X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/0c530ab8987f0ae6a1a3d9284f40182b88852816..2d21ac55c334faf3a56e5634905ed6987fc787d4:/iokit/Kernel/IOSharedDataQueue.cpp?ds=sidebyside

diff --git a/iokit/Kernel/IOSharedDataQueue.cpp b/iokit/Kernel/IOSharedDataQueue.cpp
new file mode 100644
index 000000000..85bd0e3db
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+++ b/iokit/Kernel/IOSharedDataQueue.cpp
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+/*
+ * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#include <IOKit/IOSharedDataQueue.h>
+#include <IOKit/IODataQueueShared.h>
+#include <IOKit/IOLib.h>
+#include <IOKit/IOMemoryDescriptor.h>
+
+#ifdef dequeue
+#undef dequeue
+#endif
+
+#define super IODataQueue
+
+OSDefineMetaClassAndStructors(IOSharedDataQueue, IODataQueue)
+
+IOSharedDataQueue *IOSharedDataQueue::withCapacity(UInt32 size)
+{
+    IOSharedDataQueue *dataQueue = new IOSharedDataQueue;
+
+    if (dataQueue) {
+        if  (!dataQueue->initWithCapacity(size)) {
+            dataQueue->release();
+            dataQueue = 0;
+        }
+    }
+
+    return dataQueue;
+}
+
+IOSharedDataQueue *IOSharedDataQueue::withEntries(UInt32 numEntries, UInt32 entrySize)
+{
+    IOSharedDataQueue *dataQueue = new IOSharedDataQueue;
+
+    if (dataQueue) {
+        if (!dataQueue->initWithEntries(numEntries, entrySize)) {
+            dataQueue->release();
+            dataQueue = 0;
+        }
+    }
+
+    return dataQueue;
+}
+
+Boolean IOSharedDataQueue::initWithCapacity(UInt32 size)
+{
+    IODataQueueAppendix *   appendix;
+    
+    if (!super::init()) {
+        return false;
+    }
+    
+    dataQueue = (IODataQueueMemory *)IOMallocAligned(round_page_32(size + DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE), PAGE_SIZE);
+    if (dataQueue == 0) {
+        return false;
+    }
+
+    dataQueue->queueSize    = size;
+    dataQueue->head         = 0;
+    dataQueue->tail         = 0;
+    
+    appendix            = (IODataQueueAppendix *)((UInt8 *)dataQueue + size + DATA_QUEUE_MEMORY_HEADER_SIZE);
+    appendix->version   = 0;
+    notifyMsg           = &(appendix->msgh);
+    setNotificationPort(MACH_PORT_NULL);
+
+    return true;
+}
+
+void IOSharedDataQueue::free()
+{
+    if (dataQueue) {
+        IOFreeAligned(dataQueue, round_page_32(dataQueue->queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE));
+        dataQueue = NULL;
+    }
+
+    super::free();
+}
+
+IOMemoryDescriptor *IOSharedDataQueue::getMemoryDescriptor()
+{
+    IOMemoryDescriptor *descriptor = 0;
+
+    if (dataQueue != 0) {
+        descriptor = IOMemoryDescriptor::withAddress(dataQueue, dataQueue->queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE, kIODirectionOutIn);
+    }
+
+    return descriptor;
+}
+
+
+IODataQueueEntry * IOSharedDataQueue::peek()
+{
+    IODataQueueEntry *entry = 0;
+
+    if (dataQueue && (dataQueue->head != dataQueue->tail)) {
+        IODataQueueEntry *  head		= 0;
+        UInt32              headSize    = 0;
+        UInt32              headOffset  = dataQueue->head;
+        UInt32              queueSize   = dataQueue->queueSize;
+
+        head 		= (IODataQueueEntry *)((char *)dataQueue->queue + headOffset);
+        headSize 	= head->size;
+        
+		// Check if there's enough room before the end of the queue for a header.
+        // If there is room, check if there's enough room to hold the header and
+        // the data.
+
+        if ((headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize) ||
+            ((headOffset + headSize + DATA_QUEUE_ENTRY_HEADER_SIZE) > queueSize))
+        {
+            // No room for the header or the data, wrap to the beginning of the queue.
+            entry = dataQueue->queue;
+        } else {
+            entry = head;
+        }
+    }
+
+    return entry;
+}
+
+Boolean IOSharedDataQueue::dequeue(void *data, UInt32 *dataSize)
+{
+    Boolean             retVal          = TRUE;
+    IODataQueueEntry *  entry           = 0;
+    UInt32              entrySize       = 0;
+    UInt32              newHeadOffset   = 0;
+
+    if (dataQueue) {
+        if (dataQueue->head != dataQueue->tail) {
+            IODataQueueEntry *  head		= 0;
+            UInt32              headSize    = 0;
+            UInt32              headOffset  = dataQueue->head;
+            UInt32              queueSize   = dataQueue->queueSize;
+
+            head 		= (IODataQueueEntry *)((char *)dataQueue->queue + headOffset);
+            headSize 	= head->size;
+            
+            // we wraped around to beginning, so read from there
+			// either there was not even room for the header
+			if ((headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize) ||
+				// or there was room for the header, but not for the data
+				((headOffset + headSize + DATA_QUEUE_ENTRY_HEADER_SIZE) > queueSize)) {
+                entry           = dataQueue->queue;
+                entrySize       = entry->size;
+                newHeadOffset   = entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE;
+            // else it is at the end
+            } else {
+                entry           = head;
+                entrySize       = entry->size;
+                newHeadOffset   = headOffset + entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE;
+            }
+        }
+
+        if (entry) {
+            if (data) {
+                if (dataSize) {
+                    if (entrySize <= *dataSize) {
+                        memcpy(data, &(entry->data), entrySize);
+                        dataQueue->head = newHeadOffset;
+                    } else {
+                        retVal = FALSE;
+                    }
+                } else {
+                    retVal = FALSE;
+                }
+            } else {
+                dataQueue->head = newHeadOffset;
+            }
+
+            if (dataSize) {
+                *dataSize = entrySize;
+            }
+        } else {
+            retVal = FALSE;
+        }
+    } else {
+        retVal = FALSE;
+    }
+    
+    return retVal;
+}
+
+
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 0);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 1);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 2);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 3);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 4);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 5);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 6);
+OSMetaClassDefineReservedUnused(IOSharedDataQueue, 7);