| // Copyright 2012 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. |
| |
| // Platform-specific code for Cygwin goes here. For the POSIX-compatible |
| // parts, the implementation is in platform-posix.cc. |
| |
| #include <errno.h> |
| #include <pthread.h> |
| #include <semaphore.h> |
| #include <stdarg.h> |
| #include <strings.h> // index |
| #include <sys/mman.h> // mmap & munmap |
| #include <sys/time.h> |
| #include <unistd.h> // sysconf |
| |
| #include <cmath> |
| |
| #undef MAP_TYPE |
| |
| #include "src/base/macros.h" |
| #include "src/base/platform/platform.h" |
| #include "src/base/win32-headers.h" |
| |
| namespace v8 { |
| namespace base { |
| |
| |
| const char* OS::LocalTimezone(double time, TimezoneCache* cache) { |
| if (std::isnan(time)) return ""; |
| time_t tv = static_cast<time_t>(std::floor(time/msPerSecond)); |
| struct tm* t = localtime(&tv); // NOLINT(runtime/threadsafe_fn) |
| if (NULL == t) return ""; |
| return tzname[0]; // The location of the timezone string on Cygwin. |
| } |
| |
| |
| double OS::LocalTimeOffset(TimezoneCache* cache) { |
| // On Cygwin, struct tm does not contain a tm_gmtoff field. |
| time_t utc = time(NULL); |
| DCHECK(utc != -1); |
| struct tm* loc = localtime(&utc); // NOLINT(runtime/threadsafe_fn) |
| DCHECK(loc != NULL); |
| // time - localtime includes any daylight savings offset, so subtract it. |
| return static_cast<double>((mktime(loc) - utc) * msPerSecond - |
| (loc->tm_isdst > 0 ? 3600 * msPerSecond : 0)); |
| } |
| |
| |
| void* OS::Allocate(const size_t requested, |
| size_t* allocated, |
| bool is_executable) { |
| const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE)); |
| int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); |
| void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| if (mbase == MAP_FAILED) return NULL; |
| *allocated = msize; |
| return mbase; |
| } |
| |
| |
| std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() { |
| std::vector<SharedLibraryAddresses> result; |
| // This function assumes that the layout of the file is as follows: |
| // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name] |
| // If we encounter an unexpected situation we abort scanning further entries. |
| FILE* fp = fopen("/proc/self/maps", "r"); |
| if (fp == NULL) return result; |
| |
| // Allocate enough room to be able to store a full file name. |
| const int kLibNameLen = FILENAME_MAX + 1; |
| char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen)); |
| |
| // This loop will terminate once the scanning hits an EOF. |
| while (true) { |
| uintptr_t start, end; |
| char attr_r, attr_w, attr_x, attr_p; |
| // Parse the addresses and permission bits at the beginning of the line. |
| if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break; |
| if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break; |
| |
| int c; |
| if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') { |
| // Found a read-only executable entry. Skip characters until we reach |
| // the beginning of the filename or the end of the line. |
| do { |
| c = getc(fp); |
| } while ((c != EOF) && (c != '\n') && (c != '/')); |
| if (c == EOF) break; // EOF: Was unexpected, just exit. |
| |
| // Process the filename if found. |
| if (c == '/') { |
| ungetc(c, fp); // Push the '/' back into the stream to be read below. |
| |
| // Read to the end of the line. Exit if the read fails. |
| if (fgets(lib_name, kLibNameLen, fp) == NULL) break; |
| |
| // Drop the newline character read by fgets. We do not need to check |
| // for a zero-length string because we know that we at least read the |
| // '/' character. |
| lib_name[strlen(lib_name) - 1] = '\0'; |
| } else { |
| // No library name found, just record the raw address range. |
| snprintf(lib_name, kLibNameLen, |
| "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end); |
| } |
