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authorGisle Vanem <gvanem@broadpark.no>2004-10-16 12:59:05 +0000
committerGisle Vanem <gvanem@broadpark.no>2004-10-16 12:59:05 +0000
commite3564201232ed2b7aea2111bb1c5383a8316fadb (patch)
tree1406f45248b9d5e24935f7932e7bac382e186004
parente8f85cba0f8c19369d39b1c6616dc51dae1dd179 (diff)
Added Traian Nicolescu's patches for threaded resolver on
Windows. Plugged some potential handle and memory leaks. Refs. http://curl.haxx.se/mail/lib-2004-10/0134.html http://curl.haxx.se/mail/lib-2004-10/0157.html
-rw-r--r--lib/hostthre.c177
1 files changed, 142 insertions, 35 deletions
diff --git a/lib/hostthre.c b/lib/hostthre.c
index 738efa52f..fad335b45 100644
--- a/lib/hostthre.c
+++ b/lib/hostthre.c
@@ -64,6 +64,7 @@
#endif
#ifdef WIN32
+#include <stdlib.h>
#include <process.h>
#endif
@@ -156,6 +157,8 @@ struct thread_data {
DWORD thread_status;
curl_socket_t dummy_sock; /* dummy for Curl_fdset() */
FILE *stderr_file;
+ HANDLE mutex_waiting; /* marks that we are still waiting for a resolve */
+ HANDLE event_resolved; /* marks that the thread obtained the information */
#ifdef CURLRES_IPV6
struct addrinfo hints;
#endif
@@ -174,7 +177,19 @@ static unsigned __stdcall gethostbyname_thread (void *arg)
struct connectdata *conn = (struct connectdata*) arg;
struct thread_data *td = (struct thread_data*) conn->async.os_specific;
struct hostent *he;
- int rc;
+ int rc = 0;
+
+ /* Duplicate the passed mutex handle.
+ * This allows us to use it even after the container gets destroyed
+ * due to a resolver timeout.
+ */
+ HANDLE mutex_waiting = NULL;
+ if (!DuplicateHandle(GetCurrentProcess(), td->mutex_waiting,
+ GetCurrentProcess(), &mutex_waiting, 0, FALSE,
+ DUPLICATE_SAME_ACCESS)) {
+ /* failed to duplicate the mutex, no point in continuing */
+ return 0;
+ }
/* Sharing the same _iob[] element with our parent thread should
* hopefully make printouts synchronised. I'm not sure it works
@@ -184,16 +199,31 @@ static unsigned __stdcall gethostbyname_thread (void *arg)
WSASetLastError (conn->async.status = NO_DATA); /* pending status */
he = gethostbyname (conn->async.hostname);
- if (he) {
- Curl_addrinfo4_callback(conn, CURL_ASYNC_SUCCESS, he);
- rc = 1;
- }
- else {
- Curl_addrinfo4_callback(conn, (int)WSAGetLastError(), NULL);
- rc = 0;
+
+ /* is the thread initiator still waiting for us ? */
+ if (WaitForSingleObject(mutex_waiting, 0) == WAIT_TIMEOUT) {
+ /* yes, it is */
+
+ /* Mark that we have obtained the information, and that we are
+ * calling back with it.
+ */
+ SetEvent(td->event_resolved);
+
+ if (he) {
+ Curl_addrinfo4_callback(conn, CURL_ASYNC_SUCCESS, he);
+ rc = 1;
+ }
+ else {
+ Curl_addrinfo4_callback(conn, (int)WSAGetLastError(), NULL);
+ rc = 0;
+ }
+ TRACE(("Winsock-error %d, addr %s\n", conn->async.status,
+ he ? inet_ntoa(*(struct in_addr*)he->h_addr) : "unknown"));
}
- TRACE(("Winsock-error %d, addr %s\n", conn->async.status,
- he ? inet_ntoa(*(struct in_addr*)he->h_addr) : "unknown"));
+
+ /* clean up */
+ CloseHandle(mutex_waiting);
+
return (rc);
/* An implicit _endthreadex() here */
}
@@ -215,6 +245,18 @@ static unsigned __stdcall getaddrinfo_thread (void *arg)
char service [NI_MAXSERV];
int rc;
+ /* Duplicate the passed mutex handle.
+ * This allows us to use it even after the container gets destroyed
+ * due to a resolver timeout.
+ */
+ HANDLE mutex_waiting = NULL;
+ if (!DuplicateHandle(GetCurrentProcess(), td->mutex_waiting,
+ GetCurrentProcess(), &mutex_waiting, 0, FALSE,
+ DUPLICATE_SAME_ACCESS)) {
+ /* failed to duplicate the mutex, no point in continuing */
+ return 0;
+ }
+
*stderr = *td->stderr_file;
itoa(conn->async.port, service, 10);
@@ -223,16 +265,30 @@ static unsigned __stdcall getaddrinfo_thread (void *arg)
rc = getaddrinfo(conn->async.hostname, service, &td->hints, &res);
- if (rc == 0) {
+ /* is the thread initiator still waiting for us ? */
+ if (WaitForSingleObject(mutex_waiting, 0) == WAIT_TIMEOUT) {
+ /* yes, it is */
+
+ /* Mark that we have obtained the information, and that we are
+ * calling back with it.
