Sampling profiler

runtime/vm/signal_handler_linux.cc

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/globals.h"
+#include "vm/signal_handler.h"
+#if defined(TARGET_OS_LINUX)
+
+namespace dart {
+
+uintptr_t SignalHandler::GetProgramCounter(const mcontext_t& mcontext) {
+  uintptr_t pc = 0;
+
+#if defined(TARGET_ARCH_IA32)
+  pc = static_cast<uintptr_t>(mcontext.gregs[REG_EIP]);
+#elif defined(TARGET_ARCH_X64)
+  pc = static_cast<uintptr_t>(mcontext.gregs[REG_RIP]);
+#elif defined(TARGET_ARCH_MIPS) && defined(USING_SIMULATOR)
+  pc = static_cast<uintptr_t>(mcontext.gregs[REG_EIP]);
+#elif defined(TARGET_ARCH_ARM) && defined(USING_SIMULATOR)
+  pc = static_cast<uintptr_t>(mcontext.gregs[REG_EIP]);
+#else
+  UNIMPLEMENTED()
+#endif  // TARGET_ARCH_...
+  return pc;
+}
+
+
+uintptr_t SignalHandler::GetFramePointer(const mcontext_t& mcontext) {
+  uintptr_t fp = 0;
+
+#if defined(TARGET_ARCH_IA32)
+  fp = static_cast<uintptr_t>(mcontext.gregs[REG_EBP]);
+#elif defined(TARGET_ARCH_X64)
+  fp = static_cast<uintptr_t>(mcontext.gregs[REG_RBP]);
+#elif defined(TARGET_ARCH_MIPS) && defined(USING_SIMULATOR)
+  fp = static_cast<uintptr_t>(mcontext.gregs[REG_EBP]);
+#elif defined(TARGET_ARCH_ARM) && defined(USING_SIMULATOR)
+  fp = static_cast<uintptr_t>(mcontext.gregs[REG_EBP]);
+#else
+  UNIMPLEMENTED()
+#endif  // TARGET_ARCH_...
+
+  return fp;
+}
+
+
+uintptr_t SignalHandler::GetStackPointer(const mcontext_t& mcontext) {
+  uintptr_t sp = 0;
+
+#if defined(TARGET_ARCH_IA32)
+  sp = static_cast<uintptr_t>(mcontext.gregs[REG_ESP]);
+#elif defined(TARGET_ARCH_X64)
+  sp = static_cast<uintptr_t>(mcontext.gregs[REG_RSP]);
+#elif defined(TARGET_ARCH_MIPS) && defined(USING_SIMULATOR)
+  sp = static_cast<uintptr_t>(mcontext.gregs[REG_ESP]);
+#elif defined(TARGET_ARCH_ARM) && defined(USING_SIMULATOR)
+  sp = static_cast<uintptr_t>(mcontext.gregs[REG_ESP]);
+#else
+  UNIMPLEMENTED()
+#endif  // TARGET_ARCH_...
+  return sp;
+}
+
+
+void SignalHandler::Install(SignalAction action) {
+  struct sigaction act;
+  act.sa_handler = NULL;
+  act.sa_sigaction = action;
+  sigemptyset(&act.sa_mask);
+  act.sa_flags = SA_RESTART | SA_SIGINFO;
+  // TODO(johnmccutchan): Do we care about restoring the signal handler?
+  struct sigaction old_act;
+  int r = sigaction(SIGPROF, &act, &old_act);
+  ASSERT(r == 0);
+}
+
+
+ScopedSignalBlocker::ScopedSignalBlocker() {
+  sigset_t set;
+  sigemptyset(&set);
+  sigaddset(&set, SIGPROF);
+  pthread_sigmask(SIG_SETMASK, &set, &old_);
+}
+
+
+ScopedSignalBlocker::~ScopedSignalBlocker() {
+  pthread_sigmask(SIG_SETMASK, &old_, NULL);
+}
+
+}  // namespace dart
+
+#endif  // defined(TARGET_OS_LINUX)