[V8] Add support for QNX platform

This submission is based on code originally contributed by Jeff Rogers <jrogers@rim.com> with permission from Research in
Motion.

We have tried to make this change as unobtrusive as possible. For example in the atomic_ops.h header we have added a
conditional include for a qnx-specific atomicops_internals_arm_qnx.h as the existing atomicops_internals_arm_gcc.h is
actually Linux-specific despite the name of the file. In the longer term it would make sense to use an asm implementation
that is only dependent upon the CPU rather than OS-specific system calls. See qtbase/src/corelib/arch/qatomic_armv*.h
for a good reference.

Here we decided not to risk breaking existing platforms for the initial introduction of this new platform.

The QNX platform integration is built on top of the posix base.

Change-Id: Ie2a591bf1876915ca062034b22124ab27ff6d127
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

4 files changed, 1211 insertions, 4 deletions

diff --git a/src/3rdparty/v8/src/arm/cpu-arm.cc b/src/3rdparty/v8/src/arm/cpu-arm.cc
index 7b08ed8..f7da6c3 100644
--- a/src/3rdparty/v8/src/arm/cpu-arm.cc
+++ b/src/3rdparty/v8/src/arm/cpu-arm.cc
@@ -26,12 +26,17 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // CPU specific code for arm independent of OS goes here.
-#ifdef __arm__
-#include <sys/syscall.h>  // for cache flushing.
-#endif
 
 #include "v8.h"
 
+#if defined(__arm__)
+  #if !defined(__QNXNTO__)
+    #include <sys/syscall.h>  // for cache flushing.
+  #else
+    #include <sys/mman.h>  // for cache flushing.
+  #endif
+#endif
+
 #if defined(V8_TARGET_ARCH_ARM)
 
 #include "cpu.h"
@@ -64,6 +69,10 @@ void CPU::FlushICache(void* start, size_t size) {
   // None of this code ends up in the snapshot so there are no issues
   // around whether or not to generate the code when building snapshots.
   Simulator::FlushICache(Isolate::Current()->simulator_i_cache(), start, size);
+#elif defined(__QNXNTO__)
+  // The QNX kernel does not expose the symbol __ARM_NR_cacheflush so we
+  // use the msync system call instead of the approach used on Linux
+  msync(start, size, MS_SYNC|MS_INVALIDATE_ICACHE);
 #else
   // Ideally, we would call
   //   syscall(__ARM_NR_cacheflush, start,
diff --git a/src/3rdparty/v8/src/atomicops.h b/src/3rdparty/v8/src/atomicops.h
index 1f0c44a..754eb6b 100644
--- a/src/3rdparty/v8/src/atomicops.h
+++ b/src/3rdparty/v8/src/atomicops.h
@@ -161,7 +161,16 @@ Atomic64 Release_Load(volatile const Atomic64* ptr);
   (defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_X64))
 #include "atomicops_internals_x86_gcc.h"
 #elif defined(__GNUC__) && defined(V8_HOST_ARCH_ARM)
-#include "atomicops_internals_arm_gcc.h"
+  // We need special handling for QNX as the existing code in
+  // atomicops_internals_arm_gcc.h is actually Linux-specific. This is due to
+  // it using a magic hard-wired function address for LinuxKernelCmpxchgFunc.
+  // The QNX implementation uses the equivalent system call for that platform
+  // but is not source compatible.
+  #if defined(__QNXNTO__)
+    #include "atomicops_internals_arm_qnx.h"
+  #else
+    #include "atomicops_internals_arm_gcc.h"
+  #endif
 #elif defined(__GNUC__) && defined(V8_HOST_ARCH_MIPS)
 #include "atomicops_internals_mips_gcc.h"
 #else
diff --git a/src/3rdparty/v8/src/atomicops_internals_arm_qnx.h b/src/3rdparty/v8/src/atomicops_internals_arm_qnx.h
new file mode 100644
index 0000000..39c9850
--- /dev/null
+++ b/src/3rdparty/v8/src/atomicops_internals_arm_qnx.h
@@ -0,0 +1,117 @@
+// Copyright 2012 Research in Motion. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#ifndef V8_ATOMICOPS_INTERNALS_ARM_QNX_H_
+#define V8_ATOMICOPS_INTERNALS_ARM_QNX_H_
+
+#include <arm/cpuinline.h>
+#include <arm/smpxchg.h>
+
+namespace v8 {
+namespace internal {
+
+inline void MemoryBarrier() {
+  __cpu_membarrier();
+}
+
+inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
+                                         Atomic32 old_value,
+                                         Atomic32 new_value) {
+  return _smp_cmpxchg(reinterpret_cast<volatile unsigned*>(ptr), old_value, new_value);
+}
+
+inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
+                                         Atomic32 new_value) {
+  return _smp_xchg(reinterpret_cast<volatile unsigned*>(ptr), new_value);
+}
+
+inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
+                                          Atomic32 increment) {
+  for (;;) {
+    // Atomic exchange the old value with an incremented one.
