1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <err.h>
18 #include <errno.h>
19 #include <pthread.h>
20 #include <stdint.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/mman.h>
25 #include <unistd.h>
26
27 #include <new>
28
29 #include "Alloc.h"
30 #include "Pointers.h"
31 #include "Thread.h"
32 #include "Threads.h"
33
ThreadRunner(void * data)34 void* ThreadRunner(void* data) {
35 Thread* thread = reinterpret_cast<Thread*>(data);
36 while (true) {
37 thread->WaitForPending();
38 const AllocEntry& entry = thread->GetAllocEntry();
39 thread->AddTimeNsecs(AllocExecute(entry, thread->pointers()));
40 bool thread_done = entry.type == THREAD_DONE;
41 thread->ClearPending();
42 if (thread_done) {
43 break;
44 }
45 }
46 return nullptr;
47 }
48
Threads(Pointers * pointers,size_t max_threads)49 Threads::Threads(Pointers* pointers, size_t max_threads)
50 : pointers_(pointers), max_threads_(max_threads) {
51 size_t pagesize = getpagesize();
52 data_size_ = (max_threads_ * sizeof(Thread) + pagesize - 1) & ~(pagesize - 1);
53 max_threads_ = data_size_ / sizeof(Thread);
54
55 void* memory = mmap(nullptr, data_size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
56 if (memory == MAP_FAILED) {
57 err(1, "Failed to map in memory for Threads: map size %zu, max threads %zu\n",
58 data_size_, max_threads_);
59 }
60
61 threads_ = new (memory) Thread[max_threads_];
62 }
63
~Threads()64 Threads::~Threads() {
65 if (threads_) {
66 munmap(threads_, data_size_);
67 threads_ = nullptr;
68 data_size_ = 0;
69 }
70 }
71
CreateThread(pid_t tid)72 Thread* Threads::CreateThread(pid_t tid) {
73 if (num_threads_ == max_threads_) {
74 err(1, "Too many threads created, current max %zu.\n", num_threads_);
75 }
76 Thread* thread = FindEmptyEntry(tid);
77 if (thread == nullptr) {
78 err(1, "No empty entries found, current max %zu, num threads %zu\n",
79 max_threads_, num_threads_);
80 }
81 thread->tid_ = tid;
82 thread->pointers_ = pointers_;
83 thread->total_time_nsecs_ = 0;
84 if ((errno = pthread_create(&thread->thread_id_, nullptr, ThreadRunner, thread)) != 0) {
85 err(1, "Failed to create thread %d: %s\n", tid, strerror(errno));
86 }
87
88 num_threads_++;
89 return thread;
90 }
91
FindThread(pid_t tid)92 Thread* Threads::FindThread(pid_t tid) {
93 size_t index = GetHashEntry(tid);
94 for (size_t entries = num_threads_; entries != 0; ) {
95 pid_t cur_tid = threads_[index].tid_;
96 if (cur_tid == tid) {
97 return threads_ + index;
98 }
99 if (cur_tid != 0) {
100 entries--;
101 }
102 if (++index == max_threads_) {
103 index = 0;
104 }
105 }
106 return nullptr;
107 }
108
WaitForAllToQuiesce()109 void Threads::WaitForAllToQuiesce() {
110 for (size_t i = 0, threads = 0; threads < num_threads_; i++) {
111 pid_t cur_tid = threads_[i].tid_;
112 if (cur_tid != 0) {
113 threads++;
114 threads_[i].WaitForReady();
115 }
116 }
117 }
118
GetHashEntry(pid_t tid)119 size_t Threads::GetHashEntry(pid_t tid) {
120 return tid % max_threads_;
121 }
122
FindEmptyEntry(pid_t tid)123 Thread* Threads::FindEmptyEntry(pid_t tid) {
124 size_t index = GetHashEntry(tid);
125 for (size_t entries = 0; entries < max_threads_; entries++) {
126 if (threads_[index].tid_ == 0) {
127 return threads_ + index;
128 }
129 if (++index == max_threads_) {
130 index = 0;
131 }
132 }
133 return nullptr;
134 }
135
Finish(Thread * thread)136 void Threads::Finish(Thread* thread) {
137 int ret = pthread_join(thread->thread_id_, nullptr);
138 if (ret != 0) {
139 fprintf(stderr, "pthread_join failed: %s\n", strerror(ret));
140 exit(1);
141 }
142 total_time_nsecs_ += thread->total_time_nsecs_;
143 thread->tid_ = 0;
144 num_threads_--;
145 }
146
FinishAll()147 void Threads::FinishAll() {
148 AllocEntry thread_done = {.type = THREAD_DONE};
149 for (size_t i = 0; i < max_threads_; i++) {
150 if (threads_[i].tid_ != 0) {
151 threads_[i].SetAllocEntry(&thread_done);
152 threads_[i].SetPending();
153 Finish(threads_ + i);
154 }
155 }
156 }
157