以下代码使用标志 Od、O1 按预期工作,但使用 O2、Ox 失败。任何想法为什么?
编辑:“失败”是指该函数什么都不做,似乎只是返回。
void thread_sleep()
{
listIterator nextThread = getNextThread();
void * pStack = 0;
struct ProcessControlBlock * currPcb = pPCBs->getData(currentThread);
struct ProcessControlBlock * nextPcb = pPCBs->getData(nextThread);
if(currentThread == nextThread)
{
return;
}
else
{
currentThread = nextThread;
__asm pushad // push general purpose registers
__asm pushfd // push control registers
__asm mov pStack, esp // store stack pointer in temporary
currPcb->pStack = pStack; // store current stack pointer in pcb
pStack = nextPcb->pStack; // grab new stack pointer from pcb
if(nextPcb->state == RUNNING_STATE)// only pop if function was running before
{
__asm mov esp, pStack // restore new stack pointer
__asm popfd
__asm popad;
}
else
{
__asm mov esp, pStack // restore new stack pointer
startThread(currentThread);
}
}
}
// 执行建议后:(还是不行)
listIterator nextThread = getNextThread();
struct ProcessControlBlock * currPcb = pPCBs->getData(currentThread);
struct ProcessControlBlock * nextPcb = pPCBs->getData(nextThread);
void * pStack = 0;
void * pNewStack = nextPcb->pStack; // grab new stack pointer from pcb
pgVoid2 = nextPcb->pStack;
if(currentThread == nextThread)
{
return;
}
else
{
lastThread = currentThread; // global var
currentThread = nextThread;
if(nextPcb->state == RUNNING_STATE)// only pop if function was running before
{
__asm pushad // push general purpose registers
__asm pushfd // push control registers
__asm mov pgVoid1, esp // store stack pointer in temporary
__asm mov esp, pgVoid2 // restore new stack pointer
__asm popfd
__asm popad;
{
struct ProcessControlBlock * pcb = pPCBs->getData(lastThread);
pcb->pStack = pgVoid1; // store old stack pointer in pcb
}
}
else
{
__asm pushad // push general purpose registers
__asm pushfd // push control registers
__asm mov pgVoid1, esp // store stack pointer in temporary
__asm mov esp, pgVoid2 // restore new stack pointer
{
struct ProcessControlBlock * pcb = pPCBs->getData(lastThread);
pcb->pStack = pgVoid1; // store old stack pointer in pcb
}
startThread(currentThread);
}
}