tShbError ShbIpcAllocBuffer (
unsigned long ulBufferSize_p,
const char* pszBufferID_p,
tShbInstance* ppShbInstance_p,
unsigned int* pfShbNewCreated_p)
{
tShbError ShbError;
int iBufferId=0;
unsigned long ulCrc32=0;
unsigned int uiFirstProcess=0;
unsigned long ulShMemSize;
tShbMemHeader* pShbMemHeader;
tShbMemInst* pShbMemInst=NULL;
tShbInstance pShbInstance;
unsigned int fShMemNewCreated=FALSE;
void *pSharedMem=NULL;
struct sShbMemTable *psMemTableElement;
DEBUG_LVL_29_TRACE0("ShbIpcAllocBuffer \n");
ulShMemSize = ulBufferSize_p + sizeof(tShbMemHeader);
//create Buffer ID
#ifndef CONFIG_CRC32
{
unsigned long aulCrcTable[256];
ShbIpcCrc32GenTable(aulCrcTable);
ulCrc32 = ShbIpcCrc32GetCrc(pszBufferID_p, aulCrcTable);
}
#else
ulCrc32 = crc32(0xFFFFFFFF, pszBufferID_p, strlen(pszBufferID_p));
#endif
iBufferId=ulCrc32;
DEBUG_LVL_29_TRACE2("ShbIpcAllocBuffer BufferSize:%d sizeof(tShb..):%d\n",ulBufferSize_p,sizeof(tShbMemHeader));
DEBUG_LVL_29_TRACE2("ShbIpcAllocBuffer BufferId:%d MemSize:%d\n",iBufferId,ulShMemSize);
//---------------------------------------------------------------
// (1) open an existing or create a new shared memory
//---------------------------------------------------------------
//test if buffer already exists
if (ShbIpcFindListElement(iBufferId, &psMemTableElement) == 0)
{
//Buffer already exists
fShMemNewCreated=FALSE;
pSharedMem = psMemTableElement->m_pBuffer;
DEBUG_LVL_29_TRACE1("ShbIpcAllocBuffer attach Buffer at:%p Id:%d\n",pSharedMem);
uiFirstProcess=1;
}
else
{
//create new Buffer
fShMemNewCreated = TRUE;
uiFirstProcess=0;
pSharedMem = kmalloc(ulShMemSize,GFP_KERNEL);
DEBUG_LVL_29_TRACE2("ShbIpcAllocBuffer Create New Buffer at:%p Id:%d\n",pSharedMem,iBufferId);
if (pSharedMem == NULL)
{
//unable to create mem
ShbError = kShbOutOfMem;
goto Exit;
}
DEBUG_LVL_29_TRACE0("ShbIpcAllocBuffer create semas\n");
// append Element to Mem Table
psMemTableElement = kmalloc(sizeof(struct sShbMemTable),GFP_KERNEL);
psMemTableElement->m_iBufferId = iBufferId;
psMemTableElement->m_pBuffer = pSharedMem;
psMemTableElement->m_psNextMemTableElement = NULL;
ShbIpcAppendListElement (psMemTableElement);
}
DEBUG_LVL_29_TRACE0("ShbIpcAllocBuffer update header\n");
//update header
pShbMemHeader = (tShbMemHeader*)pSharedMem;
DEBUG_LVL_29_TRACE1("ShbIpcAllocBuffer 0 pShbMemHeader->m_ulShMemSize: %d\n",pShbMemHeader->m_ulShMemSize);
// allocate a memory block from process specific mempool to save
// process local information to administrate/manage the shared buffer
DEBUG_LVL_29_TRACE0("ShbIpcAllocBuffer alloc private mem\n");
pShbMemInst = (tShbMemInst*) ShbIpcAllocPrivateMem (sizeof(tShbMemInst));
if (pShbMemInst == NULL)
{
ShbError = kShbOutOfMem;
goto Exit;
}
// reset complete header to default values
//pShbMemInst->m_SbiMagicID = SBI_MAGIC_ID;
// pShbMemInst->m_pSharedMem = pSharedMem;
pShbMemInst->m_tThreadNewDataId = INVALID_ID;
pShbMemInst->m_tThreadJobReadyId = INVALID_ID;
pShbMemInst->m_pfnSigHndlrNewData = NULL;
pShbMemInst->m_ulTimeOutMsJobReady = 0;
pShbMemInst->m_pfnSigHndlrJobReady = NULL;
sema_init(&pShbMemInst->m_SemaphoreStopThreadJobReady, 1);
pShbMemInst->m_pShbMemHeader = pShbMemHeader;
ShbError = kShbOk;
if ( fShMemNewCreated )
{
// this process was the first who wanted to use the shared memory,
// so a new shared memory was created
// -> setup new header information inside the shared memory region
// itself
pShbMemHeader->m_ulShMemSize = ulShMemSize;
pShbMemHeader->m_ulRefCount = 1;
pShbMemHeader->m_iBufferId=iBufferId;
pShbMemHeader->m_pShbInstMaster = NULL;
// initialize spinlock
spin_lock_init(&pShbMemHeader->m_SpinlockBuffAccess);
// initialize wait queues
init_waitqueue_head(&pShbMemHeader->m_WaitQueueNewData);
init_waitqueue_head(&pShbMemHeader->m_WaitQueueJobReady);
}
else
{
// any other process has created the shared memory and this
// process only has to attach to it
// -> check and update existing header information inside the
// shared memory region itself
if (pShbMemHeader->m_ulShMemSize != ulShMemSize)
{
ShbError = kShbOpenMismatch;
goto Exit;
}
pShbMemHeader->m_ulRefCount++;
}
Exit:
pShbInstance = (tShbInstance*)pShbMemInst;
*pfShbNewCreated_p = fShMemNewCreated;
*ppShbInstance_p = pShbInstance;
return (ShbError);
}
tShbError ShbIpcAllocBuffer (
unsigned long ulBufferSize_p,
const char* pszBufferID_p,
tShbInstance* ppShbInstance_p,
unsigned int* pfShbNewCreated_p)
{
tShbError ShbError;
int iBufferId=0;
unsigned long ulCrc32=0;
unsigned int uiFirstProcess=0;
unsigned long ulShMemSize;
tShbMemHeader* pShbMemHeader;
tShbMemInst* pShbMemInst=NULL;
tShbInstance pShbInstance;
unsigned int fShMemNewCreated=FALSE;
void *pSharedMem=NULL;
struct sShbMemTable *psMemTableElement;
unsigned long aulCrcTable[256];
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer \n");
if (ShbTgtIsInterruptContext())
{
ShbError = kShbInterruptContextNotAllowed;
goto Exit;
}
ulShMemSize = ulBufferSize_p + sizeof(tShbMemHeader);
//create Buffer ID
ShbIpcCrc32GenTable(aulCrcTable);
ulCrc32 = ShbIpcCrc32GetCrc(pszBufferID_p, aulCrcTable);
iBufferId=ulCrc32;
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer BufferSize:%d sizeof(tShb..):%d\n",ulBufferSize_p,sizeof(tShbMemHeader));
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer BufferId:%d MemSize:%d\n",iBufferId,ulShMemSize);
//---------------------------------------------------------------
// (1) open an existing or create a new shared memory
//---------------------------------------------------------------
//test if buffer already exists
if (ShbIpcFindListElement(iBufferId, &psMemTableElement) == 0)
{
//Buffer already exists
fShMemNewCreated=FALSE;
pSharedMem = psMemTableElement->m_pBuffer;
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer attach Buffer at:%p Id:%d\n",pSharedMem, iBufferId);
uiFirstProcess=1;
}
else
{
//create new Buffer
fShMemNewCreated = TRUE;
uiFirstProcess=0;
pSharedMem = malloc(ulShMemSize);
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer Create New Buffer at:%p Id:%d\n",pSharedMem,iBufferId);
if (pSharedMem == NULL)
{
//unable to create mem
ShbError = kShbOutOfMem;
goto Exit;
}
// append Element to Mem Table
psMemTableElement = malloc(sizeof(struct sShbMemTable));
psMemTableElement->m_iBufferId = iBufferId;
psMemTableElement->m_pBuffer = pSharedMem;
psMemTableElement->m_psNextMemTableElement = NULL;
ShbIpcAppendListElement (psMemTableElement);
}
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer update header\n");
//update header
pShbMemHeader = (tShbMemHeader*)pSharedMem;
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer 0 pShbMemHeader->m_ulShMemSize: %d\n",pShbMemHeader->m_ulShMemSize);
// allocate a memory block for instance local information
// to administrate/manage the shared buffer
DEBUG_LVL_29_TRACE("ShbIpcAllocBuffer alloc private mem\n");
pShbMemInst = (tShbMemInst*) malloc(sizeof(tShbMemInst));
if (pShbMemInst == NULL)
{
ShbError = kShbOutOfMem;
goto Exit;
}
// reset complete header to default values
//pShbMemInst->m_SbiMagicID = SBI_MAGIC_ID;
pShbMemInst->m_pfnSigHndlrNewData = NULL;
pShbMemInst->m_ulTimeOutMsJobReady = 0;
pShbMemInst->m_ulStartTimeMsJobReady = 0;
pShbMemInst->m_pfnSigHndlrJobReady = NULL;
pShbMemInst->m_pShbMemHeader = pShbMemHeader;
pShbMemInst->m_pProcessListNewDataNext = NULL;
pShbMemInst->m_pProcessListJobReadyNext = NULL;
// initialize
ShbError = kShbOk;
if ( fShMemNewCreated )
{
// this process was the first who wanted to use the shared memory,
// so a new shared memory was created
// -> setup new header information inside the shared memory region
// itself
pShbMemHeader->m_ulShMemSize = ulShMemSize;
pShbMemHeader->m_ulRefCount = 1;
pShbMemHeader->m_iBufferId = iBufferId;
pShbMemHeader->m_pShbInstMaster = NULL;
}
else
{
// any other process has created the shared memory and this
// process only has to attach to it
// -> check and update existing header information inside the
// shared memory region itself
if (pShbMemHeader->m_ulShMemSize != ulShMemSize)
{
ShbError = kShbOpenMismatch;
goto Exit;
}
pShbMemHeader->m_ulRefCount++;
}
Exit:
pShbInstance = (tShbInstance*)pShbMemInst;
*pfShbNewCreated_p = fShMemNewCreated;
*ppShbInstance_p = pShbInstance;
return (ShbError);
}