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Diffstat (limited to 'common/src/tx_mutex_get.c')
| -rw-r--r-- | common/src/tx_mutex_get.c | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/common/src/tx_mutex_get.c b/common/src/tx_mutex_get.c new file mode 100644 index 00000000..1d805c84 --- /dev/null +++ b/common/src/tx_mutex_get.c @@ -0,0 +1,409 @@ +/**************************************************************************/ +/* */ +/* 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 */ +/** */ +/** Mutex */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + +#define TX_SOURCE_CODE + + +/* Include necessary system files. */ + +#include "tx_api.h" +#include "tx_trace.h" +#include "tx_thread.h" +#include "tx_mutex.h" + + +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_mutex_get PORTABLE C */ +/* 6.0 */ +/* AUTHOR */ +/* */ +/* William E. Lamie, Microsoft Corporation */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function gets the specified mutex. If the calling thread */ +/* already owns the mutex, an ownership count is simply increased. */ +/* */ +/* INPUT */ +/* */ +/* mutex_ptr Pointer to mutex control block */ +/* wait_option Suspension option */ +/* */ +/* OUTPUT */ +/* */ +/* status Completion status */ +/* */ +/* CALLS */ +/* */ +/* _tx_thread_system_suspend Suspend thread service */ +/* _tx_thread_system_ni_suspend Non-interruptable suspend thread */ +/* _tx_mutex_priority_change Inherit thread priority */ +/* */ +/* CALLED BY */ +/* */ +/* Application Code */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 05-19-2020 William E. Lamie Initial Version 6.0 */ +/* */ +/**************************************************************************/ +UINT _tx_mutex_get(TX_MUTEX *mutex_ptr, ULONG wait_option) +{ + +TX_INTERRUPT_SAVE_AREA + +TX_THREAD *thread_ptr; +TX_MUTEX *next_mutex; +TX_MUTEX *previous_mutex; +TX_THREAD *mutex_owner; +TX_THREAD *next_thread; +TX_THREAD *previous_thread; +UINT status; + + + /* Disable interrupts to get an instance from the mutex. */ + TX_DISABLE + +#ifdef TX_MUTEX_ENABLE_PERFORMANCE_INFO + + /* Increment the total mutex get counter. */ + _tx_mutex_performance_get_count++; + + /* Increment the number of attempts to get this mutex. */ + mutex_ptr -> tx_mutex_performance_get_count++; +#endif + + /* If trace is enabled, insert this event into the trace buffer. */ + TX_TRACE_IN_LINE_INSERT(TX_TRACE_MUTEX_GET, mutex_ptr, wait_option, TX_POINTER_TO_ULONG_CONVERT(mutex_ptr -> tx_mutex_owner), mutex_ptr -> tx_mutex_ownership_count, TX_TRACE_MUTEX_EVENTS) + + /* Log this kernel call. */ + TX_EL_MUTEX_GET_INSERT + + /* Pickup thread pointer. */ + TX_THREAD_GET_CURRENT(thread_ptr) + + /* Determine if this mutex is available. */ + if (mutex_ptr -> tx_mutex_ownership_count == ((UINT) 0)) + { + + /* Set the ownership count to 1. */ + mutex_ptr -> tx_mutex_ownership_count = ((UINT) 1); + + /* Remember that the calling thread owns the mutex. */ + mutex_ptr -> tx_mutex_owner = thread_ptr; + + /* Determine if the thread pointer is valid. */ + if (thread_ptr != TX_NULL) + { + + /* Determine if priority inheritance is required. */ + if (mutex_ptr -> tx_mutex_inherit == TX_TRUE) + { + + /* Remember the current priority of thread. */ + mutex_ptr -> tx_mutex_original_priority = thread_ptr -> tx_thread_priority; + + /* Setup the highest priority waiting thread. */ + mutex_ptr -> tx_mutex_highest_priority_waiting = ((UINT) TX_MAX_PRIORITIES); + } + + /* Pickup next mutex pointer, which is the head of the list. */ + next_mutex = thread_ptr -> tx_thread_owned_mutex_list; + + /* Determine if this thread owns any other mutexes that have priority inheritance. */ + if (next_mutex != TX_NULL) + { + + /* Non-empty list. Link up the mutex. */ + + /* Pickup the next and previous mutex pointer. */ + previous_mutex = next_mutex -> tx_mutex_owned_previous; + + /* Place the owned mutex in the list. */ + next_mutex -> tx_mutex_owned_previous = mutex_ptr; + previous_mutex -> tx_mutex_owned_next = mutex_ptr; + + /* Setup this mutex's next and previous created links. */ + mutex_ptr -> tx_mutex_owned_previous = previous_mutex; + mutex_ptr -> tx_mutex_owned_next = next_mutex; + } + else + { + + /* The owned mutex list is empty. Add mutex to empty list. */ + thread_ptr -> tx_thread_owned_mutex_list = mutex_ptr; + mutex_ptr -> tx_mutex_owned_next = mutex_ptr; + mutex_ptr -> tx_mutex_owned_previous = mutex_ptr; + } + + /* Increment the number of mutexes owned counter. */ + thread_ptr -> tx_thread_owned_mutex_count++; + } + + /* Restore interrupts. */ + TX_RESTORE + + /* Return success. */ + status = TX_SUCCESS; + } + + /* Otherwise, see if the owning thread is trying to obtain the same mutex. */ + else if (mutex_ptr -> tx_mutex_owner == thread_ptr) + { + + /* The owning thread is requesting the mutex again, just + increment the ownership count. */ + mutex_ptr -> tx_mutex_ownership_count++; + + /* Restore interrupts. */ + TX_RESTORE + + /* Return success. */ + status = TX_SUCCESS; + } + else + { + + /* Determine if the request specifies suspension. */ + if (wait_option != TX_NO_WAIT) + { + + /* Determine if the preempt disable flag is non-zero. */ + if (_tx_thread_preempt_disable != ((UINT) 0)) + { + + /* Restore interrupts. */ + TX_RESTORE + + /* Suspension is not allowed if the preempt disable flag is non-zero at this point - return error completion. */ + status = TX_NOT_AVAILABLE; + } + else + { + + /* Prepare for suspension of this thread. */ + + /* Pickup the mutex owner. */ + mutex_owner = mutex_ptr -> tx_mutex_owner; + +#ifdef TX_MUTEX_ENABLE_PERFORMANCE_INFO + + /* Increment the total mutex suspension counter. */ + _tx_mutex_performance_suspension_count++; + + /* Increment the number of suspensions on this mutex. */ + mutex_ptr -> tx_mutex_performance_suspension_count++; + + /* Determine if a priority inversion is present. */ + if (thread_ptr -> tx_thread_priority < mutex_owner -> tx_thread_priority) + { + + /* Yes, priority inversion is present! */ + + /* Increment the total mutex priority inversions counter. */ + _tx_mutex_performance_priority_inversion_count++; + + /* Increment the number of priority inversions on this mutex. */ + mutex_ptr -> tx_mutex_performance_priority_inversion_count++; + +#ifdef TX_THREAD_ENABLE_PERFORMANCE_INFO + + /* Increment the number of total thread priority inversions. */ + _tx_thread_performance_priority_inversion_count++; + + /* Increment the number of priority inversions for this thread. */ + thread_ptr -> tx_thread_performance_priority_inversion_count++; +#endif + } +#endif + + /* Setup cleanup routine pointer. */ + thread_ptr -> tx_thread_suspend_cleanup = &(_tx_mutex_cleanup); + + /* Setup cleanup information, i.e. this mutex control + block. */ + thread_ptr -> tx_thread_suspend_control_block = (VOID *) mutex_ptr; + +#ifndef TX_NOT_INTERRUPTABLE + + /* Increment the suspension sequence number, which is used to identify + this suspension event. */ + thread_ptr -> tx_thread_suspension_sequence++; +#endif + + /* Setup suspension list. */ + if (mutex_ptr -> tx_mutex_suspended_count == TX_NO_SUSPENSIONS) + { + + /* No other threads are suspended. Setup the head pointer and + just setup this threads pointers to itself. */ + mutex_ptr -> tx_mutex_suspension_list = thread_ptr; + thread_ptr -> tx_thread_suspended_next = thread_ptr; + thread_ptr -> tx_thread_suspended_previous = thread_ptr; + } + else + { + + /* This list is not NULL, add current thread to the end. */ + next_thread = mutex_ptr -> tx_mutex_suspension_list; + thread_ptr -> tx_thread_suspended_next = next_thread; + previous_thread = next_thread -> tx_thread_suspended_previous; + thread_ptr -> tx_thread_suspended_previous = previous_thread; + previous_thread -> tx_thread_suspended_next = thread_ptr; + next_thread -> tx_thread_suspended_previous = thread_ptr; + } + + /* Increment the suspension