2 FreeRTOS V8.2.2 - Copyright (C) 2015 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 This file is part of the FreeRTOS distribution.
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9 FreeRTOS is free software; you can redistribute it and/or modify it under
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10 the terms of the GNU General Public License (version 2) as published by the
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11 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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13 ***************************************************************************
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14 >>! NOTE: The modification to the GPL is included to allow you to !<<
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15 >>! distribute a combined work that includes FreeRTOS without being !<<
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16 >>! obliged to provide the source code for proprietary components !<<
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17 >>! outside of the FreeRTOS kernel. !<<
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18 ***************************************************************************
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20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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22 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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23 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * FreeRTOS provides completely free yet professionally developed, *
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28 * robust, strictly quality controlled, supported, and cross *
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29 * platform software that is more than just the market leader, it *
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30 * is the industry's de facto standard. *
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32 * Help yourself get started quickly while simultaneously helping *
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33 * to support the FreeRTOS project by purchasing a FreeRTOS *
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34 * tutorial book, reference manual, or both: *
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35 * http://www.FreeRTOS.org/Documentation *
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37 ***************************************************************************
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39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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40 the FAQ page "My application does not run, what could be wrong?". Have you
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41 defined configASSERT()?
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43 http://www.FreeRTOS.org/support - In return for receiving this top quality
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44 embedded software for free we request you assist our global community by
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45 participating in the support forum.
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47 http://www.FreeRTOS.org/training - Investing in training allows your team to
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48 be as productive as possible as early as possible. Now you can receive
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49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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50 Ltd, and the world's leading authority on the world's leading RTOS.
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52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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54 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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61 licenses offer ticketed support, indemnification and commercial middleware.
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63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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64 engineered and independently SIL3 certified version for use in safety and
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65 mission critical applications that require provable dependability.
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70 /* Standard includes. */
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73 /* Scheduler includes. */
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74 #include "FreeRTOS.h"
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78 #include "mmsystem.h"
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80 #pragma comment(lib, "winmm.lib")
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83 #define portMAX_INTERRUPTS ( ( uint32_t ) sizeof( uint32_t ) * 8UL ) /* The number of bits in an uint32_t. */
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84 #define portNO_CRITICAL_NESTING ( ( uint32_t ) 0 )
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87 * Created as a high priority thread, this function uses a timer to simulate
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88 * a tick interrupt being generated on an embedded target. In this Windows
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89 * environment the timer does not achieve anything approaching real time
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90 * performance though.
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92 static DWORD WINAPI prvSimulatedPeripheralTimer( LPVOID lpParameter );
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95 * Process all the simulated interrupts - each represented by a bit in
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96 * ulPendingInterrupts variable.
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98 static void prvProcessSimulatedInterrupts( void );
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101 * Interrupt handlers used by the kernel itself. These are executed from the
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102 * simulated interrupt handler thread.
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104 static uint32_t prvProcessYieldInterrupt( void );
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105 static uint32_t prvProcessTickInterrupt( void );
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108 * Called when the process exits to let Windows know the high timer resolution
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109 * is no longer required.
