From 4682deeb62247d34de87f8e777f99e2d337fd377 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= <debian@jff.email>
Date: Sun, 20 Oct 2024 15:21:43 +0200
Subject: New upstream version 1.3
---
tests/windows-timedrwlock.c | 669 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 669 insertions(+)
create mode 100644 tests/windows-timedrwlock.c
(limited to 'tests/windows-timedrwlock.c')
diff --git a/tests/windows-timedrwlock.c b/tests/windows-timedrwlock.c
new file mode 100644
index 00000000..e818407c
--- /dev/null
+++ b/tests/windows-timedrwlock.c
@@ -0,0 +1,669 @@
+/* Timed read-write locks (native Windows implementation).
+ Copyright (C) 2005-2024 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file 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 Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2019. */
+
+#include <config.h>
+
+/* Specification. */
+#include "windows-timedrwlock.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+/* Don't assume that UNICODE is not defined. */
+#undef CreateEvent
+#define CreateEvent CreateEventA
+
+/* In this file, the waitqueues are implemented as linked lists. */
+#define glwthread_waitqueue_t glwthread_clinked_waitqueue_t
+
+/* All links of a circular list, except the anchor, are of this type, carrying
+ a payload. */
+struct glwthread_waitqueue_element
+{
+ struct glwthread_waitqueue_link link; /* must be the first field! */
+ HANDLE event; /* Waiting thread, represented by an event.
+ This field is immutable once initialized. */
+};
+
+static void
+glwthread_waitqueue_init (glwthread_waitqueue_t *wq)
+{
+ wq->wq_list.wql_next = &wq->wq_list;
+ wq->wq_list.wql_prev = &wq->wq_list;
+ wq->count = 0;
+}
+
+/* Enqueues the current thread, represented by an event, in a wait queue.
+ Returns NULL if an allocation failure occurs. */
+static struct glwthread_waitqueue_element *
+glwthread_waitqueue_add (glwthread_waitqueue_t *wq)
+{
+ struct glwthread_waitqueue_element *elt;
+ HANDLE event;
+
+ /* Allocate the memory for the waitqueue element on the heap, not on the
+ thread's stack. If the thread exits unexpectedly, we prefer to leak
+ some memory rather than to access unavailable memory and crash. */
+ elt =
+ (struct glwthread_waitqueue_element *)
+ malloc (sizeof (struct glwthread_waitqueue_element));
+ if (elt == NULL)
+ /* No more memory. */
+ return NULL;
+
+ /* Whether the created event is a manual-reset one or an auto-reset one,
+ does not matter, since we will wait on it only once. */
+ event = CreateEvent (NULL, TRUE, FALSE, NULL);
+ if (event == INVALID_HANDLE_VALUE)
+ {
+ /* No way to allocate an event. */
+ free (elt);
+ return NULL;
+ }
+ elt->event = event;
+ /* Insert elt at the end of the circular list. */
+ (elt->link.wql_prev = wq->wq_list.wql_prev)->wql_next = &elt->link;
+ (elt->link.wql_next = &wq->wq_list)->wql_prev = &elt->link;
+ wq->count++;
+ return elt;
+}
+
+/* Removes the current thread, represented by a
+ 'struct glwthread_waitqueue_element *', from a wait queue.
