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/*
* Copyright (c) 2000, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include <iostream>
#include "Reaper.hpp"
using namespace std;
Reaper::Reaper(ReaperCB* cb) {
InitializeCriticalSection(&crit);
event = CreateEvent(NULL, TRUE, FALSE, NULL);
this->cb = cb;
active = false;
shouldShutDown = false;
}
bool
Reaper::start() {
bool result = false;
EnterCriticalSection(&crit);
if (!active) {
DWORD id;
HANDLE reaper = CreateThread(NULL, 0, &Reaper::reaperThreadEntry,
this, 0, &id);
if (reaper != NULL) {
result = true;
}
}
LeaveCriticalSection(&crit);
return result;
}
bool
Reaper::stop() {
bool result = false;
EnterCriticalSection(&crit);
if (active) {
shouldShutDown = true;
SetEvent(event);
while (active) {
Sleep(1);
}
shouldShutDown = false;
result = true;
}
LeaveCriticalSection(&crit);
return result;
}
void
Reaper::registerProcess(HANDLE processHandle, void* userData) {
ProcessInfo info;
info.handle = processHandle;
info.userData = userData;
EnterCriticalSection(&crit);
procInfo.push_back(info);
SetEvent(event);
LeaveCriticalSection(&crit);
}
void
Reaper::reaperThread() {
while (!shouldShutDown) {
// Take atomic snapshot of the current process list and user data
EnterCriticalSection(&crit);
int num = procInfo.size();
HANDLE* handleList = new HANDLE[1 + num];
void** dataList = new void*[num];
for (int i = 0; i < num; i++) {
handleList[i] = procInfo[i].handle;
dataList[i] = procInfo[i].userData;
}
LeaveCriticalSection(&crit);
// Topmost handle becomes the event object, so other threads can
// signal this one to notice differences in the above list (or
// shut down)
handleList[num] = event;
// Wait for these objects
DWORD idx = WaitForMultipleObjects(1 + num, handleList,
FALSE, INFINITE);
if ((idx >= WAIT_OBJECT_0) && (idx <= WAIT_OBJECT_0 + num)) {
idx -= WAIT_OBJECT_0;
if (idx < num) {
// A process exited (i.e., it wasn't that we were woken up
// just because the event went off)
(*cb)(dataList[idx]);
// Remove this process from the list (NOTE: requires that
// ordering does not change, i.e., that all additions are to
// the back of the process list)
EnterCriticalSection(&crit);
std::vector<ProcessInfo>::iterator iter = procInfo.begin();
iter += idx;
procInfo.erase(iter);
LeaveCriticalSection(&crit);
} else {
// Notification from other thread
ResetEvent(event);
}
} else {
// Unexpected return value. For now, warn.
cerr << "Reaper::reaperThread(): unexpected return value "
<< idx << " from WaitForMultipleObjects" << endl;
}
// Clean up these lists
delete[] handleList;
delete[] dataList;
}
// Time to shut down
active = false;
}
DWORD WINAPI
Reaper::reaperThreadEntry(LPVOID data) {
Reaper* reaper = (Reaper*) data;
reaper->reaperThread();
return 0;
}
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