From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- js/src/jit/ProcessExecutableMemory.h | 48 ++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 js/src/jit/ProcessExecutableMemory.h (limited to 'js/src/jit/ProcessExecutableMemory.h') diff --git a/js/src/jit/ProcessExecutableMemory.h b/js/src/jit/ProcessExecutableMemory.h new file mode 100644 index 000000000..078ce7cb7 --- /dev/null +++ b/js/src/jit/ProcessExecutableMemory.h @@ -0,0 +1,48 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef jit_ProcessExecutableMemory_h +#define jit_ProcessExecutableMemory_h + +#include "mozilla/Attributes.h" + +namespace js { +namespace jit { + +// Executable code is allocated in 64K chunks. ExecutableAllocator uses pools +// that are at least this big. Code we allocate does not necessarily have 64K +// alignment though. +static const size_t ExecutableCodePageSize = 64 * 1024; + +enum class ProtectionSetting { + Protected, // Not readable, writable, or executable. + Writable, + Executable, +}; + +extern MOZ_MUST_USE bool ReprotectRegion(void* start, size_t size, ProtectionSetting protection); + +// Functions called at process start-up/shutdown to initialize/release the +// executable memory region. +extern MOZ_MUST_USE bool InitProcessExecutableMemory(); +extern void ReleaseProcessExecutableMemory(); + +// Allocate/deallocate executable pages. +extern void* AllocateExecutableMemory(size_t bytes, ProtectionSetting protection); +extern void DeallocateExecutableMemory(void* addr, size_t bytes); + +// Returns true if we can allocate a few more MB of executable code without +// hitting our code limit. This function can be used to stop compiling things +// that are optional (like Baseline and Ion code) when we're about to reach the +// limit, so we are less likely to OOM or crash. Note that the limit is +// per-process, so other threads can also allocate code after we call this +// function. +extern bool CanLikelyAllocateMoreExecutableMemory(); + +} // namespace jit +} // namespace js + +#endif // jit_ProcessExecutableMemory_h -- cgit v1.2.3