1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "mozilla/SchedulerGroup.h"
8
9 #include <utility>
10
11 #include "jsfriendapi.h"
12 #include "mozilla/Atomics.h"
13 #include "mozilla/Telemetry.h"
14 #include "mozilla/Unused.h"
15 #include "mozilla/dom/DocGroup.h"
16 #include "mozilla/dom/ScriptSettings.h"
17 #include "nsINamed.h"
18 #include "nsQueryObject.h"
19 #include "nsThreadUtils.h"
20
21 using namespace mozilla;
22
23 namespace {
24
25 static Atomic<uint64_t> gEarliestUnprocessedVsync(0);
26
27 } // namespace
28
29 /* static */
UnlabeledDispatch(TaskCategory aCategory,already_AddRefed<nsIRunnable> && aRunnable)30 nsresult SchedulerGroup::UnlabeledDispatch(
31 TaskCategory aCategory, already_AddRefed<nsIRunnable>&& aRunnable) {
32 if (NS_IsMainThread()) {
33 return NS_DispatchToCurrentThread(std::move(aRunnable));
34 } else {
35 return NS_DispatchToMainThread(std::move(aRunnable));
36 }
37 }
38
39 /* static */
MarkVsyncReceived()40 void SchedulerGroup::MarkVsyncReceived() {
41 // May be called on any thread when a vsync is received and scheduled to be
42 // processed. This may occur on the main thread due to queued messages when
43 // the channel is connected.
44 bool inconsistent = false;
45 TimeStamp creation = TimeStamp::ProcessCreation(&inconsistent);
46 if (inconsistent) {
47 return;
48 }
49
50 // Attempt to set gEarliestUnprocessedVsync to our new value. If we've seen a
51 // vsync already, but haven't handled it, the `compareExchange` will fail and
52 // the static won't be updated.
53 uint64_t unprocessedVsync =
54 uint64_t((TimeStamp::Now() - creation).ToMicroseconds());
55 gEarliestUnprocessedVsync.compareExchange(0, unprocessedVsync);
56 }
57
58 /* static */
MarkVsyncRan()59 void SchedulerGroup::MarkVsyncRan() { gEarliestUnprocessedVsync = 0; }
60
SchedulerGroup()61 SchedulerGroup::SchedulerGroup() : mIsRunning(false) {}
62
63 /* static */
Dispatch(TaskCategory aCategory,already_AddRefed<nsIRunnable> && aRunnable)64 nsresult SchedulerGroup::Dispatch(TaskCategory aCategory,
65 already_AddRefed<nsIRunnable>&& aRunnable) {
66 return LabeledDispatch(aCategory, std::move(aRunnable), nullptr);
67 }
68
69 /* static */
LabeledDispatch(TaskCategory aCategory,already_AddRefed<nsIRunnable> && aRunnable,mozilla::PerformanceCounter * aPerformanceCounter)70 nsresult SchedulerGroup::LabeledDispatch(
71 TaskCategory aCategory, already_AddRefed<nsIRunnable>&& aRunnable,
72 mozilla::PerformanceCounter* aPerformanceCounter) {
73 nsCOMPtr<nsIRunnable> runnable(aRunnable);
74 if (XRE_IsContentProcess()) {
75 RefPtr<Runnable> internalRunnable =
76 new Runnable(runnable.forget(), aPerformanceCounter);
77 return InternalUnlabeledDispatch(aCategory, internalRunnable.forget());
78 }
79 return UnlabeledDispatch(aCategory, runnable.forget());
80 }
81
82 /*static*/
InternalUnlabeledDispatch(TaskCategory aCategory,already_AddRefed<Runnable> && aRunnable)83 nsresult SchedulerGroup::InternalUnlabeledDispatch(
84 TaskCategory aCategory, already_AddRefed<Runnable>&& aRunnable) {
85 if (NS_IsMainThread()) {
86 // NS_DispatchToCurrentThread will not leak the passed in runnable
87 // when it fails, so we don't need to do anything special.
88 return NS_DispatchToCurrentThread(std::move(aRunnable));
89 }
90
91 RefPtr<Runnable> runnable(aRunnable);
92 nsresult rv = NS_DispatchToMainThread(do_AddRef(runnable));
93 if (NS_FAILED(rv)) {
94 // Dispatch failed. This is a situation where we would have used
95 // NS_DispatchToMainThread rather than calling into the SchedulerGroup
96 // machinery, and the caller would be expecting to leak the nsIRunnable
97 // originally passed in. But because we've had to wrap things up
98 // internally, we were going to leak the nsIRunnable *and* our Runnable
99 // wrapper. But there's no reason that we have to leak our Runnable
100 // wrapper; we can just leak the wrapped nsIRunnable, and let the caller
101 // take care of unleaking it if they need to.
102 Unused << runnable->mRunnable.forget().take();
103 nsrefcnt refcnt = runnable.get()->Release();
104 MOZ_RELEASE_ASSERT(refcnt == 1, "still holding an unexpected reference!");
105 }
106
107 return rv;
108 }
109
Runnable(already_AddRefed<nsIRunnable> && aRunnable,mozilla::PerformanceCounter * aPerformanceCounter)110 SchedulerGroup::Runnable::Runnable(
111 already_AddRefed<nsIRunnable>&& aRunnable,
112 mozilla::PerformanceCounter* aPerformanceCounter)
113 : mozilla::Runnable("SchedulerGroup::Runnable"),
114 mRunnable(std::move(aRunnable)),
115 mPerformanceCounter(aPerformanceCounter) {}
116
GetPerformanceCounter() const117 mozilla::PerformanceCounter* SchedulerGroup::Runnable::GetPerformanceCounter()
118 const {
119 return mPerformanceCounter;
120 }
121
122 #ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY
123 NS_IMETHODIMP
GetName(nsACString & aName)124 SchedulerGroup::Runnable::GetName(nsACString& aName) {
125 // Try to get a name from the underlying runnable.
126 nsCOMPtr<nsINamed> named = do_QueryInterface(mRunnable);
127 if (named) {
128 named->GetName(aName);
129 }
130 if (aName.IsEmpty()) {
131 aName.AssignLiteral("anonymous");
132 }
133
134 return NS_OK;
135 }
136 #endif
137
138 NS_IMETHODIMP
Run()139 SchedulerGroup::Runnable::Run() {
140 MOZ_RELEASE_ASSERT(NS_IsMainThread());
141 // The runnable's destructor can have side effects, so try to execute it in
142 // the scope of the SchedulerGroup.
143 nsCOMPtr<nsIRunnable> runnable(std::move(mRunnable));
144 return runnable->Run();
145 }
146
147 NS_IMETHODIMP
GetPriority(uint32_t * aPriority)148 SchedulerGroup::Runnable::GetPriority(uint32_t* aPriority) {
149 *aPriority = nsIRunnablePriority::PRIORITY_NORMAL;
150 nsCOMPtr<nsIRunnablePriority> runnablePrio = do_QueryInterface(mRunnable);
151 return runnablePrio ? runnablePrio->GetPriority(aPriority) : NS_OK;
152 }
153
154 NS_IMPL_ISUPPORTS_INHERITED(SchedulerGroup::Runnable, mozilla::Runnable,
155 nsIRunnablePriority, SchedulerGroup::Runnable)
156