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111 static BOOL WINAPI prvEndProcess( DWORD dwCtrlType );
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113 /*-----------------------------------------------------------*/
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115 /* The WIN32 simulator runs each task in a thread. The context switching is
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116 managed by the threads, so the task stack does not have to be managed directly,
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117 although the task stack is still used to hold an xThreadState structure this is
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118 the only thing it will ever hold. The structure indirectly maps the task handle
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119 to a thread handle. */
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122 /* Handle of the thread that executes the task. */
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127 /* Simulated interrupts waiting to be processed. This is a bit mask where each
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128 bit represents one interrupt, so a maximum of 32 interrupts can be simulated. */
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129 static volatile uint32_t ulPendingInterrupts = 0UL;
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131 /* An event used to inform the simulated interrupt processing thread (a high
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132 priority thread that simulated interrupt processing) that an interrupt is
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134 static void *pvInterruptEvent = NULL;
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136 /* Mutex used to protect all the simulated interrupt variables that are accessed
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137 by multiple threads. */
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138 static void *pvInterruptEventMutex = NULL;
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140 /* The critical nesting count for the currently executing task. This is
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141 initialised to a non-zero value so interrupts do not become enabled during
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142 the initialisation phase. As each task has its own critical nesting value
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143 ulCriticalNesting will get set to zero when the first task runs. This
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144 initialisation is probably not critical in this simulated environment as the
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145 simulated interrupt handlers do not get created until the FreeRTOS scheduler is
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147 static uint32_t ulCriticalNesting = 9999UL;
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149 /* Handlers for all the simulated software interrupts. The first two positions
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150 are used for the Yield and Tick interrupts so are handled slightly differently,
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151 all the other interrupts can be user defined. */
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152 static uint32_t (*ulIsrHandler[ portMAX_INTERRUPTS ])( void ) = { 0 };
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154 /* Pointer to the TCB of the currently executing task. */
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155 extern void *pxCurrentTCB;
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157 /* Used to ensure nothing is processed during the startup sequence. */
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158 static BaseType_t xPortRunning = pdFALSE;
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160 /*-----------------------------------------------------------*/
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162 static DWORD WINAPI prvSimulatedPeripheralTimer( LPVOID lpParameter )
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164 TickType_t xMinimumWindowsBlockTime;
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165 TIMECAPS xTimeCaps;
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167 /* Set the timer resolution to the maximum possible. */
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168 if( timeGetDevCaps( &xTimeCaps, sizeof( xTimeCaps ) ) == MMSYSERR_NOERROR )
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170 xMinimumWindowsBlockTime = ( TickType_t ) xTimeCaps.wPeriodMin;
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171 timeBeginPeriod( xTimeCaps.wPeriodMin );
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173 /* Register an exit handler so the timeBeginPeriod() function can be
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174 matched with a timeEndPeriod() when the application exits. */
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175 SetConsoleCtrlHandler( prvEndProcess, TRUE );
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179 xMinimumWindowsBlockTime = ( TickType_t ) 20;
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182 /* Just to prevent compiler warnings. */
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183 ( void ) lpParameter;
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187 /* Wait until the timer expires and we can access the simulated interrupt
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188 variables. *NOTE* this is not a 'real time' way of generating tick
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189 events as the next wake time should be relative to the previous wake
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190 time, not the time that Sleep() is called. It is done this way to
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191 prevent overruns in this very non real time simulated/emulated
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193 if( portTICK_PERIOD_MS < xMinimumWindowsBlockTime )
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195 Sleep( xMinimumWindowsBlockTime );
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199 Sleep( portTICK_PERIOD_MS );
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202 configASSERT( xPortRunning );
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204 WaitForSingleObject( pvInterruptEventMutex, INFINITE );
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206 /* The timer has expired, generate the simulated tick event. */
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207 ulPendingInterrupts |= ( 1 << portINTERRUPT_TICK );
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209 /* The interrupt is now pending - notify the simulated interrupt
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211 if( ulCriticalNesting == 0 )
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213 SetEvent( pvInterruptEvent );
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216 /* Give back the mutex so the simulated interrupt handler unblocks
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217 and can access the interrupt handler variables. */
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218 ReleaseMutex( pvInterruptEventMutex );
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222 /* Should never reach here - MingW complains if you leave this line out,
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223 MSVC complains if you put it in. */
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227 /*-----------------------------------------------------------*/
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229 static BOOL WINAPI prvEndProcess( DWORD dwCtrlType )
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231 TIMECAPS xTimeCaps;
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233 ( void ) dwCtrlType;
