fix: allow 2 threads for CreateIoCompletionPort on single-core to prevent busy looping (backport: 3-1-x) (#16011)

* allow 2 threads for CreateIoCompletionPort on single-core

* use base::SysInfo::NumberOfProcessors instead of env var

* CHECK that uv_loop_ has not been used before replacing its iocp
This commit is contained in:
trop[bot] 2018-12-11 16:11:47 +09:00 committed by Cheng Zhao
parent 3c4cd3f662
commit 9490a9f9ba

View file

@ -7,6 +7,7 @@
#include <windows.h>
#include "base/logging.h"
#include "base/sys_info.h"
extern "C" {
#include "vendor/node/deps/uv/src/win/internal.h"
@ -15,7 +16,20 @@ extern "C" {
namespace atom {
NodeBindingsWin::NodeBindingsWin(BrowserEnvironment browser_env)
: NodeBindings(browser_env) {}
: NodeBindings(browser_env) {
// on single-core the io comp port NumberOfConcurrentThreads needs to be 2
// to avoid cpu pegging likely caused by a busy loop in PollEvents
if (base::SysInfo::NumberOfProcessors() == 1) {
// the expectation is the uv_loop_ has just been initialized
// which makes iocp replacement safe
CHECK_EQ(0u, uv_loop_->active_handles);
CHECK_EQ(0u, uv_loop_->active_reqs.count);
if (uv_loop_->iocp && uv_loop_->iocp != INVALID_HANDLE_VALUE)
CloseHandle(uv_loop_->iocp);
uv_loop_->iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 2);
}
}
NodeBindingsWin::~NodeBindingsWin() {}