Imported Upstream version 1.4upstream/1.4

1 files changed, 0 insertions, 322 deletions

diff --git a/src/pkg/runtime/cgocall.c b/src/pkg/runtime/cgocall.c
deleted file mode 100644
index 75d3850ef..000000000
--- a/src/pkg/runtime/cgocall.c
+++ /dev/null
@@ -1,322 +0,0 @@
-// 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 "arch_GOARCH.h"
-#include "stack.h"
-#include "cgocall.h"
-#include "race.h"
-#include "../../cmd/ld/textflag.h"
-
-// Cgo call and callback support.
-//
-// To call into the C function f from Go, the cgo-generated code calls
-// runtime.cgocall(_cgo_Cfunc_f, frame), where _cgo_Cfunc_f is a
-// gcc-compiled function written by cgo.
-//
-// runtime.cgocall (below) locks g to m, calls entersyscall
-// so as not to block other goroutines or the garbage collector,
-// and then calls runtime.asmcgocall(_cgo_Cfunc_f, frame). 
-//
-// runtime.asmcgocall (in asm_$GOARCH.s) switches to the m->g0 stack
-// (assumed to be an operating system-allocated stack, so safe to run
-// gcc-compiled code on) and calls _cgo_Cfunc_f(frame).
-//
-// _cgo_Cfunc_f invokes the actual C function f with arguments
-// taken from the frame structure, records the results in the frame,
-// and returns to runtime.asmcgocall.
-//
-// After it regains control, runtime.asmcgocall switches back to the
-// original g (m->curg)'s stack and returns to runtime.cgocall.
-//
-// After it regains control, runtime.cgocall calls exitsyscall, which blocks
-// until this m can run Go code without violating the $GOMAXPROCS limit,
-// and then unlocks g from m.
-//
-// The above description skipped over the possibility of the gcc-compiled
-// function f calling back into Go.  If that happens, we continue down
-// the rabbit hole during the execution of f.
-//
-// To make it possible for gcc-compiled C code to call a Go function p.GoF,
-// cgo writes a gcc-compiled function named GoF (not p.GoF, since gcc doesn't
-// know about packages).  The gcc-compiled C function f calls GoF.
-//
-// GoF calls crosscall2(_cgoexp_GoF, frame, framesize).  Crosscall2
-// (in cgo/gcc_$GOARCH.S, a gcc-compiled assembly file) is a two-argument
-// adapter from the gcc function call ABI to the 6c function call ABI.
-// It is called from gcc to call 6c functions.  In this case it calls
-// _cgoexp_GoF(frame, framesize), still running on m->g0's stack
-// and outside the $GOMAXPROCS limit.  Thus, this code cannot yet
-// call arbitrary Go code directly and must be careful not to allocate
-// memory or use up m->g0's stack.
-//
-// _cgoexp_GoF calls runtime.cgocallback(p.GoF, frame, framesize).
-// (The reason for having _cgoexp_GoF instead of writing a crosscall3
-// to make this call directly is that _cgoexp_GoF, because it is compiled
-// with 6c instead of gcc, can refer to dotted names like
-// runtime.cgocallback and p.GoF.)
-//
-// runtime.cgocallback (in asm_$GOARCH.s) switches from m->g0's
-// stack to the original g (m->curg)'s stack, on which it calls
-// runtime.cgocallbackg(p.GoF, frame, framesize).
-// As part of the stack switch, runtime.cgocallback saves the current
-// SP as m->g0->sched.sp, so that any use of m->g0's stack during the
-// execution of the callback will be done below the existing stack frames.
-// Before overwriting m->g0->sched.sp, it pushes the old value on the
-// m->g0 stack, so that it can be restored later.
-//
-// runtime.cgocallbackg (below) is now running on a real goroutine
-// stack (not an m->g0 stack).  First it calls runtime.exitsyscall, which will
-// block until the $GOMAXPROCS limit allows running this goroutine.
