platform-linux.cc revision 257744e915dfc84d6d07a6b2accf8402d9ffc708
1// Copyright 2011 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28// Platform specific code for Linux goes here. For the POSIX comaptible parts 29// the implementation is in platform-posix.cc. 30 31#include <pthread.h> 32#include <semaphore.h> 33#include <signal.h> 34#include <sys/prctl.h> 35#include <sys/time.h> 36#include <sys/resource.h> 37#include <sys/syscall.h> 38#include <sys/types.h> 39#include <stdlib.h> 40 41// Ubuntu Dapper requires memory pages to be marked as 42// executable. Otherwise, OS raises an exception when executing code 43// in that page. 44#include <sys/types.h> // mmap & munmap 45#include <sys/mman.h> // mmap & munmap 46#include <sys/stat.h> // open 47#include <fcntl.h> // open 48#include <unistd.h> // sysconf 49#ifdef __GLIBC__ 50#include <execinfo.h> // backtrace, backtrace_symbols 51#endif // def __GLIBC__ 52#include <strings.h> // index 53#include <errno.h> 54#include <stdarg.h> 55 56#undef MAP_TYPE 57 58#include "v8.h" 59 60#include "platform.h" 61#include "v8threads.h" 62#include "vm-state-inl.h" 63 64 65namespace v8 { 66namespace internal { 67 68// 0 is never a valid thread id on Linux since tids and pids share a 69// name space and pid 0 is reserved (see man 2 kill). 70static const pthread_t kNoThread = (pthread_t) 0; 71 72 73double ceiling(double x) { 74 return ceil(x); 75} 76 77 78static Mutex* limit_mutex = NULL; 79 80 81void OS::Setup() { 82 // Seed the random number generator. 83 // Convert the current time to a 64-bit integer first, before converting it 84 // to an unsigned. Going directly can cause an overflow and the seed to be 85 // set to all ones. The seed will be identical for different instances that 86 // call this setup code within the same millisecond. 87 uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis()); 88 srandom(static_cast<unsigned int>(seed)); 89 limit_mutex = CreateMutex(); 90 91#ifdef __arm__ 92 // When running on ARM hardware check that the EABI used by V8 and 93 // by the C code is the same. 94 bool hard_float = OS::ArmUsingHardFloat(); 95 if (hard_float) { 96#if !USE_EABI_HARDFLOAT 97 PrintF("ERROR: Binary compiled with -mfloat-abi=hard but without " 98 "-DUSE_EABI_HARDFLOAT\n"); 99 exit(1); 100#endif 101 } else { 102#if USE_EABI_HARDFLOAT 103 PrintF("ERROR: Binary not compiled with -mfloat-abi=hard but with " 104 "-DUSE_EABI_HARDFLOAT\n"); 105 exit(1); 106#endif 107 } 108#endif 109} 110 111 112uint64_t OS::CpuFeaturesImpliedByPlatform() { 113#if(defined(__mips_hard_float) && __mips_hard_float != 0) 114 // Here gcc is telling us that we are on an MIPS and gcc is assuming that we 115 // have FPU instructions. If gcc can assume it then so can we. 116 return 1u << FPU; 117#else 118 return 0; // Linux runs on anything. 119#endif 120} 121 122 123#ifdef __arm__ 124static bool CPUInfoContainsString(const char * search_string) { 125 const char* file_name = "/proc/cpuinfo"; 126 // This is written as a straight shot one pass parser 127 // and not using STL string and ifstream because, 128 // on Linux, it's reading from a (non-mmap-able) 129 // character special device. 130 FILE* f = NULL; 131 const char* what = search_string; 132 133 if (NULL == (f = fopen(file_name, "r"))) 134 return false; 135 136 int k; 137 while (EOF != (k = fgetc(f))) { 138 if (k == *what) { 139 ++what; 140 while ((*what != '\0') && (*what == fgetc(f))) { 141 ++what; 142 } 143 if (*what == '\0') { 144 fclose(f); 145 return true; 146 } else { 147 what = search_string; 148 } 149 } 150 } 151 fclose(f); 152 153 // Did not find string in the proc file. 154 return false; 155} 156 157 158bool OS::ArmCpuHasFeature(CpuFeature feature) { 159 const char* search_string = NULL; 160 // Simple detection of VFP at runtime for Linux. 