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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 OpenBSD and NetBSD goes here. For the | |
| 6 // POSIX-compatible parts, the implementation is in platform-posix.cc. | |
| 7 | |
| 8 #include <pthread.h> | |
| 9 #include <semaphore.h> | |
| 10 #include <signal.h> | |
| 11 #include <stdlib.h> | |
| 12 #include <sys/resource.h> | |
| 13 #include <sys/syscall.h> | |
| 14 #include <sys/time.h> | |
| 15 #include <sys/types.h> | |
| 16 | |
| 17 #include <errno.h> | |
| 18 #include <fcntl.h> // open | |
| 19 #include <stdarg.h> | |
| 20 #include <strings.h> // index | |
| 21 #include <sys/mman.h> // mmap & munmap | |
| 22 #include <sys/stat.h> // open | |
| 23 #include <sys/types.h> // mmap & munmap | |
| 24 #include <unistd.h> // sysconf | |
| 25 | |
| 26 #include <cmath> | |
| 27 | |
| 28 #undef MAP_TYPE | |
| 29 | |
| 30 #include "src/platform.h" | |
| 31 #include "src/utils.h" | |
| 32 | |
| 33 | |
| 34 namespace v8 { | |
| 35 namespace internal { | |
| 36 | |
| 37 | |
| 38 const char* OS::LocalTimezone(double time, TimezoneCache* cache) { | |
| 39 if (std::isnan(time)) return ""; | |
| 40 time_t tv = static_cast<time_t>(std::floor(time/msPerSecond)); | |
| 41 struct tm* t = localtime(&tv); | |
| 42 if (NULL == t) return ""; | |
| 43 return t->tm_zone; | |
| 44 } | |
| 45 | |
| 46 | |
| 47 double OS::LocalTimeOffset(TimezoneCache* cache) { | |
| 48 time_t tv = time(NULL); | |
| 49 struct tm* t = localtime(&tv); | |
| 50 // tm_gmtoff includes any daylight savings offset, so subtract it. | |
| 51 return static_cast<double>(t->tm_gmtoff * msPerSecond - | |
| 52 (t->tm_isdst > 0 ? 3600 * msPerSecond : 0)); | |
| 53 } | |
| 54 | |
| 55 | |
| 56 void* OS::Allocate(const size_t requested, | |
| 57 size_t* allocated, | |
| 58 bool is_executable) { | |
| 59 const size_t msize = RoundUp(requested, AllocateAlignment()); | |
| 60 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); | |
| 61 void* addr = OS::GetRandomMmapAddr(); | |
| 62 void* mbase = mmap(addr, msize, prot, MAP_PRIVATE | MAP_ANON, -1, 0); | |
| 63 if (mbase == MAP_FAILED) return NULL; | |
| 64 *allocated = msize; | |
| 65 return mbase; | |
| 66 } | |
| 67 | |
| 68 | |
| 69 class PosixMemoryMappedFile : public OS::MemoryMappedFile { | |
| 70 public: | |
| 71 PosixMemoryMappedFile(FILE* file, void* memory, int size) | |
| 72 : file_(file), memory_(memory), size_(size) { } | |
| 73 virtual ~PosixMemoryMappedFile(); | |
| 74 virtual void* memory() { return memory_; } | |
| 75 virtual int size() { return size_; } | |
| 76 private: | |
| 77 FILE* file_; | |
| 78 void* memory_; | |
| 79 int size_; | |
| 80 }; | |
| 81 | |
| 82 | |
| 83 OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) { | |
| 84 FILE* file = fopen(name, "r+"); | |
| 85 if (file == NULL) return NULL; | |
| 86 | |
| 87 fseek(file, 0, SEEK_END); | |
| 88 int size = ftell(file); | |
| 89 | |
| 90 void* memory = | |
| 91 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); | |
| 92 return new PosixMemoryMappedFile(file, memory, size); | |
| 93 } | |
| 94 | |
| 95 | |
| 96 OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size, | |
| 97 void* initial) { | |
| 98 FILE* file = fopen(name, "w+"); | |
| 99 if (file == NULL) return NULL; | |
| 100 int result = fwrite(initial, size, 1, file); | |
| 101 if (result < 1) { | |
| 102 fclose(file); | |
| 103 return NULL; | |
| 104 } | |
| 105 void* memory = | |
| 106 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); | |
| 107 return new PosixMemoryMappedFile(file, memory, size); | |
| 108 } | |
| 109 | |
| 110 | |
| 111 PosixMemoryMappedFile::~PosixMemoryMappedFile() { | |
| 112 if (memory_) OS::Free(memory_, size_); | |
| 113 fclose(file_); | |
| 114 } | |
| 115 | |
| 116 | |
| 117 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() { | |
| 118 std::vector<SharedLibraryAddress> result; | |
