OLD | NEW |
---|---|
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/metrics/field_trial.h" | 5 #include "base/metrics/field_trial.h" |
6 | 6 |
7 #include <algorithm> | 7 #include <algorithm> |
8 #include <utility> | 8 #include <utility> |
9 | 9 |
10 #include "base/base_switches.h" | |
10 #include "base/build_time.h" | 11 #include "base/build_time.h" |
12 #include "base/command_line.h" | |
13 #include "base/feature_list.h" | |
11 #include "base/logging.h" | 14 #include "base/logging.h" |
12 #include "base/rand_util.h" | 15 #include "base/rand_util.h" |
13 #include "base/strings/string_number_conversions.h" | 16 #include "base/strings/string_number_conversions.h" |
14 #include "base/strings/string_util.h" | 17 #include "base/strings/string_util.h" |
15 #include "base/strings/stringprintf.h" | 18 #include "base/strings/stringprintf.h" |
16 #include "base/strings/utf_string_conversions.h" | 19 #include "base/strings/utf_string_conversions.h" |
17 | 20 |
18 namespace base { | 21 namespace base { |
19 | 22 |
20 namespace { | 23 namespace { |
21 | 24 |
22 // Define a separator character to use when creating a persistent form of an | 25 // Define a separator character to use when creating a persistent form of an |
23 // instance. This is intended for use as a command line argument, passed to a | 26 // instance. This is intended for use as a command line argument, passed to a |
24 // second process to mimic our state (i.e., provide the same group name). | 27 // second process to mimic our state (i.e., provide the same group name). |
25 const char kPersistentStringSeparator = '/'; // Currently a slash. | 28 const char kPersistentStringSeparator = '/'; // Currently a slash. |
26 | 29 |
27 // Define a marker character to be used as a prefix to a trial name on the | 30 // Define a marker character to be used as a prefix to a trial name on the |
28 // command line which forces its activation. | 31 // command line which forces its activation. |
29 const char kActivationMarker = '*'; | 32 const char kActivationMarker = '*'; |
30 | 33 |
34 // Use shared memory to communicate field trial (experiment) state. | |
35 const base::Feature kShareFieldTrialStateViaSharedMemory{ | |
36 "ShareFieldTrialStateViaSharedMemory", base::FEATURE_DISABLED_BY_DEFAULT}; | |
Alexei Svitkine (slow)
2016/10/06 21:39:28
Nit: How about "UseSharedMemoryForFieldTrials" - a
lawrencewu
2016/10/07 15:07:21
Done.
| |
37 | |
31 // Created a time value based on |year|, |month| and |day_of_month| parameters. | 38 // Created a time value based on |year|, |month| and |day_of_month| parameters. |
32 Time CreateTimeFromParams(int year, int month, int day_of_month) { | 39 Time CreateTimeFromParams(int year, int month, int day_of_month) { |
33 DCHECK_GT(year, 1970); | 40 DCHECK_GT(year, 1970); |
34 DCHECK_GT(month, 0); | 41 DCHECK_GT(month, 0); |
35 DCHECK_LT(month, 13); | 42 DCHECK_LT(month, 13); |
36 DCHECK_GT(day_of_month, 0); | 43 DCHECK_GT(day_of_month, 0); |
37 DCHECK_LT(day_of_month, 32); | 44 DCHECK_LT(day_of_month, 32); |
38 | 45 |
39 Time::Exploded exploded; | 46 Time::Exploded exploded; |
40 exploded.year = year; | 47 exploded.year = year; |
(...skipping 510 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
551 // Call |group()| to mark the trial as "used" and notify observers, if | 558 // Call |group()| to mark the trial as "used" and notify observers, if |
552 // any. This is useful to ensure that field trials created in child | 559 // any. This is useful to ensure that field trials created in child |
553 // processes are properly reported in crash reports. | 560 // processes are properly reported in crash reports. |
554 trial->group(); | 561 trial->group(); |
555 } | 562 } |
556 } | 563 } |
557 return true; | 564 return true; |
558 } | 565 } |
559 | 566 |
560 // static | 567 // static |
568 void FieldTrialList::CreateTrialsFromCommandLine( | |
569 const base::CommandLine& cmd_line, | |
570 const char* field_trial_handle_switch) { | |
571 DCHECK(global_); | |
572 | |
573 #if defined(OS_WIN) | |
574 if (cmd_line.HasSwitch(field_trial_handle_switch)) { | |
575 std::string arg = cmd_line.GetSwitchValueASCII(field_trial_handle_switch); | |
576 size_t token = arg.find(","); | |
577 int field_trial_handle = std::stoi(arg.substr(0, token)); | |
578 int field_trial_length = std::stoi(arg.substr(token + 1, arg.length())); | |
Alexei Svitkine (slow)
2016/10/06 21:39:28
Do you need to do any kind of error handling here?
