used for anything\r
        other than holding this structure. */\r
-       pxThreadState = ( xThreadState * ) ( pcTopOfStack - sizeof( xThreadState ) );\r
+       pxThreadState = ( ThreadState_t * ) ( pcTopOfStack - sizeof( ThreadState_t ) );\r
+\r
+       /* Create the event used to prevent the thread from executing past its yield\r
+       point if the SuspendThread() call that suspends the thread does not take\r
+       effect immediately (it is an asynchronous call). */\r
+       pxThreadState->pvYieldEvent = CreateEvent(  NULL,  /* Default security attributes. */\r
+                                                                                               FALSE, /* Auto reset. */\r
+                                                                                               FALSE, /* Start not signalled. */\r
+                                                                                               NULL );/* No name. */\r
 \r
        /* Create the thread itself. */\r
-       pxThreadState->pvThread = CreateThread( NULL, 0, ( LPTHREAD_START_ROUTINE ) pxCode, pvParameters, CREATE_SUSPENDED, NULL );\r
-       configASSERT( pxThreadState->pvThread );\r
+       pxThreadState->pvThread = CreateThread( NULL, xStackSize, ( LPTHREAD_START_ROUTINE ) pxCode, pvParameters, CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION, NULL );\r
+       configASSERT( pxThreadState->pvThread ); /* See comment where TerminateThread() is called. */\r
        SetThreadAffinityMask( pxThreadState->pvThread, 0x01 );\r
        SetThreadPriorityBoost( pxThreadState->pvThread, TRUE );\r
-       SetThreadPriority( pxThreadState->pvThread, THREAD_PRIORITY_IDLE );\r
+       SetThreadPriority( pxThreadState->pvThread, portTASK_THREAD_PRIORITY );\r
 \r
        return ( StackType_t * ) pxThreadState;\r
 }\r
@@ -295,36 +257,58 @@ int8_t *pcTopOfStack = ( int8_t * ) pxTopOfStack;
 \r
 BaseType_t xPortStartScheduler( void )\r
 {\r
-void *pvHandle;\r
-int32_t lSuccess = pdPASS;\r
-xThreadState *pxThreadState;\r
-\r
-       /* Install the interrupt handlers used by the scheduler itself. */\r
-       vPortSetInterruptHandler( portINTERRUPT_YIELD, prvProcessYieldInterrupt );\r
-       vPortSetInterruptHandler( portINTERRUPT_TICK, prvProcessTickInterrupt );\r
-\r
-       /* Create the events and mutexes that are used to synchronise all the\r
-       threads. */\r
-       pvInterruptEventMutex = CreateMutex( NULL, FALSE, NULL );\r
-       pvInterruptEvent = CreateEvent( NULL, FALSE, FALSE, NULL );\r
-\r
-       if( ( pvInterruptEventMutex == NULL ) || ( pvInterruptEvent == NULL ) )\r
+void *pvHandle = NULL;\r
+int32_t lSuccess;\r
+ThreadState_t *pxThreadState = NULL;\r
+SYSTEM_INFO xSystemInfo;\r
+\r
+       /* This port runs windows threads with extremely high priority.  All the\r
+       threads execute on the same core - to prevent locking up the host only start\r
+       if the host has multiple cores. */\r
+       GetSystemInfo( &xSystemInfo );\r
+       if( xSystemInfo.dwNumberOfProcessors <= 1 )\r
        {\r
+               printf( "This version of the FreeRTOS Windows port can only be used on multi-core hosts.\r\n" );\r
                lSuccess = pdFAIL;\r
        }\r
-\r
-       /* Set the priority of this thread such that it is above the priority of\r
-       the threads that run tasks.  This higher priority is required to ensure\r
-       simulated interrupts take priority over tasks. */\r
-       pvHandle = GetCurrentThread();\r
-       if( pvHandle == NULL )\r
+       else\r
        {\r
-               lSuccess = pdFAIL;\r
+               lSuccess = pdPASS;\r
+\r
+               /* The highest priority class is used to [try to] prevent other Windows\r
+               activity interfering with FreeRTOS timing too much. */\r
+               if( SetPriorityClass( GetCurrentProcess(), REALTIME_PRIORITY_CLASS ) == 0 )\r
+               {\r
+                       printf( "SetPriorityClass() failed\r\n" );\r
+               }\r
+\r
+               /* Install the interrupt handlers used by the scheduler itself. */\r
+               vPortSetInterruptHandler( portINTERRUPT_YIELD, prvProcessYieldInterrupt );\r
+               vPortSetInterruptHandler( portINTERRUPT_TICK, prvProcessTickInterrupt );\r
+\r
+               /* Create the events and mutexes that are used to synchronise all the\r
+               threads. */\r
+               pvInterruptEventMutex = CreateMutex( NULL, FALSE, NULL );\r
+               pvInterruptEvent = CreateEvent( NULL, FALSE, FALSE, NULL );\r
+\r
+               if( ( pvInterruptEventMutex == NULL ) || ( pvInterruptEvent == NULL ) )\r
+               {\r
+                       lSuccess = pdFAIL;\r
+               }\r
+\r
+               /* Set the priority of this thread such that it is above the priority of\r
+               the threads that run tasks.  This higher priority is required to ensure\r
+               simulated interrupts take priority over tasks. */\r
+               pvHandle = GetCurrentThread();\r
+               if( pvHandle == NULL )\r
+               {\r
+                       lSuccess = pdFAIL;\r
+               }\r
        }\r
 \r
        if( lSuccess == pdPASS )\r
        {\r
-               if( SetThreadPriority( pvHandle, THREAD_PRIORITY_NORMAL ) == 0 )\r
+               if( SetThreadPriority( pvHandle, portSIMULATED_INTERRUPTS_THREAD_PRIORITY ) == 0 )\r
                {\r
                        lSuccess = pdFAIL;\r
                }\r
@@ -338,22 +322,21 @@ xThreadState *pxThreadState;
                tick interrupts.  The priority is set below that of the simulated\r
                interrupt handler so the interrupt event mutex is used for the\r
                handshake / overrun protection. */\r
-               pvHandle = CreateThread( NULL, 0, prvSimulatedPeripheralTimer, NULL, 0, NULL );\r
+               pvHandle = CreateThread( NULL, 0, prvSimulatedPeripheralTimer, NULL, CREATE_SUSPENDED, NULL );\r
                if( pvHandle != NULL )\r
                {\r
-                       SetThreadPriority( pvHandle, THREAD_PRIORITY_BELOW_NORMAL );\r
+                       SetThreadPriority( pvHandle, portSIMULATED_TIMER_THREAD_PRIORITY );\r
                        SetThreadPriorityBoost( pvHandle, TRUE );\r
                        SetThreadAffinityMask( pvHandle, 0x01 );\r
+                       ResumeThread( pvHandle );\r
                }\r
 \r
                /* Start the highest priority task by obtaining its associated thread\r
                state structure, in which is stored the thread handle. */\r
-               pxThreadState = ( xThreadState * ) *( ( uint32_t * ) pxCurrentTCB );\r
+               pxThreadState = ( ThreadState_t * ) *( ( size_t * ) pxCurrentTCB );\r
                ulCriticalNesting = portNO_CRITICAL_NESTING;\r
 \r
-               /* Bump up the priority of the thread that is going to run, in the\r
-               hope that this will assist in getting the Windows thread scheduler to\r
-               behave as an embedded engineer might expect. */\r
+               /* Start the first task. */\r
                ResumeThread( pxThreadState->pvThread );\r
 \r
                /* Handle all simulated interrupts - including yield requests and\r
@@ -369,6 +352,7 @@ xThreadState *pxThreadState;
 \r
 static uint32_t prvProcessYieldInterrupt( void )\r
 {\r
+       /* Always return true as this is a yield. */\r
        return pdTRUE;\r
 }\r
 /*-----------------------------------------------------------*/\r
@@ -388,8 +372,9 @@ uint32_t ulSwitchRequired;
 static void prvProcessSimulatedInterrupts( void )\r
 {\r
 uint32_t ulSwitchRequired, i;\r
-xThreadState *pxThreadState;\r
+ThreadState_t *pxThreadState;\r
 void *pvObjectList[ 2 ];\r
+CONTEXT xContext;\r
 \r
        /* Going to block on the mutex that ensured exclusive access to the simulated\r
        interrupt objects, and the event that signals that a simulated interrupt\r
@@ -406,8 +391,16 @@ void *pvObjectList[ 2 ];
 \r
        for(;;)\r
        {\r
+               xInsideInterrupt = pdFALSE;\r
                WaitForMultipleObjects( sizeof( pvObjectList ) / sizeof( void * ), pvObjectList, TRUE, INFINITE );\r
 \r
+               /* Cannot be in a critical section to get here.  Tasks that exit a\r
+               critical section will block on a yield mutex to wait for an interrupt to\r
+               process if an interrupt was set pending while the task was inside the\r
+               critical section.  xInsideInterrupt prevents interrupts that contain\r
+               critical sections from doing the same. */\r
+               xInsideInterrupt = pdTRUE;\r
+\r
                /* Used to indicate whether the simulated interrupt processing has\r
                necessitated a context switch to another task/thread. */\r
                ulSwitchRequired = pdFALSE;\r
@@ -417,14 +410,16 @@ void *pvObjectList[ 2 ];
                for( i = 0; i < portMAX_INTERRUPTS; i++ )\r
                {\r
                        /* Is the simulated interrupt pending? */\r
-                       if( ulPendingInterrupts & ( 1UL << i ) )\r
+                       if( ( ulPendingInterrupts & ( 1UL << i ) ) != 0 )\r
                        {\r
                                /* Is a handler installed? */\r
                                if( ulIsrHandler[ i ] != NULL )\r
                                {\r
-                                       /* Run the actual handler. */\r
+                                       /* Run the actual handler.  Handlers return pdTRUE if they\r
+                                       necessitate a context switch. */\r
                                        if( ulIsrHandler[ i ]() != pdFALSE )\r
                                        {\r
+                                               /* A bit mask is used purely to help debugging. */\r
                                                ulSwitchRequired |= ( 1 << i );\r
                                        }\r
                                }\r
@@ -447,17 +442,49 @@ void *pvObjectList[ 2 ];
                        that is already in the running state. */\r
                        if( pvOldCurrentTCB != pxCurrentTCB )\r
                        {\r
-                               /* Suspend the old thread. */\r
-                               pxThreadState = ( xThreadState *) *( ( uint32_t * ) pvOldCurrentTCB );\r
+                               /* Suspend the old thread.  In the cases where the (simulated)\r
+                               interrupt is asynchronous (tick event swapping a task out rather\r
+                               than a task blocking or yielding) it doesn't matter if the\r
+                               'suspend' operation doesn't take effect immediately - if it\r
+                               doesn't it would just be like the interrupt occurring slightly\r
+                               later.  In cases where the yield was caused by a task blocking\r
+                               or yielding then the task will block on a yield event after the\r
+                               yield operation in case the 'suspend' operation doesn't take\r
+                               effect immediately.  */\r
+                               pxThreadState = ( ThreadState_t *) *( ( size_t * ) pvOldCurrentTCB );\r
                                SuspendThread( pxThreadState->pvThread );\r
 \r
+                               /* Ensure the thread is actually suspended by performing a\r
+                               synchronous operation that can only complete when the thread is\r
+                               actually suspended.  The code below asks for dummy register\r
+                               data. Experimentation shows that these two lines don't appear\r
+                               to do anything now, but according to\r
+                               https://devblogs.microsoft.com/oldnewthing/20150205-00/?p=44743\r
+                               they do - so as they do not harm (slight run-time hit). */\r
+                               xContext.ContextFlags = CONTEXT_INTEGER;\r
+                               ( void ) GetThreadContext( pxThreadState->pvThread, &xContext );\r
+\r
                                /* Obtain the state of the task now selected to enter the\r
                                Running state. */\r
-                               pxThreadState = ( xThreadState * ) ( *( uint32_t *) pxCurrentTCB );\r
+                               pxThreadState = ( ThreadState_t * ) ( *( size_t *) pxCurrentTCB );\r
+\r
+                               /* pxThreadState->pvThread can be NULL if the task deleted\r
+                               itself - but a deleted task should never be resumed here. */\r
+                               configASSERT( pxThreadState->pvThread != NULL );\r
                                ResumeThread( pxThreadState->pvThread );\r
                        }\r
                }\r
 \r
+               /* If the thread that is about to be resumed stopped running\r
+               because it yielded then it will wait on an event when it resumed\r
+               (to ensure it does not continue running after the call to\r
+               SuspendThread() above as SuspendThread() is asynchronous).\r
+               Signal the event to ensure the thread can proceed now it is\r
+               valid for it to do so.  Signaling the event is benign in the case that\r
+               the task was switched out asynchronously by an interrupt as the event\r
+               is reset before the task blocks on it. */\r
+               pxThreadState = ( ThreadState_t * ) ( *( size_t *) pxCurrentTCB );\r
+               SetEvent( pxThreadState->pvYieldEvent );\r
                ReleaseMutex( pvInterruptEventMutex );\r
        }\r
 }\r
@@ -465,14 +492,14 @@ void *pvObjectList[ 2 ];
 \r
 void vPortDeleteThread( void *pvTaskToDelete )\r
 {\r
-xThreadState *pxThreadState;\r
+ThreadState_t *pxThreadState;\r
 uint32_t ulErrorCode;\r
 \r
        /* Remove compiler warnings if configASSERT() is not defined. */\r
        ( void ) ulErrorCode;\r
 \r
        /* Find the handle of the thread being deleted. */\r
-       pxThreadState = ( xThreadState * ) ( *( uint32_t *) pvTaskToDelete );\r
+       pxThreadState = ( ThreadState_t * ) ( *( size_t *) pvTaskToDelete );\r
 \r
        /* Check that the thread is still valid, it might have been closed by\r
        vPortCloseRunningThread() - which will be the case if the task associated\r
@@ -482,6 +509,10 @@ uint32_t ulErrorCode;
        {\r
                WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
 \r
+               /* !!! This is not a nice way to terminate a thread, and will eventually\r
+               result in resources being depleted if tasks frequently delete other\r
+               tasks (rather than deleting themselves) as the task stacks will not be\r
+               freed. */\r
                ulErrorCode = TerminateThread( pxThreadState->pvThread, 0 );\r
                configASSERT( ulErrorCode );\r
 \r
@@ -495,7 +526,7 @@ uint32_t ulErrorCode;
 \r
 void vPortCloseRunningThread( void *pvTaskToDelete, volatile BaseType_t *pxPendYield )\r
 {\r
-xThreadState *pxThreadState;\r
+ThreadState_t *pxThreadState;\r
 void *pvThread;\r
 uint32_t ulErrorCode;\r
 \r
@@ -503,14 +534,14 @@ uint32_t ulErrorCode;
        ( void ) ulErrorCode;\r
 \r
        /* Find the handle of the thread being deleted. */\r
-       pxThreadState = ( xThreadState * ) ( *( uint32_t *) pvTaskToDelete );\r
+       pxThreadState = ( ThreadState_t * ) ( *( size_t *) pvTaskToDelete );\r
        pvThread = pxThreadState->pvThread;\r
 \r
        /* Raise the Windows priority of the thread to ensure the FreeRTOS scheduler\r
        does not run and swap it out before it is closed.  If that were to happen\r
        the thread would never run again and effectively be a thread handle and\r
        memory leak. */\r
-       SetThreadPriority( pvThread, THREAD_PRIORITY_ABOVE_NORMAL );\r
+       SetThreadPriority( pvThread, portDELETE_SELF_THREAD_PRIORITY );\r
 \r
        /* This function will not return, therefore a yield is set as pending to\r
        ensure a context switch occurs away from this thread on the next tick. */\r
@@ -524,36 +555,55 @@ uint32_t ulErrorCode;
        ulErrorCode = CloseHandle( pvThread );\r
        configASSERT( ulErrorCode );\r
 \r
+       /* This is called from a critical section, which must be exited before the\r
+       thread stops. */\r
+       taskEXIT_CRITICAL();\r
+       CloseHandle( pxThreadState->pvYieldEvent );\r
        ExitThread( 0 );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
 void vPortEndScheduler( void )\r
 {\r
-       /* This function IS NOT TESTED! */\r
-       TerminateProcess( GetCurrentProcess(), 0 );\r
+       exit( 0 );\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
 void vPortGenerateSimulatedInterrupt( uint32_t ulInterruptNumber )\r
 {\r
+ThreadState_t *pxThreadState = ( ThreadState_t *) *( ( size_t * ) pxCurrentTCB );\r
+\r
        configASSERT( xPortRunning );\r
 \r
        if( ( ulInterruptNumber < portMAX_INTERRUPTS ) && ( pvInterruptEventMutex != NULL ) )\r
        {\r
-               /* Yield interrupts are processed even when critical nesting is non-zero. */\r
                WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
                ulPendingInterrupts |= ( 1 << ulInterruptNumber );\r
 \r
-               /* The simulated interrupt is now held pending, but don't actually process it\r
-               yet if this call is within a critical section.  It is possible for this to\r
-               be in a critical section as calls to wait for mutexes are accumulative. */\r
-               if( ulCriticalNesting == 0 )\r
+               /* The simulated interrupt is now held pending, but don't actually\r
+               process it yet if this call is within a critical section.  It is\r
+               possible for this to be in a critical section as calls to wait for\r
+               mutexes are accumulative.  If in a critical section then the event\r
+               will get set when the critical section nesting count is wound back\r
+               down to zero. */\r
+               if( ulCriticalNesting == portNO_CRITICAL_NESTING )\r
                {\r
                        SetEvent( pvInterruptEvent );\r
+\r
+                       /* Going to wait for an event - make sure the event is not already\r
+                       signaled. */\r