count. */ + mutex_ptr -> tx_mutex_suspended_count++; + + /* Set the state to suspended. */ + thread_ptr -> tx_thread_state = TX_MUTEX_SUSP; + +#ifdef TX_NOT_INTERRUPTABLE + + /* Determine if we need to raise the priority of the thread + owning the mutex. */ + if (mutex_ptr -> tx_mutex_inherit == TX_TRUE) + { + + /* Determine if this is the highest priority to raise for this mutex. */ + if (mutex_ptr -> tx_mutex_highest_priority_waiting > thread_ptr -> tx_thread_priority) + { + + /* Remember this priority. */ + mutex_ptr -> tx_mutex_highest_priority_waiting = thread_ptr -> tx_thread_priority; + } + + /* Determine if we have to update inherit priority level of the mutex owner. */ + if (thread_ptr -> tx_thread_priority < mutex_owner -> tx_thread_inherit_priority) + { + + /* Remember the new priority inheritance priority. */ + mutex_owner -> tx_thread_inherit_priority = thread_ptr -> tx_thread_priority; + } + + /* Priority inheritance is requested, check to see if the thread that owns the mutex is lower priority. */ + if (mutex_owner -> tx_thread_priority > thread_ptr -> tx_thread_priority) + { + + /* Yes, raise the suspended, owning thread's priority to that + of the current thread. */ + _tx_mutex_priority_change(mutex_owner, thread_ptr -> tx_thread_priority); + +#ifdef TX_MUTEX_ENABLE_PERFORMANCE_INFO + + /* Increment the total mutex priority inheritance counter. */ + _tx_mutex_performance__priority_inheritance_count++; + + /* Increment the number of priority inheritance situations on this mutex. */ + mutex_ptr -> tx_mutex_performance__priority_inheritance_count++; +#endif + } + } + + /* Call actual non-interruptable thread suspension routine. */ + _tx_thread_system_ni_suspend(thread_ptr, wait_option); + + /* Restore interrupts. */ + TX_RESTORE +#else + + /* Set the suspending flag. */ + thread_ptr -> tx_thread_suspending = TX_TRUE; + + /* Setup the timeout period. */ + thread_ptr -> tx_thread_timer.tx_timer_internal_remaining_ticks = wait_option; + + /* Temporarily disable preemption. */ + _tx_thread_preempt_disable++; + + /* Restore interrupts. */ + TX_RESTORE + + /* Determine if we need to raise the priority of the thread + owning the mutex. */ + if (mutex_ptr -> tx_mutex_inherit == TX_TRUE) + { + + /* Determine if this is the highest priority to raise for this mutex. */ + if (mutex_ptr -> tx_mutex_highest_priority_waiting > thread_ptr -> tx_thread_priority) + { + + /* Remember this priority. */ + mutex_ptr -> tx_mutex_highest_priority_waiting = thread_ptr -> tx_thread_priority; + } + + /* Determine if we have to update inherit priority level of the mutex owner. */ + if (thread_ptr -> tx_thread_priority < mutex_owner -> tx_thread_inherit_priority) + { + + /* Remember the new priority inheritance priority. */ + mutex_owner -> tx_thread_inherit_priority = thread_ptr -> tx_thread_priority; + } + + /* Priority inheritance is requested, check to see if the thread that owns the mutex is lower priority. */ + if (mutex_owner -> tx_thread_priority > thread_ptr -> tx_thread_priority) + { + + /* Yes, raise the suspended, owning thread's priority to that + of the current thread. */ + _tx_mutex_priority_change(mutex_owner, thread_ptr -> tx_thread_priority); + +#ifdef TX_MUTEX_ENABLE_PERFORMANCE_INFO + + /* Increment the total mutex priority inheritance counter. */ + _tx_mutex_performance__priority_inheritance_count++; + + /* Increment the number of priority inheritance situations on this mutex. */ + mutex_ptr -> tx_mutex_performance__priority_inheritance_count++; +#endif + } + } + + /* Call actual thread suspension routine. */ + _tx_thread_system_suspend(thread_ptr); +#endif + /* Return the completion status. */ + status = thread_ptr -> tx_thread_suspend_status; + } + } + else + { + + /* Restore interrupts. */ + TX_RESTORE + + /* Immediate return, return error completion. */ + status = TX_NOT_AVAILABLE; + } + } + + /* Return completion status. */ + return(status); +} + |