161 // It is based on /proc/cpuinfo, which reveals hardware configuration 162 // to user-space applications. According to ARM (mid 2009), no similar 163 // facility is universally available on the ARM architectures, 164 // so it's up to individual OSes to provide such. 165 switch (feature) { 166 case VFP3: 167 search_string = "vfpv3"; 168 break; 169 case ARMv7: 170 search_string = "ARMv7"; 171 break; 172 default: 173 UNREACHABLE(); 174 } 175 176 if (CPUInfoContainsString(search_string)) { 177 return true; 178 } 179 180 if (feature == VFP3) { 181 // Some old kernels will report vfp not vfpv3. Here we make a last attempt 182 // to detect vfpv3 by checking for vfp *and* neon, since neon is only 183 // available on architectures with vfpv3. 184 // Checking neon on its own is not enough as it is possible to have neon 185 // without vfp. 186 if (CPUInfoContainsString("vfp") && CPUInfoContainsString("neon")) { 187 return true; 188 } 189 } 190 191 return false; 192} 193 194 195// Simple helper function to detect whether the C code is compiled with 196// option -mfloat-abi=hard. The register d0 is loaded with 1.0 and the register 197// pair r0, r1 is loaded with 0.0. If -mfloat-abi=hard is pased to GCC then 198// calling this will return 1.0 and otherwise 0.0. 199static void ArmUsingHardFloatHelper() { 200 asm("mov r0, #0"); 201#if defined(__VFP_FP__) && !defined(__SOFTFP__) 202 // Load 0x3ff00000 into r1 using instructions available in both ARM 203 // and Thumb mode. 204 asm("mov r1, #3"); 205 asm("mov r2, #255"); 206 asm("lsl r1, r1, #8"); 207 asm("orr r1, r1, r2"); 208 asm("lsl r1, r1, #20"); 209 // For vmov d0, r0, r1 use ARM mode. 210#ifdef __thumb__ 211 asm volatile( 212 "@ Enter ARM Mode \n\t" 213 " adr r3, 1f \n\t" 214 " bx r3 \n\t" 215 " .ALIGN 4 \n\t" 216 " .ARM \n" 217 "1: vmov d0, r0, r1 \n\t" 218 "@ Enter THUMB Mode\n\t" 219 " adr r3, 2f+1 \n\t" 220 " bx r3 \n\t" 221 " .THUMB \n" 222 "2: \n\t"); 223#else 224 asm("vmov d0, r0, r1"); 225#endif // __thumb__ 226#endif // defined(__VFP_FP__) && !defined(__SOFTFP__) 227 asm("mov r1, #0"); 228} 229 230 231bool OS::ArmUsingHardFloat() { 232 // Cast helper function from returning void to returning double. 233 typedef double (*F)(); 234 F f = FUNCTION_CAST<F>(FUNCTION_ADDR(ArmUsingHardFloatHelper)); 235 return f() == 1.0; 236} 237#endif // def __arm__ 238 239 240#ifdef __mips__ 241bool OS::MipsCpuHasFeature(CpuFeature feature) { 242 const char* search_string = NULL; 243 const char* file_name = "/proc/cpuinfo"; 244 // Simple detection of FPU at runtime for Linux. 245 // It is based on /proc/cpuinfo, which reveals hardware configuration 246 // to user-space applications. According to MIPS (early 2010), no similar 247 // facility is universally available on the MIPS architectures, 248 // so it's up to individual OSes to provide such. 249 // 250 // This is written as a straight shot one pass parser 251 // and not using STL string and ifstream because, 252 // on Linux, it's reading from a (non-mmap-able) 253 // character special device. 254 255 switch (feature) { 256 case FPU: 257 search_string = "FPU"; 258 break; 259 default: 260 UNREACHABLE(); 261 } 262 263 FILE* f = NULL; 264 const char* what = search_string; 265 266 if (NULL == (f = fopen(file_name, "r"))) 267 return false; 268 269 int k; 270 while (EOF != (k = fgetc(f))) { 271 if (k == *what) { 272 ++what; 273 while ((*what != '\0') && (*what == fgetc(f))) { 274 ++what; 275 } 276 if (*what == '\0') { 277 fclose(f); 278 return true; 279 } else { 280 what = search_string; 281 } 282 } 283 } 284 fclose(f); 285 286 // Did not find string in the proc file. 287 return false; 288} 289#endif // def __mips__ 290 291 292int OS::ActivationFrameAlignment() { 293#ifdef V8_TARGET_ARCH_ARM 294 // On EABI ARM targets this is required for fp correctness in the 295 // runtime system. 296 return 8; 297#elif V8_TARGET_ARCH_MIPS 298 return 8; 299#endif 300 // With gcc 4.4 the tree vectorization optimizer can generate code 301 // that requires 16 byte alignment such as movdqa on x86. 302 return 16; 303} 304 305 306void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) { 307#if (defined(V8_TARGET_ARCH_ARM) && defined(__arm__)) || \ 308 (defined(V8_TARGET_ARCH_MIPS) && defined(__mips__)) 309 // Only use on ARM or MIPS hardware. 310 MemoryBarrier(); 311#else 312 __asm__ __volatile__("" : : : "memory"); 313 // An x86 store acts as a release barrier. 