Change shutdown behavior to allow graceful handle leaks.

This avoids crashing in case of any handle references left-over in GC allocated memory that gets finalized after module destructors have already been run.
This commit is contained in:
Sönke Ludwig 2018-10-26 15:43:21 +02:00
parent 38a4e4ca5f
commit e2e8bf30aa
7 changed files with 96 additions and 13 deletions

View file

@ -22,7 +22,7 @@ else alias NativeEventDriver = EventDriver;
assert(s_driver !is null, "setupEventDriver() was not called for this thread.");
else {
if (!s_driver) {
s_driver = mallocT!NativeEventDriver();
s_driver = mallocT!NativeEventDriver;
}
}
return s_driver;
@ -43,7 +43,7 @@ static if (!is(NativeEventDriver == EventDriver)) {
if (!s_isMainThread) {
if (!--s_initCount) {
if (s_driver) {
s_driver.dispose();
if (s_driver.dispose())
freeT(s_driver);
}
}
@ -61,7 +61,7 @@ static if (!is(NativeEventDriver == EventDriver)) {
{
if (!--s_initCount) {
if (s_driver) {
s_driver.dispose();
if (s_driver.dispose())
freeT(s_driver);
}
}

View file

@ -52,8 +52,13 @@ interface EventDriver {
/// Directory change watching
@property inout(EventDriverWatchers) watchers() inout;
/// Releases all resources associated with the driver
void dispose();
/** Releases all resources associated with the driver.
In case of any left-over referenced handles, this function returns
`false` and does not free any resources. It may choose to free the
resources once the last handle gets dereferenced.
*/
bool dispose();
}

View file

@ -88,9 +88,29 @@ final class PosixEventDriver(Loop : PosixEventLoop) : EventDriver {
final override @property inout(FileDriver) files() inout { return m_files; }
final override @property inout(WatcherDriver) watchers() inout { return m_watchers; }
final override void dispose()
final override bool dispose()
{
if (!m_loop) return;
import core.thread : Thread;
import taggedalgebraic : hasType;
if (!m_loop) return true;
static string getThreadName()
{
string thname;
try thname = Thread.getThis().name;
catch (Exception e) assert(false, e.msg);
return thname.length ? thname : "unknown";
}
if (m_loop.m_handleCount > 0) {
print("Warning (thread: %s): leaking eventcore driver because there are still active handles", getThreadName());
foreach (id, ref s; m_loop.m_fds)
if (!s.specific.hasType!(typeof(null)) && !(s.common.flags & FDFlags.internal))
print(" FD %s (%s)", id, s.specific.kind);
return false;
}
m_files.dispose();
m_dns.dispose();
m_core.dispose();
@ -108,6 +128,8 @@ final class PosixEventDriver(Loop : PosixEventLoop) : EventDriver {
freeT(m_loop);
} ();
catch (Exception e) assert(false, e.msg);
return true;
}
}
@ -279,6 +301,7 @@ package class PosixEventLoop {
package {
AlgebraicChoppedVector!(FDSlot, StreamSocketSlot, StreamListenSocketSlot, DgramSocketSlot, DNSSlot, WatcherSlot, EventSlot, SignalSlot) m_fds;
size_t m_handleCount = 0;
size_t m_waiterCount = 0;
}
@ -338,6 +361,8 @@ package class PosixEventLoop {
common.flags = flags;
specific = slot_init;
}
if (!(flags & FDFlags.internal))
m_handleCount++;
}
package void clearFD(T)(FD fd)
@ -347,6 +372,10 @@ package class PosixEventLoop {
auto slot = () @trusted { return &m_fds[fd.value]; } ();
assert(slot.common.refCount == 0, "Clearing referenced file descriptor slot.");
assert(slot.specific.hasType!T, "Clearing file descriptor slot with unmatched type.");
if (!(slot.common.flags & FDFlags.internal))
m_handleCount--;
if (slot.common.userDataDestructor)
() @trusted { slot.common.userDataDestructor(slot.common.userData.ptr); } ();
if (!(slot.common.flags & FDFlags.internal))