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235 if( timeGetDevCaps( &xTimeCaps, sizeof( xTimeCaps ) ) == MMSYSERR_NOERROR )
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237 /* Match the call to timeBeginPeriod( xTimeCaps.wPeriodMin ) made when
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238 the process started with a timeEndPeriod() as the process exits. */
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239 timeEndPeriod( xTimeCaps.wPeriodMin );
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244 /*-----------------------------------------------------------*/
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246 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
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248 xThreadState *pxThreadState = NULL;
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249 int8_t *pcTopOfStack = ( int8_t * ) pxTopOfStack;
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251 /* In this simulated case a stack is not initialised, but instead a thread
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252 is created that will execute the task being created. The thread handles
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253 the context switching itself. The xThreadState object is placed onto
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254 the stack that was created for the task - so the stack buffer is still
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255 used, just not in the conventional way. It will not be used for anything
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256 other than holding this structure. */
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257 pxThreadState = ( xThreadState * ) ( pcTopOfStack - sizeof( xThreadState ) );
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259 /* Create the thread itself. */
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260 pxThreadState->pvThread = CreateThread( NULL, 0, ( LPTHREAD_START_ROUTINE ) pxCode, pvParameters, CREATE_SUSPENDED, NULL );
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261 configASSERT( pxThreadState->pvThread );
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262 SetThreadAffinityMask( pxThreadState->pvThread, 0x01 );
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263 SetThreadPriorityBoost( pxThreadState->pvThread, TRUE );
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264 SetThreadPriority( pxThreadState->pvThread, THREAD_PRIORITY_IDLE );
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266 return ( StackType_t * ) pxThreadState;
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268 /*-----------------------------------------------------------*/
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270 BaseType_t xPortStartScheduler( void )
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273 int32_t lSuccess = pdPASS;
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274 xThreadState *pxThreadState;
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276 /* Install the interrupt handlers used by the scheduler itself. */
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277 vPortSetInterruptHandler( portINTERRUPT_YIELD, prvProcessYieldInterrupt );
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278 vPortSetInterruptHandler( portINTERRUPT_TICK, prvProcessTickInterrupt );
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280 /* Create the events and mutexes that are used to synchronise all the
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282 pvInterruptEventMutex = CreateMutex( NULL, FALSE, NULL );
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283 pvInterruptEvent = CreateEvent( NULL, FALSE, FALSE, NULL );
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285 if( ( pvInterruptEventMutex == NULL ) || ( pvInterruptEvent == NULL ) )
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290 /* Set the priority of this thread such that it is above the priority of
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291 the threads that run tasks. This higher priority is required to ensure
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292 simulated interrupts take priority over tasks. */
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293 pvHandle = GetCurrentThread();
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294 if( pvHandle == NULL )
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299 if( lSuccess == pdPASS )
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301 if( SetThreadPriority( pvHandle, THREAD_PRIORITY_NORMAL ) == 0 )
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305 SetThreadPriorityBoost( pvHandle, TRUE );
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306 SetThreadAffinityMask( pvHandle, 0x01 );
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309 if( lSuccess == pdPASS )
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311 /* Start the thread that simulates the timer peripheral to generate
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312 tick interrupts. The priority is set below that of the simulated
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313 interrupt handler so the interrupt event mutex is used for the
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314 handshake / overrun protection. */
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315 pvHandle = CreateThread( NULL, 0, prvSimulatedPeripheralTimer, NULL, CREATE_SUSPENDED, NULL );
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316 if( pvHandle != NULL )
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318 SetThreadPriority( pvHandle, THREAD_PRIORITY_BELOW_NORMAL );
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319 SetThreadPriorityBoost( pvHandle, TRUE );
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320 SetThreadAffinityMask( pvHandle, 0x01 );
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321 ResumeThread( pvHandle );
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324 /* Start the highest priority task by obtaining its associated thread
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325 state structure, in which is stored the thread handle. */
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326 pxThreadState = ( xThreadState * ) *( ( size_t * ) pxCurrentTCB );
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327 ulCriticalNesting = portNO_CRITICAL_NESTING;
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329 /* Bump up the priority of the thread that is going to run, in the
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330 hope that this will assist in getting the Windows thread scheduler to
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331 behave as an embedded engineer might expect. */
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332 ResumeThread( pxThreadState->pvThread );
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334 /* Handle all simulated interrupts - including yield requests and
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335 simulated ticks. */
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336 prvProcessSimulatedInterrupts();
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339 /* Would not expect to return from prvProcessSimulatedInterrupts(), so should
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343 /*-----------------------------------------------------------*/
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345 static uint32_t prvProcessYieldInterrupt( void )
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349 /*-----------------------------------------------------------*/
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351 static uint32_t prvProcessTickInterrupt( void )
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353 uint32_t ulSwitchRequired;
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355 /* Process the tick itself. */
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356 configASSERT( xPortRunning );
