//set the JMP
void JMP::set(int type, intptr_t val) {
if (type == TCONSTANT || type == TINSTRUCTION || type == TINSTRUCTIONRELATIVE)
setjump(type, val, "\xEB", "\xE9");
else if (type == TREG32 || type == TDWORDPTR)
setregptr(type, val, "\xFF", "", "", 0x20);
else if (isdataptr(type))
setdataptr(type, val);
}
//set a jump instruction using the given bytes
void AssemblyInstruction::setjump(int type, intptr_t val,
string ocsmall, string oclarge) {
if (type == TCONSTANT) {
if (val >= -128 && val <= 127)
bytes.assign(ocsmall).append(1, (char)(val));
else
bytes.assign(oclarge).append(to4bytes(val));
} else if (type == TINSTRUCTION) {
setjump(TCONSTANT, 0, ocsmall, oclarge);
tag = TAGJMPINSTRUCTIONSHORT;
tag2 = val;
} else if (type == TINSTRUCTIONRELATIVE) {
setjump(TCONSTANT, 0, ocsmall, oclarge);
tag = TAGJMPINSTRUCTIONSHORTRELATIVE;
tag2 = val;
}
}
void dwthread_yield()
{
/*
* 1. save the context of caller
*/
// we do this before all other works
// to keep registers untouched
volatile dwt_reg_t eax, ebx, ecx, edx, esi, edi;
__asm__("movl %%eax, %0\n\t"
"movl %%ebx, %1\n\t"
"movl %%ecx, %2\n\t"
"movl %%edx, %3\n\t"
"movl %%esi, %4\n\t"
"movl %%edi, %5\n\t"
:"=m"(eax), "=m"(ebx), "=m"(ecx),
"=m"(edx), "=m"(esi), "=m"(edi));
dwt_tid_t cur_tid = dwthread_get_tid();
dwt_task_t *cur_task = dw_find(cur_tid);
// TODO: for the first task, init its task_t
if (cur_task == NULL) {
cur_task = malloc(sizeof(dwt_task_t));
cur_task->tid = current_tid;
cur_task->statue = DWT_STATUE_RUNNING;
dw_inqueue(cur_task);
}
/*
* 2. set jump and schedule()
*/
if (setjump(&cur_task->context.jmp_restorer) == 0) {
schedule();
}else { // long jump from schedule(), run the task
// restore registers
__asm__("movl %0, %%eax\n\t"
"movl %1, %%ebx\n\t"
"movl %2, %%ecx\n\t"
"movl %3, %%edx\n\t"
"movl %4, %%esi\n\t"
"movl %5, %%edi\n\t"
::"m"(eax), "m"(ebx), "m"(ecx),
"m"(edx), "m"(esi), "m"(edi));
}
return;
}
//set the JGE
void JGE::set(int type, intptr_t val) {
setjump(type, val, "\x7D", "\x0F\x8D");
}
//set the JG
void JG::set(int type, intptr_t val) {
setjump(type, val, "\x7F", "\x0F\x8F");
}
//set the JLE
void JLE::set(int type, intptr_t val) {
setjump(type, val, "\x7E", "\x0F\x8E");
}
//set the JL
void JL::set(int type, intptr_t val) {
setjump(type, val, "\x7C", "\x0F\x8C");
}
//set the JNE
void JNE::set(int type, intptr_t val) {
setjump(type, val, "\x75", "\x0F\x85");
}
//set the JE
void JE::set(int type, intptr_t val) {
setjump(type, val, "\x74", "\x0F\x84");
}