| result.push_back(SharedLibraryAddress(lib_name, start, end)); |
| } else { |
| // Entry not describing executable data. Skip to end of line to set up |
| // reading the next entry. |
| do { |
| c = getc(fp); |
| } while ((c != EOF) && (c != '\n')); |
| if (c == EOF) break; |
| } |
| } |
| free(lib_name); |
| fclose(fp); |
| return result; |
| } |
| |
| |
| void OS::SignalCodeMovingGC() { |
| // Nothing to do on Cygwin. |
| } |
| |
| |
| // The VirtualMemory implementation is taken from platform-win32.cc. |
| // The mmap-based virtual memory implementation as it is used on most posix |
| // platforms does not work well because Cygwin does not support MAP_FIXED. |
| // This causes VirtualMemory::Commit to not always commit the memory region |
| // specified. |
| |
| static void* RandomizedVirtualAlloc(size_t size, int action, int protection) { |
| LPVOID base = NULL; |
| |
| if (protection == PAGE_EXECUTE_READWRITE || protection == PAGE_NOACCESS) { |
| // For exectutable pages try and randomize the allocation address |
| for (size_t attempts = 0; base == NULL && attempts < 3; ++attempts) { |
| base = VirtualAlloc(OS::GetRandomMmapAddr(), size, action, protection); |
| } |
| } |
| |
| // After three attempts give up and let the OS find an address to use. |
| if (base == NULL) base = VirtualAlloc(NULL, size, action, protection); |
| |
| return base; |
| } |
| |
| |
| VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { } |
| |
| |
| VirtualMemory::VirtualMemory(size_t size) |
| : address_(ReserveRegion(size)), size_(size) { } |
| |
| |
| VirtualMemory::VirtualMemory(size_t size, size_t alignment) |
| : address_(NULL), size_(0) { |
| DCHECK((alignment % OS::AllocateAlignment()) == 0); |
| size_t request_size = RoundUp(size + alignment, |
| static_cast<intptr_t>(OS::AllocateAlignment())); |
| void* address = ReserveRegion(request_size); |
| if (address == NULL) return; |
| uint8_t* base = RoundUp(static_cast<uint8_t*>(address), alignment); |
| // Try reducing the size by freeing and then reallocating a specific area. |
| bool result = ReleaseRegion(address, request_size); |
| USE(result); |
| DCHECK(result); |
| address = VirtualAlloc(base, size, MEM_RESERVE, PAGE_NOACCESS); |
| if (address != NULL) { |
| request_size = size; |
| DCHECK(base == static_cast<uint8_t*>(address)); |
| } else { |
| // Resizing failed, just go with a bigger area. |
| address = ReserveRegion(request_size); |
| if (address == NULL) return; |
| } |
| address_ = address; |
| size_ = request_size; |
| } |
| |
| |
| VirtualMemory::~VirtualMemory() { |
| if (IsReserved()) { |
| bool result = ReleaseRegion(address_, size_); |
| DCHECK(result); |
| USE(result); |
| } |
| } |
| |
| |
| bool VirtualMemory::IsReserved() { |
| 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::Uncommit(void* address, size_t size) { |
| DCHECK(IsReserved()); |
| return UncommitRegion(address, size); |
| } |
| |
| |
| void* VirtualMemory::ReserveRegion(size_t size) { |
| return RandomizedVirtualAlloc(size, MEM_RESERVE, PAGE_NOACCESS); |
| } |
| |
| |
| bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) { |
| int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE; |
| if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) { |
| return false; |
| } |
| return true; |
| } |
| |
| |
| bool VirtualMemory::Guard(void* address) { |
| if (NULL == VirtualAlloc(address, |
| OS::CommitPageSize(), |
| MEM_COMMIT, |
| PAGE_NOACCESS)) { |
| return false; |
| } |
| return true; |
| } |
| |
| |
| bool VirtualMemory::UncommitRegion(void* base, size_t size) { |
| return VirtualFree(base, size, MEM_DECOMMIT) != 0; |
| } |
| |
| |
| bool VirtualMemory::ReleaseRegion(void* base, size_t size) { |
| return VirtualFree(base, 0, MEM_RELEASE) != 0; |
| } |
| |
| |
| bool VirtualMemory::HasLazyCommits() { |
| // TODO(alph): implement for the platform. |
| return false; |
| } |
| |
| } // namespace base |
| } // namespace v8 |