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357 ulSwitchRequired = ( uint32_t ) xTaskIncrementTick();
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359 return ulSwitchRequired;
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361 /*-----------------------------------------------------------*/
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363 static void prvProcessSimulatedInterrupts( void )
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365 uint32_t ulSwitchRequired, i;
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366 xThreadState *pxThreadState;
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367 void *pvObjectList[ 2 ];
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370 /* Going to block on the mutex that ensured exclusive access to the simulated
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371 interrupt objects, and the event that signals that a simulated interrupt
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372 should be processed. */
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373 pvObjectList[ 0 ] = pvInterruptEventMutex;
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374 pvObjectList[ 1 ] = pvInterruptEvent;
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376 /* Create a pending tick to ensure the first task is started as soon as
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377 this thread pends. */
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378 ulPendingInterrupts |= ( 1 << portINTERRUPT_TICK );
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379 SetEvent( pvInterruptEvent );
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381 xPortRunning = pdTRUE;
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385 WaitForMultipleObjects( sizeof( pvObjectList ) / sizeof( void * ), pvObjectList, TRUE, INFINITE );
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387 /* Used to indicate whether the simulated interrupt processing has
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388 necessitated a context switch to another task/thread. */
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389 ulSwitchRequired = pdFALSE;
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391 /* For each interrupt we are interested in processing, each of which is
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392 represented by a bit in the 32bit ulPendingInterrupts variable. */
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393 for( i = 0; i < portMAX_INTERRUPTS; i++ )
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395 /* Is the simulated interrupt pending? */
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396 if( ulPendingInterrupts & ( 1UL << i ) )
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398 /* Is a handler installed? */
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399 if( ulIsrHandler[ i ] != NULL )
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401 /* Run the actual handler. */
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402 if( ulIsrHandler[ i ]() != pdFALSE )
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404 ulSwitchRequired |= ( 1 << i );
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408 /* Clear the interrupt pending bit. */
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409 ulPendingInterrupts &= ~( 1UL << i );
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413 if( ulSwitchRequired != pdFALSE )
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415 void *pvOldCurrentTCB;
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417 pvOldCurrentTCB = pxCurrentTCB;
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419 /* Select the next task to run. */
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420 vTaskSwitchContext();
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422 /* If the task selected to enter the running state is not the task
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423 that is already in the running state. */
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424 if( pvOldCurrentTCB != pxCurrentTCB )
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426 /* Suspend the old thread. */
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427 pxThreadState = ( xThreadState *) *( ( size_t * ) pvOldCurrentTCB );
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428 SuspendThread( pxThreadState->pvThread );
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430 /* Ensure the thread is actually suspended by performing a
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431 synchronous operation that can only complete when the thread is
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432 actually suspended. The below code asks for dummy register
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434 xContext.ContextFlags = CONTEXT_INTEGER;
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435 ( void ) GetThreadContext( pxThreadState->pvThread, &xContext );
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437 /* Obtain the state of the task now selected to enter the
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439 pxThreadState = ( xThreadState * ) ( *( size_t *) pxCurrentTCB );
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440 ResumeThread( pxThreadState->pvThread );
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444 ReleaseMutex( pvInterruptEventMutex );
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447 /*-----------------------------------------------------------*/
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449 void vPortDeleteThread( void *pvTaskToDelete )
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451 xThreadState *pxThreadState;
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452 uint32_t ulErrorCode;
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454 /* Remove compiler warnings if configASSERT() is not defined. */
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455 ( void ) ulErrorCode;
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457 /* Find the handle of the thread being deleted. */
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458 pxThreadState = ( xThreadState * ) ( *( size_t *) pvTaskToDelete );
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460 /* Check that the thread is still valid, it might have been closed by
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461 vPortCloseRunningThread() - which will be the case if the task associated
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462 with the thread originally deleted itself rather than being deleted by a
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464 if( pxThreadState->pvThread != NULL )
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466 WaitForSingleObject( pvInterruptEventMutex, INFINITE );
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468 ulErrorCode = TerminateThread( pxThreadState->pvThread, 0 );
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469 configASSERT( ulErrorCode );
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471 ulErrorCode = CloseHandle( pxThreadState->pvThread );
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472 configASSERT( ulErrorCode );
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474 ReleaseMutex( pvInterruptEventMutex );
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477 /*-----------------------------------------------------------*/
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479 void vPortCloseRunningThread( void *pvTaskToDelete, volatile BaseType_t *pxPendYield )
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481 xThreadState *pxThreadState;
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483 uint32_t ulErrorCode;
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485 /* Remove compiler warnings if configASSERT() is not defined. */
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486 ( void ) ulErrorCode;