314#endif 315 *ptr = value; 316} 317 318 319const char* OS::LocalTimezone(double time) { 320 if (isnan(time)) return ""; 321 time_t tv = static_cast<time_t>(floor(time/msPerSecond)); 322 struct tm* t = localtime(&tv); 323 if (NULL == t) return ""; 324 return t->tm_zone; 325} 326 327 328double OS::LocalTimeOffset() { 329 time_t tv = time(NULL); 330 struct tm* t = localtime(&tv); 331 // tm_gmtoff includes any daylight savings offset, so subtract it. 332 return static_cast<double>(t->tm_gmtoff * msPerSecond - 333 (t->tm_isdst > 0 ? 3600 * msPerSecond : 0)); 334} 335 336 337// We keep the lowest and highest addresses mapped as a quick way of 338// determining that pointers are outside the heap (used mostly in assertions 339// and verification). The estimate is conservative, ie, not all addresses in 340// 'allocated' space are actually allocated to our heap. The range is 341// [lowest, highest), inclusive on the low and and exclusive on the high end. 342static void* lowest_ever_allocated = reinterpret_cast<void*>(-1); 343static void* highest_ever_allocated = reinterpret_cast<void*>(0); 344 345 346static void UpdateAllocatedSpaceLimits(void* address, int size) { 347 ASSERT(limit_mutex != NULL); 348 ScopedLock lock(limit_mutex); 349 350 lowest_ever_allocated = Min(lowest_ever_allocated, address); 351 highest_ever_allocated = 352 Max(highest_ever_allocated, 353 reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size)); 354} 355 356 357bool OS::IsOutsideAllocatedSpace(void* address) { 358 return address < lowest_ever_allocated || address >= highest_ever_allocated; 359} 360 361 362size_t OS::AllocateAlignment() { 363 return sysconf(_SC_PAGESIZE); 364} 365 366 367void* OS::Allocate(const size_t requested, 368 size_t* allocated, 369 bool is_executable) { 370 // TODO(805): Port randomization of allocated executable memory to Linux. 371 const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE)); 372 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); 373 void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 374 if (mbase == MAP_FAILED) { 375 LOG(i::Isolate::Current(), 376 StringEvent("OS::Allocate", "mmap failed")); 377 return NULL; 378 } 379 *allocated = msize; 380 UpdateAllocatedSpaceLimits(mbase, msize); 381 return mbase; 382} 383 384 385void OS::Free(void* address, const size_t size) { 386 // TODO(1240712): munmap has a return value which is ignored here. 387 int result = munmap(address, size); 388 USE(result); 389 ASSERT(result == 0); 390} 391 392 393#ifdef ENABLE_HEAP_PROTECTION 394 395void OS::Protect(void* address, size_t size) { 396 // TODO(1240712): mprotect has a return value which is ignored here. 397 mprotect(address, size, PROT_READ); 398} 399 400 401void OS::Unprotect(void* address, size_t size, bool is_executable) { 402 // TODO(1240712): mprotect has a return value which is ignored here. 403 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); 404 mprotect(address, size, prot); 405} 406 407#endif 408 409 410void OS::Sleep(int milliseconds) { 411 unsigned int ms = static_cast<unsigned int>(milliseconds); 412 usleep(1000 * ms); 413} 414 415 416void OS::Abort() { 417 // Redirect to std abort to signal abnormal program termination. 418 abort(); 419} 420 421 422void OS::DebugBreak() { 423// TODO(lrn): Introduce processor define for runtime system (!= V8_ARCH_x, 424// which is the architecture of generated code). 425#if (defined(__arm__) || defined(__thumb__)) 426# if defined(CAN_USE_ARMV5_INSTRUCTIONS) 427 asm("bkpt 0"); 428# endif 429#elif defined(__mips__) 430 asm("break"); 431#else 432 asm("int $3"); 433#endif 434} 435 436 437class PosixMemoryMappedFile : public OS::MemoryMappedFile { 438 public: 439 PosixMemoryMappedFile(FILE* file, void* memory, int size) 440 : file_(file), memory_(memory), size_(size) { } 441 virtual ~PosixMemoryMappedFile(); 442 virtual void* memory() { return memory_; } 443 virtual int size() { return size_; } 444 private: 445 FILE* file_; 446 void* memory_; 447 int size_; 448}; 449 450 451OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) { 452 FILE* file = fopen(name, "r+"); 453 if (file == NULL) return NULL; 454 455 fseek(file, 0, SEEK_END); 456 int size = ftell(file); 457 458 void* memory = 459 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); 460 return new PosixMemoryMappedFile(file, memory, size); 461} 462 463 464OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size, 465 void* initial) { 466 FILE* file = fopen(name, "w+"); 467 if (file == NULL) return NULL; 468 int result = fwrite(initial, size, 1, file); 469 if (result < 1) { 470 fclose(file); 471 return NULL; 472 } 473 void* memory = 474 mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); 475 return new PosixMemoryMappedFile(file, memory, size); 476} 477 478 479PosixMemoryMappedFile::~PosixMemoryMappedFile() { 480 if (memory_) munmap(memory_, size_); 481 fclose(file_); 482} 483 484 485void OS::LogSharedLibraryAddresses() { 486#ifdef ENABLE_LOGGING_AND_PROFILING 487 // This function assumes that the layout of the file is as follows: 488 // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name] 489 // If we encounter an unexpected situation we abort scanning further entries. 490 FILE* fp = fopen("/proc/self/maps", "r"); 491 if (fp == NULL) return; 492 493 // Allocate enough room to be able to store a full file name. 494 const int kLibNameLen = FILENAME_MAX + 1; 495 char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen)); 496 497 i::Isolate* isolate = ISOLATE; 498 // This loop will terminate once the scanning hits an EOF. 499 while (true) { 500 uintptr_t start, end; 501 char attr_r, attr_w, attr_x, attr_p; 502 // Parse the addresses and permission bits at the beginning of the line. 503 if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break; 504 if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break; 505 506 int c; 507 if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') { 508 // Found a read-only executable entry. Skip characters until we reach 509 // the beginning of the filename or the end of the line. 510 do { 511 c = getc(fp); 512 } while ((c != EOF) && (c != '\n') && (c != '/')); 513 if (c == EOF) break; // EOF: Was unexpected, just exit. 514 515 // Process the filename if found. 516 if (c == '/') { 517 ungetc(c, fp); // Push the '/' back into the stream to be read below. 518 519 // Read to the end of the line. Exit if the read fails. 520 if (fgets(lib_name, kLibNameLen, fp) == NULL) break; 521 522 // Drop the newline character read by fgets. We do not need to check 523 // for a zero-length string because we know that we at least read the 524 // '/' character. 525 lib_name[strlen(lib_name) - 1] = '\0'; 526 } else { 527 // No library name found, just record the raw address range. 528 snprintf(lib_name, kLibNameLen, 529 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end); 530 } 531 LOG(isolate, SharedLibraryEvent(lib_name, start, end)); 532 } else { 533 // Entry not describing executable data. Skip to end of line to setup 534 // reading the next entry. 535 do { 536 c = getc(fp); 537 } while ((c != EOF) && (c != '\n')); 538 if (c == EOF) break; 539 } 540 } 541 free(lib_name); 542 fclose(fp); 543#endif 544} 545 546 547static const char kGCFakeMmap[] = "/tmp/__v8_gc__"; 548 549 550void OS::SignalCodeMovingGC() { 551#ifdef ENABLE_LOGGING_AND_PROFILING 552 // Support for ll_prof.py. 553 // 554 // The Linux profiler built into the kernel logs all mmap's with 555 // PROT_EXEC so that analysis tools can properly attribute ticks. We 556 // do a mmap with a name known by ll_prof.py and immediately munmap 557 // it. This injects a GC marker into the stream of events generated 558 // by the kernel and allows us to synchronize V8 code log and the 559 // kernel log. 560 int size = sysconf(_SC_PAGESIZE); 561 FILE* f = fopen(kGCFakeMmap, "w+"); 562 void* addr = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE, 563 fileno(f), 0); 564 ASSERT(addr != MAP_FAILED); 565 munmap(addr, size); 566 fclose(f); 567#endif 568} 569 570 571int OS::StackWalk(Vector<OS::StackFrame> frames) { 572 // backtrace is a glibc extension. 