+    Atomic32 old_value = *ptr;
+    Atomic32 new_value = old_value + increment;
+    if (_smp_cmpxchg(reinterpret_cast<volatile unsigned*>(ptr), old_value, new_value)) {
+      // The exchange took place as expected.
+      return new_value;
+    }
+    // Otherwise, *ptr changed mid-loop and we need to retry.
+  }
+}
+
+inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
+                                        Atomic32 increment) {
+  MemoryBarrier();
+  return NoBarrier_AtomicIncrement(ptr, increment);
+}
+
+inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+}
+
+inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+}
+
+inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
+  *ptr = value;
+}
+
+inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
+  return *ptr;
+}
+
+inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
+  Atomic32 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+
+} }  // namespace v8::internal
+
+#endif  // V8_ATOMICOPS_INTERNALS_ARM_QNX_H_
+
diff --git a/src/3rdparty/v8/src/platform-qnx.cc b/src/3rdparty/v8/src/platform-qnx.cc
new file mode 100644
index 0000000..43a2fc5
--- /dev/null
+++ b/src/3rdparty/v8/src/platform-qnx.cc
@@ -0,0 +1,1072 @@
+// Copyright 2012 Research in Motion. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Platform specific code for QNX goes here. For the POSIX comaptible parts
+// the implementation is in platform-posix.cc.
+
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <stdlib.h>
+#include <ucontext.h>
+#include <backtrace.h>
+
+// QNX requires memory pages to be marked as
+// executable. Otherwise, OS raises an exception when executing code
+// in that page.
+#include <sys/types.h>  // mmap & munmap
+#include <sys/mman.h>   // mmap & munmap
+#include <sys/stat.h>   // open
+#include <fcntl.h>      // open
+#include <unistd.h>     // sysconf
+#include <strings.h>    // index
+#include <errno.h>
+#include <stdarg.h>
+#include <sys/procfs.h>
+#include <sys/syspage.h>
+
+#undef MAP_TYPE
+
+#include "v8.h"
+
+#include "platform.h"
+#include "v8threads.h"
+#include "vm-state-inl.h"
+
+
+namespace v8 {
+namespace internal {
+
+// 0 is never a valid thread id on QNX since tids and pids share a
+// name space and pid 0 is reserved (see man 2 kill).
+static const pthread_t kNoThread = (pthread_t) 0;
+
+
+double ceiling(double x) {
+  return ceil(x);
+}
+
+
+static Mutex* limit_mutex = NULL;
+
+
+void OS::Setup() {
+  // Seed the random number generator. We preserve microsecond resolution.
+  uint64_t seed = Ticks() ^ (getpid() << 16);
+  srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
+
+#ifdef __arm__
+  // When running on ARM hardware check that the EABI used by V8 and
+  // by the C code is the same.
+  bool hard_float = OS::ArmUsingHardFloat();
+  if (hard_float) {
+#if !USE_EABI_HARDFLOAT
+    PrintF("ERROR: Binary compiled with -mfloat-abi=hard but without "
+           "-DUSE_EABI_HARDFLOAT\n");
+    exit(1);
+#endif
+  } else {
+#if USE_EABI_HARDFLOAT
+    PrintF("ERROR: Binary not compiled with -mfloat-abi=hard but with "
+           "-DUSE_EABI_HARDFLOAT\n");
+    exit(1);
+#endif
+  }
+#endif
+}
+
+
+uint64_t OS::CpuFeaturesImpliedByPlatform() {
+  return 0;  // QNX runs on anything.
+}
+
+
+#ifdef __arm__
+static bool CPUInfoContainsString(const char * search_string) {
+  const char* file_name = "/proc/cpuinfo";
+  // This is written as a straight shot one pass parser
+  // and not using STL string and ifstream because,
+  // on QNX, it's reading from a (non-mmap-able)
+  // character special device.
