Contribution of PowerPC port (continuation of 422063005) - AIX Common1

src/sampler.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/sampler.h"
 
 #if V8_OS_POSIX && !V8_OS_CYGWIN
 
 #define USE_SIGNALS
 
 #include <errno.h>
 #include <pthread.h>
 #include <signal.h>
 #include <sys/time.h>
 
-#if !V8_OS_QNX && !V8_OS_NACL
+#if !(V8_OS_QNX || V8_OS_AIX) && !V8_OS_NACL

[Sven Panne, 2015/01/27 11:47:06]

De Morgan's law, please. :-)

[michael_dawson, 2015/01/29 00:08:29]

Will do 

 #include <sys/syscall.h>  // NOLINT
 #endif
 
 #if V8_OS_MACOSX
 #include <mach/mach.h>
 // OpenBSD doesn't have <ucontext.h>. ucontext_t lives in <signal.h>
 // and is a typedef for struct sigcontext. There is no uc_mcontext.
 #elif(!V8_OS_ANDROID || defined(__BIONIC_HAVE_UCONTEXT_T)) && \
     !V8_OS_OPENBSD && !V8_OS_NACL
 #include <ucontext.h>
@@ skipping 277 matching lines @@
     sa.sa_flags = SA_RESTART | SA_SIGINFO;
 #endif
     signal_handler_installed_ =
         (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
 #endif
   }
 
   static void Restore() {
 #if !V8_OS_NACL
     if (signal_handler_installed_) {
+#if V8_OS_AIX
+      // Ensure delivery of any pending SIGPROF before removing the handler

[Sven Panne, 2015/01/27 11:47:06]

Hmmm, why is this AIX-specific? Why can't there be yet another SIGPROF after the
handler and coming back to the yield?

In a nutshell: This looks wrong, like 99.9% of all yield uses I've seen so far.
:-) If it's really OK, we need an extensive comment here.

[michael_dawson, 2015/01/29 00:08:29]

We went to validate our explanation of why it was needed, but we can no longer
recreate the issue with the current level so we will remove

+      base::Thread::YieldCPU();
+#endif
       sigaction(SIGPROF, &old_signal_handler_, 0);
       signal_handler_installed_ = false;
     }
 #endif
   }
 
 #if !V8_OS_NACL
   static void HandleProfilerSignal(int signal, siginfo_t* info, void* context);
 #endif
   // Protects the process wide state below.
@@ skipping 148 matching lines @@
 #elif V8_OS_QNX
 #if V8_HOST_ARCH_IA32
   state.pc = reinterpret_cast<Address>(mcontext.cpu.eip);
   state.sp = reinterpret_cast<Address>(mcontext.cpu.esp);
   state.fp = reinterpret_cast<Address>(mcontext.cpu.ebp);
 #elif V8_HOST_ARCH_ARM
   state.pc = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_PC]);
   state.sp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_SP]);
   state.fp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_FP]);
 #endif  // V8_HOST_ARCH_*
-#endif  // V8_OS_QNX
+#elif V8_OS_AIX
+  state.pc = reinterpret_cast<Address>(mcontext.jmp_context.iar);
+  state.sp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[1]);
+  state.fp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[31]);
+#endif  // V8_OS_AIX
 #endif  // USE_SIMULATOR
   sampler->SampleStack(state);
 }
 #endif  // V8_OS_NACL
 
 #endif
 
 
 class SamplerThread : public base::Thread {
  public:
@@ skipping 272 matching lines @@
 #endif  // USE_SIMULATOR
     SampleStack(state);
   }
   ResumeThread(profiled_thread);
 }
 
 #endif  // USE_SIGNALS
 
 
 } }  // namespace v8::internal