+ */
+ SetEvent(td->event_resolved);
+
+ if (rc == 0) {
#ifdef DEBUG_THREADING_GETADDRINFO
- dump_addrinfo (conn, res);
+ dump_addrinfo (conn, res);
#endif
- Curl_addrinfo6_callback(conn, CURL_ASYNC_SUCCESS, res);
- }
- else {
- Curl_addrinfo6_callback(conn, (int)WSAGetLastError(), NULL);
- TRACE(("Winsock-error %d, no address\n", conn->async.status));
+ Curl_addrinfo6_callback(conn, CURL_ASYNC_SUCCESS, res);
+ }
+ else {
+ Curl_addrinfo6_callback(conn, (int)WSAGetLastError(), NULL);
+ TRACE(("Winsock-error %d, no address\n", conn->async.status));
+ }
}
+
+ /* clean up */
+ CloseHandle(mutex_waiting);
+
return (rc);
/* An implicit _endthreadex() here */
}
@@ -248,10 +304,18 @@ static void destroy_thread_data (struct Curl_async *async)
free(async->hostname);
if (async->os_specific) {
- curl_socket_t sock = ((const struct thread_data*)async->os_specific)->dummy_sock;
+ struct thread_data *td = (struct thread_data*) async->os_specific;
+ curl_socket_t sock = td->dummy_sock;
if (sock != CURL_SOCKET_BAD)
sclose(sock);
+
+ /* destroy the synchronization objects */
+ if (td->mutex_waiting)
+ CloseHandle(td->mutex_waiting);
+ if (td->event_resolved)
+ CloseHandle(td->event_resolved);
+
free(async->os_specific);
}
async->hostname = NULL;
@@ -288,8 +352,28 @@ static bool init_resolve_thread (struct connectdata *conn,
conn->async.status = 0;
conn->async.dns = NULL;
conn->async.os_specific = (void*) td;
-
td->dummy_sock = CURL_SOCKET_BAD;
+
+ /* Create the mutex used to inform the resolver thread that we're
+ * still waiting, and take initial ownership.
+ */
+ td->mutex_waiting = CreateMutex(NULL, TRUE, NULL);
+ if (td->mutex_waiting == NULL) {
+ destroy_thread_data(&conn->async);
+ SetLastError(EAGAIN);
+ return FALSE;
+ }
+
+ /* Create the event that the thread uses to inform us that it's
+ * done resolving. Do not signal it.
+ */
+ td->event_resolved = CreateEvent(NULL, TRUE, FALSE, NULL);
+ if (td->event_resolved == NULL) {
+ destroy_thread_data(&conn->async);
+ SetLastError(EAGAIN);
+ return FALSE;
+ }
+
td->stderr_file = stderr;
td->thread_hnd = (HANDLE) _beginthreadex(NULL, 0, THREAD_FUNC,
conn, 0, &td->thread_id);
@@ -342,20 +426,43 @@ CURLcode Curl_wait_for_resolv(struct connectdata *conn,
CURL_TIMEOUT_RESOLVE; /* default name resolve timeout */
ticks = GetTickCount();
- status = WaitForSingleObject(td->thread_hnd, 1000UL*timeout);
- if (status == WAIT_OBJECT_0 || status == WAIT_ABANDONED) {
- /* Thread finished before timeout; propagate Winsock error to this thread.
- * 'conn->async.done = TRUE' is set in Curl_addrinfo4/6_callback().
- */
- WSASetLastError(conn->async.status);
- GetExitCodeThread(td->thread_hnd, &td->thread_status);
- TRACE(("%s() status %lu, thread retval %lu, ",
- THREAD_NAME, status, td->thread_status));
+ /* wait for the thread to resolve the name */
+ status = WaitForSingleObject(td->event_resolved, 1000UL*timeout);
+
+ /* mark that we are now done waiting */
+ ReleaseMutex(td->mutex_waiting);
+
+ /* close our handle to the mutex, no point in hanging on to it */
+ CloseHandle(td->mutex_waiting);
+ td->mutex_waiting = NULL;
+
+ /* close the event handle, it's useless now */
+ CloseHandle(td->event_resolved);
+ td->event_resolved = NULL;
+
+ /* has the resolver thread succeeded in resolving our query ? */
+ if (status == WAIT_OBJECT_0) {
+ /* wait for the thread to exit, it's in the callback sequence */
+ if (WaitForSingleObject(td->thread_hnd, 5000) == WAIT_TIMEOUT) {
+ TerminateThread(td->thread_hnd, 0);
+ conn->async.done = TRUE;
+ td->thread_status = (DWORD)-1;
+ TRACE(("%s() thread stuck?!, ", THREAD_NAME));
+ }
+ else {
+ /* Thread finished before timeout; propagate Winsock error to this thread.
+ * 'conn->async.done = TRUE' is set in Curl_addrinfo4/6_callback().
+ */
+ WSASetLastError(conn->async.status);
+ GetExitCodeThread(td->thread_hnd, &td->thread_status);
+ TRACE(("%s() status %lu, thread retval %lu, ",
+ THREAD_NAME, status, td->thread_status));
+ }
}
else {
- conn->async.done = TRUE;
- td->thread_status = (DWORD)-1;
- TRACE(("%s() timeout, ", THREAD_NAME));
+ conn->async.done = TRUE;
+ td->thread_status = (DWORD)-1;
+ TRACE(("%s() timeout, ", THREAD_NAME));
}
TRACE(("elapsed %lu ms\n", GetTickCount()-ticks));
@@ -460,8 +567,8 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
}
/* fall-back to blocking version */
- infof(data, "init_resolve_thread() failed for %s; code %lu\n",
- hostname, GetLastError());
+ infof(data, "init_resolve_thread() failed for %s; %s\n",
+ hostname, Curl_strerror(conn,GetLastError()));
h = gethostbyname(hostname);
if (!h) {
@@ -535,8 +642,8 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
}
/* fall-back to blocking version */
- infof(data, "init_resolve_thread() failed for %s; code %lu\n",
- hostname, GetLastError());
+ infof(data, "init_resolve_thread() failed for %s; %s\n",
+ hostname, Curl_strerror(conn,GetLastError()));
error = getaddrinfo(hostname, sbuf, &hints, &res);
if (error) {