+  FILE* f = NULL;
+  const char* what = search_string;
+
+  if (NULL == (f = fopen(file_name, "r")))
+    return false;
+
+  int k;
+  while (EOF != (k = fgetc(f))) {
+    if (k == *what) {
+      ++what;
+      while ((*what != '\0') && (*what == fgetc(f))) {
+        ++what;
+      }
+      if (*what == '\0') {
+        fclose(f);
+        return true;
+      } else {
+        what = search_string;
+      }
+    }
+  }
+  fclose(f);
+
+  // Did not find string in the proc file.
+  return false;
+}
+
+
+bool OS::ArmCpuHasFeature(CpuFeature feature) {
+  switch (feature) {
+    case VFP3:
+      // All shipping devices currently support this and QNX has no easy way to
+      // determine this at runtime.
+      return true;
+    case ARMv7:
+      return (SYSPAGE_ENTRY(cpuinfo)->flags & ARM_CPU_FLAG_V7) != 0;
+    default:
+      UNREACHABLE();
+  }
+
+  return false;
+}
+
+
+// Simple helper function to detect whether the C code is compiled with
+// option -mfloat-abi=hard. The register d0 is loaded with 1.0 and the register
+// pair r0, r1 is loaded with 0.0. If -mfloat-abi=hard is passed to GCC then
+// calling this will return 1.0 and otherwise 0.0.
+static void ArmUsingHardFloatHelper() {
+  asm("mov r0, #0");
+#if defined(__VFP_FP__) && !defined(__SOFTFP__)
+  // Load 0x3ff00000 into r1 using instructions available in both ARM
+  // and Thumb mode.
+  asm("mov r1, #3");
+  asm("mov r2, #255");
+  asm("lsl r1, r1, #8");
+  asm("orr r1, r1, r2");
+  asm("lsl r1, r1, #20");
+  // For vmov d0, r0, r1 use ARM mode.
+#ifdef __thumb__
+  asm volatile(
+    "@   Enter ARM Mode  \n\t"
+    "    adr r3, 1f      \n\t"
+    "    bx  r3          \n\t"
+    "    .ALIGN 4        \n\t"
+    "    .ARM            \n"
+    "1:  vmov d0, r0, r1 \n\t"
+    "@   Enter THUMB Mode\n\t"
+    "    adr r3, 2f+1    \n\t"
+    "    bx  r3          \n\t"
+    "    .THUMB          \n"
+    "2:                  \n\t");
+#else
+  asm("vmov d0, r0, r1");
+#endif  // __thumb__
+#endif  // defined(__VFP_FP__) && !defined(__SOFTFP__)
+  asm("mov r1, #0");
+}
+
+
+bool OS::ArmUsingHardFloat() {
+  // Cast helper function from returning void to returning double.
+  typedef double (*F)();
+  F f = FUNCTION_CAST<F>(FUNCTION_ADDR(ArmUsingHardFloatHelper));
+  return f() == 1.0;
+}
+#endif  // def __arm__
+
+
+int OS::ActivationFrameAlignment() {
+#ifdef V8_TARGET_ARCH_ARM
+  // On EABI ARM targets this is required for fp correctness in the
+  // runtime system.
+  return 8;
+#endif
+  // With gcc 4.4 the tree vectorization optimizer can generate code
+  // that requires 16 byte alignment such as movdqa on x86.
+  return 16;
+}
+
+
+void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
+#if defined(V8_TARGET_ARCH_ARM) && defined(__arm__)
+  // Only use on ARM hardware.
+  MemoryBarrier();
+#else
+  __asm__ __volatile__("" : : : "memory");
+  // An x86 store acts as a release barrier.
+#endif
+  *ptr = value;
+}
+
+
+const char* OS::LocalTimezone(double time) {
+  if (isnan(time)) return "";
+  time_t tv = static_cast<time_t>(floor(time/msPerSecond));
+  struct tm* t = localtime(&tv);
+  if (NULL == t) return "";
+  return t->tm_zone;
+}
+
+
+double OS::LocalTimeOffset() {
+  time_t tv = time(NULL);
+  struct tm* t = localtime(&tv);
+  // tm_gmtoff includes any daylight savings offset, so subtract it.
+  return static_cast<double>(t->tm_gmtoff * msPerSecond -
+                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
+}
+
+
+// We keep the lowest and highest addresses mapped as a quick way of
+// determining that pointers are outside the heap (used mostly in assertions
+// and verification).  The estimate is conservative, ie, not all addresses in
+// 'allocated' space are actually allocated to our heap.  The range is
+// [lowest, highest), inclusive on the low and and exclusive on the high end.
