activation.c

一个操作系统的源代码

/** activation.c
 **
 ** Original Author: Kasper Verdich Lund
 ** Date: 11.13.99
 **
 ** Description:
 ** Activation routines
 ** 
 ** This program is free software, you can redistribute it and/or
 ** modify it under the terms of the GNU General Public License
 ** as published by the Free Software Foundation; either version
 ** 2 of the License, or (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be
 ** useful, but WITHOUT ANY WARRANTY; without even the implied
 ** warranty or MERCHANTABILITY or FITNESS FOR A PARTICULAR
 ** PURPOSE.  See the GNU General Public License for more
 ** details.
 **
 ** You should have received a copy of the GNU General Public
 ** License along with this program; if not, write to the
 ** Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 ** Boston, MA 02111-1307 USA
 **
 *********************************************************Apostle OS**/

#include <activation.h>
#include <paging.h>
#include <mem.h>
#ifdef DEBUG
#include <debug/conio.h>
#endif

extern void __KernelResume(dword edi, dword esi, dword ebp,
			   dword ebx, dword edx, dword ecx, dword eax,
			   dword eflags, dword eip, dword esp);
extern void __ProcessResume(dword edi, dword esi, dword ebp,
			    dword ebx, dword edx, dword ecx, dword eax,
			    dword eip, dword cs, dword eflags, dword esp, dword ss);

Activation *NewActivation(void)
{
  Activation *a = (Activation *)malloc(sizeof(Activation));
  a->esp0 = (dword)pmalloc() + PAGE_SIZE;
  a->quantum = QUANTUM;
  a->upcallCount = 0;
  a->next = NULL;
  return a;
}

void InitializeActivation(Activation *a)
{
  a->esp0 = (dword)pmalloc() + PAGE_SIZE;
  a->quantum = QUANTUM;
  a->upcallCount = 0;
  a->next = NULL;
}

void InsertActivation(ActivationQueue *q, Activation *a)
{
  if (*q == NULL)
    *q = a;
  else
    a->next = (*q)->next;
  (*q)->next = a;
  *q = a;
}

Activation* RemoveActivation(ActivationQueue *q, int count)
{
  Activation *a = NULL;
  if ((*q) && (count - (*q)->next->upcallCount >= UPCALL_SAVES))
    {
      a = (*q)->next;
      if (*q == a)
        *q = NULL;
      else
        (*q)->next = a->next;
      a->next = NULL;
    }
  return a;
}

void KernelResume(Activation *a)
{
  __KernelResume(a->edi, a->esi, a->ebp, a->ebx, a->edx, a->ecx, a->eax,
  		 a->eflags, a->eip, a->esp);
}

void ProcessResume(Activation *a)
{
  __ProcessResume(a->edi, a->esi, a->ebp, a->ebx, a->edx, a->ecx, a->eax,
  		  a->eip, 0x1b, a->eflags, a->esp, 0x23);
}