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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "gpu/command_buffer/common/mailbox.h"
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "base/logging.h"
#include "base/rand_util.h"
namespace gpu {
Mailbox::Mailbox() {
memset(name, 0, sizeof(name));
}
bool Mailbox::IsZero() const {
for (size_t i = 0; i < arraysize(name); ++i) {
if (name[i])
return false;
}
return true;
}
void Mailbox::SetZero() {
memset(name, 0, sizeof(name));
}
void Mailbox::SetName(const int8_t* n) {
DCHECK(IsZero() || !memcmp(name, n, sizeof(name)));
memcpy(name, n, sizeof(name));
}
Mailbox Mailbox::Generate() {
Mailbox result;
// Generates cryptographically-secure bytes.
base::RandBytes(result.name, sizeof(result.name));
#if !defined(NDEBUG)
int8_t value = 1;
for (size_t i = 1; i < sizeof(result.name); ++i)
value ^= result.name[i];
result.name[0] = value;
#endif
return result;
}
bool Mailbox::Verify() const {
#if !defined(NDEBUG)
int8_t value = 1;
for (size_t i = 0; i < sizeof(name); ++i)
value ^= name[i];
return value == 0;
#else
return true;
#endif
}
} // namespace gpu
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