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authorPProvost <[email protected]>2020-05-11 08:55:07 -0600
committerPProvost <[email protected]>2020-05-11 08:55:07 -0600
commit852421fda03a7722d7adb45b187235cd66fa264e (patch)
treeb117e1339a047347a3d7ebf3eeb1891168cc9b9b /common/src/tx_thread_system_preempt_check.c
Initial commit
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-rw-r--r--common/src/tx_thread_system_preempt_check.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/common/src/tx_thread_system_preempt_check.c b/common/src/tx_thread_system_preempt_check.c
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+/**************************************************************************/
+/* */
+/* Copyright (c) Microsoft Corporation. All rights reserved. */
+/* */
+/* This software is licensed under the Microsoft Software License */
+/* Terms for Microsoft Azure RTOS. Full text of the license can be */
+/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
+/* and in the root directory of this software. */
+/* */
+/**************************************************************************/
+
+
+/**************************************************************************/
+/**************************************************************************/
+/** */
+/** ThreadX Component */
+/** */
+/** Thread */
+/** */
+/**************************************************************************/
+/**************************************************************************/
+
+#define TX_SOURCE_CODE
+
+
+/* Include necessary system files. */
+
+#include "tx_api.h"
+#include "tx_thread.h"
+
+
+/**************************************************************************/
+/* */
+/* FUNCTION RELEASE */
+/* */
+/* _tx_thread_system_preempt_check PORTABLE C */
+/* 6.0 */
+/* AUTHOR */
+/* */
+/* William E. Lamie, Microsoft Corporation */
+/* */
+/* DESCRIPTION */
+/* */
+/* This function checks for preemption that could have occurred as a */
+/* result scheduling activities occurring while the preempt disable */
+/* flag was set. */
+/* */
+/* INPUT */
+/* */
+/* None */
+/* */
+/* OUTPUT */
+/* */
+/* None */
+/* */
+/* CALLS */
+/* */
+/* _tx_thread_system_return Return to the system */
+/* */
+/* CALLED BY */
+/* */
+/* Other ThreadX Components */
+/* */
+/* RELEASE HISTORY */
+/* */
+/* DATE NAME DESCRIPTION */
+/* */
+/* 05-19-2020 William E. Lamie Initial Version 6.0 */
+/* */
+/**************************************************************************/
+VOID _tx_thread_system_preempt_check(VOID)
+{
+
+ULONG combined_flags;
+TX_THREAD *current_thread;
+TX_THREAD *thread_ptr;
+
+
+ /* Combine the system state and preempt disable flags into one for comparison. */
+ TX_THREAD_SYSTEM_RETURN_CHECK(combined_flags)
+
+ /* Determine if we are in a system state (ISR or Initialization) or internal preemption is disabled. */
+ if (combined_flags == ((ULONG) 0))
+ {
+
+ /* No, at thread execution level so continue checking for preemption. */
+
+ /* Pickup thread pointer. */
+ TX_THREAD_GET_CURRENT(current_thread)
+
+ /* Pickup the next execute pointer. */
+ thread_ptr = _tx_thread_execute_ptr;
+
+ /* Determine if preemption should take place. */
+ if (current_thread != thread_ptr)
+ {
+
+#ifdef TX_ENABLE_STACK_CHECKING
+
+ /* Check this thread's stack. */
+ TX_THREAD_STACK_CHECK(thread_ptr)
+#endif
+
+
+#ifdef TX_THREAD_ENABLE_PERFORMANCE_INFO
+
+ /* Determine if an idle system return is present. */
+ if (thread_ptr == TX_NULL)
+ {
+
+ /* Yes, increment the return to idle return count. */
+ _tx_thread_performance_idle_return_count++;
+ }
+ else
+ {
+
+ /* No, there is another thread ready to run and will be scheduled upon return. */
+ _tx_thread_performance_non_idle_return_count++;
+ }
+#endif
+
+ /* Return to the system so the higher priority thread can be scheduled. */
+ _tx_thread_system_return();
+ }
+ }
+}
+