base/process_util_mac.mm - chromium/src - Git at Google

 // Copyright (c) 2008 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 <Cocoa/Cocoa.h>
 #include <crt_externs.h>
 #include <mach/mach.h>
 #include <mach/mach_init.h>
 #include <mach/task.h>
 #include <malloc/malloc.h>
 #import <objc/runtime.h>
 #include <spawn.h>
 #include <sys/mman.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #include <sys/wait.h>

 #include <new>
 #include <string>

 #include "base/debug_util.h"
 #include "base/eintr_wrapper.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
 #include "base/sys_string_conversions.h"
 #include "base/time.h"

 namespace base {

 void RestoreDefaultExceptionHandler() {
   // This function is tailored to remove the Breakpad exception handler.
   // exception_mask matches s_exception_mask in
   // breakpad/src/client/mac/handler/exception_handler.cc
   const exception_mask_t exception_mask = EXC_MASK_BAD_ACCESS |
                                           EXC_MASK_BAD_INSTRUCTION |
                                           EXC_MASK_ARITHMETIC |
                                           EXC_MASK_BREAKPOINT;

   // Setting the exception port to MACH_PORT_NULL may not be entirely
   // kosher to restore the default exception handler, but in practice,
   // it results in the exception port being set to Apple Crash Reporter,
   // the desired behavior.
   task_set_exception_ports(mach_task_self(), exception_mask, MACH_PORT_NULL,
                            EXCEPTION_DEFAULT, THREAD_STATE_NONE);
 }

 NamedProcessIterator::NamedProcessIterator(const std::wstring& executable_name,
                                            const ProcessFilter* filter)
     : executable_name_(executable_name),
       index_of_kinfo_proc_(0),
       filter_(filter) {
   // Get a snapshot of all of my processes (yes, as we loop it can go stale, but
   // but trying to find where we were in a constantly changing list is basically
   // impossible.

   int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_UID, geteuid() };

   // Since more processes could start between when we get the size and when
   // we get the list, we do a loop to keep trying until we get it.
   bool done = false;
   int try_num = 1;
   const int max_tries = 10;
   do {
     // Get the size of the buffer
     size_t len = 0;
     if (sysctl(mib, arraysize(mib), NULL, &len, NULL, 0) < 0) {
       LOG(ERROR) << "failed to get the size needed for the process list";
       kinfo_procs_.resize(0);
       done = true;
     } else {
       size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
       // Leave some spare room for process table growth (more could show up
       // between when we check and now)
       num_of_kinfo_proc += 4;
       kinfo_procs_.resize(num_of_kinfo_proc);
       len = num_of_kinfo_proc * sizeof(struct kinfo_proc);
       // Load the list of processes
       if (sysctl(mib, arraysize(mib), &kinfo_procs_[0], &len, NULL, 0) < 0) {
         // If we get a mem error, it just means we need a bigger buffer, so
         // loop around again.  Anything else is a real error and give up.
         if (errno != ENOMEM) {
           LOG(ERROR) << "failed to get the process list";
           kinfo_procs_.resize(0);
           done = true;
         }
       } else {
         // Got the list, just make sure we're sized exactly right
         size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
         kinfo_procs_.resize(num_of_kinfo_proc);
         done = true;
       }
     }
   } while (!done && (try_num++ < max_tries));

   if (!done) {
     LOG(ERROR) << "failed to collect the process list in a few tries";
     kinfo_procs_.resize(0);
   }
 }

 NamedProcessIterator::~NamedProcessIterator() {
 }

 const ProcessEntry* NamedProcessIterator::NextProcessEntry() {
   bool result = false;
   do {
     result = CheckForNextProcess();
   } while (result && !IncludeEntry());

   if (result) {
     return &entry_;
   }

   return NULL;
 }

 bool NamedProcessIterator::CheckForNextProcess() {
   std::string executable_name_utf8(base::SysWideToUTF8(executable_name_));

   std::string data;
   std::string exec_name;

   for (; index_of_kinfo_proc_ < kinfo_procs_.size(); ++index_of_kinfo_proc_) {
     kinfo_proc* kinfo = &kinfo_procs_[index_of_kinfo_proc_];

     // Skip processes just awaiting collection
     if ((kinfo->kp_proc.p_pid > 0) && (kinfo->kp_proc.p_stat == SZOMB))
       continue;

     int mib[] = { CTL_KERN, KERN_PROCARGS, kinfo->kp_proc.p_pid };

     // Found out what size buffer we need
     size_t data_len = 0;
     if (sysctl(mib, arraysize(mib), NULL, &data_len, NULL, 0) < 0) {
       LOG(ERROR) << "failed to figure out the buffer size for a commandline";
       continue;
     }

     data.resize(data_len);
     if (sysctl(mib, arraysize(mib), &data[0], &data_len, NULL, 0) < 0) {
       LOG(ERROR) << "failed to fetch a commandline";
       continue;
     }

     // Data starts w/ the full path null termed, so we have to extract just the
     // executable name from the path.

