こんにちは。NoMaYです。Azure RTOSでRXマイコンが使えるようになったのですね。コンパイラはGNURXが使われていました。Getting started with the Renesas Starter Kit+ for RX65N-2MB (英文です。)02/05/2021 Ryan Winterdocs.microsoft.com/ja-jp/samples/azure-rtos/getting-started/getting-started-with-the-renesas-starter-kit-for-rx65n-2mb/
試しに libs/threadx/common/src/tx_semaphore_get.c を覗いてみました。やはり割り込み禁止にした状態でゴソゴソそれなりにやっていることがありますね。続く。libs/threadx/common/src/tx_semaphore_get.c (正直なところ何をやっているのかは分かりません)
UINT _tx_semaphore_get(TX_SEMAPHORE *semaphore_ptr, ULONG wait_option){TX_INTERRUPT_SAVE_AREATX_THREAD *thread_ptr;TX_THREAD *next_thread;TX_THREAD *previous_thread;UINT status; /* Default the status to TX_SUCCESS. */ status = TX_SUCCESS; /* Disable interrupts to get an instance from the semaphore. */ TX_DISABLE#ifdef TX_SEMAPHORE_ENABLE_PERFORMANCE_INFO /* Increment the total semaphore get counter. */ _tx_semaphore_performance_get_count++; /* Increment the number of attempts to get this semaphore. */ semaphore_ptr -> tx_semaphore_performance_get_count++;#endif /* If trace is enabled, insert this event into the trace buffer. */ TX_TRACE_IN_LINE_INSERT(TX_TRACE_SEMAPHORE_GET, semaphore_ptr, wait_option, semaphore_ptr -> tx_semaphore_count, TX_POINTER_TO_ULONG_CONVERT(&thread_ptr), TX_TRACE_SEMAPHORE_EVENTS) /* Log this kernel call. */ TX_EL_SEMAPHORE_GET_INSERT /* Determine if there is an instance of the semaphore. */ if (semaphore_ptr -> tx_semaphore_count != ((ULONG) 0)) { /* Decrement the semaphore count. */ semaphore_ptr -> tx_semaphore_count--; /* Restore interrupts. */ TX_RESTORE } /* Determine if the request specifies suspension. */ else 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_NO_INSTANCE; } else { /* Prepare for suspension of this thread. */#ifdef TX_SEMAPHORE_ENABLE_PERFORMANCE_INFO /* Increment the total semaphore suspensions counter. */ _tx_semaphore_performance_suspension_count++; /* Increment the number of suspensions on this semaphore. */ semaphore_ptr -> tx_semaphore_performance_suspension_count++;#endif /* Pickup thread pointer. */ TX_THREAD_GET_CURRENT(thread_ptr) /* Setup cleanup routine pointer. */ thread_ptr -> tx_thread_suspend_cleanup = &(_tx_semaphore_cleanup); /* Setup cleanup information, i.e. this semaphore control block. */ thread_ptr -> tx_thread_suspend_control_block = (VOID *) semaphore_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 (semaphore_ptr -> tx_semaphore_suspended_count == TX_NO_SUSPENSIONS) { /* No other threads are suspended. Setup the head pointer and just setup this threads pointers to itself. */ semaphore_ptr -> tx_semaphore_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 = semaphore_ptr -> tx_semaphore_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 number of suspensions. */ semaphore_ptr -> tx_semaphore_suspended_count++; /* Set the state to suspended. */ thread_ptr -> tx_thread_state = TX_SEMAPHORE_SUSP;#ifdef TX_NOT_INTERRUPTABLE /* 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 /* 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_NO_INSTANCE; } /* Return completion status. */ return(status);}