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| 1 // Copyright 2012 the V8 project authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 // Platform-specific code for Cygwin goes here. For the POSIX-compatible | |
| 6 // parts, the implementation is in platform-posix.cc. | |
| 7 | |
| 8 #include <errno.h> | |
| 9 #include <pthread.h> | |
| 10 #include <semaphore.h> | |
| 11 #include <stdarg.h> | |
| 12 #include <strings.h> // index | |
| 13 #include <sys/mman.h> // mmap & munmap | |
| 14 #include <sys/time.h> | |
| 15 #include <unistd.h> // sysconf | |
| 16 | |
| 17 #include <cmath> | |
| 18 | |
| 19 #undef MAP_TYPE | |
| 20 | |
| 21 #include "src/base/win32-headers.h" | |
| 22 #include "src/platform.h" | |
| 23 #include "src/utils.h" | |
| 24 | |
| 25 namespace v8 { | |
| 26 namespace internal { | |
| 27 | |
| 28 | |
| 29 const char* OS::LocalTimezone(double time, TimezoneCache* cache) { | |
| 30 if (std::isnan(time)) return ""; | |
| 31 time_t tv = static_cast<time_t>(std::floor(time/msPerSecond)); | |
| 32 struct tm* t = localtime(&tv); | |
| 33 if (NULL == t) return ""; | |
| 34 return tzname[0]; // The location of the timezone string on Cygwin. | |
| 35 } | |
| 36 | |
| 37 | |
| 38 double OS::LocalTimeOffset(TimezoneCache* cache) { | |
| 39 // On Cygwin, struct tm does not contain a tm_gmtoff field. | |
| 40 time_t utc = time(NULL); | |
| 41 ASSERT(utc != -1); | |
| 42 struct tm* loc = localtime(&utc); | |
| 43 ASSERT(loc != NULL); | |
| 44 // time - localtime includes any daylight savings offset, so subtract it. | |
| 45 return static_cast<double>((mktime(loc) - utc) * msPerSecond - | |
| 46 (loc->tm_isdst > 0 ? 3600 * msPerSecond : 0)); | |
| 47 } | |
| 48 | |
| 49 | |
| 50 void* OS::Allocate(const size_t requested, | |
| 51 size_t* allocated, | |
| 52 bool is_executable) { | |
| 53 const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE)); | |
| 54 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); | |
| 55 void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
| 56 if (mbase == MAP_FAILED) return NULL; | |
| 57 *allocated = msize; | |
| 58 return mbase; | |
| 59 } | |
| 60 | |
| 61 | |
| 62 class PosixMemoryMappedFile : public OS::MemoryMappedFile { | |
| 63 public: | |
| 64 PosixMemoryMappedFile(FILE* file, void* memory, int size) | |
| 65 : file_(file), memory_(memory), size_(size) { } | |
| 66 virtual ~PosixMemoryMappedFile(); | |
| 67 virtual void* memory() { return memory_; } | |
| 68 virtual int size() { return size_; } | |
| 69 private: | |
| 70 FILE* file_; | |
| 71 void* memory_; | |
| 72 int size_; | |
| 73 }; | |
| 74 | |
| 75 | |
| 76 OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) { | |
| 77 FILE* file = fopen(name, "r+"); | |
| 78 if (file == NULL) return NULL; | |
| 79 | |
| 80 fseek(file, 0, SEEK_END); | |
| 81 int size = ftell(file); | |
| 82 | |
| 83 void* memory = | |
| 84 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); | |
| 85 return new PosixMemoryMappedFile(file, memory, size); | |
| 86 } | |
| 87 | |
| 88 | |
| 89 OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size, | |
| 90 void* initial) { | |
| 91 FILE* file = fopen(name, "w+"); | |
| 92 if (file == NULL) return NULL; | |
| 93 int result = fwrite(initial, size, 1, file); | |
| 94 if (result < 1) { | |
| 95 fclose(file); | |
| 96 return NULL; | |
| 97 } | |
| 98 void* memory = | |
| 99 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); | |
| 100 return new PosixMemoryMappedFile(file, memory, size); | |
| 101 } | |
| 102 | |
| 103 | |
| 104 PosixMemoryMappedFile::~PosixMemoryMappedFile() { | |
| 105 if (memory_) munmap(memory_, size_); | |
| 106 fclose(file_); | |
| 107 } | |
| 108 | |
| 109 | |
| 110 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() { | |
| 111 std::vector<SharedLibraryAddresses> result; | |
| 112 // This function assumes that the layout of the file is as follows: | |
| 113 // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name] | |
| 114 // If we encounter an unexpected situation we abort scanning further entries. | |
| 115 FILE* fp = fopen("/proc/self/maps", "r"); | |
| 116 if (fp == NULL) return result; | |
| 117 | |
