Squashed 'third_party/gperftools/' content from commit 54505f1
Change-Id: Id02e833828732b0efe7dac722b8485279e67c5fa
git-subtree-dir: third_party/gperftools
git-subtree-split: 54505f1d50c2d1f4676f5e87090b64a117fd980e
diff --git a/src/base/low_level_alloc.h b/src/base/low_level_alloc.h
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+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+/* Copyright (c) 2006, 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.
+ */
+
+#if !defined(_BASE_LOW_LEVEL_ALLOC_H_)
+#define _BASE_LOW_LEVEL_ALLOC_H_
+
+// A simple thread-safe memory allocator that does not depend on
+// mutexes or thread-specific data. It is intended to be used
+// sparingly, and only when malloc() would introduce an unwanted
+// dependency, such as inside the heap-checker.
+
+#include <config.h>
+#include <stddef.h> // for size_t
+#include "base/basictypes.h"
+
+class LowLevelAlloc {
+ public:
+ struct Arena; // an arena from which memory may be allocated
+
+ // Returns a pointer to a block of at least "request" bytes
+ // that have been newly allocated from the specific arena.
+ // for Alloc() call the DefaultArena() is used.
+ // Returns 0 if passed request==0.
+ // Does not return 0 under other circumstances; it crashes if memory
+ // is not available.
+ static void *Alloc(size_t request)
+ ATTRIBUTE_SECTION(malloc_hook);
+ static void *AllocWithArena(size_t request, Arena *arena)
+ ATTRIBUTE_SECTION(malloc_hook);
+
+ // Deallocates a region of memory that was previously allocated with
+ // Alloc(). Does nothing if passed 0. "s" must be either 0,
+ // or must have been returned from a call to Alloc() and not yet passed to
+ // Free() since that call to Alloc(). The space is returned to the arena
+ // from which it was allocated.
+ static void Free(void *s) ATTRIBUTE_SECTION(malloc_hook);
+
+ // ATTRIBUTE_SECTION(malloc_hook) for Alloc* and Free
+ // are to put all callers of MallocHook::Invoke* in this module
+ // into special section,
+ // so that MallocHook::GetCallerStackTrace can function accurately.
+
+ // Create a new arena.
+ // The root metadata for the new arena is allocated in the
+ // meta_data_arena; the DefaultArena() can be passed for meta_data_arena.
+ // These values may be ored into flags:
+ enum {
+ // Report calls to Alloc() and Free() via the MallocHook interface.
+ // Set in the DefaultArena.
+ kCallMallocHook = 0x0001,
+
+ // Make calls to Alloc(), Free() be async-signal-safe. Not set in
+ // DefaultArena().
+ kAsyncSignalSafe = 0x0002,
+
+ // When used with DefaultArena(), the NewArena() and DeleteArena() calls
+ // obey the flags given explicitly in the NewArena() call, even if those
+ // flags differ from the settings in DefaultArena(). So the call
+ // NewArena(kAsyncSignalSafe, DefaultArena()) is itself async-signal-safe,
+ // as well as generatating an arena that provides async-signal-safe
+ // Alloc/Free.
+ };
+ static Arena *NewArena(int32 flags, Arena *meta_data_arena);
+
+ // Destroys an arena allocated by NewArena and returns true,
+ // provided no allocated blocks remain in the arena.
+ // If allocated blocks remain in the arena, does nothing and
+ // returns false.
+ // It is illegal to attempt to destroy the DefaultArena().
+ static bool DeleteArena(Arena *arena);
+
+ // The default arena that always exists.
+ static Arena *DefaultArena();
+
+ private:
+ LowLevelAlloc(); // no instances
+};
+
+#endif