runtime: take the callback return value from the stack

R=brainman, lxn, rsc
CC=golang-dev
https://golang.org/cl/4126056
This commit is contained in:
Hector Chu 2011-02-10 23:02:27 +11:00 committed by Alex Brainman
parent 34fc17a820
commit 239ef63bf2
4 changed files with 12 additions and 9 deletions

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@ -53,13 +53,12 @@ runtime·cgocall(void (*fn)(void*), void *arg)
// (arg/argsize) on to the stack, calls the function, copies the
// arguments back where they came from, and finally returns to the old
// stack.
uintptr
void
runtime·cgocallback(void (*fn)(void), void *arg, int32 argsize)
{
Gobuf oldsched, oldg1sched;
G *g1;
void *sp;
uintptr ret;
if(g != m->g0)
runtime·throw("bad g in cgocallback");
@ -71,11 +70,11 @@ runtime·cgocallback(void (*fn)(void), void *arg, int32 argsize)
runtime·startcgocallback(g1);
sp = g1->sched.sp - argsize;
if(sp < g1->stackguard - StackGuard + 4) // +4 for return address
if(sp < g1->stackguard - StackGuard + 8) // +8 for return address
runtime·throw("g stack overflow in cgocallback");
runtime·mcpy(sp, arg, argsize);
ret = runtime·runcgocallback(g1, sp, fn);
runtime·runcgocallback(g1, sp, fn);
runtime·mcpy(arg, sp, argsize);
@ -83,8 +82,6 @@ runtime·cgocallback(void (*fn)(void), void *arg, int32 argsize)
m->sched = oldsched;
g1->sched = oldg1sched;
return ret;
}
void

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@ -7,6 +7,6 @@
*/
void runtime·cgocall(void (*fn)(void*), void*);
uintptr runtime·cgocallback(void (*fn)(void), void*, int32);
void runtime·cgocallback(void (*fn)(void), void*, int32);
void *runtime·cmalloc(uintptr);
void runtime·cfree(void*);

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@ -443,7 +443,7 @@ void runtime·breakpoint(void);
void runtime·gosched(void);
void runtime·goexit(void);
void runtime·runcgo(void (*fn)(void*), void*);
uintptr runtime·runcgocallback(G*, void*, void (*fn)());
void runtime·runcgocallback(G*, void*, void (*fn)());
void runtime·entersyscall(void);
void runtime·exitsyscall(void);
void runtime·startcgocallback(G*);

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@ -107,7 +107,11 @@ sigdone:
// DX = total size of arguments
//
TEXT runtime·callbackasm+0(SB),7,$0
// preserve whatever's at the memory location that
// the callback will use to store the return value
LEAL 8(SP), CX
PUSHL 0(CX)(DX*1)
ADDL $4, DX // extend argsize by size of return value
// save registers as required for windows callback
PUSHL 0(FS)
@ -129,7 +133,7 @@ TEXT runtime·callbackasm+0(SB),7,$0
CALL runtime·cgocallback(SB)
// restore registers as required for windows callback
POPL CX
POPL AX
POPL CX
POPL DX
POPL BX
@ -139,6 +143,8 @@ TEXT runtime·callbackasm+0(SB),7,$0
POPL 0(FS)
CLD
MOVL -4(CX)(DX*1), AX
POPL -4(CX)(DX*1)
RET
// void tstart(M *newm);