573#ifdef __GLIBC__ 574 int frames_size = frames.length(); 575 ScopedVector<void*> addresses(frames_size); 576 577 int frames_count = backtrace(addresses.start(), frames_size); 578 579 char** symbols = backtrace_symbols(addresses.start(), frames_count); 580 if (symbols == NULL) { 581 return kStackWalkError; 582 } 583 584 for (int i = 0; i < frames_count; i++) { 585 frames[i].address = addresses[i]; 586 // Format a text representation of the frame based on the information 587 // available. 588 SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen), 589 "%s", 590 symbols[i]); 591 // Make sure line termination is in place. 592 frames[i].text[kStackWalkMaxTextLen - 1] = '\0'; 593 } 594 595 free(symbols); 596 597 return frames_count; 598#else // ndef __GLIBC__ 599 return 0; 600#endif // ndef __GLIBC__ 601} 602 603 604// Constants used for mmap. 605static const int kMmapFd = -1; 606static const int kMmapFdOffset = 0; 607 608 609VirtualMemory::VirtualMemory(size_t size) { 610 address_ = mmap(NULL, size, PROT_NONE, 611 MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, 612 kMmapFd, kMmapFdOffset); 613 size_ = size; 614} 615 616 617VirtualMemory::~VirtualMemory() { 618 if (IsReserved()) { 619 if (0 == munmap(address(), size())) address_ = MAP_FAILED; 620 } 621} 622 623 624bool VirtualMemory::IsReserved() { 625 return address_ != MAP_FAILED; 626} 627 628 629bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) { 630 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); 631 if (MAP_FAILED == mmap(address, size, prot, 632 MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 633 kMmapFd, kMmapFdOffset)) { 634 return false; 635 } 636 637 UpdateAllocatedSpaceLimits(address, size); 638 return true; 639} 640 641 642bool VirtualMemory::Uncommit(void* address, size_t size) { 643 return mmap(address, size, PROT_NONE, 644 MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE | MAP_FIXED, 645 kMmapFd, kMmapFdOffset) != MAP_FAILED; 646} 647 648 649class Thread::PlatformData : public Malloced { 650 public: 651 PlatformData() : thread_(kNoThread) {} 652 653 pthread_t thread_; // Thread handle for pthread. 654}; 655 656Thread::Thread(Isolate* isolate, const Options& options) 657 : data_(new PlatformData()), 658 isolate_(isolate), 659 stack_size_(options.stack_size) { 660 set_name(options.name); 661} 662 663 664Thread::Thread(Isolate* isolate, const char* name) 665 : data_(new PlatformData()), 666 isolate_(isolate), 667 stack_size_(0) { 668 set_name(name); 669} 670 671 672Thread::~Thread() { 673 delete data_; 674} 675 676 677static void* ThreadEntry(void* arg) { 678 Thread* thread = reinterpret_cast<Thread*>(arg); 679 // This is also initialized by the first argument to pthread_create() but we 680 // don't know which thread will run first (the original thread or the new 681 // one) so we initialize it here too. 682 prctl(PR_SET_NAME, 683 reinterpret_cast<unsigned long>(thread->name()), // NOLINT 684 0, 0, 0); 685 thread->data()->thread_ = pthread_self(); 686 ASSERT(thread->data()->thread_ != kNoThread); 687 Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate()); 688 thread->Run(); 689 return NULL; 690} 691 692 693void Thread::set_name(const char* name) { 694 strncpy(name_, name, sizeof(name_)); 695 name_[sizeof(name_) - 1] = '\0'; 696} 697 698 699void Thread::Start() { 700 pthread_attr_t* attr_ptr = NULL; 701 pthread_attr_t attr; 702 if (stack_size_ > 0) { 703 pthread_attr_init(&attr); 704 pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_)); 705 attr_ptr = &attr; 706 } 707 pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this); 708 ASSERT(data_->thread_ != kNoThread); 709} 710 711 712void Thread::Join() { 713 pthread_join(data_->thread_, NULL); 714} 715 716 717Thread::LocalStorageKey Thread::CreateThreadLocalKey() { 718 pthread_key_t key; 719 int result = pthread_key_create(&key, NULL); 720 USE(result); 721 ASSERT(result == 0); 722 return static_cast<LocalStorageKey>(key); 723} 724 725 726void Thread::DeleteThreadLocalKey(LocalStorageKey key) { 727 pthread_key_t pthread_key = static_cast<pthread_key_t>(key); 728 int result = pthread_key_delete(pthread_key); 729 USE(result); 730 ASSERT(result == 0); 731} 732 733 