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![Amine Khaldi](/assets/img/avatar_default.png)
* Create a branch for some evul shell experiments. svn path=/branches/shell-experiments/; revision=61927
176 lines
5.8 KiB
C
176 lines
5.8 KiB
C
/*****************************************************************************
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* FullFAT - High Performance, Thread-Safe Embedded FAT File-System *
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* Copyright (C) 2009 James Walmsley (james@worm.me.uk) *
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* *
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* This program is free software: you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation, either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program. If not, see <http://www.gnu.org/licenses/>. *
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* *
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* IMPORTANT NOTICE: *
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* ================= *
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* Alternative Licensing is available directly from the Copyright holder, *
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* (James Walmsley). For more information consult LICENSING.TXT to obtain *
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* a Commercial license. *
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* *
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* See RESTRICTIONS.TXT for extra restrictions on the use of FullFAT. *
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* *
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* Removing the above notice is illegal and will invalidate this license. *
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*****************************************************************************
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* See http://worm.me.uk/fullfat for more information. *
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* Or http://fullfat.googlecode.com/ for latest releases and the wiki. *
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*****************************************************************************/
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/**
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* @file ff_safety.c
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* @author James Walmsley
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* @ingroup SAFETY
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*
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* @defgroup SAFETY Process Safety for FullFAT
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* @brief Provides semaphores, and thread-safety for FullFAT.
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*
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* This module aims to be as portable as possible. It is necessary to modify
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* the functions FF_CreateSemaphore, FF_PendSemaphore, FF_ReleaseSemaphore,
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* and FF_DestroySemaphore, as appropriate for your platform.
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*
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* If your application has no OS and is therefore single threaded, simply
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* have:
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*
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* FF_CreateSemaphore() return NULL.
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*
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* FF_PendSemaphore() should do nothing.
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*
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* FF_ReleaseSemaphore() should do nothing.
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*
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* FF_DestroySemaphore() should do nothing.
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*
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**/
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#include "ff_safety.h" // <20>ncludes ff_types.h
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#include <ntifs.h>
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#define TAG_FULLFAT 'FLUF'
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// Call your OS's CreateSemaphore function
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//
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void *FF_CreateSemaphore(void) {
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PKSEMAPHORE ProcessSemaphore;
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/* Allocate some memory to store the semaphore */
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ProcessSemaphore = ExAllocatePoolWithTag(NonPagedPool,
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sizeof(KSEMAPHORE),
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TAG_FULLFAT);
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if (ProcessSemaphore)
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{
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/* Initialize it */
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KeInitializeSemaphore(ProcessSemaphore,
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0,
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MAXLONG);
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}
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return ProcessSemaphore;
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}
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// Call your OS's PendSemaphore with the provided pSemaphore pointer.
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//
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// This should block indefinitely until the Semaphore
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// becomes available. (No timeout!)
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// If your OS doesn't do it for you, you should sleep
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// this thread until the Semaphore is available.
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void FF_PendSemaphore(void *pSemaphore) {
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NTSTATUS Status;
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/* Sanity check */
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if (pSemaphore)
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{
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/* Wait for the sempaphore to become signaled */
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Status = KeWaitForSingleObject(pSemaphore,
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Executive,
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KernelMode,
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FALSE,
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NULL);
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if (NT_SUCCESS(Status))
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{
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if (Status != STATUS_SUCCESS)
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{
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// log an error?
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}
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}
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else
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{
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// log an error?
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}
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}
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}
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// Call your OS's ReleaseSemaphore with the provided pSemaphore pointer.
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//
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void FF_ReleaseSemaphore(void *pSemaphore) {
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/* Sanity check */
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if (pSemaphore)
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{
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/* Increment the semaphore */
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KeReleaseSemaphore(pSemaphore,
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0,
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1,
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FALSE);
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}
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}
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// Call your OS's DestroySemaphore with the provided pSemaphore pointer.
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//
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void FF_DestroySemaphore(void *pSemaphore) {
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/* Sanity check */
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if (pSemaphore)
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{
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/* Free the semaphore memory */
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ExFreePoolWithTag(pSemaphore,
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TAG_FULLFAT);
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}
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}
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// FIXME: what do we do with this?
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void FF_Yield(void) {
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// Call your OS's thread Yield function.
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// If this doesn't work, then a deadlock will occur
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}
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// Call your OS's thread sleep function,
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// Sleep for TimeMs milliseconds
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void FF_Sleep(FF_T_UINT32 TimeMs) {
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LARGE_INTEGER Interval;
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NTSTATUS Status;
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/* Calculate the interval */
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Interval.QuadPart = -((LONGLONG)TimeMs * 10000);
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/* Do the wait */
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Status = KeDelayExecutionThread(KernelMode,
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FALSE,
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&Interval);
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if (!NT_SUCCESS(Status))
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{
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// log an error?
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}
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}
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/**
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* Notes on implementation.
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*
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*
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*
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**/
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