+ Returns true if is was found and removed, false if it was not present. */
+static bool
+glwthread_waitqueue_remove (glwthread_waitqueue_t *wq,
+ struct glwthread_waitqueue_element *elt)
+{
+ if (elt->link.wql_next != NULL && elt->link.wql_prev != NULL)
+ {
+ /* Remove elt from the circular list. */
+ struct glwthread_waitqueue_link *prev = elt->link.wql_prev;
+ struct glwthread_waitqueue_link *next = elt->link.wql_next;
+ prev->wql_next = next;
+ next->wql_prev = prev;
+ elt->link.wql_next = NULL;
+ elt->link.wql_prev = NULL;
+ wq->count--;
+ return true;
+ }
+ else
+ return false;
+}
+
+/* Notifies the first thread from a wait queue and dequeues it. */
+static void
+glwthread_waitqueue_notify_first (glwthread_waitqueue_t *wq)
+{
+ if (wq->wq_list.wql_next != &wq->wq_list)
+ {
+ struct glwthread_waitqueue_element *elt =
+ (struct glwthread_waitqueue_element *) wq->wq_list.wql_next;
+ struct glwthread_waitqueue_link *prev;
+ struct glwthread_waitqueue_link *next;
+
+ /* Remove elt from the circular list. */
+ prev = &wq->wq_list; /* = elt->link.wql_prev; */
+ next = elt->link.wql_next;
+ prev->wql_next = next;
+ next->wql_prev = prev;
+ elt->link.wql_next = NULL;
+ elt->link.wql_prev = NULL;
+ wq->count--;
+
+ SetEvent (elt->event);
+ /* After the SetEvent, this thread cannot access *elt any more, because
+ the woken-up thread will quickly call free (elt). */
+ }
+}
+
+/* Notifies all threads from a wait queue and dequeues them all. */
+static void
+glwthread_waitqueue_notify_all (glwthread_waitqueue_t *wq)
+{
+ struct glwthread_waitqueue_link *l;
+
+ for (l = wq->wq_list.wql_next; l != &wq->wq_list; )
+ {
+ struct glwthread_waitqueue_element *elt =
+ (struct glwthread_waitqueue_element *) l;
+ struct glwthread_waitqueue_link *prev;
+ struct glwthread_waitqueue_link *next;
+
+ /* Remove elt from the circular list. */
+ prev = &wq->wq_list; /* = elt->link.wql_prev; */
+ next = elt->link.wql_next;
+ prev->wql_next = next;
+ next->wql_prev = prev;
+ elt->link.wql_next = NULL;
+ elt->link.wql_prev = NULL;
+ wq->count--;
+
+ SetEvent (elt->event);
+ /* After the SetEvent, this thread cannot access *elt any more, because
+ the woken-up thread will quickly call free (elt). */
+
+ l = next;
+ }
+ if (!(wq->wq_list.wql_next == &wq->wq_list
+ && wq->wq_list.wql_prev == &wq->wq_list
+ && wq->count == 0))
+ abort ();
+}
+
+void
+glwthread_timedrwlock_init (glwthread_timedrwlock_t *lock)
+{
+ InitializeCriticalSection (&lock->lock);
+ glwthread_waitqueue_init (&lock->waiting_readers);
+ glwthread_waitqueue_init (&lock->waiting_writers);
+ lock->runcount = 0;
+ lock->guard.done = 1;
+}
+
+int
+glwthread_timedrwlock_rdlock (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Test whether only readers are currently running, and whether the runcount
+ field will not overflow, and whether no writer is waiting. The latter
+ condition is because POSIX recommends that "write locks shall take
+ precedence over read locks", to avoid "writer starvation". */
+ if (!(lock->runcount + 1 > 0 && lock->waiting_writers.count == 0))
+ {
+ /* This thread has to wait for a while. Enqueue it among the
+ waiting_readers. */
+ struct glwthread_waitqueue_element *elt =
+ glwthread_waitqueue_add (&lock->waiting_readers);
+ if (elt != NULL)
+ {
+ HANDLE event = elt->event;
+ DWORD result;
+ LeaveCriticalSection (&lock->lock);
+ /* Wait until another thread signals this event. */
+ result = WaitForSingleObject (event, INFINITE);
+ if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
+ abort ();
+ CloseHandle (event);
+ free (elt);
+ /* The thread which signalled the event already did the bookkeeping:
+ removed us from the waiting_readers, incremented lock->runcount. */
+ if (!(lock->runcount > 0))
+ abort ();
+ return 0;
+ }
+ else
+ {
+ /* Allocation failure. Weird. */
+ do
+ {
+ LeaveCriticalSection (&lock->lock);
+ Sleep (1);
+ EnterCriticalSection (&lock->lock);
+ }
+ while (!(lock->runcount + 1 > 0));
+ }
+ }
+ lock->runcount++;
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_wrlock (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Test whether no readers or writers are currently running. */
+ if (!(lock->runcount == 0))
+ {
+ /* This thread has to wait for a while. Enqueue it among the
+ waiting_writers. */
+ struct glwthread_waitqueue_element *elt =