734void* Thread::GetThreadLocal(LocalStorageKey key) { 735 pthread_key_t pthread_key = static_cast<pthread_key_t>(key); 736 return pthread_getspecific(pthread_key); 737} 738 739 740void Thread::SetThreadLocal(LocalStorageKey key, void* value) { 741 pthread_key_t pthread_key = static_cast<pthread_key_t>(key); 742 pthread_setspecific(pthread_key, value); 743} 744 745 746void Thread::YieldCPU() { 747 sched_yield(); 748} 749 750 751class LinuxMutex : public Mutex { 752 public: 753 754 LinuxMutex() { 755 pthread_mutexattr_t attrs; 756 int result = pthread_mutexattr_init(&attrs); 757 ASSERT(result == 0); 758 result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE); 759 ASSERT(result == 0); 760 result = pthread_mutex_init(&mutex_, &attrs); 761 ASSERT(result == 0); 762 } 763 764 virtual ~LinuxMutex() { pthread_mutex_destroy(&mutex_); } 765 766 virtual int Lock() { 767 int result = pthread_mutex_lock(&mutex_); 768 return result; 769 } 770 771 virtual int Unlock() { 772 int result = pthread_mutex_unlock(&mutex_); 773 return result; 774 } 775 776 virtual bool TryLock() { 777 int result = pthread_mutex_trylock(&mutex_); 778 // Return false if the lock is busy and locking failed. 779 if (result == EBUSY) { 780 return false; 781 } 782 ASSERT(result == 0); // Verify no other errors. 783 return true; 784 } 785 786 private: 787 pthread_mutex_t mutex_; // Pthread mutex for POSIX platforms. 788}; 789 790 791Mutex* OS::CreateMutex() { 792 return new LinuxMutex(); 793} 794 795 796class LinuxSemaphore : public Semaphore { 797 public: 798 explicit LinuxSemaphore(int count) { sem_init(&sem_, 0, count); } 799 virtual ~LinuxSemaphore() { sem_destroy(&sem_); } 800 801 virtual void Wait(); 802 virtual bool Wait(int timeout); 803 virtual void Signal() { sem_post(&sem_); } 804 private: 805 sem_t sem_; 806}; 807 808 809void LinuxSemaphore::Wait() { 810 while (true) { 811 int result = sem_wait(&sem_); 812 if (result == 0) return; // Successfully got semaphore. 813 CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup. 814 } 815} 816 817 818#ifndef TIMEVAL_TO_TIMESPEC 819#define TIMEVAL_TO_TIMESPEC(tv, ts) do { \ 820 (ts)->tv_sec = (tv)->tv_sec; \ 821 (ts)->tv_nsec = (tv)->tv_usec * 1000; \ 822} while (false) 823#endif 824 825 826bool LinuxSemaphore::Wait(int timeout) { 827 const long kOneSecondMicros = 1000000; // NOLINT 828 829 // Split timeout into second and nanosecond parts. 830 struct timeval delta; 831 delta.tv_usec = timeout % kOneSecondMicros; 832 delta.tv_sec = timeout / kOneSecondMicros; 833 834 struct timeval current_time; 835 // Get the current time. 836 if (gettimeofday(¤t_time, NULL) == -1) { 837 return false; 838 } 839 840 // Calculate time for end of timeout. 841 struct timeval end_time; 842 timeradd(¤t_time, &delta, &end_time); 843 844 struct timespec ts; 845 TIMEVAL_TO_TIMESPEC(&end_time, &ts); 846 // Wait for semaphore signalled or timeout. 847 while (true) { 848 int result = sem_timedwait(&sem_, &ts); 849 if (result == 0) return true; // Successfully got semaphore. 850 if (result > 0) { 851 // For glibc prior to 2.3.4 sem_timedwait returns the error instead of -1. 852 errno = result; 853 result = -1; 854 } 855 if (result == -1 && errno == ETIMEDOUT) return false; // Timeout. 856 CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup. 857 } 858} 859 860 861Semaphore* OS::CreateSemaphore(int count) { 862 return new LinuxSemaphore(count); 863} 864 865 866#ifdef ENABLE_LOGGING_AND_PROFILING 867 868#if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__)) 869// Android runs a fairly new Linux kernel, so signal info is there, 870// but the C library doesn't have the structs defined. 871 872struct sigcontext { 873 uint32_t trap_no; 874 uint32_t error_code; 875 uint32_t oldmask; 876 uint32_t gregs[16]; 877 uint32_t arm_cpsr; 878 uint32_t fault_address; 879}; 880typedef uint32_t __sigset_t; 881typedef struct sigcontext mcontext_t; 882typedef struct ucontext { 883 uint32_t uc_flags; 884 struct ucontext* uc_link; 885 stack_t uc_stack; 886 mcontext_t uc_mcontext; 887 __sigset_t uc_sigmask; 888} ucontext_t; 889enum ArmRegisters {R15 = 15, R13 = 13, R11 = 11}; 890 891#endif 892 893 894static int GetThreadID() { 895 // Glibc doesn't provide a wrapper for gettid(2). 