re: Designing Applications for High Performance - Part II

Mike — Thu, 25 Sep 2008 01:19:37 GMT

// program to demonstrate producer/consumer using SLIST

#define INCL_BASE
#include <windows.h>
#include <stdio.h>

typedef struct _WORK_ITEM {
SLIST_ENTRY ItemEntry;
ULONG Data;
} WORK_ITEM;

SLIST_HEADER ListHead;
HANDLE DataReady;

void Consumer (DWORD n)
{
WORK_ITEM *pWorkItem, *pPrev, *Temp;

for(;;) {

// grab entire list
pWorkItem = (WORK_ITEM*)InterlockedFlushSList(&ListHead);

if( pWorkItem ) {

            // reverse to process FIFO (if required)
            for( pPrev=NULL; pWorkItem; pWorkItem=Temp ) {
                Temp = (WORK_ITEM*)pWorkItem->ItemEntry.Next;
                pWorkItem->ItemEntry.Next = (SLIST_ENTRY*)pPrev;
                pPrev = pWorkItem;
            }
            pWorkItem = pPrev;

            // process each item in local list
            for( ; pWorkItem; pWorkItem = (WORK_ITEM*)pWorkItem->ItemEntry.Next ) {
                printf("Data=%d\n", pWorkItem->Data);
            }

            // check list again before waiting
        } else {
            // if list was empty, wait to be signaled
            WaitForSingleObject(DataReady,INFINITE);
        }
    }
}

main(
    int   argc,
    char* argv[]
){
    WORK_ITEM *pWorkItem;
    int i;

InitializeSListHead(&ListHead);

DataReady = CreateEvent(NULL,FALSE,FALSE,NULL);
CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)Consumer, (LPVOID)0, 0, NULL);

// add 10 items
for( i=0; i<10; i++ ) {

pWorkItem = (WORK_ITEM*)_aligned_malloc(sizeof(WORK_ITEM), MEMORY_ALLOCATION_ALIGNMENT);
pWorkItem->Data = i;

        // if adding this item drives list from empty to non-empty, wake consumer
        if( !InterlockedPushEntrySList(&ListHead, &(pWorkItem->ItemEntry)) ) {
            SetEvent(DataReady);
        }
    }

    // test program only, wait for consumer to process all items
    while( QueryDepthSList(&ListHead) ) {
        Sleep(1);
    }
}

Do you have sample code on how to create a producer/consumer queue with s-list?