Add minimal support for process_utils on iOS

base/process_util_ios.mm

Index: base/process_util_ios.mm
diff --git a/base/process_util_ios.mm b/base/process_util_ios.mm
new file mode 100644
index 0000000000000000000000000000000000000000..7e2c507d987f0ba137e475de7029788a518506ec
--- /dev/null
+++ b/base/process_util_ios.mm
@@ -0,0 +1,95 @@
+// 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 "base/process_util.h"
+
+#import <Foundation/Foundation.h>
+#include <iostream>

[Mark Mentovai, 2012/07/11 12:36:51]

C++ system headers belong in a separate section than C system headers, and they
should be after C system headers.

But you can maybe just remove this (see the next comment).

[stuartmorgan, 2012/07/11 13:56:57]

Done.

+#include <mach/task.h>
+
+#include "base/logging.h"
+
+// This is just enough of a shim to let the support needed by test_support
+// link.  In general, process_util isn't valid on iOS.
+
+namespace base {
+
+namespace {
+
+void StackDumpSignalHandler(int signal) {
+  LOG(ERROR) << "Received signal " << signal;
+  NSArray *stack_symbols = [NSThread callStackSymbols];
+  for (NSString* stack_symbol in stack_symbols) {
+    std::cerr << "\t" << [stack_symbol UTF8String] << "\n";

[Mark Mentovai, 2012/07/11 12:36:51]

When do we ever use C++ streams and cerr as opposed to fprintf and stderr?
Never. The style guide forbids streams except for logging.

[stuartmorgan, 2012/07/11 13:56:57]

Done.

+  }
+  _exit(1);
+}
+
+bool GetTaskInfo(task_basic_info_64* task_info_data) {
+  mach_msg_type_number_t count = TASK_BASIC_INFO_64_COUNT;
+  kern_return_t kr = task_info(mach_task_self(),
+                               TASK_BASIC_INFO_64,
+                               reinterpret_cast<task_info_t>(task_info_data),
+                               &count);
+  return kr == KERN_SUCCESS;
+}
+
+}  // anonymous namespace

[Mark Mentovai, 2012/07/11 12:36:51]

Normally, anonymous namespaces just close with // namespace.

[stuartmorgan, 2012/07/11 13:56:57]

Done.

+
+ProcessId GetCurrentProcId() {
+  return getpid();
+}
+
+void EnableTerminationOnHeapCorruption() {
+  // On iOS, there nothing to do AFAIK.
+}
+
+void EnableTerminationOnOutOfMemory() {
+  // iOS provides this for free!
+}
+
+bool EnableInProcessStackDumping() {
+  // When running in an application, our code typically expects SIGPIPE
+  // to be ignored.  Therefore, when testing that same code, it should run
+  // with SIGPIPE ignored as well.
+  struct sigaction action;
+  action.sa_handler = SIG_IGN;
+  action.sa_flags = 0;
+  sigemptyset(&action.sa_mask);
+  bool success = (sigaction(SIGPIPE, &action, NULL) == 0);
+
+  success &= (signal(SIGILL, &StackDumpSignalHandler) != SIG_ERR);
+  success &= (signal(SIGABRT, &StackDumpSignalHandler) != SIG_ERR);
+  success &= (signal(SIGFPE, &StackDumpSignalHandler) != SIG_ERR);
+  success &= (signal(SIGBUS, &StackDumpSignalHandler) != SIG_ERR);
+  success &= (signal(SIGSEGV, &StackDumpSignalHandler) != SIG_ERR);
+  success &= (signal(SIGSYS, &StackDumpSignalHandler) != SIG_ERR);
+
+  return success;
+}
+
+void RaiseProcessToHighPriority() {
+  // Impossible on iOS. Do nothing.
+}
+
+ProcessMetrics::ProcessMetrics(ProcessHandle process,
+                               ProcessMetrics::PortProvider* port_provider) {}

[Mark Mentovai, 2012/07/11 12:36:51]

The port provider interface is nonsense on iOS, which normally I’d ignore,
except we also have the non-Mac form of ProcessMetrics that doesn’t have a
PortProvider argument to the constructor. Why don’t we use that
PortProvider-free form for iOS too?

[stuartmorgan, 2012/07/11 13:56:57]

Done. (I suspect it was the other way to avoid changing the ifdef's on all the
call sites, but now that we're upstreaming it there's no reason to care about
that any more)

[Mark Mentovai, 2012/07/11 14:04:21]

stuartmorgan wrote:
I thought that might be it and even hypothesized about it a bit in my comment
and gave you some wishy-washy latitude to weigh call sites against cleanliness.
In the end, I tore all of that stuff out when I realized that the ProcessMetrics
constructor is private and is only called by CreateProcessMetrics.

[stuartmorgan, 2012/07/11 14:18:03]

Sure, but the same logic applies to the CreateProcessMetrics function fronting
it, which also has both forms. So there will be call sites that need changing,
but I'm fine changing them. It won't add any new ifdefs, just make the existing
ones have a longer condition.

+
+ProcessMetrics::~ProcessMetrics() {}
+
+// static
+ProcessMetrics* ProcessMetrics::CreateProcessMetrics(
+    ProcessHandle process,
+    ProcessMetrics::PortProvider* port_provider) {
+  return new ProcessMetrics(process, port_provider);
+}
+
+size_t ProcessMetrics::GetWorkingSetSize() const {
+  task_basic_info_64 task_info_data;
+  if (!GetTaskInfo(&task_info_data))
+    return 0;
+  return task_info_data.resident_size;
+}
+
+}  // namespace base