| 118 // Allocate enough room to be able to store a full file name. | |
| 119 const int kLibNameLen = FILENAME_MAX + 1; | |
| 120 char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen)); | |
| 121 | |
| 122 // This loop will terminate once the scanning hits an EOF. | |
| 123 while (true) { | |
| 124 uintptr_t start, end; | |
| 125 char attr_r, attr_w, attr_x, attr_p; | |
| 126 // Parse the addresses and permission bits at the beginning of the line. | |
| 127 if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break; | |
| 128 if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break; | |
| 129 | |
| 130 int c; | |
| 131 if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') { | |
| 132 // Found a read-only executable entry. Skip characters until we reach | |
| 133 // the beginning of the filename or the end of the line. | |
| 134 do { | |
| 135 c = getc(fp); | |
| 136 } while ((c != EOF) && (c != '\n') && (c != '/')); | |
| 137 if (c == EOF) break; // EOF: Was unexpected, just exit. | |
| 138 | |
| 139 // Process the filename if found. | |
| 140 if (c == '/') { | |
| 141 ungetc(c, fp); // Push the '/' back into the stream to be read below. | |
| 142 | |
| 143 // Read to the end of the line. Exit if the read fails. | |
| 144 if (fgets(lib_name, kLibNameLen, fp) == NULL) break; | |
| 145 | |
| 146 // Drop the newline character read by fgets. We do not need to check | |
| 147 // for a zero-length string because we know that we at least read the | |
| 148 // '/' character. | |
| 149 lib_name[strlen(lib_name) - 1] = '\0'; | |
| 150 } else { | |
| 151 // No library name found, just record the raw address range. | |
| 152 snprintf(lib_name, kLibNameLen, | |
| 153 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end); | |
| 154 } | |
| 155 result.push_back(SharedLibraryAddress(lib_name, start, end)); | |
| 156 } else { | |
| 157 // Entry not describing executable data. Skip to end of line to set up | |
| 158 // reading the next entry. | |
| 159 do { | |
| 160 c = getc(fp); | |
| 161 } while ((c != EOF) && (c != '\n')); | |
| 162 if (c == EOF) break; | |
| 163 } | |
| 164 } | |
| 165 free(lib_name); | |
| 166 fclose(fp); | |
| 167 return result; | |
| 168 } | |
| 169 | |
| 170 | |
| 171 void OS::SignalCodeMovingGC() { | |
| 172 // Nothing to do on Cygwin. | |
| 173 } | |
| 174 | |
| 175 | |
| 176 // The VirtualMemory implementation is taken from platform-win32.cc. | |
| 177 // The mmap-based virtual memory implementation as it is used on most posix | |
| 178 // platforms does not work well because Cygwin does not support MAP_FIXED. | |
| 179 // This causes VirtualMemory::Commit to not always commit the memory region | |
| 180 // specified. | |
| 181 | |
| 182 static void* GetRandomAddr() { | |
| 183 Isolate* isolate = Isolate::UncheckedCurrent(); | |
| 184 // Note that the current isolate isn't set up in a call path via | |
| 185 // CpuFeatures::Probe. We don't care about randomization in this case because | |
| 186 // the code page is immediately freed. | |
| 187 if (isolate != NULL) { | |
| 188 // The address range used to randomize RWX allocations in OS::Allocate | |
| 189 // Try not to map pages into the default range that windows loads DLLs | |
| 190 // Use a multiple of 64k to prevent committing unused memory. | |
| 191 // Note: This does not guarantee RWX regions will be within the | |
| 192 // range kAllocationRandomAddressMin to kAllocationRandomAddressMax | |
| 193 #ifdef V8_HOST_ARCH_64_BIT | |
| 194 static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000; | |
| 195 static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000; | |
| 196 #else | |
| 197 static const intptr_t kAllocationRandomAddressMin = 0x04000000; | |
| 198 static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000; | |
| 199 #endif | |
| 200 uintptr_t address = | |
| 201 (isolate->random_number_generator()->NextInt() << kPageSizeBits) | | |
| 202 kAllocationRandomAddressMin; | |
| 203 address &= kAllocationRandomAddressMax; | |
| 204 return reinterpret_cast<void *>(address); | |
| 205 } | |
| 206 return NULL; | |
| 207 } | |
| 208 | |
| 209 | |
| 210 static void* RandomizedVirtualAlloc(size_t size, int action, int protection) { | |
| 211 LPVOID base = NULL; | |
