reactos/rosapps/tests/fiber/fiber.c

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/* $Id$
*/
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <tchar.h>
#include <windows.h>
#ifndef InitializeListHead
#define InitializeListHead(PLH__) ((PLH__)->Flink = (PLH__)->Blink = (PLH__))
#endif
#ifndef IsListEmpty
#define IsListEmpty(PLH__) ((PLH__)->Flink == (PVOID)(PLH__))
#endif
#ifndef RemoveEntryList
#define RemoveEntryList(PLE__) \
{ \
PLIST_ENTRY pleBack__ = (PLIST_ENTRY)((PLE__)->Blink); \
PLIST_ENTRY pleForward__ = (PLIST_ENTRY)((PLE__)->Flink); \
\
pleBack__->Flink = pleForward__; \
pleForward__->Blink = pleBack__; \
}
#endif
#ifndef InsertTailList
#define InsertTailList(PLH__, PLE__) \
{ \
PLIST_ENTRY pleListHead__ = (PLH__); \
PLIST_ENTRY pleBlink__ = (PLIST_ENTRY)((PLH__)->Blink); \
\
(PLE__)->Flink = pleListHead__; \
(PLE__)->Blink = pleBlink__; \
pleBlink__->Flink = (PLE__); \
pleListHead__->Blink = (PLE__); \
}
#endif
#ifndef RemoveHeadList
#define RemoveHeadList(PLH__) \
(PLIST_ENTRY)((PLH__)->Flink); \
RemoveEntryList((PLIST_ENTRY)((PLH__)->Flink));
#endif
#define FIBERTEST_COUNT 500
struct FiberData
{
unsigned nMagic;
unsigned nId;
unsigned nPrio;
unsigned nRealPrio;
PVOID pFiber;
LIST_ENTRY leQueue;
int nQuantumQueued;
int nBoost;
struct FiberData * pfdPrev;
int bExitPrev;
};
static LIST_ENTRY a_leQueues[32];
static unsigned nQuantum = 0;
static struct FiberData * pfdLastStarveScan = NULL;
void Fbt_Create(int);
void Fbt_Exit(void);
void Fbt_Yield(void);
struct FiberData * Fbt_GetCurrent(void);
unsigned Fbt_GetCurrentId(void);
VOID CALLBACK Fbt_Startup(PVOID);
void Fbt_Dispatch(struct FiberData *, int);
void Fbt_AfterSwitch(struct FiberData *);
void DoStuff(void);
struct FiberData * Fbt_GetCurrent(VOID)
{
return GetFiberData();
}
unsigned Fbt_GetCurrentId(VOID)
{
return Fbt_GetCurrent()->nId;
}
void Fbt_Yield(VOID)
{
struct FiberData * pfdCur;
pfdCur = Fbt_GetCurrent();
if(pfdCur->nBoost)
{
-- pfdCur->nBoost;
if(!pfdCur->nBoost)
pfdCur->nPrio = pfdCur->nRealPrio;
}
else if((rand() % 100) > 50 - (45 * pfdCur->nPrio) / 32)
Fbt_Dispatch(pfdCur, 0);
}
void Fbt_AfterSwitch(struct FiberData * pfdCur)
{
struct FiberData * pfdPrev;
pfdPrev = pfdCur->pfdPrev;
/* The previous fiber left some homework for us */
if(pfdPrev)
{
/* Kill the predecessor */
if(pfdCur->bExitPrev)
{
if(pfdLastStarveScan == pfdPrev)
pfdLastStarveScan = 0;
DeleteFiber(pfdPrev->pFiber);
free(pfdPrev);
}
/* Enqueue the previous fiber in the correct ready queue */
else
{
/* Remember the quantum in which the previous fiber was queued */
pfdPrev->nQuantumQueued = nQuantum;
/* Disable the anti-starvation boost */
if(pfdPrev->nBoost)
{
pfdPrev->nBoost = 0;
pfdPrev->nPrio = pfdPrev->nRealPrio;
}
/* Enqueue the previous fiber */
InsertTailList
