// The current implementation will exit if the allocation
// of any worker fails. Still, return a boolean so that
// a future implementation can possibly do a partial
// initialization of the workers and report such to the
// caller.
bool WorkGang::initialize_workers() {
if (TraceWorkGang) {
tty->print_cr("Constructing work gang %s with %d threads",
name(),
total_workers());
}
_gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers(), mtInternal);
if (gang_workers() == NULL) {
vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GangWorker array.");
return false;
}
os::ThreadType worker_type;
if (are_ConcurrentGC_threads()) {
worker_type = os::cgc_thread;
} else {
worker_type = os::pgc_thread;
}
for (uint worker = 0; worker < total_workers(); worker += 1) {
GangWorker* new_worker = allocate_worker(worker);
assert(new_worker != NULL, "Failed to allocate GangWorker");
_gang_workers[worker] = new_worker;
if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
vm_exit_out_of_memory(0, OOM_MALLOC_ERROR,
"Cannot create worker GC thread. Out of system resources.");
return false;
}
if (!DisableStartThread) {
os::start_thread(new_worker);
}
}
return true;
}
GangWorker* AbstractWorkGang::gang_worker(uint i) const {
// Array index bounds checking.
GangWorker* result = NULL;
assert(gang_workers() != NULL, "No workers for indexing");
assert(((i >= 0) && (i < total_workers())), "Worker index out of bounds");
result = _gang_workers[i];
assert(result != NULL, "Indexing to null worker");
return result;
}
AbstractWorkGang::~AbstractWorkGang() {
if (TraceWorkGang) {
tty->print_cr("Destructing work gang %s", name());
}
stop(); // stop all the workers
for (uint worker = 0; worker < total_workers(); worker += 1) {
delete gang_worker(worker);
}
delete gang_workers();
delete monitor();
}
WorkGang::~WorkGang() {
if (TraceWorkGang) {
tty->print_cr("Destructing work gang %s", name());
}
stop_task();
for (int worker = 0; worker < total_workers(); worker += 1) {
delete gang_worker(worker);
}
delete gang_workers();
delete monitor();
}
/**
* 创建并初始化所有的工作线程
*/
bool WorkGang::initialize_workers() {
if (TraceWorkGang) {
tty->print_cr("Constructing work gang %s with %d threads",
name(),
total_workers());
}
_gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers());
if (gang_workers() == NULL) {
vm_exit_out_of_memory(0, "Cannot create GangWorker array.");
return false;
}
os::ThreadType worker_type;
if (are_ConcurrentGC_threads()) {
worker_type = os::cgc_thread;
} else {
worker_type = os::pgc_thread;
}
printf("%s[%d] [tid: %lu]: 开始创建 %u 个 %s Gc线程.\n", __FILE__, __LINE__, pthread_self(), total_workers(),
worker_type == os::cgc_thread? "Concurrent" : "Parallel");
for (uint worker = 0; worker < total_workers(); worker += 1) {
GangWorker* new_worker = allocate_worker(worker);
assert(new_worker != NULL, "Failed to allocate GangWorker");
_gang_workers[worker] = new_worker;
if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) {
vm_exit_out_of_memory(0, "Cannot create worker GC thread. Out of system resources.");
return false;
}
if (!DisableStartThread) {
os::start_thread(new_worker);
}
}
return true;
}
WorkGang::WorkGang(const char* name,
int workers,
bool are_GC_threads) {
// Save arguments.
_name = name;
_total_workers = workers;
_are_GC_threads = are_GC_threads;
if (TraceWorkGang) {
tty->print_cr("Constructing work gang %s with %d threads", name, workers);
}
// Other initialization.
if (are_GC_threads) {
_monitor = new Monitor(/* priority */ Mutex::safepoint,
/* name */ "WorkGroup monitor",
/* allow_vm_block */ true);
} else {
_monitor = new Monitor(/* priority */ Mutex::leaf,
/* name */ "WorkGroup monitor",
/* allow_vm_block */ false);
}
assert(monitor() != NULL, "Failed to allocate monitor");
_terminate = false;
_task = NULL;
_sequence_number = 0;
_started_workers = 0;
_finished_workers = 0;
_gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, workers);
assert(gang_workers() != NULL, "Failed to allocate gang workers");
for (int worker = 0; worker < total_workers(); worker += 1) {
GangWorker* new_worker = new GangWorker(this, worker);
assert(new_worker != NULL, "Failed to allocate GangWorker");
_gang_workers[worker] = new_worker;
bool os_thread_create = os::create_thread(new_worker, os::gc_thread);
assert(os_thread_create, "os thread create failed");
if (!DisableStartThread) {
os::start_thread(new_worker);
}
}
}