View file

@ -5,7 +5,7 @@ version (Windows):
import eventcore.driver;
import eventcore.drivers.timer;
import eventcore.internal.consumablequeue;
import eventcore.internal.utils : mallocT, freeT, nogc_assert;
import eventcore.internal.utils : mallocT, freeT, nogc_assert, print;
import eventcore.internal.win32;
import core.sync.mutex : Mutex;
import core.time : Duration;
@ -61,6 +61,29 @@ final class WinAPIEventDriverCore : EventDriverCore {
} catch (Exception e) assert(false, e.msg);
}
package bool checkForLeakedHandles()
@trusted {
import core.thread : Thread;
static string getThreadName()
{
string thname;
try thname = Thread.getThis().name;
catch (Exception e) assert(false, e.msg);
return thname.length ? thname : "unknown";
}
foreach (k; m_handles.byKey) {
print("Warning (thread: %s): Leaked handles detected at driver shutdown", getThreadName());
foreach (ks; m_handles.byKeyValue)
if (!ks.value.specific.hasType!(typeof(null)))
print(" FD %04X (%s)", ks.key, ks.value.specific.kind);
return true;
}
return false;
}
override size_t waiterCount() { return m_waiterCount + m_timers.pendingCount; }
package void addWaiter() @nogc { m_waiterCount++; }

View file

@ -74,9 +74,14 @@ final class WinAPIEventDriver : EventDriver {
override @property inout(WinAPIEventDriverSignals) signals() inout { return m_signals; }
override @property inout(WinAPIEventDriverWatchers) watchers() inout { return m_watchers; }
override void dispose()
override bool dispose()
{
if (!m_events) return;
if (!m_events) return true;
if (m_core.checkForLeakedHandles()) return false;
if (m_events.checkForLeakedHandles()) return false;
if (m_sockets.checkForLeakedHandles()) return false;
m_events.dispose();
m_core.dispose();
assert(threadInstance !is null);
@ -93,5 +98,7 @@ final class WinAPIEventDriver : EventDriver {
freeT(m_signals);
} ();
catch (Exception e) assert(false, e.msg);
return true;
}
}

View file

@ -6,7 +6,7 @@ import eventcore.driver;
import eventcore.drivers.winapi.core;
import eventcore.internal.win32;
import eventcore.internal.consumablequeue;
import eventcore.internal.utils : mallocT, freeT, nogc_assert;
import eventcore.internal.utils : mallocT, freeT, nogc_assert, print;
final class WinAPIEventDriverEvents : EventDriverEvents {
@ -45,6 +45,15 @@ final class WinAPIEventDriverEvents : EventDriverEvents {
freeT(m_pending);
}
package bool checkForLeakedHandles()
@trusted {
foreach (evt; m_events.byKey) {
print("Warning: Event handles leaked at driver shutdown.");
return true;
}
return false;
}
override EventID create()
{
auto id = EventID(m_idCounter++);

View file

@ -18,6 +18,7 @@ final class WinAPIEventDriverSockets : EventDriverSockets {
private {
alias SocketVector = AlgebraicChoppedVector!(SocketSlot, StreamSocketSlot, StreamListenSocketSlot, DatagramSocketSlot);
SocketVector m_sockets;
size_t m_socketCount = 0;
WinAPIEventDriverCore m_core;
DWORD m_tid;
HWND m_hwnd;
@ -38,6 +39,13 @@ final class WinAPIEventDriverSockets : EventDriverSockets {
package @property size_t waiterCount() const { return m_waiters; }
package bool checkForLeakedHandles()
{
if (m_socketCount == 0) return false;
print("Warning: Socket handles leaked at driver shutdown.");
return true;
}
override StreamSocketFD connectStream(scope Address peer_address, scope Address bind_address, ConnectCallback on_connect)
@trusted {
assert(m_tid == GetCurrentThreadId());
@ -802,6 +810,7 @@ final class WinAPIEventDriverSockets : EventDriverSockets {
private void initSocketSlot(SocketFD fd)
{
m_socketCount++;
m_sockets[fd.value].common.refCount = 1;
m_sockets[fd.value].common.fd = fd;
m_sockets[fd.value].common.driver = this;
@ -809,6 +818,7 @@ final class WinAPIEventDriverSockets : EventDriverSockets {
package void clearSocketSlot(FD fd)
@nogc {
m_socketCount--;
auto slot = () @trusted { return &m_sockets[fd]; } ();
if (slot.common.userDataDestructor)
() @trusted { slot.common.userDataDestructor(slot.common.userData.ptr); } ();