blob: 88ee53bb5eb5759320ea700ff8f207ac14c68ec0 [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "runtime.h"
#include "type.h"
#include "typekind.h"
#include "defs_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "zasm_GOOS_GOARCH.h"
typedef struct Callbacks Callbacks;
struct Callbacks {
Lock;
WinCallbackContext* ctxt[cb_max];
int32 n;
};
static Callbacks cbs;
WinCallbackContext** runtime·cbctxts; // to simplify access to cbs.ctxt in sys_windows_*.s
// Call back from windows dll into go.
byte *
runtime·compilecallback(Eface fn, bool cleanstack)
{
FuncType *ft;
Type *t;
int32 argsize, i, n;
WinCallbackContext *c;
if(fn.type == nil || fn.type->kind != KindFunc)
runtime·panicstring("compilecallback: not a function");
ft = (FuncType*)fn.type;
if(ft->out.len != 1)
runtime·panicstring("compilecallback: function must have one output parameter");
if(((Type**)ft->out.array)[0]->size != sizeof(uintptr))
runtime·panicstring("compilecallback: output parameter size is wrong");
argsize = 0;
for(i=0; i<ft->in.len; i++) {
t = ((Type**)ft->in.array)[i];
if(t->size > sizeof(uintptr))
runtime·panicstring("compilecallback: input parameter size is wrong");
argsize += sizeof(uintptr);
}
runtime·lock(&cbs);
if(runtime·cbctxts == nil)
runtime·cbctxts = &(cbs.ctxt[0]);
n = cbs.n;
for(i=0; i<n; i++) {
if(cbs.ctxt[i]->gobody == fn.data) {
runtime·unlock(&cbs);
// runtime·callbackasm is just a series of CALL instructions
// (each is 5 bytes long), and we want callback to arrive at
// correspondent call instruction instead of start of
// runtime·callbackasm.
return (byte*)runtime·callbackasm + i * 5;
}
}
if(n >= cb_max)
runtime·throw("too many callback functions");
c = runtime·mal(sizeof *c);
c->gobody = fn.data;
c->argsize = argsize;
if(cleanstack && argsize!=0)
c->restorestack = argsize;
else
c->restorestack = 0;
cbs.ctxt[n] = c;
cbs.n++;
runtime·unlock(&cbs);
// as before
return (byte*)runtime·callbackasm + n * 5;
}