+static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
+static void* highest_ever_allocated = reinterpret_cast<void*>(0);
+
+
+static void UpdateAllocatedSpaceLimits(void* address, int size) {
+  ASSERT(limit_mutex != NULL);
+  ScopedLock lock(limit_mutex);
+
+  lowest_ever_allocated = Min(lowest_ever_allocated, address);
+  highest_ever_allocated =
+      Max(highest_ever_allocated,
+          reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
+}
+
+
+bool OS::IsOutsideAllocatedSpace(void* address) {
+  return address < lowest_ever_allocated || address >= highest_ever_allocated;
+}
+
+
+size_t OS::AllocateAlignment() {
+  return sysconf(_SC_PAGESIZE);
+}
+
+
+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* addr = GetRandomMmapAddr();
+  void* mbase = mmap(addr, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (mbase == MAP_FAILED) {
+    LOG(i::Isolate::Current(),
+        StringEvent("OS::Allocate", "mmap failed"));
+    return NULL;
+  }
+  *allocated = msize;
+  UpdateAllocatedSpaceLimits(mbase, msize);
+  return mbase;
+}
+
+
+void OS::Free(void* address, const size_t size) {
+  // TODO(1240712): munmap has a return value which is ignored here.
+  int result = munmap(address, size);
+  USE(result);
+  ASSERT(result == 0);
+}
+
+
+void OS::Sleep(int milliseconds) {
+  unsigned int ms = static_cast<unsigned int>(milliseconds);
+  usleep(1000 * ms);
+}
+
+
+void OS::Abort() {
+  // Redirect to std abort to signal abnormal program termination.
+  abort();
+}
+
+
+void OS::DebugBreak() {
+// TODO(lrn): Introduce processor define for runtime system (!= V8_ARCH_x,
+//  which is the architecture of generated code).
+#if (defined(__arm__) || defined(__thumb__))
+# if defined(CAN_USE_ARMV5_INSTRUCTIONS)
+  asm("bkpt 0");
+# endif
+#else
+  asm("int $3");
+#endif
+}
+
+
+class PosixMemoryMappedFile : public OS::MemoryMappedFile {
+ public:
+  PosixMemoryMappedFile(FILE* file, void* memory, int size)
+    : file_(file), memory_(memory), size_(size) { }
+  virtual ~PosixMemoryMappedFile();
+  virtual void* memory() { return memory_; }
+  virtual int size() { return size_; }
+ private:
+  FILE* file_;
+  void* memory_;
+  int size_;
+};
+
+
+OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) {
+  FILE* file = fopen(name, "r+");
+  if (file == NULL) return NULL;
+
+  fseek(file, 0, SEEK_END);
+  int size = ftell(file);
+
+  void* memory =
+      mmap(OS::GetRandomMmapAddr(),
+           size,
+           PROT_READ | PROT_WRITE,
+           MAP_SHARED,
+           fileno(file),
+           0);
+  return new PosixMemoryMappedFile(file, memory, size);
+}
+
+
+OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
+    void* initial) {
+  FILE* file = fopen(name, "w+");
+  if (file == NULL) return NULL;
+  int result = fwrite(initial, size, 1, file);
+  if (result < 1) {
+    fclose(file);
+    return NULL;
+  }
+  void* memory =
+      mmap(OS::GetRandomMmapAddr(),
+           size,
+           PROT_READ | PROT_WRITE,
+           MAP_SHARED,
+           fileno(file),
+           0);
+  return new PosixMemoryMappedFile(file, memory, size);
+}
+
+
+PosixMemoryMappedFile::~PosixMemoryMappedFile() {
+  if (memory_) munmap(memory_, size_);
+  fclose(file_);
+}
+
+
+void OS::LogSharedLibraryAddresses() {
+  procfs_mapinfo *mapinfos = NULL, *mapinfo;
+  int proc_fd, num, i;
+
+  struct {
+    procfs_debuginfo info;
+    char buff[PATH_MAX];
+  } map;
+
+  char buf[PATH_MAX + 1];
+  sprintf(buf, "/proc/%d/as", getpid());
+
+  if ((proc_fd = open(buf, O_RDONLY)) == -1) {
+    close(proc_fd);
+    return;
+  }
+
+  /* Get the number of map entries.  */
+  if (devctl(proc_fd, DCMD_PROC_MAPINFO, NULL, 0, &num) != EOK) {
+    close(proc_fd);
+    return;
+  }
+
+  mapinfos =(procfs_mapinfo *)malloc(num * sizeof(procfs_mapinfo));
+  if (mapinfos == NULL) {
+    close(proc_fd);