lawrencewu
2016/10/07 15:07:21
I thought about it, and I think it is unnecessary
| |
579 | |
580 HANDLE handle = reinterpret_cast<HANDLE>(field_trial_handle); | |
581 base::SharedMemoryHandle shm_handle = | |
582 base::SharedMemoryHandle(handle, base::GetCurrentProcId()); | |
583 | |
584 base::SharedMemory shared_memory(shm_handle, false); | |
Alexei Svitkine (slow)
2016/10/06 21:39:28
Add a comment that this will be deleted when this
lawrencewu
2016/10/07 15:07:21
Done.
| |
585 shared_memory.Map(field_trial_length); | |
586 | |
587 char* field_trial_state = static_cast<char*>(shared_memory.memory()); | |
588 bool result = FieldTrialList::CreateTrialsFromString( | |
589 std::string(field_trial_state), std::set<std::string>()); | |
590 DCHECK(result); | |
591 return; | |
592 } | |
593 #endif | |
594 | |
595 if (cmd_line.HasSwitch(switches::kForceFieldTrials)) { | |
596 bool result = FieldTrialList::CreateTrialsFromString( | |
597 cmd_line.GetSwitchValueASCII(switches::kForceFieldTrials), | |
598 std::set<std::string>()); | |
599 DCHECK(result); | |
600 } | |
601 } | |
602 | |
603 // static | |
604 std::unique_ptr<base::SharedMemory> FieldTrialList::CopyFieldTrialStateToFlags( | |
605 const char* field_trial_handle_switch, | |
606 base::CommandLine* cmd_line) { | |
607 std::string field_trial_states; | |
608 base::FieldTrialList::AllStatesToString(&field_trial_states); | |
609 if (!field_trial_states.empty()) { | |
610 // Use shared memory to pass the state if the feature is enabled, otherwise | |
611 // fallback to passing it via the command line as a string. | |
612 if (base::FeatureList::IsEnabled(kShareFieldTrialStateViaSharedMemory)) { | |
613 #if defined(OS_WIN) | |
Alexei Svitkine (slow)
2016/10/06 21:39:28
Put the whole if under ifdef and remove the else -
lawrencewu
2016/10/07 15:07:21
Done.
| |
614 std::unique_ptr<base::SharedMemory> shm(new base::SharedMemory()); | |
615 size_t length = field_trial_states.size() + 1; | |
616 shm->CreateAndMapAnonymous(length); | |
617 memcpy(shm->memory(), field_trial_states.c_str(), length); | |
Alexei Svitkine (slow)
2016/10/06 21:39:28
Is it guaranteed to be null terminated? If not, pl
lawrencewu
2016/10/07 15:07:21
c_str() is guaranteed to be null terminated: http:
| |
618 | |
619 // HANDLE is just typedef'd to void * | |
620 auto uintptr_handle = | |
621 reinterpret_cast<std::uintptr_t>(shm->handle().GetHandle()); | |
622 std::string field_trial_handle = | |
623 std::to_string(uintptr_handle) + "," + std::to_string(length); | |
624 | |
625 cmd_line->AppendSwitchASCII(field_trial_handle_switch, | |
626 field_trial_handle); | |
627 return shm; | |
628 #else | |
629 return std::unique_ptr<base::SharedMemory>(nullptr); | |
630 #endif | |
631 } else { | |
632 cmd_line->AppendSwitchASCII(switches::kForceFieldTrials, | |
633 field_trial_states); | |
634 } | |
635 } | |
636 return std::unique_ptr<base::SharedMemory>(nullptr); | |
637 } | |
638 | |
639 // static | |
561 FieldTrial* FieldTrialList::CreateFieldTrial( | 640 FieldTrial* FieldTrialList::CreateFieldTrial( |
562 const std::string& name, | 641 const std::string& name, |
563 const std::string& group_name) { | 642 const std::string& group_name) { |
564 DCHECK(global_); | 643 DCHECK(global_); |
565 DCHECK_GE(name.size(), 0u); | 644 DCHECK_GE(name.size(), 0u); |
566 DCHECK_GE(group_name.size(), 0u); | 645 DCHECK_GE(group_name.size(), 0u); |
567 if (name.empty() || group_name.empty() || !global_) | 646 if (name.empty() || group_name.empty() || !global_) |
568 return NULL; | 647 return NULL; |
569 | 648 |
570 FieldTrial* field_trial = FieldTrialList::Find(name); | 649 FieldTrial* field_trial = FieldTrialList::Find(name); |
(...skipping 79 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
650 return; | 729 return; |
651 } | 730 } |
652 AutoLock auto_lock(global_->lock_); | 731 AutoLock auto_lock(global_->lock_); |
653 CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name(); | 732 CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name(); |
654 trial->AddRef(); | 733 trial->AddRef(); |
655 trial->SetTrialRegistered(); | 734 trial->SetTrialRegistered(); |
656 global_->registered_[trial->trial_name()] = trial; | 735 global_->registered_[trial->trial_name()] = trial; |
657 } | 736 } |
658 | 737 |
659 } // namespace base | 738 } // namespace base |
OLD | NEW |