-// Once exitsyscall has returned, it is safe to do things like call the memory
-// allocator or invoke the Go callback function p.GoF.  runtime.cgocallbackg
-// first defers a function to unwind m->g0.sched.sp, so that if p.GoF
-// panics, m->g0.sched.sp will be restored to its old value: the m->g0 stack
-// and the m->curg stack will be unwound in lock step.
-// Then it calls p.GoF.  Finally it pops but does not execute the deferred
-// function, calls runtime.entersyscall, and returns to runtime.cgocallback.
-//
-// After it regains control, runtime.cgocallback switches back to
-// m->g0's stack (the pointer is still in m->g0.sched.sp), restores the old
-// m->g0.sched.sp value from the stack, and returns to _cgoexp_GoF.
-//
-// _cgoexp_GoF immediately returns to crosscall2, which restores the
-// callee-save registers for gcc and returns to GoF, which returns to f.
-
-void *_cgo_init;	/* filled in by dynamic linker when Cgo is available */
-static int64 cgosync;  /* represents possible synchronization in C code */
-
-static void unwindm(void);
-
-// Call from Go to C.
-
-static void endcgo(void);
-static FuncVal endcgoV = { endcgo };
-
-void
-runtime·cgocall(void (*fn)(void*), void *arg)
-{
-	Defer d;
-
-	if(!runtime·iscgo && !Solaris && !Windows)
-		runtime·throw("cgocall unavailable");
-
-	if(fn == 0)
-		runtime·throw("cgocall nil");
-
-	if(raceenabled)
-		runtime·racereleasemerge(&cgosync);
-
-	// Create an extra M for callbacks on threads not created by Go on first cgo call.
-	if(runtime·needextram && runtime·cas(&runtime·needextram, 1, 0))
-		runtime·newextram();
-
-	m->ncgocall++;
-
-	/*
-	 * Lock g to m to ensure we stay on the same stack if we do a
-	 * cgo callback. Add entry to defer stack in case of panic.
-	 */
-	runtime·lockOSThread();
-	d.fn = &endcgoV;
-	d.siz = 0;
-	d.link = g->defer;
-	d.argp = NoArgs;
-	d.special = true;
-	g->defer = &d;
-	
-	m->ncgo++;
-
-	/*
-	 * Announce we are entering a system call
-	 * so that the scheduler knows to create another
-	 * M to run goroutines while we are in the
-	 * foreign code.
-	 *
-	 * The call to asmcgocall is guaranteed not to
-	 * split the stack and does not allocate memory,
-	 * so it is safe to call while "in a system call", outside
-	 * the $GOMAXPROCS accounting.
-	 */
-	runtime·entersyscall();
-	runtime·asmcgocall(fn, arg);
-	runtime·exitsyscall();
-
-	if(g->defer != &d || d.fn != &endcgoV)
-		runtime·throw("runtime: bad defer entry in cgocallback");
-	g->defer = d.link;
-	endcgo();
-}
-
-static void
-endcgo(void)
-{
-	runtime·unlockOSThread();
-	m->ncgo--;
-	if(m->ncgo == 0) {
-		// We are going back to Go and are not in a recursive
-		// call.  Let the GC collect any memory allocated via
-		// _cgo_allocate that is no longer referenced.
-		m->cgomal = nil;
-	}
-
-	if(raceenabled)
-		runtime·raceacquire(&cgosync);
-}
-
-// Helper functions for cgo code.
-
-void (*_cgo_malloc)(void*);
-void (*_cgo_free)(void*);
-
-void*
-runtime·cmalloc(uintptr n)
-{
-	struct {
-		uint64 n;
-		void *ret;
-	} a;
-
-	a.n = n;
-	a.ret = nil;
-	runtime·cgocall(_cgo_malloc, &a);
-	if(a.ret == nil)
-		runtime·throw("runtime: C malloc failed");
-	return a.ret;
-}
-
-void
-runtime·cfree(void *p)
-{
-	runtime·cgocall(_cgo_free, p);
-}
-
-// Call from C back to Go.