+    return;
+  }
+
+  /* Fill the map entries.  */
+  if (devctl(proc_fd, DCMD_PROC_PAGEDATA, mapinfos, num * sizeof(procfs_mapinfo), &num) != EOK) {
+    free(mapinfos);
+    close(proc_fd);
+    return;
+  }
+
+  i::Isolate* isolate = ISOLATE;
+
+  for (i = 0; i < num; i++) {
+    mapinfo = mapinfos + i;
+    if (mapinfo->flags & MAP_ELF) {
+      map.info.vaddr = mapinfo->vaddr;
+      if (devctl(proc_fd, DCMD_PROC_MAPDEBUG, &map, sizeof(map), 0) != EOK)
+	    continue;
+
+	  LOG(isolate, SharedLibraryEvent(map.info.path, mapinfo->vaddr, mapinfo->vaddr + mapinfo->size));
+	}
+  }
+  free(mapinfos);
+  close(proc_fd);
+}
+
+
+static const char kGCFakeMmap[] = "/tmp/__v8_gc__";
+
+
+void OS::SignalCodeMovingGC() {
+  // Support for ll_prof.py.
+  //
+  // The QNX profiler built into the kernel logs all mmap's with
+  // PROT_EXEC so that analysis tools can properly attribute ticks. We
+  // do a mmap with a name known by ll_prof.py and immediately munmap
+  // it. This injects a GC marker into the stream of events generated
+  // by the kernel and allows us to synchronize V8 code log and the
+  // kernel log.
+  int size = sysconf(_SC_PAGESIZE);
+  FILE* f = fopen(kGCFakeMmap, "w+");
+  void* addr = mmap(OS::GetRandomMmapAddr(),
+                    size,
+                    PROT_READ | PROT_EXEC,
+                    MAP_PRIVATE,
+                    fileno(f),
+                    0);
+  ASSERT(addr != MAP_FAILED);
+  munmap(addr, size);
+  fclose(f);
+}
+
+
+int OS::StackWalk(Vector<OS::StackFrame> frames) {
+  int frames_size = frames.length();
+  bt_addr_t addresses[frames_size];
+  bt_accessor_t acc;
+  bt_memmap_t memmap;
+  bt_init_accessor(&acc, BT_SELF);
+  bt_load_memmap(&acc, &memmap);
+  int frames_count = bt_get_backtrace(&acc, addresses, frames_size);
+  bt_addr_t temp_addr[1];
+  for (int i = 0; i < frames_count; i++) {
+    frames[i].address = reinterpret_cast<void*>(addresses[i]);
+    temp_addr[0] = addresses[i];
+    // Format a text representation of the frame based on the information
+    // available.
+    bt_sprnf_addrs(&memmap, temp_addr, 1, "%a", frames[i].text, kStackWalkMaxTextLen, 0);
+    // Make sure line termination is in place.
+    frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
+  }
+  bt_unload_memmap(&memmap);
+  bt_release_accessor(&acc);
+  return 0;
+}
+
+
+// Constants used for mmap.
+static const int kMmapFd = -1;
+static const int kMmapFdOffset = 0;
+
+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) {
+  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(OS::GetRandomMmapAddr(),
+                           request_size,
+                           PROT_NONE,
+                           MAP_PRIVATE | MAP_ANONYMOUS,
+                           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()) {
+    bool result = ReleaseRegion(address(), size());
+    ASSERT(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) {
+  return UncommitRegion(address, size);
+}
+
+
+void* VirtualMemory::ReserveRegion(size_t size) {
+  void* result = mmap(OS::GetRandomMmapAddr(),
+                      size,
+                      PROT_NONE,
+                      MAP_PRIVATE | MAP_ANONYMOUS,
+                      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(base, size);
+  return true;
+}
+
+
+bool VirtualMemory::UncommitRegion(void* base, size_t size) {
+  return mmap(base,
+              size,
+              PROT_NONE,
+              MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+              kMmapFd,
+              kMmapFdOffset) != MAP_FAILED;
+}
+
+
+bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
+  return munmap(base, size) == 0;
+}
+
+
+class Thread::PlatformData : public Malloced {
+ public:
+  PlatformData() : thread_(kNoThread) {}
+
+  pthread_t thread_;  // Thread handle for pthread.