896#if defined(ANDROID) 897 return syscall(__NR_gettid); 898#else 899 return syscall(SYS_gettid); 900#endif 901} 902 903 904static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) { 905#ifndef V8_HOST_ARCH_MIPS 906 USE(info); 907 if (signal != SIGPROF) return; 908 Isolate* isolate = Isolate::UncheckedCurrent(); 909 if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) { 910 // We require a fully initialized and entered isolate. 911 return; 912 } 913 if (v8::Locker::IsActive() && 914 !isolate->thread_manager()->IsLockedByCurrentThread()) { 915 return; 916 } 917 918 Sampler* sampler = isolate->logger()->sampler(); 919 if (sampler == NULL || !sampler->IsActive()) return; 920 921 TickSample sample_obj; 922 TickSample* sample = CpuProfiler::TickSampleEvent(isolate); 923 if (sample == NULL) sample = &sample_obj; 924 925 // Extracting the sample from the context is extremely machine dependent. 926 ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context); 927 mcontext_t& mcontext = ucontext->uc_mcontext; 928 sample->state = isolate->current_vm_state(); 929#if V8_HOST_ARCH_IA32 930 sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]); 931 sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]); 932 sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]); 933#elif V8_HOST_ARCH_X64 934 sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]); 935 sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]); 936 sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]); 937#elif V8_HOST_ARCH_ARM 938// An undefined macro evaluates to 0, so this applies to Android's Bionic also. 939#if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3)) 940 sample->pc = reinterpret_cast<Address>(mcontext.gregs[R15]); 941 sample->sp = reinterpret_cast<Address>(mcontext.gregs[R13]); 942 sample->fp = reinterpret_cast<Address>(mcontext.gregs[R11]); 943#else 944 sample->pc = reinterpret_cast<Address>(mcontext.arm_pc); 945 sample->sp = reinterpret_cast<Address>(mcontext.arm_sp); 946 sample->fp = reinterpret_cast<Address>(mcontext.arm_fp); 947#endif 948#elif V8_HOST_ARCH_MIPS 949 sample.pc = reinterpret_cast<Address>(mcontext.pc); 950 sample.sp = reinterpret_cast<Address>(mcontext.gregs[29]); 951 sample.fp = reinterpret_cast<Address>(mcontext.gregs[30]); 952#endif 953 sampler->SampleStack(sample); 954 sampler->Tick(sample); 955#endif 956} 957 958 959class Sampler::PlatformData : public Malloced { 960 public: 961 PlatformData() : vm_tid_(GetThreadID()) {} 962 963 int vm_tid() const { return vm_tid_; } 964 965 private: 966 const int vm_tid_; 967}; 968 969 970class SignalSender : public Thread { 971 public: 972 enum SleepInterval { 973 HALF_INTERVAL, 974 FULL_INTERVAL 975 }; 976 977 explicit SignalSender(int interval) 978 : Thread(NULL, "SignalSender"), 979 vm_tgid_(getpid()), 980 interval_(interval) {} 981 982 static void InstallSignalHandler() { 983 struct sigaction sa; 984 sa.sa_sigaction = ProfilerSignalHandler; 985 sigemptyset(&sa.sa_mask); 986 sa.sa_flags = SA_RESTART | SA_SIGINFO; 987 signal_handler_installed_ = 988 (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0); 989 } 990 991 static void RestoreSignalHandler() { 992 if (signal_handler_installed_) { 993 sigaction(SIGPROF, &old_signal_handler_, 0); 994 signal_handler_installed_ = false; 995 } 996 } 997 998 static void AddActiveSampler(Sampler* sampler) { 999 ScopedLock lock(mutex_); 1000 SamplerRegistry::AddActiveSampler(sampler); 1001 if (instance_ == NULL) { 1002 // Start a thread that will send SIGPROF signal to VM threads, 1003 // when CPU profiling will be enabled. 1004 instance_ = new SignalSender(sampler->interval()); 1005 instance_->Start(); 1006 } else { 1007 ASSERT(instance_->interval_ == sampler->interval()); 1008 } 1009 } 1010 1011 static void RemoveActiveSampler(Sampler* sampler) { 1012 ScopedLock lock(mutex_); 1013 SamplerRegistry::RemoveActiveSampler(sampler); 1014 if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) { 1015 RuntimeProfiler::WakeUpRuntimeProfilerThreadBeforeShutdown(); 1016 instance_->Join(); 1017 delete instance_; 1018 instance_ = NULL; 1019 RestoreSignalHandler(); 1020 } 1021 } 1022 1023 // Implement Thread::Run(). 