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Diffstat (limited to 'tools/profiler/lul/AutoObjectMapper.h')
-rw-r--r-- | tools/profiler/lul/AutoObjectMapper.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/tools/profiler/lul/AutoObjectMapper.h b/tools/profiler/lul/AutoObjectMapper.h new file mode 100644 index 000000000..1f813d6f2 --- /dev/null +++ b/tools/profiler/lul/AutoObjectMapper.h @@ -0,0 +1,115 @@ +/* -*- 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 AutoObjectMapper_h +#define AutoObjectMapper_h + +#include <string> + +#include "mozilla/Attributes.h" +#include "PlatformMacros.h" + +// A (nearly-) RAII class that maps an object in and then unmaps it on +// destruction. This base class version uses the "normal" POSIX +// functions: open, fstat, close, mmap, munmap. + +class MOZ_STACK_CLASS AutoObjectMapperPOSIX { +public: + // The constructor does not attempt to map the file, because that + // might fail. Instead, once the object has been constructed, + // call Map() to attempt the mapping. There is no corresponding + // Unmap() since the unmapping is done in the destructor. Failure + // messages are sent to |aLog|. + explicit AutoObjectMapperPOSIX(void(*aLog)(const char*)); + + // Unmap the file on destruction of this object. + ~AutoObjectMapperPOSIX(); + + // Map |fileName| into the address space and return the mapping + // extents. If the file is zero sized this will fail. The file is + // mapped read-only and private. Returns true iff the mapping + // succeeded, in which case *start and *length hold its extent. + // Once a call to Map succeeds, all subsequent calls to it will + // fail. + bool Map(/*OUT*/void** start, /*OUT*/size_t* length, std::string fileName); + +protected: + // If we are currently holding a mapped object, these record the + // mapped address range. + void* mImage; + size_t mSize; + + // A logging sink, for complaining about mapping failures. + void (*mLog)(const char*); + +private: + // Are we currently holding a mapped object? This is private to + // the base class. Derived classes need to have their own way to + // track whether they are holding a mapped object. + bool mIsMapped; + + // Disable copying and assignment. + AutoObjectMapperPOSIX(const AutoObjectMapperPOSIX&); + AutoObjectMapperPOSIX& operator=(const AutoObjectMapperPOSIX&); + // Disable heap allocation of this class. + void* operator new(size_t); + void* operator new[](size_t); + void operator delete(void*); + void operator delete[](void*); +}; + + +#if defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) +// This is a variant of AutoObjectMapperPOSIX suitable for use in +// conjunction with faulty.lib on Android. How it behaves depends on +// the name of the file to be mapped. There are three possible cases: +// +// (1) /foo/bar/xyzzy/blah.apk!/libwurble.so +// We hand it as-is to faulty.lib and let it fish the relevant +// bits out of the APK. +// +// (2) libmozglue.so +// This is part of the Fennec installation, but is not in the +// APK. Instead we have to figure out the installation path +// and look for it there. Because of faulty.lib limitations, +// we have to use regular open/mmap instead of faulty.lib. +// +// (3) libanythingelse.so +// faulty.lib assumes this is a system library, and prepends +// "/system/lib/" to the path. So as in (1), we can give it +// as-is to faulty.lib. +// +// Hence (1) and (3) require special-casing here. Case (2) simply +// hands the problem to the parent class. + +class MOZ_STACK_CLASS AutoObjectMapperFaultyLib : public AutoObjectMapperPOSIX { +public: + AutoObjectMapperFaultyLib(void(*aLog)(const char*)); + + ~AutoObjectMapperFaultyLib(); + + bool Map(/*OUT*/void** start, /*OUT*/size_t* length, std::string fileName); + +private: + // faulty.lib requires us to maintain an abstract handle that can be + // used later to unmap the area. If this is non-NULL, it is assumed + // that unmapping is to be done by faulty.lib. Otherwise it goes + // via the normal mechanism. + void* mHdl; + + // Disable copying and assignment. + AutoObjectMapperFaultyLib(const AutoObjectMapperFaultyLib&); + AutoObjectMapperFaultyLib& operator=(const AutoObjectMapperFaultyLib&); + // Disable heap allocation of this class. + void* operator new(size_t); + void* operator new[](size_t); + void operator delete(void*); + void operator delete[](void*); +}; + +#endif // defined(SPS_OS_android) && !defined(MOZ_WIDGET_GONK) + +#endif // AutoObjectMapper_h |