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author | Ondřej Surý <ondrej@sury.org> | 2011-01-17 12:40:45 +0100 |
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committer | Ondřej Surý <ondrej@sury.org> | 2011-01-17 12:40:45 +0100 |
commit | 3e45412327a2654a77944249962b3652e6142299 (patch) | |
tree | bc3bf69452afa055423cbe0c5cfa8ca357df6ccf /src/pkg/runtime/cgo/callbacks.c | |
parent | c533680039762cacbc37db8dc7eed074c3e497be (diff) | |
download | golang-3e45412327a2654a77944249962b3652e6142299.tar.gz |
Imported Upstream version 2011.01.12upstream/2011.01.12
Diffstat (limited to 'src/pkg/runtime/cgo/callbacks.c')
-rw-r--r-- | src/pkg/runtime/cgo/callbacks.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/src/pkg/runtime/cgo/callbacks.c b/src/pkg/runtime/cgo/callbacks.c new file mode 100644 index 000000000..f36fb3fd7 --- /dev/null +++ b/src/pkg/runtime/cgo/callbacks.c @@ -0,0 +1,73 @@ +// Copyright 2011 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 "../cgocall.h" + +// These utility functions are available to be called from code +// compiled with gcc via crosscall2. + +// The declaration of crosscall2 is: +// void crosscall2(void (*fn)(void *, int), void *, int); +// +// We need to export the symbol crosscall2 in order to support +// callbacks from shared libraries. +#pragma dynexport crosscall2 crosscall2 + +// Allocate memory. This allocates the requested number of bytes in +// memory controlled by the Go runtime. The allocated memory will be +// zeroed. You are responsible for ensuring that the Go garbage +// collector can see a pointer to the allocated memory for as long as +// it is valid, e.g., by storing a pointer in a local variable in your +// C function, or in memory allocated by the Go runtime. If the only +// pointers are in a C global variable or in memory allocated via +// malloc, then the Go garbage collector may collect the memory. + +// Call like this in code compiled with gcc: +// struct { size_t len; void *ret; } a; +// a.len = /* number of bytes to allocate */; +// crosscall2(_cgo_allocate, &a, sizeof a); +// /* Here a.ret is a pointer to the allocated memory. */ + +static void +_cgo_allocate_internal(uintptr len, byte *ret) +{ + ret = runtime·mal(len); + FLUSH(&ret); +} + +#pragma dynexport _cgo_allocate _cgo_allocate +void +_cgo_allocate(void *a, int32 n) +{ + runtime·cgocallback((void(*)(void))_cgo_allocate_internal, a, n); +} + +// Panic. The argument is converted into a Go string. + +// Call like this in code compiled with gcc: +// struct { const char *p; } a; +// a.p = /* string to pass to panic */; +// crosscall2(_cgo_panic, &a, sizeof a); +// /* The function call will not return. */ + +extern void ·cgoStringToEface(String, Eface*); + +static void +_cgo_panic_internal(byte *p) +{ + String s; + Eface err; + + s = runtime·gostring(p); + ·cgoStringToEface(s, &err); + runtime·panic(err); +} + +#pragma dynexport _cgo_panic _cgo_panic +void +_cgo_panic(void *a, int32 n) +{ + runtime·cgocallback((void(*)(void))_cgo_panic_internal, a, n); +} |