Fix shell build on Solaris and cleanup Solaris SignalSender Run()

src/platform-solaris.cc

Index: src/platform-solaris.cc
===================================================================
--- src/platform-solaris.cc	(revision 8500)
+++ src/platform-solaris.cc	(working copy)
@@ -595,17 +595,6 @@
   return pthread_self();
 }
 
-class Sampler::PlatformData : public Malloced {
- public:
-  PlatformData() : vm_tid_(GetThreadID()) {}
-
-  pthread_t vm_tid() const { return vm_tid_; }
-
- private:
-  pthread_t vm_tid_;
-};
-
-
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
   USE(info);
   if (signal != SIGPROF) return;
@@ -639,6 +628,17 @@
   sampler->Tick(sample);
 }
 
+class Sampler::PlatformData : public Malloced {
+ public:
+  PlatformData() : vm_tid_(GetThreadID()) {}
+
+  pthread_t vm_tid() const { return vm_tid_; }
+
+ private:
+  pthread_t vm_tid_;
+};
+
+
 class SignalSender : public Thread {
  public:
   enum SleepInterval {
@@ -650,19 +650,28 @@
       : Thread("SignalSender"),
         interval_(interval) {}
 
+  static void InstallSignalHandler() {
+    struct sigaction sa;
+    sa.sa_sigaction = ProfilerSignalHandler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_RESTART | 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) {
-      // Install a signal handler.
-      struct sigaction sa;
-      sa.sa_sigaction = ProfilerSignalHandler;
-      sigemptyset(&sa.sa_mask);
-      sa.sa_flags = SA_RESTART | SA_SIGINFO;
-      signal_handler_installed_ =
-          (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
-
-      // Start a thread that sends SIGPROF signal to VM threads.
+      // 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 {
@@ -678,12 +687,7 @@
       instance_->Join();
       delete instance_;
       instance_ = NULL;
-
-      // Restore the old signal handler.
-      if (signal_handler_installed_) {
-        sigaction(SIGPROF, &old_signal_handler_, 0);
-        signal_handler_installed_ = false;
-      }
+      RestoreSignalHandler();
     }
   }
 
@@ -695,6 +699,12 @@
       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) {