-
-static FuncVal unwindmf = {unwindm};
-
-typedef struct CallbackArgs CallbackArgs;
-struct CallbackArgs
-{
-	FuncVal *fn;
-	void *arg;
-	uintptr argsize;
-};
-
-// Location of callback arguments depends on stack frame layout
-// and size of stack frame of cgocallback_gofunc.
-
-// On arm, stack frame is two words and there's a saved LR between
-// SP and the stack frame and between the stack frame and the arguments.
-#ifdef GOARCH_arm
-#define CBARGS (CallbackArgs*)((byte*)m->g0->sched.sp+4*sizeof(void*))
-#endif
-
-// On amd64, stack frame is one word, plus caller PC.
-#ifdef GOARCH_amd64
-#define CBARGS (CallbackArgs*)((byte*)m->g0->sched.sp+2*sizeof(void*))
-#endif
-
-// Unimplemented on amd64p32
-#ifdef GOARCH_amd64p32
-#define CBARGS (CallbackArgs*)(nil)
-#endif
-
-// On 386, stack frame is three words, plus caller PC.
-#ifdef GOARCH_386
-#define CBARGS (CallbackArgs*)((byte*)m->g0->sched.sp+4*sizeof(void*))
-#endif
-
-void runtime·cgocallbackg1(void);
-
-#pragma textflag NOSPLIT
-void
-runtime·cgocallbackg(void)
-{
-	uintptr pc, sp;
-
-	if(g != m->curg) {
-		runtime·prints("runtime: bad g in cgocallback");
-		runtime·exit(2);
-	}
-
-	pc = g->syscallpc;
-	sp = g->syscallsp;
-	runtime·exitsyscall();	// coming out of cgo call
-	runtime·cgocallbackg1();
-	runtime·reentersyscall((void*)pc, sp);	// going back to cgo call
-}
-
-void
-runtime·cgocallbackg1(void)
-{
-	CallbackArgs *cb;
-	Defer d;
-
-	if(m->needextram) {
-		m->needextram = 0;
-		runtime·newextram();
-	}
-
-	// Add entry to defer stack in case of panic.
-	d.fn = &unwindmf;
-	d.siz = 0;
-	d.link = g->defer;
-	d.argp = NoArgs;
-	d.special = true;
-	g->defer = &d;
-
-	if(raceenabled)
-		runtime·raceacquire(&cgosync);
-
-	// Invoke callback.
-	cb = CBARGS;
-	runtime·newstackcall(cb->fn, cb->arg, cb->argsize);
-
-	if(raceenabled)
-		runtime·racereleasemerge(&cgosync);
-
-	// Pop defer.
-	// Do not unwind m->g0->sched.sp.
-	// Our caller, cgocallback, will do that.
-	if(g->defer != &d || d.fn != &unwindmf)
-		runtime·throw("runtime: bad defer entry in cgocallback");
-	g->defer = d.link;
-}
-
-static void
-unwindm(void)
-{
-	// Restore sp saved by cgocallback during
-	// unwind of g's stack (see comment at top of file).
-	switch(thechar){
-	default:
-		runtime·throw("runtime: unwindm not implemented");
-	case '8':
-	case '6':
-		m->g0->sched.sp = *(uintptr*)m->g0->sched.sp;
-		break;
-	case '5':
-		m->g0->sched.sp = *(uintptr*)((byte*)m->g0->sched.sp + 4);
-		break;
-	}
-}
-
-void
-runtime·badcgocallback(void)	// called from assembly
-{
-	runtime·throw("runtime: misaligned stack in cgocallback");
-}
-
-void
-runtime·cgounimpl(void)	// called from (incomplete) assembly
-{
-	runtime·throw("runtime: cgo not implemented");
-}
-
-// For cgo-using programs with external linking,
-// export "main" (defined in assembly) so that libc can handle basic
-// C runtime startup and call the Go program as if it were
-// the C main function.
-#pragma cgo_export_static main