Mypal/js/src/wasm/WasmSignalHandlers.h

81 lines
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef wasm_signal_handlers_h
#define wasm_signal_handlers_h
#include "mozilla/Attributes.h"
#if defined(XP_DARWIN)
# include <mach/mach.h>
#endif
#include "threading/Thread.h"
struct JSRuntime;
namespace js {
// Force any currently-executing asm.js/ion code to call HandleExecutionInterrupt.
extern void
InterruptRunningJitCode(JSRuntime* rt);
namespace wasm {
// Ensure the given JSRuntime is set up to use signals. Failure to enable signal
// handlers indicates some catastrophic failure and creation of the runtime must
// fail.
MOZ_MUST_USE bool
EnsureSignalHandlers(JSRuntime* rt);
// Return whether signals can be used in this process for interrupts or
// asm.js/wasm out-of-bounds.
bool
HaveSignalHandlers();
#if defined(XP_DARWIN)
// On OSX we are forced to use the lower-level Mach exception mechanism instead
// of Unix signals. Mach exceptions are not handled on the victim's stack but
// rather require an extra thread. For simplicity, we create one such thread
// per JSRuntime (upon the first use of asm.js in the JSRuntime). This thread
// and related resources are owned by AsmJSMachExceptionHandler which is owned
// by JSRuntime.
class MachExceptionHandler
{
bool installed_;
js::Thread thread_;
mach_port_t port_;
void uninstall();
public:
MachExceptionHandler();
~MachExceptionHandler() { uninstall(); }
mach_port_t port() const { return port_; }
bool installed() const { return installed_; }
bool install(JSRuntime* rt);
};
#endif
// Test whether the given PC is within the innermost wasm activation. Return
// false if it is not, or it cannot be determined.
bool IsPCInWasmCode(void *pc);
} // namespace wasm
} // namespace js
#endif // wasm_signal_handlers_h