view src/gpf/osl/os_sem_fl.c @ 268:f2e52cab0a73

abb_inth.c: check all interrupt causes, not just one The original code used if - else if - else if etc constructs, thus the first detected interrupt was the only one handled. However, Iota ITSTATREG is a clear-on-read register, thus if we only handle the first detected interrupt and skip checking the others, then the other interrupts will be lost, if more than one interrupt happened to occur in one ABB interrupt handling cycle - a form of rare race condition. Change the code to check all interrupts that were read in this cycle.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 13 Jun 2021 18:17:53 +0000
parents 4e78acac3d88
children
line wrap: on
line source

/*
 * This C module is a reconstruction based on the disassembly of
 * os_sem.obj in frame_na7_db_fl.lib from the Leonardo package.
 */

/* set of included headers from COFF symtab: */
#include <stdio.h>
#include <string.h>
#include "nucleus.h"
#include "typedefs.h"
#include "os.h"
#include "gdi.h"
#include "os_types.h"
#include "os_glob.h"

extern T_OS_SEM_TABLE_ENTRY SemTable[];

static NU_SEMAPHORE SemSemCB;

static int
os_GetSemaphoreEntry(USHORT Index, OS_HANDLE *Handle)
{
	static USHORT Idx;

	if (Index == FIRST_ENTRY)
		Idx = 0;
	if (Index == FIRST_ENTRY || Index == NEXT_ENTRY) {
		for (;;) {
			Idx++;
			if (Idx > MaxSemaphores)
				return(OS_ERROR);
			if (SemTable[Idx].Name[0])
				break;
		}
	} else
		Idx = Index;
	if (Idx > MaxSemaphores)
		return(OS_ERROR);
	if (SemTable[Idx].Name[0]) {
		*Handle = Idx;
		return(OS_OK);
	} else
		return(OS_ERROR);
}

GLOBAL LONG
os_SemaphoreInformation(USHORT Index, char *Buffer)
{
	OS_HANDLE Handle;
	OPTION SuspendType;
	UNSIGNED Current, TasksWaiting;
	NU_TASK *First;
	CHAR Name[NU_MAX_NAME];

	if (os_GetSemaphoreEntry(Index, &Handle) < 0)
		return(OS_ERROR);
	if (NU_Semaphore_Information(&SemTable[Handle].SemCB, Name, &Current,
				     &SuspendType, &TasksWaiting, &First)
			!= NU_SUCCESS)
		return(OS_ERROR);
	sprintf(Buffer, "Semname:%s Count:%ld Suspend:%d Waiting:%ld", Name,
		Current, SuspendType, TasksWaiting);
	return(OS_OK);
}

GLOBAL LONG
os_SemInit(void)
{
	USHORT i;

	if (NU_Create_Semaphore(&SemSemCB, "SEMSEM", 1, NU_PRIORITY)
			!= NU_SUCCESS)
		return(OS_ERROR);
	for (i = 1; i <= MaxSemaphores; i++)
		memset(&SemTable[i], 0, sizeof(T_OS_SEM_TABLE_ENTRY));
	return(OS_OK);
}

GLOBAL LONG
os_ResetSemaphore(OS_HANDLE TaskHandle, OS_HANDLE SemHandle,
		  USHORT init_counter)
{
	STATUS sts;

	sts = NU_Obtain_Semaphore(&SemSemCB, NU_SUSPEND);
	if (!SemTable[SemHandle].Name[0]) {
error_out:	if (sts == NU_SUCCESS)
			NU_Release_Semaphore(&SemSemCB);
		return(OS_ERROR);
	}
	if (NU_Reset_Semaphore(&SemTable[SemHandle].SemCB, init_counter)
			!= NU_SUCCESS)
		goto error_out;
	if (sts == NU_SUCCESS)
		NU_Release_Semaphore(&SemSemCB);
	return(OS_OK);
}

