diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /mfbt/TaggedAnonymousMemory.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mfbt/TaggedAnonymousMemory.h')
-rw-r--r-- | mfbt/TaggedAnonymousMemory.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/mfbt/TaggedAnonymousMemory.h b/mfbt/TaggedAnonymousMemory.h new file mode 100644 index 0000000000..ebd2c00318 --- /dev/null +++ b/mfbt/TaggedAnonymousMemory.h @@ -0,0 +1,87 @@ +/* -*- 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/. */ + +// Some Linux kernels -- specifically, newer versions of Android and +// some B2G devices -- have a feature for assigning names to ranges of +// anonymous memory (i.e., memory that doesn't have a "name" in the +// form of an underlying mapped file). These names are reported in +// /proc/<pid>/smaps alongside system-level memory usage information +// such as Proportional Set Size (memory usage adjusted for sharing +// between processes), which allows reporting this information at a +// finer granularity than would otherwise be possible (e.g., +// separating malloc() heap from JS heap). +// +// Existing memory can be tagged with MozTagAnonymousMemory(); it will +// tag the range of complete pages containing the given interval, so +// the results may be inexact if the range isn't page-aligned. +// MozTaggedAnonymousMmap() can be used like mmap() with an extra +// parameter, and will tag the returned memory if the mapping was +// successful (and if it was in fact anonymous). +// +// NOTE: The pointer given as the "tag" argument MUST remain valid as +// long as the mapping exists. The referenced string is read when +// /proc/<pid>/smaps or /proc/<pid>/maps is read, not when the tag is +// established, so freeing it or changing its contents will have +// unexpected results. Using a static string is probably best. +// +// Also note that this header can be used by both C and C++ code. + +#ifndef mozilla_TaggedAnonymousMemory_h +#define mozilla_TaggedAnonymousMemory_h + +#ifndef XP_WIN + +# ifdef __wasi__ +# include <stdlib.h> +# else +# include <sys/types.h> +# include <sys/mman.h> +# endif // __wasi__ + +# include "mozilla/Types.h" + +# ifdef ANDROID + +# ifdef __cplusplus +extern "C" { +# endif + +MFBT_API void MozTagAnonymousMemory(const void* aPtr, size_t aLength, + const char* aTag); + +MFBT_API void* MozTaggedAnonymousMmap(void* aAddr, size_t aLength, int aProt, + int aFlags, int aFd, off_t aOffset, + const char* aTag); + +MFBT_API int MozTaggedMemoryIsSupported(void); + +# ifdef __cplusplus +} // extern "C" +# endif + +# else // ANDROID + +static inline void MozTagAnonymousMemory(const void* aPtr, size_t aLength, + const char* aTag) {} + +static inline void* MozTaggedAnonymousMmap(void* aAddr, size_t aLength, + int aProt, int aFlags, int aFd, + off_t aOffset, const char* aTag) { +# ifdef __wasi__ + MOZ_CRASH("We don't use this memory for WASI right now."); + return nullptr; +# else + return mmap(aAddr, aLength, aProt, aFlags, aFd, aOffset); +# endif +} + +static inline int MozTaggedMemoryIsSupported(void) { return 0; } + +# endif // ANDROID + +#endif // !XP_WIN + +#endif // mozilla_TaggedAnonymousMemory_h |