| 119 // This function assumes that the layout of the file is as follows: | |
| 120 // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name] | |
| 121 // If we encounter an unexpected situation we abort scanning further entries. | |
| 122 FILE* fp = fopen("/proc/self/maps", "r"); | |
| 123 if (fp == NULL) return result; | |
| 124 | |
| 125 // Allocate enough room to be able to store a full file name. | |
| 126 const int kLibNameLen = FILENAME_MAX + 1; | |
| 127 char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen)); | |
| 128 | |
| 129 // This loop will terminate once the scanning hits an EOF. | |
| 130 while (true) { | |
| 131 uintptr_t start, end; | |
| 132 char attr_r, attr_w, attr_x, attr_p; | |
| 133 // Parse the addresses and permission bits at the beginning of the line. | |
| 134 if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break; | |
| 135 if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break; | |
| 136 | |
| 137 int c; | |
| 138 if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') { | |
| 139 // Found a read-only executable entry. Skip characters until we reach | |
| 140 // the beginning of the filename or the end of the line. | |
| 141 do { | |
| 142 c = getc(fp); | |
| 143 } while ((c != EOF) && (c != '\n') && (c != '/')); | |
| 144 if (c == EOF) break; // EOF: Was unexpected, just exit. | |
| 145 | |
| 146 // Process the filename if found. | |
| 147 if (c == '/') { | |
| 148 ungetc(c, fp); // Push the '/' back into the stream to be read below. | |
| 149 | |
| 150 // Read to the end of the line. Exit if the read fails. | |
| 151 if (fgets(lib_name, kLibNameLen, fp) == NULL) break; | |
| 152 | |
| 153 // Drop the newline character read by fgets. We do not need to check | |
| 154 // for a zero-length string because we know that we at least read the | |
| 155 // '/' character. | |
| 156 lib_name[strlen(lib_name) - 1] = '\0'; | |
| 157 } else { | |
| 158 // No library name found, just record the raw address range. | |
| 159 snprintf(lib_name, kLibNameLen, | |
| 160 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end); | |
| 161 } | |
| 162 result.push_back(SharedLibraryAddress(lib_name, start, end)); | |
| 163 } else { | |
| 164 // Entry not describing executable data. Skip to end of line to set up | |
| 165 // reading the next entry. | |
| 166 do { | |
| 167 c = getc(fp); | |
| 168 } while ((c != EOF) && (c != '\n')); | |
| 169 if (c == EOF) break; | |
| 170 } | |
| 171 } | |
| 172 free(lib_name); | |
| 173 fclose(fp); | |
| 174 return result; | |
| 175 } | |
| 176 | |
| 177 | |
| 178 void OS::SignalCodeMovingGC() { | |
| 179 // Support for ll_prof.py. | |
| 180 // | |
| 181 // The Linux profiler built into the kernel logs all mmap's with | |
| 182 // PROT_EXEC so that analysis tools can properly attribute ticks. We | |
| 183 // do a mmap with a name known by ll_prof.py and immediately munmap | |
| 184 // it. This injects a GC marker into the stream of events generated | |
| 185 // by the kernel and allows us to synchronize V8 code log and the | |
| 186 // kernel log. | |
| 187 int size = sysconf(_SC_PAGESIZE); | |
| 188 FILE* f = fopen(OS::GetGCFakeMMapFile(), "w+"); | |
| 189 if (f == NULL) { | |
| 190 OS::PrintError("Failed to open %s\n", OS::GetGCFakeMMapFile()); | |
| 191 OS::Abort(); | |
| 192 } | |
| 193 void* addr = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE, | |
| 194 fileno(f), 0); | |
| 195 ASSERT(addr != MAP_FAILED); | |
| 196 OS::Free(addr, size); | |
| 197 fclose(f); | |
| 198 } | |
| 199 | |
| 200 | |
| 201 | |
| 202 // Constants used for mmap. | |
| 203 static const int kMmapFd = -1; | |
| 204 static const int kMmapFdOffset = 0; | |
| 205 | |
| 206 | |
| 207 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { } | |
| 208 | |
| 209 | |
| 210 VirtualMemory::VirtualMemory(size_t size) | |
| 211 : address_(ReserveRegion(size)), size_(size) { } | |
| 212 | |
| 213 | |