GLOBAL LONG
os_QuerySemaphore(OS_HANDLE TaskHandle, OS_HANDLE SemHandle, USHORT *Count)
{
	OPTION SuspendType;
	UNSIGNED SemCount, TasksWaiting;
	NU_TASK *First;
	CHAR Name[NU_MAX_NAME];

	if (NU_Semaphore_Information(&SemTable[SemHandle].SemCB, Name,
				     &SemCount, &SuspendType, &TasksWaiting,
				     &First) != NU_SUCCESS)
		return(OS_ERROR);
	*Count = SemCount;
	return(OS_OK);
}

GLOBAL LONG
os_OpenSemaphore(OS_HANDLE TaskHandle, char *Name, OS_HANDLE *SemHandle)
{
	USHORT i;

	for (i = 1; i <= MaxSemaphores; i++) {
		if (!SemTable[i].Name[0])
			continue;
		if (strncmp(Name, SemTable[i].Name, RESOURCE_NAMELEN-1))
			continue;
		*SemHandle = i;
		return(OS_OK);
	}
	return(OS_ERROR);
}

GLOBAL unsigned char *
os_FindSuspendingSema(unsigned int *tcb)
{
	USHORT i;
	SM_SUSPEND *susp, *susp_loopchk;

	for (i = 1; i <= MaxSemaphores; i++) {
		if (!SemTable[i].Name[0])
			continue;
		susp = SemTable[i].SemCB.sm_suspension_list;
		if (!susp)
			continue;
		if (susp->sm_suspended_task == (NU_TASK *)tcb)
			return((unsigned char *) SemTable[i].SemCB.sm_name);
		susp = (SM_SUSPEND *)susp->sm_suspend_link.cs_next;
		for (susp_loopchk = susp; susp != susp_loopchk;
		     susp = (SM_SUSPEND *)susp->sm_suspend_link.cs_next)
			if (susp->sm_suspended_task == (NU_TASK *)tcb)
				return((unsigned char *)
					SemTable[i].SemCB.sm_name);
	}
	return(0);
}

GLOBAL LONG
os_DestroySemaphore(OS_HANDLE TaskHandle, OS_HANDLE SemHandle)
{
	STATUS sts;

	sts = NU_Obtain_Semaphore(&SemSemCB, NU_SUSPEND);
	if (!SemTable[SemHandle].Name[0]) {
error_out:	if (sts == NU_SUCCESS)
			NU_Release_Semaphore(&SemSemCB);
		return(OS_ERROR);
	}
	if (NU_Delete_Semaphore(&SemTable[SemHandle].SemCB) != NU_SUCCESS)
		goto error_out;
	SemTable[SemHandle].Name[0] = 0;
	if (sts == NU_SUCCESS)
		NU_Release_Semaphore(&SemSemCB);
	return(OS_OK);
}

GLOBAL LONG
os_CreateSemaphore(OS_HANDLE TaskHandle, char *Name, USHORT Count,
		   OS_HANDLE *SemHandle, OS_HANDLE MemPoolHandle)
{
	USHORT i;
	STATUS sts;

	if (os_OpenSemaphore(TaskHandle, Name, SemHandle) == OS_OK)
		return(OS_ERROR);
	sts = NU_Obtain_Semaphore(&SemSemCB, NU_SUSPEND);
	for (i = 1; i <= MaxSemaphores; i++) {
		if (SemTable[i].Name[0])
			continue;
		if (NU_Create_Semaphore(&SemTable[i].SemCB, Name, Count,
					NU_PRIORITY) != NU_SUCCESS)
			break;
		strncpy(SemTable[i].Name, Name, RESOURCE_NAMELEN);
		SemTable[i].Name[RESOURCE_NAMELEN-1] = 0;
		*SemHandle = i;
		if (sts == NU_SUCCESS)
			NU_Release_Semaphore(&SemSemCB);
		return(OS_OK);
	}
	if (sts == NU_SUCCESS)
		NU_Release_Semaphore(&SemSemCB);
	return(OS_ERROR);
}

GLOBAL LONG
os_CloseSemaphore(OS_HANDLE TaskHandle, OS_HANDLE SemHandle)
{
	return(OS_OK);
}