     size_t exec_name_end = data.find('\0');
     if (exec_name_end == std::string::npos) {
       LOG(ERROR) << "command line data didn't match expected format";
       continue;
     }
     size_t last_slash = data.rfind('/', exec_name_end);
     if (last_slash == std::string::npos)
       exec_name = data.substr(0, exec_name_end);
     else
       exec_name = data.substr(last_slash + 1, exec_name_end - last_slash - 1);

     // Check the name
     if (executable_name_utf8 == exec_name) {
       entry_.pid = kinfo->kp_proc.p_pid;
       entry_.ppid = kinfo->kp_eproc.e_ppid;
       base::strlcpy(entry_.szExeFile, exec_name.c_str(),
                     sizeof(entry_.szExeFile));
       // Start w/ the next entry next time through
       ++index_of_kinfo_proc_;
       // Done
       return true;
     }
   }
   return false;
 }

 bool NamedProcessIterator::IncludeEntry() {
   // Don't need to check the name, we did that w/in CheckForNextProcess.
   if (!filter_)
     return true;
   return filter_->Includes(entry_.pid, entry_.ppid);
 }


 // ------------------------------------------------------------------------
 // NOTE: about ProcessMetrics
 //
 // Getting a mach task from a pid for another process requires permissions in
 // general, so there doesn't really seem to be a way to do these (and spinning
 // up ps to fetch each stats seems dangerous to put in a base api for anyone to
 // call). Child processes ipc their port, so return something if available,
 // otherwise return 0.
 //
 bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
   return false;
 }

 static bool GetTaskInfo(mach_port_t task, task_basic_info_64* task_info_data) {
   if (task == MACH_PORT_NULL)
     return false;
   mach_msg_type_number_t count = TASK_BASIC_INFO_64_COUNT;
   kern_return_t kr = task_info(task,
                                TASK_BASIC_INFO_64,
                                reinterpret_cast<task_info_t>(task_info_data),
                                &count);
   // Most likely cause for failure: |task| is a zombie.
   return kr == KERN_SUCCESS;
 }

 size_t ProcessMetrics::GetPagefileUsage() const {
   task_basic_info_64 task_info_data;
   if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
     return 0;
   return task_info_data.virtual_size;
 }

 size_t ProcessMetrics::GetPeakPagefileUsage() const {
   return 0;
 }

 size_t ProcessMetrics::GetWorkingSetSize() const {
   task_basic_info_64 task_info_data;
   if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
     return 0;
   return task_info_data.resident_size;
 }

 size_t ProcessMetrics::GetPeakWorkingSetSize() const {
   return 0;
 }

 size_t ProcessMetrics::GetPrivateBytes() const {
   return 0;
 }

 void ProcessMetrics::GetCommittedKBytes(CommittedKBytes* usage) const {
 }

 bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
   size_t priv = GetWorkingSetSize();
   if (!priv)
     return false;
   ws_usage->priv = priv / 1024;
   ws_usage->shareable = 0;
   ws_usage->shared = 0;
   return true;
 }

 #define TIME_VALUE_TO_TIMEVAL(a, r) do {  \
   (r)->tv_sec = (a)->seconds;             \
   (r)->tv_usec = (a)->microseconds;       \
 } while (0)

 double ProcessMetrics::GetCPUUsage() {
   mach_port_t task = TaskForPid(process_);
   if (task == MACH_PORT_NULL)
     return 0;

   kern_return_t kr;

   // Libtop explicitly loops over the threads (libtop_pinfo_update_cpu_usage()
   // in libtop.c), but this is more concise and gives the same results:
   task_thread_times_info thread_info_data;
   mach_msg_type_number_t thread_info_count = TASK_THREAD_TIMES_INFO_COUNT;
   kr = task_info(task,
                  TASK_THREAD_TIMES_INFO,
                  reinterpret_cast<task_info_t>(&thread_info_data),
                  &thread_info_count);
   if (kr != KERN_SUCCESS) {
     // Most likely cause: |task| is a zombie.
     return 0;
   }

   task_basic_info_64 task_info_data;
   if (!GetTaskInfo(task, &task_info_data))
     return 0;

   /* Set total_time. */
   // thread info contains live time...
   struct timeval user_timeval, system_timeval, task_timeval;
   TIME_VALUE_TO_TIMEVAL(&thread_info_data.user_time, &user_timeval);
   TIME_VALUE_TO_TIMEVAL(&thread_info_data.system_time, &system_timeval);
   timeradd(&user_timeval, &system_timeval, &task_timeval);

   // ... task info contains terminated time.
   TIME_VALUE_TO_TIMEVAL(&task_info_data.user_time, &user_timeval);
   TIME_VALUE_TO_TIMEVAL(&task_info_data.system_time, &system_timeval);
   timeradd(&user_timeval, &task_timeval, &task_timeval);
   timeradd(&system_timeval, &task_timeval, &task_timeval);

   struct timeval now;
   int retval = gettimeofday(&now, NULL);
   if (retval)
     return 0;

   int64 time = TimeValToMicroseconds(now);
   int64 task_time = TimeValToMicroseconds(task_timeval);

   if ((last_system_time_ == 0) || (last_time_ == 0)) {
     // First call, just set the last values.
     last_system_time_ = task_time;
     last_time_ = time;
     return 0;
   }

   int64 system_time_delta = task_time - last_system_time_;
   int64 time_delta = time - last_time_;
   DCHECK(time_delta != 0);
   if (time_delta == 0)
     return 0;

   // We add time_delta / 2 so the result is rounded.
   double cpu = static_cast<double>((system_time_delta * 100.0) / time_delta);

   last_system_time_ = task_time;
   last_time_ = time;

   return cpu;
 }

 mach_port_t ProcessMetrics::TaskForPid(ProcessHandle process) const {
   mach_port_t task = MACH_PORT_NULL;
   if (port_provider_)
     task = port_provider_->TaskForPid(process_);
   if (task == MACH_PORT_NULL && process_ == getpid())
     task = mach_task_self();
   return task;
 }

 // ------------------------------------------------------------------------

 // Bytes committed by the system.
 size_t GetSystemCommitCharge() {
   host_name_port_t host = mach_host_self();
   mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
   vm_statistics_data_t data;
   kern_return_t kr = host_statistics(host, HOST_VM_INFO,
                                      reinterpret_cast<host_info_t>(&data),
                                      &count);
   if (kr) {
     LOG(WARNING) << "Failed to fetch host statistics.";
     return 0;
   }

   vm_size_t page_size;
   kr = host_page_size(host, &page_size);
   if (kr) {
     LOG(ERROR) << "Failed to fetch host page size.";
     return 0;
   }

   return (data.active_count * page_size) / 1024;
 }

 // ------------------------------------------------------------------------

 namespace {

 bool g_oom_killer_enabled;

 // === C malloc/calloc/valloc/realloc ===

 typedef void* (*malloc_type)(struct _malloc_zone_t* zone,
                              size_t size);
 typedef void* (*calloc_type)(struct _malloc_zone_t* zone,
                              size_t num_items,
                              size_t size);
 typedef void* (*valloc_type)(struct _malloc_zone_t* zone,
                              size_t size);
 typedef void* (*realloc_type)(struct _malloc_zone_t* zone,
                               void* ptr,
                               size_t size);

 malloc_type g_old_malloc;
 calloc_type g_old_calloc;
 valloc_type g_old_valloc;
 realloc_type g_old_realloc;

 void* oom_killer_malloc(struct _malloc_zone_t* zone,
                         size_t size) {
   void* result = g_old_malloc(zone, size);
   if (size && !result)
     DebugUtil::BreakDebugger();
   return result;
 }

 void* oom_killer_calloc(struct _malloc_zone_t* zone,
                         size_t num_items,
                         size_t size) {
   void* result = g_old_calloc(zone, num_items, size);
   if (num_items && size && !result)
     DebugUtil::BreakDebugger();
   return result;
 }

 void* oom_killer_valloc(struct _malloc_zone_t* zone,
                         size_t size) {
   void* result = g_old_valloc(zone, size);
   if (size && !result)
     DebugUtil::BreakDebugger();
   return result;
 }

 void* oom_killer_realloc(struct _malloc_zone_t* zone,
                          void* ptr,
                          size_t size) {
   void* result = g_old_realloc(zone, ptr, size);
   if (size && !result)
     DebugUtil::BreakDebugger();
   return result;
 }

 // === C++ operator new ===

 void oom_killer_new() {
   DebugUtil::BreakDebugger();
 }

 // === Core Foundation CFAllocators ===

 // This is the real structure of a CFAllocatorRef behind the scenes. See
 // http://opensource.apple.com/source/CF/CF-550/CFBase.c for details.
 struct ChromeCFAllocator {
   _malloc_zone_t fake_malloc_zone;
   void* allocator;
   CFAllocatorContext context;
 };
 typedef ChromeCFAllocator* ChromeCFAllocatorRef;

 CFAllocatorAllocateCallBack g_old_cfallocator_system_default;
 CFAllocatorAllocateCallBack g_old_cfallocator_malloc;
 CFAllocatorAllocateCallBack g_old_cfallocator_malloc_zone;

 void* oom_killer_cfallocator_system_default(CFIndex alloc_size,
                                             CFOptionFlags hint,
                                             void* info) {
   void* result = g_old_cfallocator_system_default(alloc_size, hint, info);
   if (!result)
     DebugUtil::BreakDebugger();
   return result;
 }

 void* oom_killer_cfallocator_malloc(CFIndex alloc_size,
                                     CFOptionFlags hint,
                                     void* info) {
   void* result = g_old_cfallocator_malloc(alloc_size, hint, info);
   if (!result)
     DebugUtil::BreakDebugger();
   return result;
 }

 void* oom_killer_cfallocator_malloc_zone(CFIndex alloc_size,
                                          CFOptionFlags hint,
                                          void* info) {
   void* result = g_old_cfallocator_malloc_zone(alloc_size, hint, info);
   if (!result)
     DebugUtil::BreakDebugger();
   return result;
 }

 // === Cocoa NSObject allocation ===

 typedef id (*allocWithZone_t)(id, SEL, NSZone*);
 allocWithZone_t g_old_allocWithZone;

 id oom_killer_allocWithZone(id self, SEL _cmd, NSZone* zone)
 {
   id result = g_old_allocWithZone(self, _cmd, zone);
   if (!result)
     DebugUtil::BreakDebugger();
   return result;
 }

 }  // namespace

 void EnableTerminationOnOutOfMemory() {
   if (g_oom_killer_enabled)
     return;

   g_oom_killer_enabled = true;

   // === C malloc/calloc/valloc/realloc ===

   // This approach is not perfect, as requests for amounts of memory larger than
   // MALLOC_ABSOLUTE_MAX_SIZE (currently SIZE_T_MAX - (2 * PAGE_SIZE)) will
   // still fail with a NULL rather than dying (see
   // http://opensource.apple.com/source/Libc/Libc-583/gen/malloc.c for details).
   // Unfortunately, it's the best we can do. Also note that this does not affect
   // allocations from non-default zones.

   CHECK(!g_old_malloc && !g_old_calloc && !g_old_valloc && !g_old_realloc)
       << "Old allocators unexpectedly non-null";

   int32 major;
   int32 minor;
   int32 bugfix;
   SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
   bool zone_allocators_protected = ((major == 10 && minor > 6) || major > 10);

   malloc_zone_t* default_zone = malloc_default_zone();

   vm_address_t page_start = NULL;
   vm_size_t len = 0;
   if (zone_allocators_protected) {
     // See http://trac.webkit.org/changeset/53362/trunk/WebKitTools/DumpRenderTree/mac
     page_start = reinterpret_cast<vm_address_t>(default_zone) &
         static_cast<vm_size_t>(~(getpagesize() - 1));
     len = reinterpret_cast<vm_address_t>(default_zone) -
         page_start + sizeof(malloc_zone_t);
     mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ | PROT_WRITE);
   }

   g_old_malloc = default_zone->malloc;
   g_old_calloc = default_zone->calloc;
   g_old_valloc = default_zone->valloc;
   g_old_realloc = default_zone->realloc;
   CHECK(g_old_malloc && g_old_calloc && g_old_valloc && g_old_realloc)
       << "Failed to get system allocation functions.";

   default_zone->malloc = oom_killer_malloc;
   default_zone->calloc = oom_killer_calloc;
   default_zone->valloc = oom_killer_valloc;
   default_zone->realloc = oom_killer_realloc;

   if (zone_allocators_protected) {
     mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ);
   }

   // === C++ operator new ===

   // Yes, operator new does call through to malloc, but this will catch failures
   // that our imperfect handling of malloc cannot.

   std::set_new_handler(oom_killer_new);

   // === Core Foundation CFAllocators ===

   // This will not catch allocation done by custom allocators, but will catch
   // all allocation done by system-provided ones.

   CHECK(!g_old_cfallocator_system_default && !g_old_cfallocator_malloc &&
         !g_old_cfallocator_malloc_zone)
       << "Old allocators unexpectedly non-null";

   ChromeCFAllocatorRef allocator = const_cast<ChromeCFAllocatorRef>(
       reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorSystemDefault));
   g_old_cfallocator_system_default = allocator->context.allocate;
   CHECK(g_old_cfallocator_system_default)
       << "Failed to get kCFAllocatorSystemDefault allocation function.";
   allocator->context.allocate = oom_killer_cfallocator_system_default;

   allocator = const_cast<ChromeCFAllocatorRef>(
       reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorMalloc));
   g_old_cfallocator_malloc = allocator->context.allocate;
   CHECK(g_old_cfallocator_malloc)
       << "Failed to get kCFAllocatorMalloc allocation function.";
   allocator->context.allocate = oom_killer_cfallocator_malloc;

   allocator = const_cast<ChromeCFAllocatorRef>(
       reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorMallocZone));
   g_old_cfallocator_malloc_zone = allocator->context.allocate;
   CHECK(g_old_cfallocator_malloc_zone)
       << "Failed to get kCFAllocatorMallocZone allocation function.";
   allocator->context.allocate = oom_killer_cfallocator_malloc_zone;

   // === Cocoa NSObject allocation ===

   // Note that both +[NSObject new] and +[NSObject alloc] call through to
   // +[NSObject allocWithZone:].

   CHECK(!g_old_allocWithZone)
       << "Old allocator unexpectedly non-null";

   Class nsobject_class = [NSObject class];
   Method orig_method = class_getClassMethod(nsobject_class,
                                             @selector(allocWithZone:));
   g_old_allocWithZone = reinterpret_cast<allocWithZone_t>(
       method_getImplementation(orig_method));
   CHECK(g_old_allocWithZone)
       << "Failed to get allocWithZone allocation function.";
   method_setImplementation(orig_method,
                            reinterpret_cast<IMP>(oom_killer_allocWithZone));
 }

 }  // namespace base
	// Copyright (c) 2008 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 <Cocoa/Cocoa.h>
	#include <crt_externs.h>
	#include <mach/mach.h>
	#include <mach/mach_init.h>
	#include <mach/task.h>
	#include <malloc/malloc.h>
	#import <objc/runtime.h>
	#include <spawn.h>
	#include <sys/mman.h>
	#include <sys/sysctl.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	#include <new>
	#include <string>

	#include "base/debug_util.h"
	#include "base/eintr_wrapper.h"
	#include "base/logging.h"
	#include "base/string_util.h"
	#include "base/sys_info.h"
	#include "base/sys_string_conversions.h"
	#include "base/time.h"

	namespace base {

	void RestoreDefaultExceptionHandler() {
	// This function is tailored to remove the Breakpad exception handler.
	// exception_mask matches s_exception_mask in
	// breakpad/src/client/mac/handler/exception_handler.cc
	const exception_mask_t exception_mask = EXC_MASK_BAD_ACCESS \|
	EXC_MASK_BAD_INSTRUCTION \|
	EXC_MASK_ARITHMETIC \|
	EXC_MASK_BREAKPOINT;

	// Setting the exception port to MACH_PORT_NULL may not be entirely
	// kosher to restore the default exception handler, but in practice,
	// it results in the exception port being set to Apple Crash Reporter,
	// the desired behavior.
	task_set_exception_ports(mach_task_self(), exception_mask, MACH_PORT_NULL,
	EXCEPTION_DEFAULT, THREAD_STATE_NONE);
	}

	NamedProcessIterator::NamedProcessIterator(const std::wstring& executable_name,
	const ProcessFilter* filter)
	: executable_name_(executable_name),
	index_of_kinfo_proc_(0),
	filter_(filter) {
	// Get a snapshot of all of my processes (yes, as we loop it can go stale, but
	// but trying to find where we were in a constantly changing list is basically
	// impossible.

	int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_UID, geteuid() };

	// Since more processes could start between when we get the size and when
	// we get the list, we do a loop to keep trying until we get it.
	bool done = false;
	int try_num = 1;
	const int max_tries = 10;
	do {
	// Get the size of the buffer
	size_t len = 0;
	if (sysctl(mib, arraysize(mib), NULL, &len, NULL, 0) < 0) {
	LOG(ERROR) << "failed to get the size needed for the process list";
	kinfo_procs_.resize(0);
	done = true;
	} else {
	size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
	// Leave some spare room for process table growth (more could show up
	// between when we check and now)
	num_of_kinfo_proc += 4;
	kinfo_procs_.resize(num_of_kinfo_proc);
	len = num_of_kinfo_proc * sizeof(struct kinfo_proc);
	// Load the list of processes
	if (sysctl(mib, arraysize(mib), &kinfo_procs_[0], &len, NULL, 0) < 0) {
	// If we get a mem error, it just means we need a bigger buffer, so
	// loop around again. Anything else is a real error and give up.
	if (errno != ENOMEM) {
	LOG(ERROR) << "failed to get the process list";
	kinfo_procs_.resize(0);
	done = true;
	}
	} else {
	// Got the list, just make sure we're sized exactly right
	size_t num_of_kinfo_proc = len / sizeof(struct kinfo_proc);
	kinfo_procs_.resize(num_of_kinfo_proc);
	done = true;
	}
	}
	} while (!done && (try_num++ < max_tries));

	if (!done) {
	LOG(ERROR) << "failed to collect the process list in a few tries";
	kinfo_procs_.resize(0);
	}
	}

	NamedProcessIterator::~NamedProcessIterator() {
	}

	const ProcessEntry* NamedProcessIterator::NextProcessEntry() {
	bool result = false;
	do {
	result = CheckForNextProcess();
	} while (result && !IncludeEntry());

	if (result) {
	return &entry_;
	}

	return NULL;
	}

	bool NamedProcessIterator::CheckForNextProcess() {
	std::string executable_name_utf8(base::SysWideToUTF8(executable_name_));

	std::string data;
	std::string exec_name;

	for (; index_of_kinfo_proc_ < kinfo_procs_.size(); ++index_of_kinfo_proc_) {
	kinfo_proc* kinfo = &kinfo_procs_[index_of_kinfo_proc_];

	// Skip processes just awaiting collection
	if ((kinfo->kp_proc.p_pid > 0) && (kinfo->kp_proc.p_stat == SZOMB))
	continue;

	int mib[] = { CTL_KERN, KERN_PROCARGS, kinfo->kp_proc.p_pid };

	// Found out what size buffer we need
	size_t data_len = 0;
	if (sysctl(mib, arraysize(mib), NULL, &data_len, NULL, 0) < 0) {
	LOG(ERROR) << "failed to figure out the buffer size for a commandline";
	continue;
	}

	data.resize(data_len);
	if (sysctl(mib, arraysize(mib), &data[0], &data_len, NULL, 0) < 0) {
	LOG(ERROR) << "failed to fetch a commandline";
	continue;
	}

	// Data starts w/ the full path null termed, so we have to extract just the
	// executable name from the path.

	size_t exec_name_end = data.find('\0');
	if (exec_name_end == std::string::npos) {
	LOG(ERROR) << "command line data didn't match expected format";
	continue;
	}
	size_t last_slash = data.rfind('/', exec_name_end);
	if (last_slash == std::string::npos)
	exec_name = data.substr(0, exec_name_end);
	else
	exec_name = data.substr(last_slash + 1, exec_name_end - last_slash - 1);

	// Check the name
	if (executable_name_utf8 == exec_name) {
	entry_.pid = kinfo->kp_proc.p_pid;
	entry_.ppid = kinfo->kp_eproc.e_ppid;
	base::strlcpy(entry_.szExeFile, exec_name.c_str(),
	sizeof(entry_.szExeFile));
	// Start w/ the next entry next time through
	++index_of_kinfo_proc_;
	// Done
	return true;
	}
	}
	return false;
	}

	bool NamedProcessIterator::IncludeEntry() {
	// Don't need to check the name, we did that w/in CheckForNextProcess.
	if (!filter_)
	return true;
	return filter_->Includes(entry_.pid, entry_.ppid);
	}


	// ------------------------------------------------------------------------
	// NOTE: about ProcessMetrics
	//
	// Getting a mach task from a pid for another process requires permissions in
	// general, so there doesn't really seem to be a way to do these (and spinning
	// up ps to fetch each stats seems dangerous to put in a base api for anyone to
	// call). Child processes ipc their port, so return something if available,
	// otherwise return 0.
	//
	bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
	return false;
	}

	static bool GetTaskInfo(mach_port_t task, task_basic_info_64* task_info_data) {
	if (task == MACH_PORT_NULL)
	return false;
	mach_msg_type_number_t count = TASK_BASIC_INFO_64_COUNT;
	kern_return_t kr = task_info(task,
	TASK_BASIC_INFO_64,
	reinterpret_cast<task_info_t>(task_info_data),
	&count);
	// Most likely cause for failure: \|task\| is a zombie.
	return kr == KERN_SUCCESS;
	}

	size_t ProcessMetrics::GetPagefileUsage() const {
	task_basic_info_64 task_info_data;
	if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
	return 0;
	return task_info_data.virtual_size;
	}

	size_t ProcessMetrics::GetPeakPagefileUsage() const {
	return 0;
	}

	size_t ProcessMetrics::GetWorkingSetSize() const {
	task_basic_info_64 task_info_data;
	if (!GetTaskInfo(TaskForPid(process_), &task_info_data))
	return 0;
	return task_info_data.resident_size;
	}

	size_t ProcessMetrics::GetPeakWorkingSetSize() const {
	return 0;
	}

	size_t ProcessMetrics::GetPrivateBytes() const {
	return 0;
	}

	void ProcessMetrics::GetCommittedKBytes(CommittedKBytes* usage) const {
	}

	bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
	size_t priv = GetWorkingSetSize();
	if (!priv)
	return false;
	ws_usage->priv = priv / 1024;
	ws_usage->shareable = 0;
	ws_usage->shared = 0;
	return true;
	}

	#define TIME_VALUE_TO_TIMEVAL(a, r) do { \
	(r)->tv_sec = (a)->seconds; \
	(r)->tv_usec = (a)->microseconds; \
	} while (0)

	double ProcessMetrics::GetCPUUsage() {
	mach_port_t task = TaskForPid(process_);
	if (task == MACH_PORT_NULL)
	return 0;

	kern_return_t kr;

	// Libtop explicitly loops over the threads (libtop_pinfo_update_cpu_usage()
	// in libtop.c), but this is more concise and gives the same results:
	task_thread_times_info thread_info_data;
	mach_msg_type_number_t thread_info_count = TASK_THREAD_TIMES_INFO_COUNT;
	kr = task_info(task,
	TASK_THREAD_TIMES_INFO,
	reinterpret_cast<task_info_t>(&thread_info_data),
	&thread_info_count);
	if (kr != KERN_SUCCESS) {
	// Most likely cause: \|task\| is a zombie.
	return 0;
	}

	task_basic_info_64 task_info_data;
	if (!GetTaskInfo(task, &task_info_data))
	return 0;

	/* Set total_time. */
	// thread info contains live time...
	struct timeval user_timeval, system_timeval, task_timeval;
	TIME_VALUE_TO_TIMEVAL(&thread_info_data.user_time, &user_timeval);
	TIME_VALUE_TO_TIMEVAL(&thread_info_data.system_time, &system_timeval);
	timeradd(&user_timeval, &system_timeval, &task_timeval);

	// ... task info contains terminated time.
	TIME_VALUE_TO_TIMEVAL(&task_info_data.user_time, &user_timeval);
	TIME_VALUE_TO_TIMEVAL(&task_info_data.system_time, &system_timeval);
	timeradd(&user_timeval, &task_timeval, &task_timeval);
	timeradd(&system_timeval, &task_timeval, &task_timeval);

	struct timeval now;
	int retval = gettimeofday(&now, NULL);
	if (retval)
	return 0;

	int64 time = TimeValToMicroseconds(now);
	int64 task_time = TimeValToMicroseconds(task_timeval);

	if ((last_system_time_ == 0) \|\| (last_time_ == 0)) {
	// First call, just set the last values.
	last_system_time_ = task_time;
	last_time_ = time;
	return 0;
	}

	int64 system_time_delta = task_time - last_system_time_;
	int64 time_delta = time - last_time_;
	DCHECK(time_delta != 0);
	if (time_delta == 0)
	return 0;

	// We add time_delta / 2 so the result is rounded.
	double cpu = static_cast<double>((system_time_delta * 100.0) / time_delta);

	last_system_time_ = task_time;
	last_time_ = time;

	return cpu;
	}

	mach_port_t ProcessMetrics::TaskForPid(ProcessHandle process) const {
	mach_port_t task = MACH_PORT_NULL;
	if (port_provider_)
	task = port_provider_->TaskForPid(process_);
	if (task == MACH_PORT_NULL && process_ == getpid())
	task = mach_task_self();
	return task;
	}

	// ------------------------------------------------------------------------

	// Bytes committed by the system.
	size_t GetSystemCommitCharge() {
	host_name_port_t host = mach_host_self();
	mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
	vm_statistics_data_t data;
	kern_return_t kr = host_statistics(host, HOST_VM_INFO,
	reinterpret_cast<host_info_t>(&data),
	&count);
	if (kr) {
	LOG(WARNING) << "Failed to fetch host statistics.";
	return 0;
	}

	vm_size_t page_size;
	kr = host_page_size(host, &page_size);
	if (kr) {
	LOG(ERROR) << "Failed to fetch host page size.";
	return 0;
	}

	return (data.active_count * page_size) / 1024;
	}

	// ------------------------------------------------------------------------

	namespace {

	bool g_oom_killer_enabled;

	// === C malloc/calloc/valloc/realloc ===

	typedef void* (malloc_type)(struct _malloc_zone_t zone,
	size_t size);
	typedef void* (calloc_type)(struct _malloc_zone_t zone,
	size_t num_items,
	size_t size);
	typedef void* (valloc_type)(struct _malloc_zone_t zone,
	size_t size);
	typedef void* (realloc_type)(struct _malloc_zone_t zone,
	void* ptr,
	size_t size);

	malloc_type g_old_malloc;
	calloc_type g_old_calloc;
	valloc_type g_old_valloc;
	realloc_type g_old_realloc;

	void* oom_killer_malloc(struct _malloc_zone_t* zone,
	size_t size) {
	void* result = g_old_malloc(zone, size);
	if (size && !result)
	DebugUtil::BreakDebugger();
	return result;
	}

	void* oom_killer_calloc(struct _malloc_zone_t* zone,
	size_t num_items,
	size_t size) {
	void* result = g_old_calloc(zone, num_items, size);
	if (num_items && size && !result)
	DebugUtil::BreakDebugger();
	return result;
	}

	void* oom_killer_valloc(struct _malloc_zone_t* zone,
	size_t size) {
	void* result = g_old_valloc(zone, size);
	if (size && !result)
	DebugUtil::BreakDebugger();
	return result;
	}

	void* oom_killer_realloc(struct _malloc_zone_t* zone,
	void* ptr,
	size_t size) {
	void* result = g_old_realloc(zone, ptr, size);
	if (size && !result)
	DebugUtil::BreakDebugger();
	return result;
	}

	// === C++ operator new ===

	void oom_killer_new() {
	DebugUtil::BreakDebugger();
	}

	// === Core Foundation CFAllocators ===

	// This is the real structure of a CFAllocatorRef behind the scenes. See
	// http://opensource.apple.com/source/CF/CF-550/CFBase.c for details.
	struct ChromeCFAllocator {
	_malloc_zone_t fake_malloc_zone;
	void* allocator;
	CFAllocatorContext context;
	};
	typedef ChromeCFAllocator* ChromeCFAllocatorRef;

	CFAllocatorAllocateCallBack g_old_cfallocator_system_default;
	CFAllocatorAllocateCallBack g_old_cfallocator_malloc;
	CFAllocatorAllocateCallBack g_old_cfallocator_malloc_zone;

	void* oom_killer_cfallocator_system_default(CFIndex alloc_size,
	CFOptionFlags hint,
	void* info) {
	void* result = g_old_cfallocator_system_default(alloc_size, hint, info);
	if (!result)
	DebugUtil::BreakDebugger();
	return result;
	}

	void* oom_killer_cfallocator_malloc(CFIndex alloc_size,
	CFOptionFlags hint,
	void* info) {
	void* result = g_old_cfallocator_malloc(alloc_size, hint, info);
	if (!result)
	DebugUtil::BreakDebugger();
	return result;
	}

	void* oom_killer_cfallocator_malloc_zone(CFIndex alloc_size,
	CFOptionFlags hint,
	void* info) {
	void* result = g_old_cfallocator_malloc_zone(alloc_size, hint, info);
	if (!result)
	DebugUtil::BreakDebugger();
	return result;
	}

	// === Cocoa NSObject allocation ===

	typedef id (allocWithZone_t)(id, SEL, NSZone);
	allocWithZone_t g_old_allocWithZone;

	id oom_killer_allocWithZone(id self, SEL _cmd, NSZone* zone)
	{
	id result = g_old_allocWithZone(self, _cmd, zone);
	if (!result)
	DebugUtil::BreakDebugger();
	return result;
	}

	} // namespace

	void EnableTerminationOnOutOfMemory() {
	if (g_oom_killer_enabled)
	return;

	g_oom_killer_enabled = true;

	// === C malloc/calloc/valloc/realloc ===

	// This approach is not perfect, as requests for amounts of memory larger than
	// MALLOC_ABSOLUTE_MAX_SIZE (currently SIZE_T_MAX - (2 * PAGE_SIZE)) will
	// still fail with a NULL rather than dying (see
	// http://opensource.apple.com/source/Libc/Libc-583/gen/malloc.c for details).
	// Unfortunately, it's the best we can do. Also note that this does not affect
	// allocations from non-default zones.

	CHECK(!g_old_malloc && !g_old_calloc && !g_old_valloc && !g_old_realloc)
	<< "Old allocators unexpectedly non-null";

	int32 major;
	int32 minor;
	int32 bugfix;
	SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
	bool zone_allocators_protected = ((major == 10 && minor > 6) \|\| major > 10);

	malloc_zone_t* default_zone = malloc_default_zone();

	vm_address_t page_start = NULL;
	vm_size_t len = 0;
	if (zone_allocators_protected) {
	// See http://trac.webkit.org/changeset/53362/trunk/WebKitTools/DumpRenderTree/mac
	page_start = reinterpret_cast<vm_address_t>(default_zone) &
	static_cast<vm_size_t>(~(getpagesize() - 1));
	len = reinterpret_cast<vm_address_t>(default_zone) -
	page_start + sizeof(malloc_zone_t);
	mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ \| PROT_WRITE);
	}

	g_old_malloc = default_zone->malloc;
	g_old_calloc = default_zone->calloc;
	g_old_valloc = default_zone->valloc;
	g_old_realloc = default_zone->realloc;
	CHECK(g_old_malloc && g_old_calloc && g_old_valloc && g_old_realloc)
	<< "Failed to get system allocation functions.";

	default_zone->malloc = oom_killer_malloc;
	default_zone->calloc = oom_killer_calloc;
	default_zone->valloc = oom_killer_valloc;
	default_zone->realloc = oom_killer_realloc;

	if (zone_allocators_protected) {
	mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ);
	}

	// === C++ operator new ===

	// Yes, operator new does call through to malloc, but this will catch failures
	// that our imperfect handling of malloc cannot.

	std::set_new_handler(oom_killer_new);

	// === Core Foundation CFAllocators ===

	// This will not catch allocation done by custom allocators, but will catch
	// all allocation done by system-provided ones.

	CHECK(!g_old_cfallocator_system_default && !g_old_cfallocator_malloc &&
	!g_old_cfallocator_malloc_zone)
	<< "Old allocators unexpectedly non-null";

	ChromeCFAllocatorRef allocator = const_cast<ChromeCFAllocatorRef>(
	reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorSystemDefault));
	g_old_cfallocator_system_default = allocator->context.allocate;
	CHECK(g_old_cfallocator_system_default)
	<< "Failed to get kCFAllocatorSystemDefault allocation function.";
	allocator->context.allocate = oom_killer_cfallocator_system_default;

	allocator = const_cast<ChromeCFAllocatorRef>(
	reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorMalloc));
	g_old_cfallocator_malloc = allocator->context.allocate;
	CHECK(g_old_cfallocator_malloc)
	<< "Failed to get kCFAllocatorMalloc allocation function.";
	allocator->context.allocate = oom_killer_cfallocator_malloc;

	allocator = const_cast<ChromeCFAllocatorRef>(
	reinterpret_cast<const ChromeCFAllocator*>(kCFAllocatorMallocZone));
	g_old_cfallocator_malloc_zone = allocator->context.allocate;
	CHECK(g_old_cfallocator_malloc_zone)
	<< "Failed to get kCFAllocatorMallocZone allocation function.";
	allocator->context.allocate = oom_killer_cfallocator_malloc_zone;

	// === Cocoa NSObject allocation ===

	// Note that both +[NSObject new] and +[NSObject alloc] call through to
	// +[NSObject allocWithZone:].

	CHECK(!g_old_allocWithZone)
	<< "Old allocator unexpectedly non-null";

	Class nsobject_class = [NSObject class];
	Method orig_method = class_getClassMethod(nsobject_class,
	@selector(allocWithZone:));
	g_old_allocWithZone = reinterpret_cast<allocWithZone_t>(
	method_getImplementation(orig_method));
	CHECK(g_old_allocWithZone)
	<< "Failed to get allocWithZone allocation function.";
	method_setImplementation(orig_method,
	reinterpret_cast<IMP>(oom_killer_allocWithZone));
	}

	} // namespace base