(
&a_leQueues[pfdPrev->nPrio],
&pfdPrev->leQueue
);
}
}
}
VOID CALLBACK Fbt_Startup(PVOID pParam)
{
assert(pParam == GetFiberData());
Fbt_AfterSwitch(pParam);
DoStuff();
Fbt_Exit();
}
void Fbt_Dispatch(struct FiberData * pfdCur, int bExit)
{
UCHAR i;
UCHAR n;
struct FiberData * pfdNext;
assert(pfdCur == GetFiberData());
++ nQuantum;
/* Every ten quantums check for starving threads */
/* FIXME: this implementation of starvation prevention isn't that great */
if(nQuantum % 10 == 0)
{
int j;
int k;
int b;
int bResume;
PLIST_ENTRY ple = NULL;
bResume = 0;
i = 0;
/* Pick up from where we left last time */
if(pfdLastStarveScan)
{
unsigned nPrio;
nPrio = pfdLastStarveScan->nPrio;
/* The last fiber we scanned for starvation isn't queued anymore */
if(IsListEmpty(&pfdLastStarveScan->leQueue))
/* Scan the ready queue for its priority */
i = nPrio;
/* Last fiber for its priority level */
else if(pfdLastStarveScan->leQueue.Flink == &a_leQueues[nPrio])
/* Scan the ready queue for the next priority level */
i = nPrio + 1;
/* Scan the next fiber in the ready queue */
else
{
i = nPrio;
ple = pfdLastStarveScan->leQueue.Flink;
bResume = 1;
}
/* Priority levels 15-31 are never checked for starvation */
if(i >= 15)
{
if(bResume)
bResume = 0;
i = 0;
}
}
/*
Scan at most 16 threads, in the priority range 0-14, applying in total at
most 10 boosts. This loop scales O(1)
*/
for(j = 0, k = 0, b = 0; j < 16 && k < 15 && b < 10; ++ j)
{
unsigned nDiff;
/* No previous state to resume from */
if(!bResume)
{
int nQueue;
/* Get the first element in the current queue */
nQueue = (k + i) % 15;
if(IsListEmpty(&a_leQueues[nQueue]))
{
++ k;
continue;
}
ple = (PLIST_ENTRY)a_leQueues[nQueue].Flink;
}
else
bResume = 0;
/* Get the current fiber */
pfdLastStarveScan = CONTAINING_RECORD(ple, struct FiberData, leQueue);
assert(pfdLastStarveScan->nMagic == 0x12345678);
assert(pfdLastStarveScan != pfdCur);
/* Calculate the number of quantums the fiber has been in the queue */
if(nQuantum > pfdLastStarveScan->nQuantumQueued)
nDiff = nQuantum - pfdLastStarveScan->nQuantumQueued;
else
nDiff = UINT_MAX - pfdLastStarveScan->nQuantumQueued + nQuantum;
/* The fiber has been ready for more than 30 quantums: it's starving */
if(nDiff > 30)
{
/* Plus one boost applied */
++ b;
/* Apply the boost */
pfdLastStarveScan->nBoost = 1;
pfdLastStarveScan->nRealPrio = pfdLastStarveScan->nPrio;
pfdLastStarveScan->nPrio = 15;
/* Re-enqueue the fiber in the correct priority queue */
RemoveEntryList(&pfdLastStarveScan->leQueue);
InsertTailList(&a_leQueues[15], &pfdLastStarveScan->leQueue);
}
}
}
pfdNext = NULL;
/* This fiber is going to die: scan all ready queues */
if(bExit)
n = 1;
/*
Scan only ready queues for priorities greater than or equal to the priority of