| 212 | |
| 213 if (protection == PAGE_EXECUTE_READWRITE || protection == PAGE_NOACCESS) { | |
| 214 // For exectutable pages try and randomize the allocation address | |
| 215 for (size_t attempts = 0; base == NULL && attempts < 3; ++attempts) { | |
| 216 base = VirtualAlloc(GetRandomAddr(), size, action, protection); | |
| 217 } | |
| 218 } | |
| 219 | |
| 220 // After three attempts give up and let the OS find an address to use. | |
| 221 if (base == NULL) base = VirtualAlloc(NULL, size, action, protection); | |
| 222 | |
| 223 return base; | |
| 224 } | |
| 225 | |
| 226 | |
| 227 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { } | |
| 228 | |
| 229 | |
| 230 VirtualMemory::VirtualMemory(size_t size) | |
| 231 : address_(ReserveRegion(size)), size_(size) { } | |
| 232 | |
| 233 | |
| 234 VirtualMemory::VirtualMemory(size_t size, size_t alignment) | |
| 235 : address_(NULL), size_(0) { | |
| 236 ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment()))); | |
| 237 size_t request_size = RoundUp(size + alignment, | |
| 238 static_cast<intptr_t>(OS::AllocateAlignment())); | |
| 239 void* address = ReserveRegion(request_size); | |
| 240 if (address == NULL) return; | |
| 241 uint8_t* base = RoundUp(static_cast<uint8_t*>(address), alignment); | |
| 242 // Try reducing the size by freeing and then reallocating a specific area. | |
| 243 bool result = ReleaseRegion(address, request_size); | |
| 244 USE(result); | |
| 245 ASSERT(result); | |
| 246 address = VirtualAlloc(base, size, MEM_RESERVE, PAGE_NOACCESS); | |
| 247 if (address != NULL) { | |
| 248 request_size = size; | |
| 249 ASSERT(base == static_cast<uint8_t*>(address)); | |
| 250 } else { | |
| 251 // Resizing failed, just go with a bigger area. | |
| 252 address = ReserveRegion(request_size); | |
| 253 if (address == NULL) return; | |
| 254 } | |
| 255 address_ = address; | |
| 256 size_ = request_size; | |
| 257 } | |
| 258 | |
| 259 | |
| 260 VirtualMemory::~VirtualMemory() { | |
| 261 if (IsReserved()) { | |
| 262 bool result = ReleaseRegion(address_, size_); | |
| 263 ASSERT(result); | |
| 264 USE(result); | |
| 265 } | |
| 266 } | |
| 267 | |
| 268 | |
| 269 bool VirtualMemory::IsReserved() { | |
| 270 return address_ != NULL; | |
| 271 } | |
| 272 | |
| 273 | |
| 274 void VirtualMemory::Reset() { | |
| 275 address_ = NULL; | |
| 276 size_ = 0; | |
| 277 } | |
| 278 | |
| 279 | |
| 280 bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) { | |
| 281 return CommitRegion(address, size, is_executable); | |
| 282 } | |
| 283 | |
| 284 | |
| 285 bool VirtualMemory::Uncommit(void* address, size_t size) { | |
| 286 ASSERT(IsReserved()); | |
| 287 return UncommitRegion(address, size); | |
| 288 } | |
| 289 | |
| 290 | |
| 291 void* VirtualMemory::ReserveRegion(size_t size) { | |
| 292 return RandomizedVirtualAlloc(size, MEM_RESERVE, PAGE_NOACCESS); | |
| 293 } | |
| 294 | |
| 295 | |
| 296 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) { | |
| 297 int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE; | |
| 298 if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) { | |
| 299 return false; | |
| 300 } | |
| 301 return true; | |
| 302 } | |
| 303 | |
| 304 | |
| 305 bool VirtualMemory::Guard(void* address) { | |
| 306 if (NULL == VirtualAlloc(address, | |
| 307 OS::CommitPageSize(), | |
| 308 MEM_COMMIT, | |
| 309 PAGE_NOACCESS)) { | |
| 310 return false; | |
| 311 } | |
| 312 return true; | |
| 313 } | |
| 314 | |
| 315 | |
| 316 bool VirtualMemory::UncommitRegion(void* base, size_t size) { | |
| 317 return VirtualFree(base, size, MEM_DECOMMIT) != 0; | |
| 318 } | |
| 319 | |
| 320 | |
| 321 bool VirtualMemory::ReleaseRegion(void* base, size_t size) { | |
| 322 return VirtualFree(base, 0, MEM_RELEASE) != 0; | |
| 323 } | |
| 324 | |
| 325 | |
| 326 bool VirtualMemory::HasLazyCommits() { | |
| 327 // TODO(alph): implement for the platform. | |
| 328 return false; | |
| 329 } | |
| 330 | |
| 331 } } // namespace v8::internal | |
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Chromium Code Reviews
Issue 358363002:
Move platform abstraction to base library (Closed)
Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge