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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /devtools/shared/heapsnapshot/AutoMemMap.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'devtools/shared/heapsnapshot/AutoMemMap.h')
-rw-r--r-- | devtools/shared/heapsnapshot/AutoMemMap.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/devtools/shared/heapsnapshot/AutoMemMap.h b/devtools/shared/heapsnapshot/AutoMemMap.h new file mode 100644 index 0000000000..f67dacf0df --- /dev/null +++ b/devtools/shared/heapsnapshot/AutoMemMap.h @@ -0,0 +1,77 @@ +/* -*- 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 mozilla_devtools_AutoMemMap_h +#define mozilla_devtools_AutoMemMap_h + +#include <prio.h> +#include "nsIFile.h" +#include "mozilla/Assertions.h" +#include "mozilla/Attributes.h" +#include "ErrorList.h" + +namespace mozilla { +namespace devtools { + +// # AutoMemMap +// +// AutoMemMap is an RAII class to manage mapping a file to memory. It is a +// wrapper around managing opening and closing a file and calling PR_MemMap and +// PR_MemUnmap. +// +// Example usage: +// +// { +// AutoMemMap mm; +// if (NS_FAILED(mm.init("/path/to/desired/file"))) { +// // Handle the error however you see fit. +// return false; +// } +// +// doStuffWithMappedMemory(mm.address()); +// } +// // The memory is automatically unmapped when the AutoMemMap leaves scope. +class MOZ_RAII AutoMemMap { + // At the time of this writing, this class supports file imports up to + // UINT32_MAX bytes due to limitations in the underlying function PR_MemMap. + uint32_t fileSize; + PRFileDesc* fd; + PRFileMap* fileMap; + void* addr; + + AutoMemMap(const AutoMemMap& aOther) = delete; + void operator=(const AutoMemMap& aOther) = delete; + + public: + explicit AutoMemMap() + : fileSize(0), fd(nullptr), fileMap(nullptr), addr(nullptr){}; + ~AutoMemMap(); + + // Initialize this AutoMemMap. + nsresult init(nsIFile* file, int flags = PR_RDONLY, int mode = 0, + PRFileMapProtect prot = PR_PROT_READONLY); + + // Get the size of the memory mapped file. + uint32_t size() const { + MOZ_ASSERT(fd, "Should only call size() if init() succeeded."); + return fileSize; + } + + // Get the mapped memory. + void* address() { + MOZ_ASSERT(addr); + return addr; + } + const void* address() const { + MOZ_ASSERT(addr); + return addr; + } +}; + +} // namespace devtools +} // namespace mozilla + +#endif // mozilla_devtools_AutoMemMap_h |