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// Copyright 2017 the V8 project 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 <zircon/process.h>
#include <zircon/syscalls.h>
#include "src/base/macros.h"
#include "src/base/platform/platform-posix-time.h"
#include "src/base/platform/platform-posix.h"
#include "src/base/platform/platform.h"
namespace v8 {
namespace base {
namespace {
uint32_t GetProtectionFromMemoryPermission(OS::MemoryPermission access) {
switch (access) {
case OS::MemoryPermission::kNoAccess:
return 0; // no permissions
case OS::MemoryPermission::kRead:
return ZX_VM_PERM_READ;
case OS::MemoryPermission::kReadWrite:
return ZX_VM_PERM_READ | ZX_VM_PERM_WRITE;
case OS::MemoryPermission::kReadWriteExecute:
return ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_PERM_EXECUTE;
case OS::MemoryPermission::kReadExecute:
return ZX_VM_PERM_READ | ZX_VM_PERM_EXECUTE;
}
UNREACHABLE();
}
} // namespace
TimezoneCache* OS::CreateTimezoneCache() {
return new PosixDefaultTimezoneCache();
}
// static
void* OS::Allocate(void* address, size_t size, size_t alignment,
OS::MemoryPermission access) {
size_t page_size = OS::AllocatePageSize();
DCHECK_EQ(0, size % page_size);
DCHECK_EQ(0, alignment % page_size);
address = AlignedAddress(address, alignment);
// Add the maximum misalignment so we are guaranteed an aligned base address.
size_t request_size = size + (alignment - page_size);
zx_handle_t vmo;
if (zx_vmo_create(request_size, ZX_VMO_NON_RESIZABLE, &vmo) != ZX_OK) {
return nullptr;
}
static const char kVirtualMemoryName[] = "v8-virtualmem";
zx_object_set_property(vmo, ZX_PROP_NAME, kVirtualMemoryName,
strlen(kVirtualMemoryName));
// Always call zx_vmo_replace_as_executable() in case the memory will need
// to be marked as executable in the future.
// TOOD(https://crbug.com/v8/8899): Only call this when we know that the
// region will need to be marked as executable in the future.
if (zx_vmo_replace_as_executable(vmo, ZX_HANDLE_INVALID, &vmo) != ZX_OK) {
return nullptr;
}
uintptr_t reservation;
uint32_t prot = GetProtectionFromMemoryPermission(access);
zx_status_t status = zx_vmar_map(zx_vmar_root_self(), prot, 0, vmo, 0,
request_size, &reservation);
// Either the vmo is now referenced by the vmar, or we failed and are bailing,
// so close the vmo either way.
zx_handle_close(vmo);
if (status != ZX_OK) {
return nullptr;
}
uint8_t* base = reinterpret_cast<uint8_t*>(reservation);
uint8_t* aligned_base = reinterpret_cast<uint8_t*>(
RoundUp(reinterpret_cast<uintptr_t>(base), alignment));
// Unmap extra memory reserved before and after the desired block.
if (aligned_base != base) {
DCHECK_LT(base, aligned_base);
size_t prefix_size = static_cast<size_t>(aligned_base - base);
zx_vmar_unmap(zx_vmar_root_self(), reinterpret_cast<uintptr_t>(base),
prefix_size);
request_size -= prefix_size;
}
size_t aligned_size = RoundUp(size, page_size);
if (aligned_size != request_size) {
DCHECK_LT(aligned_size, request_size);
size_t suffix_size = request_size - aligned_size;
zx_vmar_unmap(zx_vmar_root_self(),
reinterpret_cast<uintptr_t>(aligned_base + aligned_size),
suffix_size);
request_size -= suffix_size;
}
DCHECK(aligned_size == request_size);
return static_cast<void*>(aligned_base);
}
// static
bool OS::Free(void* address, const size_t size) {
DCHECK_EQ(0, reinterpret_cast<uintptr_t>(address) % AllocatePageSize());
DCHECK_EQ(0, size % AllocatePageSize());
return zx_vmar_unmap(zx_vmar_root_self(),
reinterpret_cast<uintptr_t>(address), size) == ZX_OK;
}
// static
bool OS::Release(void* address, size_t size) {
DCHECK_EQ(0, reinterpret_cast<uintptr_t>(address) % CommitPageSize());
DCHECK_EQ(0, size % CommitPageSize());
return zx_vmar_unmap(zx_vmar_root_self(),
reinterpret_cast<uintptr_t>(address), size) == ZX_OK;
}
// static
bool OS::SetPermissions(void* address, size_t size, MemoryPermission access) {
DCHECK_EQ(0, reinterpret_cast<uintptr_t>(address) % CommitPageSize());
DCHECK_EQ(0, size % CommitPageSize());
uint32_t prot = GetProtectionFromMemoryPermission(access);
return zx_vmar_protect(zx_vmar_root_self(), prot,
reinterpret_cast<uintptr_t>(address), size) == ZX_OK;
}
// static
bool OS::DiscardSystemPages(void* address, size_t size) {
// TODO(hpayer): Does Fuchsia have madvise?
return true;
}
// static
bool OS::HasLazyCommits() {
// TODO(scottmg): Port, https://crbug.com/731217.
return false;
}
std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
UNREACHABLE(); // TODO(scottmg): Port, https://crbug.com/731217.
}
void OS::SignalCodeMovingGC() {
UNREACHABLE(); // TODO(scottmg): Port, https://crbug.com/731217.
}
int OS::GetUserTime(uint32_t* secs, uint32_t* usecs) {
const auto kNanosPerMicrosecond = 1000ULL;
const auto kMicrosPerSecond = 1000000ULL;
zx_time_t nanos_since_thread_started;
zx_status_t status =
zx_clock_get_new(ZX_CLOCK_THREAD, &nanos_since_thread_started);
if (status != ZX_OK) {
return -1;
}
// First convert to microseconds, rounding up.
const uint64_t micros_since_thread_started =
(nanos_since_thread_started + kNanosPerMicrosecond - 1ULL) /
kNanosPerMicrosecond;
*secs = static_cast<uint32_t>(micros_since_thread_started / kMicrosPerSecond);
*usecs =
static_cast<uint32_t>(micros_since_thread_started % kMicrosPerSecond);
return 0;
}
void OS::AdjustSchedulingParams() {}
} // namespace base
} // namespace v8
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