+ glwthread_waitqueue_add (&lock->waiting_writers);
+ if (elt != NULL)
+ {
+ HANDLE event = elt->event;
+ DWORD result;
+ LeaveCriticalSection (&lock->lock);
+ /* Wait until another thread signals this event. */
+ result = WaitForSingleObject (event, INFINITE);
+ if (result == WAIT_FAILED || result == WAIT_TIMEOUT)
+ abort ();
+ CloseHandle (event);
+ free (elt);
+ /* The thread which signalled the event already did the bookkeeping:
+ removed us from the waiting_writers, set lock->runcount = -1. */
+ if (!(lock->runcount == -1))
+ abort ();
+ return 0;
+ }
+ else
+ {
+ /* Allocation failure. Weird. */
+ do
+ {
+ LeaveCriticalSection (&lock->lock);
+ Sleep (1);
+ EnterCriticalSection (&lock->lock);
+ }
+ while (!(lock->runcount == 0));
+ }
+ }
+ lock->runcount--; /* runcount becomes -1 */
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_tryrdlock (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ /* It's OK to wait for this critical section, because it is never taken for a
+ long time. */
+ EnterCriticalSection (&lock->lock);
+ /* Test whether only readers are currently running, and whether the runcount
+ field will not overflow, and whether no writer is waiting. The latter
+ condition is because POSIX recommends that "write locks shall take
+ precedence over read locks", to avoid "writer starvation". */
+ if (!(lock->runcount + 1 > 0 && lock->waiting_writers.count == 0))
+ {
+ /* This thread would have to wait for a while. Return instead. */
+ LeaveCriticalSection (&lock->lock);
+ return EBUSY;
+ }
+ lock->runcount++;
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_trywrlock (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ /* It's OK to wait for this critical section, because it is never taken for a
+ long time. */
+ EnterCriticalSection (&lock->lock);
+ /* Test whether no readers or writers are currently running. */
+ if (!(lock->runcount == 0))
+ {
+ /* This thread would have to wait for a while. Return instead. */
+ LeaveCriticalSection (&lock->lock);
+ return EBUSY;
+ }
+ lock->runcount--; /* runcount becomes -1 */
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_timedrdlock (glwthread_timedrwlock_t *lock,
+ const struct timespec *abstime)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Test whether only readers are currently running, and whether the runcount
+ field will not overflow, and whether no writer is waiting. The latter
+ condition is because POSIX recommends that "write locks shall take
+ precedence over read locks", to avoid "writer starvation". */
+ if (!(lock->runcount + 1 > 0 && lock->waiting_writers.count == 0))
+ {
+ /* This thread has to wait for a while. Enqueue it among the
+ waiting_readers. */
+ struct glwthread_waitqueue_element *elt =
+ glwthread_waitqueue_add (&lock->waiting_readers);
+ if (elt != NULL)
+ {
+ HANDLE event = elt->event;
+ struct timeval currtime;
+ DWORD timeout;
+ DWORD result;
+ int retval;
+
+ LeaveCriticalSection (&lock->lock);
+
+ gettimeofday (&currtime, NULL);
+
+ /* Wait until another thread signals this event or until the
+ abstime passes. */
+ if (currtime.tv_sec > abstime->tv_sec)
+ timeout = 0;
+ else
+ {
+ unsigned long seconds = abstime->tv_sec - currtime.tv_sec;
+ timeout = seconds * 1000;
+ if (timeout / 1000 != seconds) /* overflow? */
+ timeout = INFINITE;
+ else
+ {
+ long milliseconds =
+ abstime->tv_nsec / 1000000 - currtime.tv_usec / 1000;
+ if (milliseconds >= 0)
+ {
+ timeout += milliseconds;
+ if (timeout < milliseconds) /* overflow? */
+ timeout = INFINITE;
+ }
+ else
+ {
+ if (timeout >= - milliseconds)
+ timeout -= (- milliseconds);
+ else
+ timeout = 0;
+ }
+ }
+ }
+ if (timeout != 0)
+ {
+ /* WaitForSingleObject
+ <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-waitforsingleobject> */
+ result = WaitForSingleObject (event, timeout);
+ if (result == WAIT_FAILED)
+ abort ();
+ if (result != WAIT_TIMEOUT)
+ {
+ CloseHandle (event);
+ free (elt);
+ /* The thread which signalled the event already did the
+ bookkeeping: removed us from the waiting_readers,
+ incremented lock->runcount. */
+ if (!(lock->runcount > 0))
+ abort ();
+ return 0;
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Remove ourselves from the waiting_readers. */
+ if (glwthread_waitqueue_remove (&lock->waiting_readers, elt))