+};
+
+Thread::Thread(const Options& options)
+    : data_(new PlatformData()),
+      stack_size_(options.stack_size) {
+  set_name(options.name);
+}
+
+Thread::Thread(const char* name)
+    : data_(new PlatformData()),
+      stack_size_(0) {
+  set_name(name);
+}
+
+
+Thread::~Thread() {
+  delete data_;
+}
+
+
+static void* ThreadEntry(void* arg) {
+  Thread* thread = reinterpret_cast<Thread*>(arg);
+  // This is also initialized by the first argument to pthread_create() but we
+  // don't know which thread will run first (the original thread or the new
+  // one) so we initialize it here too.
+#ifdef PR_SET_NAME
+  prctl(PR_SET_NAME,
+        reinterpret_cast<unsigned long>(thread->name()),  // NOLINT
+        0, 0, 0);
+#endif
+  thread->data()->thread_ = pthread_self();
+  ASSERT(thread->data()->thread_ != kNoThread);
+  thread->Run();
+  return NULL;
+}
+
+
+void Thread::set_name(const char* name) {
+  strncpy(name_, name, sizeof(name_));
+  name_[sizeof(name_) - 1] = '\0';
+}
+
+
+void Thread::Start() {
+  pthread_attr_t* attr_ptr = NULL;
+  pthread_attr_t attr;
+  if (stack_size_ > 0) {
+    pthread_attr_init(&attr);
+    pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
+    attr_ptr = &attr;
+  }
+  int result = pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this);
+  CHECK_EQ(0, result);
+  ASSERT(data_->thread_ != kNoThread);
+}
+
+
+void Thread::Join() {
+  pthread_join(data_->thread_, NULL);
+}
+
+
+Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
+  pthread_key_t key;
+  int result = pthread_key_create(&key, NULL);
+  USE(result);
+  ASSERT(result == 0);
+  return static_cast<LocalStorageKey>(key);
+}
+
+
+void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
+  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
+  int result = pthread_key_delete(pthread_key);
+  USE(result);
+  ASSERT(result == 0);
+}
+
+
+void* Thread::GetThreadLocal(LocalStorageKey key) {
+  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
+  return pthread_getspecific(pthread_key);
+}
+
+
+void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
+  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
+  pthread_setspecific(pthread_key, value);
+}
+
+
+void Thread::YieldCPU() {
+  sched_yield();
+}
+
+
+class QNXMutex : public Mutex {
+ public:
+  QNXMutex() {
+    pthread_mutexattr_t attrs;
+    int result = pthread_mutexattr_init(&attrs);
+    ASSERT(result == 0);
+    result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
+    ASSERT(result == 0);
+    result = pthread_mutex_init(&mutex_, &attrs);
+    ASSERT(result == 0);
+    USE(result);
+  }
+
+  virtual ~QNXMutex() { pthread_mutex_destroy(&mutex_); }
+
+  virtual int Lock() {
+    int result = pthread_mutex_lock(&mutex_);
+    return result;
+  }
+
+  virtual int Unlock() {
+    int result = pthread_mutex_unlock(&mutex_);
+    return result;
+  }
+
+  virtual bool TryLock() {
+    int result = pthread_mutex_trylock(&mutex_);
+    // Return false if the lock is busy and locking failed.
+    if (result == EBUSY) {
+      return false;
+    }
+    ASSERT(result == 0);  // Verify no other errors.
+    return true;
+  }
+
+ private:
+  pthread_mutex_t mutex_;   // Pthread mutex for POSIX platforms.
+};
+
+
+Mutex* OS::CreateMutex() {
+  return new QNXMutex();
+}
+
+
+class QNXSemaphore : public Semaphore {
+ public:
+  explicit QNXSemaphore(int count) {  sem_init(&sem_, 0, count); }
+  virtual ~QNXSemaphore() { sem_destroy(&sem_); }
+
+  virtual void Wait();
+  virtual bool Wait(int timeout);
+  virtual void Signal() { sem_post(&sem_); }
+ private:
+  sem_t sem_;
+};
+
+
+void QNXSemaphore::Wait() {
+  while (true) {
+    int result = sem_wait(&sem_);
+    if (result == 0) return;  // Successfully got semaphore.
