rf-web/vendor/bundle/gems/ffi-1.11.1/ext/ffi_c/MethodHandle.c

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2019-10-21 08:18:17 +00:00
/*
* Copyright (c) 2009, 2010 Wayne Meissner
* Copyright (c) 2008-2013, Ruby FFI project contributors
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Ruby FFI project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _MSC_VER
#include <sys/param.h>
#endif
#include <sys/types.h>
#ifndef _WIN32
# include <sys/mman.h>
#endif
#include <stdio.h>
#ifndef _MSC_VER
# include <stdint.h>
# include <stdbool.h>
#else
# include "win32/stdint.h"
# include "win32/stdbool.h"
#endif
#ifndef _WIN32
# include <unistd.h>
#endif
#include <errno.h>
#include <ruby.h>
#if defined(HAVE_NATIVETHREAD) && !defined(_WIN32) && !defined(__WIN32__)
# include <pthread.h>
#endif
#include <ffi.h>
#include "rbffi.h"
#include "compat.h"
#include "Function.h"
#include "Types.h"
#include "Type.h"
#include "LastError.h"
#include "Call.h"
#include "ClosurePool.h"
#include "MethodHandle.h"
#define MAX_METHOD_FIXED_ARITY (6)
#ifndef roundup
# define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
#endif
#ifdef _WIN32
typedef char* caddr_t;
#endif
#ifdef USE_RAW
# define METHOD_CLOSURE ffi_raw_closure
# define METHOD_PARAMS ffi_raw*
#else
# define METHOD_CLOSURE ffi_closure
# define METHOD_PARAMS void**
#endif
static bool prep_trampoline(void* ctx, void* code, Closure* closure, char* errmsg, size_t errmsgsize);
static long trampoline_size(void);
#if defined(__x86_64__) && (defined(__linux__) || defined(__APPLE__))
# define CUSTOM_TRAMPOLINE 1
#endif
struct MethodHandle {
Closure* closure;
};
static ClosurePool* defaultClosurePool;
MethodHandle*
rbffi_MethodHandle_Alloc(FunctionType* fnInfo, void* function)
{
MethodHandle* handle;
Closure* closure = rbffi_Closure_Alloc(defaultClosurePool);
if (closure == NULL) {
rb_raise(rb_eNoMemError, "failed to allocate closure from pool");
return NULL;
}
handle = xcalloc(1, sizeof(*handle));
handle->closure = closure;
closure->info = fnInfo;
closure->function = function;
return handle;
}
void
rbffi_MethodHandle_Free(MethodHandle* handle)
{
if (handle != NULL) {
rbffi_Closure_Free(handle->closure);
}
}
void*
rbffi_MethodHandle_CodeAddress(MethodHandle* handle)
{
return handle->closure->code;
}
#ifndef CUSTOM_TRAMPOLINE
static void attached_method_invoke(ffi_cif* cif, void* retval, METHOD_PARAMS parameters, void* user_data);
static ffi_type* methodHandleParamTypes[] = {
&ffi_type_sint,
&ffi_type_pointer,
&ffi_type_ulong,
};
static ffi_cif mh_cif;
static bool
prep_trampoline(void* ctx, void* code, Closure* closure, char* errmsg, size_t errmsgsize)
{
ffi_status ffiStatus;
#if defined(USE_RAW)
ffiStatus = ffi_prep_raw_closure(code, &mh_cif, attached_method_invoke, closure);
#else
ffiStatus = ffi_prep_closure(code, &mh_cif, attached_method_invoke, closure);
#endif
if (ffiStatus != FFI_OK) {
snprintf(errmsg, errmsgsize, "ffi_prep_closure failed. status=%#x", ffiStatus);
return false;
}
return true;
}
static long
trampoline_size(void)
{
return sizeof(METHOD_CLOSURE);
}
/*
* attached_method_invoke is used functions with more than 6 parameters, or
* with struct param or return values
*/
static void
attached_method_invoke(ffi_cif* cif, void* mretval, METHOD_PARAMS parameters, void* user_data)
{
Closure* handle = (Closure *) user_data;
FunctionType* fnInfo = (FunctionType *) handle->info;
#ifdef USE_RAW
int argc = parameters[0].sint;
VALUE* argv = *(VALUE **) &parameters[1];
#else
int argc = *(int *) parameters[0];
VALUE* argv = *(VALUE **) parameters[1];
#endif
*(VALUE *) mretval = (*fnInfo->invoke)(argc, argv, handle->function, fnInfo);
}
#endif
#if defined(CUSTOM_TRAMPOLINE)
#if defined(__x86_64__)
static VALUE custom_trampoline(int argc, VALUE* argv, VALUE self, Closure*);
#define TRAMPOLINE_CTX_MAGIC (0xfee1deadcafebabe)
#define TRAMPOLINE_FUN_MAGIC (0xfeedfacebeeff00d)
/*
* This is a hand-coded trampoline to speedup entry from ruby to the FFI translation
* layer for x86_64 arches.
*
* Since a ruby function has exactly 3 arguments, and the first 6 arguments are
* passed in registers for x86_64, we can tack on a context pointer by simply
* putting a value in %rcx, then jumping to the C trampoline code.
