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Diffstat (limited to '3rdParty/Breakpad/src/common/memory.h')
-rw-r--r--3rdParty/Breakpad/src/common/memory.h218
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diff --git a/3rdParty/Breakpad/src/common/memory.h b/3rdParty/Breakpad/src/common/memory.h
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+// Copyright (c) 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef GOOGLE_BREAKPAD_COMMON_MEMORY_H_
+#define GOOGLE_BREAKPAD_COMMON_MEMORY_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#ifdef __APPLE__
+#define sys_mmap mmap
+#define sys_mmap2 mmap
+#define sys_munmap munmap
+#define MAP_ANONYMOUS MAP_ANON
+#else
+#include "third_party/lss/linux_syscall_support.h"
+#endif
+
+namespace google_breakpad {
+
+// This is very simple allocator which fetches pages from the kernel directly.
+// Thus, it can be used even when the heap may be corrupted.
+//
+// There is no free operation. The pages are only freed when the object is
+// destroyed.
+class PageAllocator {
+ public:
+ PageAllocator()
+ : page_size_(getpagesize()),
+ last_(NULL),
+ current_page_(NULL),
+ page_offset_(0) {
+ }
+
+ ~PageAllocator() {
+ FreeAll();
+ }
+
+ void *Alloc(unsigned bytes) {
+ if (!bytes)
+ return NULL;
+
+ if (current_page_ && page_size_ - page_offset_ >= bytes) {
+ uint8_t *const ret = current_page_ + page_offset_;
+ page_offset_ += bytes;
+ if (page_offset_ == page_size_) {
+ page_offset_ = 0;
+ current_page_ = NULL;
+ }
+
+ return ret;
+ }
+
+ const unsigned pages =
+ (bytes + sizeof(PageHeader) + page_size_ - 1) / page_size_;
+ uint8_t *const ret = GetNPages(pages);
+ if (!ret)
+ return NULL;
+
+ page_offset_ = (page_size_ - (page_size_ * pages - (bytes + sizeof(PageHeader)))) % page_size_;
+ current_page_ = page_offset_ ? ret + page_size_ * (pages - 1) : NULL;
+
+ return ret + sizeof(PageHeader);
+ }
+
+ private:
+ uint8_t *GetNPages(unsigned num_pages) {
+#ifdef __x86_64
+ void *a = sys_mmap(NULL, page_size_ * num_pages, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#else
+ void *a = sys_mmap2(NULL, page_size_ * num_pages, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#endif
+ if (a == MAP_FAILED)
+ return NULL;
+
+ struct PageHeader *header = reinterpret_cast<PageHeader*>(a);
+ header->next = last_;
+ header->num_pages = num_pages;
+ last_ = header;
+
+ return reinterpret_cast<uint8_t*>(a);
+ }
+
+ void FreeAll() {
+ PageHeader *next;
+
+ for (PageHeader *cur = last_; cur; cur = next) {
+ next = cur->next;
+ sys_munmap(cur, cur->num_pages * page_size_);
+ }
+ }
+
+ struct PageHeader {
+ PageHeader *next; // pointer to the start of the next set of pages.
+ unsigned num_pages; // the number of pages in this set.
+ };
+
+ const unsigned page_size_;
+ PageHeader *last_;
+ uint8_t *current_page_;
+ unsigned page_offset_;
+};
+
+// A wasteful vector is like a normal std::vector, except that it's very much
+// simplier and it allocates memory from a PageAllocator. It's wasteful
+// because, when resizing, it always allocates a whole new array since the
+// PageAllocator doesn't support realloc.
+template<class T>
+class wasteful_vector {
+ public:
+ wasteful_vector(PageAllocator *allocator, unsigned size_hint = 16)
+ : allocator_(allocator),
+ a_((T*) allocator->Alloc(sizeof(T) * size_hint)),
+ allocated_(size_hint),
+ used_(0) {
+ }
+
+ T& back() {
+ return a_[used_ - 1];
+ }
+
+ const T& back() const {
+ return a_[used_ - 1];
+ }
+
+ bool empty() const {
+ return used_ == 0;
+ }
+
+ void push_back(const T& new_element) {
+ if (used_ == allocated_)
+ Realloc(allocated_ * 2);
+ a_[used_++] = new_element;
+ }
+
+ size_t size() const {
+ return used_;
+ }
+
+ void resize(unsigned sz, T c = T()) {
+ // No need to test "sz >= 0", as "sz" is unsigned.
+ if (sz <= used_) {
+ used_ = sz;
+ } else {
+ unsigned a = allocated_;
+ if (sz > a) {
+ while (sz > a) {
+ a *= 2;
+ }
+ Realloc(a);
+ }
+ while (sz > used_) {
+ a_[used_++] = c;
+ }
+ }
+ }
+
+ T& operator[](size_t index) {
+ return a_[index];
+ }
+
+ const T& operator[](size_t index) const {
+ return a_[index];
+ }
+
+ private:
+ void Realloc(unsigned new_size) {
+ T *new_array =
+ reinterpret_cast<T*>(allocator_->Alloc(sizeof(T) * new_size));
+ memcpy(new_array, a_, used_ * sizeof(T));
+ a_ = new_array;
+ allocated_ = new_size;
+ }
+
+ PageAllocator *const allocator_;
+ T *a_; // pointer to an array of |allocated_| elements.
+ unsigned allocated_; // size of |a_|, in elements.
+ unsigned used_; // number of used slots in |a_|.
+};
+
+} // namespace google_breakpad
+
+inline void* operator new(size_t nbytes,
+ google_breakpad::PageAllocator& allocator) {
+ return allocator.Alloc(nbytes);
+}
+
+#endif // GOOGLE_BREAKPAD_COMMON_MEMORY_H_