+    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
+  }
+}
+
+
+#ifndef TIMEVAL_TO_TIMESPEC
+#define TIMEVAL_TO_TIMESPEC(tv, ts) do {                            \
+    (ts)->tv_sec = (tv)->tv_sec;                                    \
+    (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
+} while (false)
+#endif
+
+
+bool QNXSemaphore::Wait(int timeout) {
+  const long kOneSecondMicros = 1000000;  // NOLINT
+
+  // Split timeout into second and nanosecond parts.
+  struct timeval delta;
+  delta.tv_usec = timeout % kOneSecondMicros;
+  delta.tv_sec = timeout / kOneSecondMicros;
+
+  struct timeval current_time;
+  // Get the current time.
+  if (gettimeofday(&current_time, NULL) == -1) {
+    return false;
+  }
+
+  // Calculate time for end of timeout.
+  struct timeval end_time;
+  timeradd(&current_time, &delta, &end_time);
+
+  struct timespec ts;
+  TIMEVAL_TO_TIMESPEC(&end_time, &ts);
+  // Wait for semaphore signalled or timeout.
+  while (true) {
+    int result = sem_timedwait(&sem_, &ts);
+    if (result == 0) return true;  // Successfully got semaphore.
+    if (result == -1 && errno == ETIMEDOUT) return false;  // Timeout.
+    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
+  }
+}
+
+
+Semaphore* OS::CreateSemaphore(int count) {
+  return new QNXSemaphore(count);
+}
+
+
+static int GetThreadID() {
+  pthread_t thread_id = pthread_self();
+  return thread_id;
+}
+
+
+static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
+  USE(info);
+  if (signal != SIGPROF) return;
+  Isolate* isolate = Isolate::UncheckedCurrent();
+  if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
+    // We require a fully initialized and entered isolate.
+    return;
+  }
+  if (v8::Locker::IsActive() &&
+      !isolate->thread_manager()->IsLockedByCurrentThread()) {
+    return;
+  }
+
+  Sampler* sampler = isolate->logger()->sampler();
+  if (sampler == NULL || !sampler->IsActive()) return;
+
+  TickSample sample_obj;
+  TickSample* sample = CpuProfiler::TickSampleEvent(isolate);
+  if (sample == NULL) sample = &sample_obj;
+
+  // Extracting the sample from the context is extremely machine dependent.
+  ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
+  mcontext_t& mcontext = ucontext->uc_mcontext;
+  sample->state = isolate->current_vm_state();
+#if V8_HOST_ARCH_IA32
+  sample->pc = reinterpret_cast<Address>(mcontext.cpu.eip);
+  sample->sp = reinterpret_cast<Address>(mcontext.cpu.esp);
+  sample->fp = reinterpret_cast<Address>(mcontext.cpu.ebp);
+#elif V8_HOST_ARCH_X64
+  sample->pc = reinterpret_cast<Address>(mcontext.cpu.rip);
+  sample->sp = reinterpret_cast<Address>(mcontext.cpu.rsp);
+  sample->fp = reinterpret_cast<Address>(mcontext.cpu.rbp);
+#elif V8_HOST_ARCH_ARM
+  sample->pc = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_PC]);
+  sample->sp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_SP]);
+  sample->fp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_FP]);
+#endif
+  sampler->SampleStack(sample);
+  sampler->Tick(sample);
+}
+
+
+class Sampler::PlatformData : public Malloced {
+ public:
+  PlatformData() : vm_tid_(GetThreadID()) {}
+
+  int vm_tid() const { return vm_tid_; }
+
+ private:
+  const int vm_tid_;
+};
+
+
+class SignalSender : public Thread {
+ public:
+  enum SleepInterval {
+    HALF_INTERVAL,
+    FULL_INTERVAL
+  };
+
+  static const int kSignalSenderStackSize = 32 * KB;
+
+  explicit SignalSender(int interval)
+      : Thread("SignalSender"),
+        vm_tgid_(getpid()),
+        interval_(interval) {}
+
+  static void InstallSignalHandler() {
+    struct sigaction sa;
+    sa.sa_sigaction = ProfilerSignalHandler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_SIGINFO;
+    signal_handler_installed_ =
+        (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
+  }
+
+  static void RestoreSignalHandler() {
+    if (signal_handler_installed_) {
+      sigaction(SIGPROF, &old_signal_handler_, 0);
+      signal_handler_installed_ = false;
+    }
+  }
+
+  static void AddActiveSampler(Sampler* sampler) {
+    ScopedLock lock(mutex_);
+    SamplerRegistry::AddActiveSampler(sampler);
+    if (instance_ == NULL) {
+      // Start a thread that will send SIGPROF signal to VM threads,
+      // when CPU profiling will be enabled.
