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v8: implement VirtualMemory class on SunOS
Unbreaks build on SunOS. Re-applies 4908e5b.
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bnoordhuis committed Oct 27, 2011
1 parent 92f5a5d commit b952954
Showing 1 changed file with 126 additions and 15 deletions.
141 changes: 126 additions & 15 deletions deps/v8/src/platform-solaris.cc
Expand Up @@ -54,6 +54,7 @@

#include "platform.h"
#include "vm-state-inl.h"
#include "v8threads.h"


// It seems there is a bug in some Solaris distributions (experienced in
Expand Down Expand Up @@ -83,6 +84,33 @@ namespace internal {
static const pthread_t kNoThread = (pthread_t) 0;


static void* GetRandomMmapAddr() {
Isolate* isolate = Isolate::UncheckedCurrent();
// Note that the current isolate isn't set up in a call path via
// CpuFeatures::Probe. We don't care about randomization in this case because
// the code page is immediately freed.
if (isolate != NULL) {
#ifdef V8_TARGET_ARCH_X64
uint64_t rnd1 = V8::RandomPrivate(isolate);
uint64_t rnd2 = V8::RandomPrivate(isolate);
uint64_t raw_addr = (rnd1 << 32) ^ rnd2;
// Currently available CPUs have 48 bits of virtual addressing. Truncate
// the hint address to 46 bits to give the kernel a fighting chance of
// fulfilling our placement request.
raw_addr &= V8_UINT64_C(0x3ffffffff000);
#else
uint32_t raw_addr = V8::RandomPrivate(isolate);
// The range 0x20000000 - 0x60000000 is relatively unpopulated across a
// variety of ASLR modes (PAE kernel, NX compat mode, etc).
raw_addr &= 0x3ffff000;
raw_addr += 0x20000000;
#endif
return reinterpret_cast<void*>(raw_addr);
}
return NULL;
}


double ceiling(double x) {
return ceil(x);
}
Expand Down Expand Up @@ -322,43 +350,126 @@ static const int kMmapFd = -1;
static const int kMmapFdOffset = 0;


VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }

VirtualMemory::VirtualMemory(size_t size) {
address_ = mmap(NULL, size, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd, kMmapFdOffset);
address_ = ReserveRegion(size);
size_ = size;
}


VirtualMemory::VirtualMemory(size_t size, size_t alignment)
: address_(NULL), size_(0) {
ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
size_t request_size = RoundUp(size + alignment,
static_cast<intptr_t>(OS::AllocateAlignment()));
void* reservation = mmap(GetRandomMmapAddr(),
request_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);
if (reservation == MAP_FAILED) return;

Address base = static_cast<Address>(reservation);
Address aligned_base = RoundUp(base, alignment);
ASSERT_LE(base, aligned_base);

// Unmap extra memory reserved before and after the desired block.
if (aligned_base != base) {
size_t prefix_size = static_cast<size_t>(aligned_base - base);
OS::Free(base, prefix_size);
request_size -= prefix_size;
}

size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
ASSERT_LE(aligned_size, request_size);

if (aligned_size != request_size) {
size_t suffix_size = request_size - aligned_size;
OS::Free(aligned_base + aligned_size, suffix_size);
request_size -= suffix_size;
}

ASSERT(aligned_size == request_size);

address_ = static_cast<void*>(aligned_base);
size_ = aligned_size;
}


VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
if (0 == munmap(address(), size())) address_ = MAP_FAILED;
bool result = ReleaseRegion(address(), size());
ASSERT(result);
USE(result);
}
}


bool VirtualMemory::IsReserved() {
return address_ != MAP_FAILED;
return address_ != NULL;
}


void VirtualMemory::Reset() {
address_ = NULL;
size_ = 0;
}


bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
return CommitRegion(address, size, is_executable);
}


bool VirtualMemory::Commit(void* address, size_t size, bool executable) {
int prot = PROT_READ | PROT_WRITE | (executable ? PROT_EXEC : 0);
if (MAP_FAILED == mmap(address, size, prot,
MAP_PRIVATE | MAP_ANON | MAP_FIXED,
kMmapFd, kMmapFdOffset)) {
bool VirtualMemory::Uncommit(void* address, size_t size) {
return UncommitRegion(address, size);
}


void* VirtualMemory::ReserveRegion(size_t size) {
void* result = mmap(GetRandomMmapAddr(),
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);

if (result == MAP_FAILED) return NULL;

return result;
}


bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
if (MAP_FAILED == mmap(base,
size,
prot,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
kMmapFd,
kMmapFdOffset)) {
return false;
}

UpdateAllocatedSpaceLimits(address, size);
UpdateAllocatedSpaceLimits(base, size);
return true;
}


bool VirtualMemory::Uncommit(void* address, size_t size) {
return mmap(address, size, PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED,
kMmapFd, kMmapFdOffset) != MAP_FAILED;
bool VirtualMemory::UncommitRegion(void* base, size_t size) {
return mmap(base,
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE | MAP_FIXED,
kMmapFd,
kMmapFdOffset) != MAP_FAILED;
}


bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
return munmap(base, size) == 0;
}


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