the current thread (round-robin)
*/
else
n = pfdCur->nPrio + 1;
/* This loop scales O(1) */
for(i = 32; i >= n; -- i)
{
PLIST_ENTRY pleNext;
/* No fiber ready for this priority level */
if(IsListEmpty(&a_leQueues[i - 1]))
continue;
/* Get the next ready fiber */
pleNext = RemoveHeadList(&a_leQueues[i - 1]);
InitializeListHead(pleNext);
pfdNext = CONTAINING_RECORD(pleNext, struct FiberData, leQueue);
assert(pfdNext->pFiber != GetCurrentFiber());
assert(pfdNext->nMagic == 0x12345678);
break;
}
/* Next fiber chosen */
if(pfdNext)
{
/* Give some homework to the next fiber */
pfdNext->pfdPrev = pfdCur;
pfdNext->bExitPrev = bExit;
/* Switch to the next fiber */
SwitchToFiber(pfdNext->pFiber);
/* Complete the switch back to this fiber */
Fbt_AfterSwitch(pfdCur);
}
/* No next fiber, and current fiber exiting */
else if(bExit)
{
PVOID pCurFiber;
/* Delete the current fiber. This kills the thread and stops the simulation */
if(pfdLastStarveScan == pfdCur)
pfdLastStarveScan = NULL;
pCurFiber = pfdCur->pFiber;
free(pfdCur);
DeleteFiber(pCurFiber);
}
/* No next fiber: continue running the current one */
}
void Fbt_Exit(VOID)
{
Fbt_Dispatch(GetFiberData(), 1);
}
void Fbt_CreateFiber(int bInitial)
{
PVOID pFiber;
struct FiberData * pData;
static int s_bFiberPrioSeeded = 0;
static LONG s_nFiberIdSeed = 0;
pData = malloc(sizeof(struct FiberData));
assert(pData);
if(bInitial)
pFiber = ConvertThreadToFiber(pData);
else
pFiber = CreateFiber(0, Fbt_Startup, pData);
if(!s_bFiberPrioSeeded)
{
unsigned nFiberPrioSeed;
time_t tCurTime;
tCurTime = time(NULL);
memcpy(&nFiberPrioSeed, &tCurTime, sizeof(nFiberPrioSeed));
srand(nFiberPrioSeed);
s_bFiberPrioSeeded = 1;
}
assert(pFiber);
pData->nMagic = 0x12345678;
pData->nId = InterlockedIncrement(&s_nFiberIdSeed);
pData->nPrio = rand() % 32;
pData->pFiber = pFiber;
pData->nQuantumQueued = 0;
pData->nBoost = 0;
pData->nRealPrio = pData->nPrio;
pData->pfdPrev = NULL;
pData->bExitPrev = 0;
if(bInitial)
{
InitializeListHead(&pData->leQueue);
}
else
{
InsertTailList
(
&a_leQueues[pData->nPrio],
&pData->leQueue
);
}
}
void DoStuff(void)
{
unsigned i;
unsigned n;
unsigned nId;
n = rand() % 1000;
nId = Fbt_GetCurrentId();
_ftprintf(stderr, _T("[%u] BEGIN\n"), nId);
for(i = 0; i < n; ++ i)
{
unsigned j;
unsigned m;
_ftprintf(stderr, _T("[%u] [%u/%u]\n"), nId, i + 1, n);
m = rand() % 1000;
for(j = 0; j < m; ++ j)
Sleep(0);
Fbt_Yield();
}
_ftprintf(stderr, _T("[%u] END\n"), nId);
}
int _tmain(int argc, _TCHAR const * const * argv)
{
unsigned i;
unsigned nFibers;
if(argc > 1)
nFibers = _tcstoul(argv[1], NULL, 0);
else
nFibers = FIBERTEST_COUNT;
for(i = 0; i < 32; ++ i)
{
InitializeListHead(&a_leQueues[i]);
}
for(i = 0; i < nFibers; ++ i)
Fbt_CreateFiber(i == 0);
Fbt_Startup(GetFiberData());
return 0;
}
/* EOF */