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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=4 et :
*/
/* 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/. */
#include "mozilla/mozalloc_abort.h"
#include "mozilla/mozalloc_oom.h"
#include "mozilla/Assertions.h"
static mozalloc_oom_abort_handler gAbortHandler;
#define OOM_MSG_LEADER "out of memory: 0x"
#define OOM_MSG_DIGITS "0000000000000000" // large enough for 2^64
#define OOM_MSG_TRAILER " bytes requested"
#define OOM_MSG_FIRST_DIGIT_OFFSET sizeof(OOM_MSG_LEADER) - 1
#define OOM_MSG_LAST_DIGIT_OFFSET \
sizeof(OOM_MSG_LEADER) + sizeof(OOM_MSG_DIGITS) - 3
static const char* hex = "0123456789ABCDEF";
void mozalloc_handle_oom(size_t size) {
char oomMsg[] = OOM_MSG_LEADER OOM_MSG_DIGITS OOM_MSG_TRAILER;
size_t i;
// NB: this is handle_oom() stage 1, which simply aborts on OOM.
// we might proceed to a stage 2 in which an attempt is made to
// reclaim memory
// Warning: when stage 2 is done by, for example, notifying
// "memory-pressure" synchronously, please audit all
// nsExpirationTrackers and ensure that the actions they take
// on memory-pressure notifications (via NotifyExpired) are safe.
// Note that Document::SelectorCache::NotifyExpired is _known_
// to not be safe: it will delete the selector it's caching,
// which might be in use at the time under querySelector or
// querySelectorAll.
if (gAbortHandler) gAbortHandler(size);
static_assert(OOM_MSG_FIRST_DIGIT_OFFSET > 0,
"Loop below will never terminate (i can't go below 0)");
// Insert size into the diagnostic message using only primitive operations
for (i = OOM_MSG_LAST_DIGIT_OFFSET; size && i >= OOM_MSG_FIRST_DIGIT_OFFSET;
i--) {
oomMsg[i] = hex[size % 16];
size /= 16;
}
mozalloc_abort(oomMsg);
}
void mozalloc_set_oom_abort_handler(mozalloc_oom_abort_handler handler) {
gAbortHandler = handler;
}
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