| 214 VirtualMemory::VirtualMemory(size_t size, size_t alignment) | |
| 215 : address_(NULL), size_(0) { | |
| 216 ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment()))); | |
| 217 size_t request_size = RoundUp(size + alignment, | |
| 218 static_cast<intptr_t>(OS::AllocateAlignment())); | |
| 219 void* reservation = mmap(OS::GetRandomMmapAddr(), | |
| 220 request_size, | |
| 221 PROT_NONE, | |
| 222 MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, | |
| 223 kMmapFd, | |
| 224 kMmapFdOffset); | |
| 225 if (reservation == MAP_FAILED) return; | |
| 226 | |
| 227 uint8_t* base = static_cast<uint8_t*>(reservation); | |
| 228 uint8_t* aligned_base = RoundUp(base, alignment); | |
| 229 ASSERT_LE(base, aligned_base); | |
| 230 | |
| 231 // Unmap extra memory reserved before and after the desired block. | |
| 232 if (aligned_base != base) { | |
| 233 size_t prefix_size = static_cast<size_t>(aligned_base - base); | |
| 234 OS::Free(base, prefix_size); | |
| 235 request_size -= prefix_size; | |
| 236 } | |
| 237 | |
| 238 size_t aligned_size = RoundUp(size, OS::AllocateAlignment()); | |
| 239 ASSERT_LE(aligned_size, request_size); | |
| 240 | |
| 241 if (aligned_size != request_size) { | |
| 242 size_t suffix_size = request_size - aligned_size; | |
| 243 OS::Free(aligned_base + aligned_size, suffix_size); | |
| 244 request_size -= suffix_size; | |
| 245 } | |
| 246 | |
| 247 ASSERT(aligned_size == request_size); | |
| 248 | |
| 249 address_ = static_cast<void*>(aligned_base); | |
| 250 size_ = aligned_size; | |
| 251 } | |
| 252 | |
| 253 | |
| 254 VirtualMemory::~VirtualMemory() { | |
| 255 if (IsReserved()) { | |
| 256 bool result = ReleaseRegion(address(), size()); | |
| 257 ASSERT(result); | |
| 258 USE(result); | |
| 259 } | |
| 260 } | |
| 261 | |
| 262 | |
| 263 bool VirtualMemory::IsReserved() { | |
| 264 return address_ != NULL; | |
| 265 } | |
| 266 | |
| 267 | |
| 268 void VirtualMemory::Reset() { | |
| 269 address_ = NULL; | |
| 270 size_ = 0; | |
| 271 } | |
| 272 | |
| 273 | |
| 274 bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) { | |
| 275 return CommitRegion(address, size, is_executable); | |
| 276 } | |
| 277 | |
| 278 | |
| 279 bool VirtualMemory::Uncommit(void* address, size_t size) { | |
| 280 return UncommitRegion(address, size); | |
| 281 } | |
| 282 | |
| 283 | |
| 284 bool VirtualMemory::Guard(void* address) { | |
| 285 OS::Guard(address, OS::CommitPageSize()); | |
| 286 return true; | |
| 287 } | |
| 288 | |
| 289 | |
| 290 void* VirtualMemory::ReserveRegion(size_t size) { | |
| 291 void* result = mmap(OS::GetRandomMmapAddr(), | |
| 292 size, | |
| 293 PROT_NONE, | |
| 294 MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, | |
| 295 kMmapFd, | |
| 296 kMmapFdOffset); | |
| 297 | |
| 298 if (result == MAP_FAILED) return NULL; | |
| 299 | |
| 300 return result; | |
| 301 } | |
| 302 | |
| 303 | |
| 304 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) { | |
| 305 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); | |
| 306 if (MAP_FAILED == mmap(base, | |
| 307 size, | |
| 308 prot, | |
| 309 MAP_PRIVATE | MAP_ANON | MAP_FIXED, | |
| 310 kMmapFd, | |
| 311 kMmapFdOffset)) { | |
| 312 return false; | |
| 313 } | |
| 314 return true; | |
| 315 } | |
| 316 | |
| 317 | |
| 318 bool VirtualMemory::UncommitRegion(void* base, size_t size) { | |
| 319 return mmap(base, | |
| 320 size, | |
| 321 PROT_NONE, | |
| 322 MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED, | |
| 323 kMmapFd, | |
| 324 kMmapFdOffset) != MAP_FAILED; | |
| 325 } | |
| 326 | |
| 327 | |
| 328 bool VirtualMemory::ReleaseRegion(void* base, size_t size) { | |
| 329 return munmap(base, size) == 0; | |
| 330 } | |
| 331 | |
| 332 | |
| 333 bool VirtualMemory::HasLazyCommits() { | |
| 334 // TODO(alph): implement for the platform. | |
| 335 return false; | |
| 336 } | |
| 337 | |
| 338 } } // 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