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488 /* Find the handle of the thread being deleted. */
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489 pxThreadState = ( xThreadState * ) ( *( size_t *) pvTaskToDelete );
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490 pvThread = pxThreadState->pvThread;
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492 /* Raise the Windows priority of the thread to ensure the FreeRTOS scheduler
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493 does not run and swap it out before it is closed. If that were to happen
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494 the thread would never run again and effectively be a thread handle and
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496 SetThreadPriority( pvThread, THREAD_PRIORITY_ABOVE_NORMAL );
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498 /* This function will not return, therefore a yield is set as pending to
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499 ensure a context switch occurs away from this thread on the next tick. */
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500 *pxPendYield = pdTRUE;
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502 /* Mark the thread associated with this task as invalid so
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503 vPortDeleteThread() does not try to terminate it. */
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504 pxThreadState->pvThread = NULL;
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506 /* Close the thread. */
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507 ulErrorCode = CloseHandle( pvThread );
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508 configASSERT( ulErrorCode );
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512 /*-----------------------------------------------------------*/
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514 void vPortEndScheduler( void )
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516 /* This function IS NOT TESTED! */
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517 TerminateProcess( GetCurrentProcess(), 0 );
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519 /*-----------------------------------------------------------*/
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521 void vPortGenerateSimulatedInterrupt( uint32_t ulInterruptNumber )
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523 configASSERT( xPortRunning );
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525 if( ( ulInterruptNumber < portMAX_INTERRUPTS ) && ( pvInterruptEventMutex != NULL ) )
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527 /* Yield interrupts are processed even when critical nesting is non-zero. */
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528 WaitForSingleObject( pvInterruptEventMutex, INFINITE );
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529 ulPendingInterrupts |= ( 1 << ulInterruptNumber );
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531 /* The simulated interrupt is now held pending, but don't actually process it
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532 yet if this call is within a critical section. It is possible for this to
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533 be in a critical section as calls to wait for mutexes are accumulative. */
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534 if( ulCriticalNesting == 0 )
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536 SetEvent( pvInterruptEvent );
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539 ReleaseMutex( pvInterruptEventMutex );
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542 /*-----------------------------------------------------------*/
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544 void vPortSetInterruptHandler( uint32_t ulInterruptNumber, uint32_t (*pvHandler)( void ) )
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546 if( ulInterruptNumber < portMAX_INTERRUPTS )
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548 if( pvInterruptEventMutex != NULL )
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550 WaitForSingleObject( pvInterruptEventMutex, INFINITE );
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551 ulIsrHandler[ ulInterruptNumber ] = pvHandler;
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552 ReleaseMutex( pvInterruptEventMutex );
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556 ulIsrHandler[ ulInterruptNumber ] = pvHandler;
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560 /*-----------------------------------------------------------*/
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562 void vPortEnterCritical( void )
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564 if( xPortRunning == pdTRUE )
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566 /* The interrupt event mutex is held for the entire critical section,
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567 effectively disabling (simulated) interrupts. */
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568 WaitForSingleObject( pvInterruptEventMutex, INFINITE );
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569 ulCriticalNesting++;
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573 ulCriticalNesting++;
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576 /*-----------------------------------------------------------*/
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578 void vPortExitCritical( void )
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580 int32_t lMutexNeedsReleasing;
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582 /* The interrupt event mutex should already be held by this thread as it was
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583 obtained on entry to the critical section. */
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585 lMutexNeedsReleasing = pdTRUE;
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587 if( ulCriticalNesting > portNO_CRITICAL_NESTING )
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589 if( ulCriticalNesting == ( portNO_CRITICAL_NESTING + 1 ) )
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591 ulCriticalNesting--;
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593 /* Were any interrupts set to pending while interrupts were
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594 (simulated) disabled? */
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595 if( ulPendingInterrupts != 0UL )
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597 configASSERT( xPortRunning );
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598 SetEvent( pvInterruptEvent );
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600 /* Mutex will be released now, so does not require releasing
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601 on function exit. */
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602 lMutexNeedsReleasing = pdFALSE;
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603 ReleaseMutex( pvInterruptEventMutex );
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608 /* Tick interrupts will still not be processed as the critical
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609 nesting depth will not be zero. */
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610 ulCriticalNesting--;
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614 if( pvInterruptEventMutex != NULL )
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616 if( lMutexNeedsReleasing == pdTRUE )
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618 configASSERT( xPortRunning );
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619 ReleaseMutex( pvInterruptEventMutex );
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623 /*-----------------------------------------------------------*/
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