*
* This results in approx a 30% speedup for x86_64 FFI dispatch
*/
__asm__(
".text\n\t"
".globl ffi_trampoline\n\t"
".globl _ffi_trampoline\n\t"
"ffi_trampoline:\n\t"
"_ffi_trampoline:\n\t"
"movabsq $0xfee1deadcafebabe, %rcx\n\t"
"movabsq $0xfeedfacebeeff00d, %r11\n\t"
"jmpq *%r11\n\t"
".globl ffi_trampoline_end\n\t"
"ffi_trampoline_end:\n\t"
".globl _ffi_trampoline_end\n\t"
"_ffi_trampoline_end:\n\t"
);
static VALUE
custom_trampoline(int argc, VALUE* argv, VALUE self, Closure* handle)
{
FunctionType* fnInfo = (FunctionType *) handle->info;
VALUE rbReturnValue;
RB_GC_GUARD(rbReturnValue) = (*fnInfo->invoke)(argc, argv, handle->function, fnInfo);
RB_GC_GUARD(self);
return rbReturnValue;
}
#elif defined(__i386__) && 0
static VALUE custom_trampoline(caddr_t args, Closure*);
#define TRAMPOLINE_CTX_MAGIC (0xfee1dead)
#define TRAMPOLINE_FUN_MAGIC (0xbeefcafe)
/*
* This is a hand-coded trampoline to speed-up entry from ruby to the FFI translation
* layer for i386 arches.
*
* This does not make a discernible difference vs a raw closure, so for now,
* it is not enabled.
*/
__asm__(
".text\n\t"
".globl ffi_trampoline\n\t"
".globl _ffi_trampoline\n\t"
"ffi_trampoline:\n\t"
"_ffi_trampoline:\n\t"
"subl $12, %esp\n\t"
"leal 16(%esp), %eax\n\t"
"movl %eax, (%esp)\n\t"
"movl $0xfee1dead, 4(%esp)\n\t"
"movl $0xbeefcafe, %eax\n\t"
"call *%eax\n\t"
"addl $12, %esp\n\t"
"ret\n\t"
".globl ffi_trampoline_end\n\t"
"ffi_trampoline_end:\n\t"
".globl _ffi_trampoline_end\n\t"
"_ffi_trampoline_end:\n\t"
);
static VALUE
custom_trampoline(caddr_t args, Closure* handle)
{
FunctionType* fnInfo = (FunctionType *) handle->info;
return (*fnInfo->invoke)(*(int *) args, *(VALUE **) (args + 4), handle->function, fnInfo);
}
#endif /* __x86_64__ else __i386__ */
extern void ffi_trampoline(int argc, VALUE* argv, VALUE self);
extern void ffi_trampoline_end(void);
static int trampoline_offsets(long *, long *);
static long trampoline_ctx_offset, trampoline_func_offset;
static long
trampoline_offset(int off, const long value)
{
caddr_t ptr;
for (ptr = (caddr_t) &ffi_trampoline + off; ptr < (caddr_t) &ffi_trampoline_end; ++ptr) {
if (*(long *) ptr == value) {
return ptr - (caddr_t) &ffi_trampoline;
}
}
return -1;
}
static int
trampoline_offsets(long* ctxOffset, long* fnOffset)
{
*ctxOffset = trampoline_offset(0, TRAMPOLINE_CTX_MAGIC);
if (*ctxOffset == -1) {
return -1;
}
*fnOffset = trampoline_offset(0, TRAMPOLINE_FUN_MAGIC);
if (*fnOffset == -1) {
return -1;
}
return 0;
}
static bool
prep_trampoline(void* ctx, void* code, Closure* closure, char* errmsg, size_t errmsgsize)
{
caddr_t ptr = (caddr_t) code;
memcpy(ptr, &ffi_trampoline, trampoline_size());
/* Patch the context and function addresses into the stub code */
*(intptr_t *)(ptr + trampoline_ctx_offset) = (intptr_t) closure;
*(intptr_t *)(ptr + trampoline_func_offset) = (intptr_t) custom_trampoline;
return true;
}
static long
trampoline_size(void)
{
return (caddr_t) &ffi_trampoline_end - (caddr_t) &ffi_trampoline;
}
#endif /* CUSTOM_TRAMPOLINE */
void
rbffi_MethodHandle_Init(VALUE module)
{
#ifndef CUSTOM_TRAMPOLINE
ffi_status ffiStatus;
#endif
defaultClosurePool = rbffi_ClosurePool_New((int) trampoline_size(), prep_trampoline, NULL);
#if defined(CUSTOM_TRAMPOLINE)
if (trampoline_offsets(&trampoline_ctx_offset, &trampoline_func_offset) != 0) {
rb_raise(rb_eFatal, "Could not locate offsets in trampoline code");
}
#else
ffiStatus = ffi_prep_cif(&mh_cif, FFI_DEFAULT_ABI, 3, &ffi_type_ulong,
methodHandleParamTypes);
if (ffiStatus != FFI_OK) {
rb_raise(rb_eFatal, "ffi_prep_cif failed. status=%#x", ffiStatus);
}
#endif
}