+                       ResetEvent( pxThreadState->pvYieldEvent );\r
                }\r
 \r
                ReleaseMutex( pvInterruptEventMutex );\r
+               if( ulCriticalNesting == portNO_CRITICAL_NESTING )\r
+               {\r
+                       /* An interrupt was pended so ensure to block to allow it to\r
+                       execute.  In most cases the (simulated) interrupt will have\r
+                       executed before the next line is reached - so this is just to make\r
+                       sure. */\r
+                       WaitForSingleObject( pxThreadState->pvYieldEvent, INFINITE );\r
+               }\r
        }\r
 }\r
 /*-----------------------------------------------------------*/\r
@@ -583,18 +633,15 @@ void vPortEnterCritical( void )
                /* The interrupt event mutex is held for the entire critical section,\r
                effectively disabling (simulated) interrupts. */\r
                WaitForSingleObject( pvInterruptEventMutex, INFINITE );\r
-               ulCriticalNesting++;\r
-       }\r
-       else\r
-       {\r
-               ulCriticalNesting++;\r
        }\r
+\r
+       ulCriticalNesting++;\r
 }\r
 /*-----------------------------------------------------------*/\r
 \r
 void vPortExitCritical( void )\r
 {\r
-int32_t lMutexNeedsReleasing;\r
+int32_t lMutexNeedsReleasing, lWaitForYield = pdFALSE;\r
 \r
        /* The interrupt event mutex should already be held by this thread as it was\r
        obtained on entry to the critical section. */\r
@@ -603,29 +650,42 @@ int32_t lMutexNeedsReleasing;
 \r
        if( ulCriticalNesting > portNO_CRITICAL_NESTING )\r
        {\r
-               if( ulCriticalNesting == ( portNO_CRITICAL_NESTING + 1 ) )\r
-               {\r
-                       ulCriticalNesting--;\r
+               ulCriticalNesting--;\r
 \r
+               /* Don't need to wait for any pending interrupts to execute if the\r
+               critical section was exited from inside an interrupt. */\r
+               if( ( ulCriticalNesting == portNO_CRITICAL_NESTING ) && ( xInsideInterrupt == pdFALSE ) )\r
+               {\r
                        /* Were any interrupts set to pending while interrupts were\r
                        (simulated) disabled? */\r
                        if( ulPendingInterrupts != 0UL )\r
                        {\r
+                               ThreadState_t *pxThreadState = ( ThreadState_t *) *( ( size_t * ) pxCurrentTCB );\r
+\r
                                configASSERT( xPortRunning );\r
-                               SetEvent( pvInterruptEvent );\r
 \r
-                               /* Mutex will be released now, so does not require releasing\r
-                               on function exit. */\r
+                               /* The interrupt won't actually executed until\r
+                               pvInterruptEventMutex is released as it waits on both\r
+                               pvInterruptEventMutex and pvInterruptEvent.\r
+                               pvInterruptEvent is only set when the simulated\r
+                               interrupt is pended if the interrupt is pended\r
+                               from outside a critical section - hence it is set\r
+                               here. */\r
+                               SetEvent( pvInterruptEvent );\r
+                               /* The calling task is going to wait for an event to ensure the\r
+                               interrupt that is pending executes immediately after the\r
+                               critical section is exited - so make sure the event is not\r
+                               already signaled. */\r
+                               ResetEvent( pxThreadState->pvYieldEvent );\r
+                               lWaitForYield = pdTRUE;\r
+\r
+                               /* Mutex will be released now so the (simulated) interrupt can\r
+                               execute, so does not require releasing on function exit. */\r
                                lMutexNeedsReleasing = pdFALSE;\r
                                ReleaseMutex( pvInterruptEventMutex );\r
+                               WaitForSingleObject( pxThreadState->pvYieldEvent, INFINITE );\r
                        }\r
                }\r
-               else\r
-               {\r
-                       /* Tick interrupts will still not be processed as the critical\r
-                       nesting depth will not be zero. */\r
-                       ulCriticalNesting--;\r
-               }\r
        }\r
 \r
        if( pvInterruptEventMutex != NULL )\r