michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: sw=4 ts=4 et :
michael@0:  */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #if defined(XP_WIN)
michael@0: #  define MOZALLOC_EXPORT __declspec(dllexport)
michael@0: #endif
michael@0: 
michael@0: #include "mozilla/mozalloc_abort.h"
michael@0: #include "mozilla/mozalloc_oom.h"
michael@0: #include "mozilla/Assertions.h"
michael@0: 
michael@0: static mozalloc_oom_abort_handler gAbortHandler;
michael@0: 
michael@0: #define OOM_MSG_LEADER "out of memory: 0x"
michael@0: #define OOM_MSG_DIGITS "0000000000000000" // large enough for 2^64
michael@0: #define OOM_MSG_TRAILER " bytes requested"
michael@0: #define OOM_MSG_FIRST_DIGIT_OFFSET sizeof(OOM_MSG_LEADER) - 1
michael@0: #define OOM_MSG_LAST_DIGIT_OFFSET sizeof(OOM_MSG_LEADER) + \
michael@0:                                   sizeof(OOM_MSG_DIGITS) - 3
michael@0: 
michael@0: static const char *hex = "0123456789ABCDEF";
michael@0: 
michael@0: void
michael@0: mozalloc_handle_oom(size_t size)
michael@0: {
michael@0:     char oomMsg[] = OOM_MSG_LEADER OOM_MSG_DIGITS OOM_MSG_TRAILER;
michael@0:     size_t i;
michael@0: 
michael@0:     // NB: this is handle_oom() stage 1, which simply aborts on OOM.
michael@0:     // we might proceed to a stage 2 in which an attempt is made to
michael@0:     // reclaim memory
michael@0: 
michael@0:     if (gAbortHandler)
michael@0:         gAbortHandler(size);
michael@0: 
michael@0:     static_assert(OOM_MSG_FIRST_DIGIT_OFFSET > 0,
michael@0:                   "Loop below will never terminate (i can't go below 0)");
michael@0: 
michael@0:     // Insert size into the diagnostic message using only primitive operations
michael@0:     for (i = OOM_MSG_LAST_DIGIT_OFFSET;
michael@0:          size && i >= OOM_MSG_FIRST_DIGIT_OFFSET; i--) {
michael@0:       oomMsg[i] = hex[size % 16];
michael@0:       size /= 16;
michael@0:     }
michael@0: 
michael@0:     mozalloc_abort(oomMsg);
michael@0: }
michael@0: 
michael@0: void
michael@0: mozalloc_set_oom_abort_handler(mozalloc_oom_abort_handler handler)
michael@0: {
michael@0:     gAbortHandler = handler;
michael@0: }