Aren/haiku
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

urlRequest: interrupt syscalls using a signal

Browse Source 
Sometimes an HTTP request would get stuck in a call to connect(). While
our read() and write() implementations are interrupted if you close()
the socket, our connect() isn't. It would nonetheless abort the
connection process, and connect would stay blocked for quite a long
time.

When navigating away from a page, WebKit closes all pending connections,
and in our network backend this also means freeing the request object.
But, the destructor can't be called until the thread has stopped
running, to ensure proper cleanup.

Avoid the lockup in connect by sending a signal (SIGUSR1) to the thread
we want to unlock. This interrupts the syscall, and the thread exits
immediately.
This commit is contained in:
Adrien Destugues 2014-01-23 15:48:04 +01:00
parent d5c2ed6b14
commit 281727261d
1 changed files with 22 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
src/kits/network/libnetapi/UrlRequest.cpp
View File

@ -90,6 +90,7 @@ BUrlRequest::Stop()
status_t threadStatus = B_OK;
fQuit = true;
send_signal(fThreadId, SIGUSR1); // unblock blocking syscalls.
wait_for_thread(fThreadId, &threadStatus);
return threadStatus;
}
@ -183,19 +184,33 @@ BUrlRequest::Status() const
// #pragma mark Thread management
void
empty(int)
{
}
/*static*/ int32
BUrlRequest::_ThreadEntry(void* arg)
{
BUrlRequest* urlProtocol = reinterpret_cast<BUrlRequest*>(arg);
urlProtocol->fThreadStatus = B_BUSY;
// Setup an (empty) signal handler so we can be stopped by a signal,
// witohut the whole process being killed.
struct sigaction action;
action.sa_handler = empty;
action.sa_mask = 0;
action.sa_flags = 0;
sigaction(SIGUSR1, &action, NULL);
status_t protocolLoopExitStatus = urlProtocol->_ProtocolLoop();
BUrlRequest* request = reinterpret_cast<BUrlRequest*>(arg);
request->fThreadStatus = B_BUSY;
urlProtocol->fRunning = false;
urlProtocol->fThreadStatus = protocolLoopExitStatus;
status_t protocolLoopExitStatus = request->_ProtocolLoop();
if (urlProtocol->fListener != NULL) {
urlProtocol->fListener->RequestCompleted(urlProtocol,
request->fRunning = false;
request->fThreadStatus = protocolLoopExitStatus;
if (request->fListener != NULL) {
request->fListener->RequestCompleted(request,
protocolLoopExitStatus == B_OK);
}