1024 virtual void Run() { 1025 SamplerRegistry::State state; 1026 while ((state = SamplerRegistry::GetState()) != 1027 SamplerRegistry::HAS_NO_SAMPLERS) { 1028 bool cpu_profiling_enabled = 1029 (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS); 1030 bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled(); 1031 if (cpu_profiling_enabled && !signal_handler_installed_) 1032 InstallSignalHandler(); 1033 else if (!cpu_profiling_enabled && signal_handler_installed_) 1034 RestoreSignalHandler(); 1035 // When CPU profiling is enabled both JavaScript and C++ code is 1036 // profiled. We must not suspend. 1037 if (!cpu_profiling_enabled) { 1038 if (rate_limiter_.SuspendIfNecessary()) continue; 1039 } 1040 if (cpu_profiling_enabled && runtime_profiler_enabled) { 1041 if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) { 1042 return; 1043 } 1044 Sleep(HALF_INTERVAL); 1045 if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) { 1046 return; 1047 } 1048 Sleep(HALF_INTERVAL); 1049 } else { 1050 if (cpu_profiling_enabled) { 1051 if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, 1052 this)) { 1053 return; 1054 } 1055 } 1056 if (runtime_profiler_enabled) { 1057 if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, 1058 NULL)) { 1059 return; 1060 } 1061 } 1062 Sleep(FULL_INTERVAL); 1063 } 1064 } 1065 } 1066 1067 static void DoCpuProfile(Sampler* sampler, void* raw_sender) { 1068 if (!sampler->IsProfiling()) return; 1069 SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender); 1070 sender->SendProfilingSignal(sampler->platform_data()->vm_tid()); 1071 } 1072 1073 static void DoRuntimeProfile(Sampler* sampler, void* ignored) { 1074 if (!sampler->isolate()->IsInitialized()) return; 1075 sampler->isolate()->runtime_profiler()->NotifyTick(); 1076 } 1077 1078 void SendProfilingSignal(int tid) { 1079 if (!signal_handler_installed_) return; 1080 // Glibc doesn't provide a wrapper for tgkill(2). 1081#if defined(ANDROID) 1082 syscall(__NR_tgkill, vm_tgid_, tid, SIGPROF); 1083#else 1084 syscall(SYS_tgkill, vm_tgid_, tid, SIGPROF); 1085#endif 1086 } 1087 1088 void Sleep(SleepInterval full_or_half) { 1089 // Convert ms to us and subtract 100 us to compensate delays 1090 // occuring during signal delivery. 1091 useconds_t interval = interval_ * 1000 - 100; 1092 if (full_or_half == HALF_INTERVAL) interval /= 2; 1093 int result = usleep(interval); 1094#ifdef DEBUG 1095 if (result != 0 && errno != EINTR) { 1096 fprintf(stderr, 1097 "SignalSender usleep error; interval = %u, errno = %d\n", 1098 interval, 1099 errno); 1100 ASSERT(result == 0 || errno == EINTR); 1101 } 1102#endif 1103 USE(result); 1104 } 1105 1106 const int vm_tgid_; 1107 const int interval_; 1108 RuntimeProfilerRateLimiter rate_limiter_; 1109 1110 // Protects the process wide state below. 1111 static Mutex* mutex_; 1112 static SignalSender* instance_; 1113 static bool signal_handler_installed_; 1114 static struct sigaction old_signal_handler_; 1115 1116 DISALLOW_COPY_AND_ASSIGN(SignalSender); 1117}; 1118 1119 1120Mutex* SignalSender::mutex_ = OS::CreateMutex(); 1121SignalSender* SignalSender::instance_ = NULL; 1122struct sigaction SignalSender::old_signal_handler_; 1123bool SignalSender::signal_handler_installed_ = false; 1124 1125 1126Sampler::Sampler(Isolate* isolate, int interval) 1127 : isolate_(isolate), 1128 interval_(interval), 1129 profiling_(false), 1130 active_(false), 1131 samples_taken_(0) { 1132 data_ = new PlatformData; 1133} 1134 1135 1136Sampler::~Sampler() { 1137 ASSERT(!IsActive()); 1138 delete data_; 1139} 1140 1141 1142void Sampler::Start() { 1143 ASSERT(!IsActive()); 1144 SetActive(true); 1145 SignalSender::AddActiveSampler(this); 1146} 1147 1148 1149void Sampler::Stop() { 1150 ASSERT(IsActive()); 1151 SignalSender::RemoveActiveSampler(this); 1152 SetActive(false); 1153} 1154 1155#endif // ENABLE_LOGGING_AND_PROFILING 1156 1157} } // namespace v8::internal 1158