+      instance_ = new SignalSender(sampler->interval());
+      instance_->Start();
+    } else {
+      ASSERT(instance_->interval_ == sampler->interval());
+    }
+  }
+
+  static void RemoveActiveSampler(Sampler* sampler) {
+    ScopedLock lock(mutex_);
+    SamplerRegistry::RemoveActiveSampler(sampler);
+    if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
+      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
+      delete instance_;
+      instance_ = NULL;
+      RestoreSignalHandler();
+    }
+  }
+
+  // Implement Thread::Run().
+  virtual void Run() {
+    SamplerRegistry::State state;
+    while ((state = SamplerRegistry::GetState()) !=
+           SamplerRegistry::HAS_NO_SAMPLERS) {
+      bool cpu_profiling_enabled =
+          (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
+      bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
+      if (cpu_profiling_enabled && !signal_handler_installed_) {
+        InstallSignalHandler();
+      } else if (!cpu_profiling_enabled && signal_handler_installed_) {
+        RestoreSignalHandler();
+      }
+      // When CPU profiling is enabled both JavaScript and C++ code is
+      // profiled. We must not suspend.
+      if (!cpu_profiling_enabled) {
+        if (rate_limiter_.SuspendIfNecessary()) continue;
+      }
+      if (cpu_profiling_enabled && runtime_profiler_enabled) {
+        if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
+          return;
+        }
+        Sleep(HALF_INTERVAL);
+        if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
+          return;
+        }
+        Sleep(HALF_INTERVAL);
+      } else {
+        if (cpu_profiling_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile,
+                                                      this)) {
+            return;
+          }
+        }
+        if (runtime_profiler_enabled) {
+          if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile,
+                                                      NULL)) {
+            return;
+          }
+        }
+        Sleep(FULL_INTERVAL);
+      }
+    }
+  }
+
+  static void DoCpuProfile(Sampler* sampler, void* raw_sender) {
+    if (!sampler->IsProfiling()) return;
+    SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender);
+    sender->SendProfilingSignal(sampler->platform_data()->vm_tid());
+  }
+
+  static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
+    if (!sampler->isolate()->IsInitialized()) return;
+    sampler->isolate()->runtime_profiler()->NotifyTick();
+  }
+
+  void SendProfilingSignal(int tid) {
+    if (!signal_handler_installed_) return;
+    pthread_kill(tid, SIGPROF);
+  }
+
+  void Sleep(SleepInterval full_or_half) {
+    // Convert ms to us and subtract 100 us to compensate delays
+    // occurring during signal delivery.
+    useconds_t interval = interval_ * 1000 - 100;
+    if (full_or_half == HALF_INTERVAL) interval /= 2;
+    int result = usleep(interval);
+#ifdef DEBUG
+    if (result != 0 && errno != EINTR) {
+      fprintf(stderr,
+              "SignalSender usleep error; interval = %u, errno = %d\n",
+              interval,
+              errno);
+      ASSERT(result == 0 || errno == EINTR);
+    }
+#endif
+    USE(result);
+  }
+
+  const int vm_tgid_;
+  const int interval_;
+  RuntimeProfilerRateLimiter rate_limiter_;
+
+  // Protects the process wide state below.
+  static Mutex* mutex_;
+  static SignalSender* instance_;
+  static bool signal_handler_installed_;
+  static struct sigaction old_signal_handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(SignalSender);
+};
+
+
+Mutex* SignalSender::mutex_ = OS::CreateMutex();
+SignalSender* SignalSender::instance_ = NULL;
+struct sigaction SignalSender::old_signal_handler_;
+bool SignalSender::signal_handler_installed_ = false;
+
+
+Sampler::Sampler(Isolate* isolate, int interval)
+    : isolate_(isolate),
+      interval_(interval),
+      profiling_(false),
+      active_(false),
+      samples_taken_(0) {
+  data_ = new PlatformData;
+}
+
+
+Sampler::~Sampler() {
+  ASSERT(!IsActive());
+  delete data_;
+}
+
+
+void Sampler::Start() {
+  ASSERT(!IsActive());
+  SetActive(true);
+  SignalSender::AddActiveSampler(this);
+}
+
+
+void Sampler::Stop() {
+  ASSERT(IsActive());
+  SignalSender::RemoveActiveSampler(this);
+  SetActive(false);
+}
+
+
+} }  // namespace v8::internal