Band-aid fix for test hangs:

base/process_util_posix.cc

 // Copyright (c) 2012 The Chromium 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 <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <sys/resource.h>
@@ skipping 123 matching lines @@
 
   return status;
 }
 
 // Android has built-in crash handling.
 #if !defined(OS_ANDROID)
 void StackDumpSignalHandler(int signal, siginfo_t* info, ucontext_t* context) {
   if (debug::BeingDebugged())
     debug::BreakDebugger();
 
-  DLOG(ERROR) << "Received signal " << signal;
-  debug::StackTrace().PrintBacktrace();
-
-  // TODO(shess): Port to Linux.
-#if defined(OS_MACOSX)
-  // TODO(shess): Port to 64-bit.
-#if ARCH_CPU_32_BITS
   char buf[1024];
   size_t len;
 
   // NOTE: Even |snprintf()| is not on the approved list for signal
   // handlers, but buffered I/O is definitely not on the list due to
   // potential for |malloc()|.
+  len = static_cast<size_t>(
+      snprintf(buf, sizeof(buf), "Received signal %d\n", signal));
+  ignore_result(write(STDERR_FILENO, buf, std::min(len, sizeof(buf) - 1)));
+
+  // TODO(phajdan.jr): Re-enable backtrace printing after fixing the hang.
+  // debug::StackTrace().PrintBacktrace();
+
+  // TODO(shess): Port to Linux.
+#if defined(OS_MACOSX)

[Scott Hess - ex-Googler, 2012/10/30 23:47:59]

I would prefer to have the PrintBacktrace() enabled on OSX, since it doesn't use
tcmalloc anyhow.

I agree that we should be using backtrace_symbols_fd() or whatever it is.  But
that will lose out on demangling on Linux, I think.

+  // TODO(shess): Port to 64-bit.
+#if ARCH_CPU_32_BITS
+  // NOTE: Even |snprintf()| is not on the approved list for signal
+  // handlers, but buffered I/O is definitely not on the list due to
+  // potential for |malloc()|.
   len = static_cast<size_t>(
       snprintf(buf, sizeof(buf),
                "ax: %x, bx: %x, cx: %x, dx: %x\n",
                context->uc_mcontext->__ss.__eax,
                context->uc_mcontext->__ss.__ebx,
                context->uc_mcontext->__ss.__ecx,
                context->uc_mcontext->__ss.__edx));
   write(STDERR_FILENO, buf, std::min(len, sizeof(buf) - 1));
 
   len = static_cast<size_t>(
@@ skipping 1171 matching lines @@
   if (IsChildDead(process))
     return;
 
   BackgroundReaper* reaper = new BackgroundReaper(process, 0);
   PlatformThread::CreateNonJoinable(0, reaper);
 }
 
 #endif  // !defined(OS_MACOSX)
 
 }  // namespace base