+ retval = ETIMEDOUT;
+ else
+ /* The event was signalled just now. */
+ retval = 0;
+ LeaveCriticalSection (&lock->lock);
+ CloseHandle (event);
+ free (elt);
+ if (retval == 0)
+ /* Same assertion as above. */
+ if (!(lock->runcount > 0))
+ abort ();
+ return retval;
+ }
+ else
+ {
+ /* Allocation failure. Weird. */
+ do
+ {
+ LeaveCriticalSection (&lock->lock);
+ Sleep (1);
+ EnterCriticalSection (&lock->lock);
+ }
+ while (!(lock->runcount + 1 > 0));
+ }
+ }
+ lock->runcount++;
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_timedwrlock (glwthread_timedrwlock_t *lock,
+ const struct timespec *abstime)
+{
+ if (!lock->guard.done)
+ {
+ if (InterlockedIncrement (&lock->guard.started) == 0)
+ /* This thread is the first one to need this lock. Initialize it. */
+ glwthread_timedrwlock_init (lock);
+ else
+ {
+ /* Don't let lock->guard.started grow and wrap around. */
+ InterlockedDecrement (&lock->guard.started);
+ /* Yield the CPU while waiting for another thread to finish
+ initializing this lock. */
+ while (!lock->guard.done)
+ Sleep (0);
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Test whether no readers or writers are currently running. */
+ if (!(lock->runcount == 0))
+ {
+ /* This thread has to wait for a while. Enqueue it among the
+ waiting_writers. */
+ struct glwthread_waitqueue_element *elt =
+ glwthread_waitqueue_add (&lock->waiting_writers);
+ if (elt != NULL)
+ {
+ HANDLE event = elt->event;
+ struct timeval currtime;
+ DWORD timeout;
+ DWORD result;
+ int retval;
+
+ LeaveCriticalSection (&lock->lock);
+
+ gettimeofday (&currtime, NULL);
+
+ /* Wait until another thread signals this event or until the
+ abstime passes. */
+ if (currtime.tv_sec > abstime->tv_sec)
+ timeout = 0;
+ else
+ {
+ unsigned long seconds = abstime->tv_sec - currtime.tv_sec;
+ timeout = seconds * 1000;
+ if (timeout / 1000 != seconds) /* overflow? */
+ timeout = INFINITE;
+ else
+ {
+ long milliseconds =
+ abstime->tv_nsec / 1000000 - currtime.tv_usec / 1000;
+ if (milliseconds >= 0)
+ {
+ timeout += milliseconds;
+ if (timeout < milliseconds) /* overflow? */
+ timeout = INFINITE;
+ }
+ else
+ {
+ if (timeout >= - milliseconds)
+ timeout -= (- milliseconds);
+ else
+ timeout = 0;
+ }
+ }
+ }
+ if (timeout != 0)
+ {
+ /* WaitForSingleObject
+ <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-waitforsingleobject> */
+ result = WaitForSingleObject (event, timeout);
+ if (result == WAIT_FAILED)
+ abort ();
+ if (result != WAIT_TIMEOUT)
+ {
+ CloseHandle (event);
+ free (elt);
+ /* The thread which signalled the event already did the
+ bookkeeping: removed us from the waiting_writers, set
+ lock->runcount = -1. */
+ if (!(lock->runcount == -1))
+ abort ();
+ return 0;
+ }
+ }
+ EnterCriticalSection (&lock->lock);
+ /* Remove ourselves from the waiting_writers. */
+ if (glwthread_waitqueue_remove (&lock->waiting_writers, elt))
+ retval = ETIMEDOUT;
+ else
+ /* The event was signalled just now. */
+ retval = 0;
+ LeaveCriticalSection (&lock->lock);
+ CloseHandle (event);
+ free (elt);
+ if (retval == 0)
+ /* Same assertion as above. */
+ if (!(lock->runcount == -1))
+ abort ();
+ return retval;
+ }
+ else
+ {
+ /* Allocation failure. Weird. */
+ do
+ {
+ LeaveCriticalSection (&lock->lock);
+ Sleep (1);
+ EnterCriticalSection (&lock->lock);
+ }
+ while (!(lock->runcount == 0));
+ }
+ }
+ lock->runcount--; /* runcount becomes -1 */
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_unlock (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ return EINVAL;
+ EnterCriticalSection (&lock->lock);
+ if (lock->runcount < 0)
+ {
+ /* Drop a writer lock. */
+ if (!(lock->runcount == -1))
+ abort ();
+ lock->runcount = 0;
+ }
+ else
+ {
+ /* Drop a reader lock. */
+ if (!(lock->runcount > 0))
+ {
+ LeaveCriticalSection (&lock->lock);
+ return EPERM;
+ }
+ lock->runcount--;
+ }
+ if (lock->runcount == 0)
+ {
+ /* POSIX recommends that "write locks shall take precedence over read
+ locks", to avoid "writer starvation". */
+ if (lock->waiting_writers.count > 0)
+ {
+ /* Wake up one of the waiting writers. */
+ lock->runcount--;
+ glwthread_waitqueue_notify_first (&lock->waiting_writers);
+ }
+ else
+ {
+ /* Wake up all waiting readers. */
+ lock->runcount += lock->waiting_readers.count;
+ glwthread_waitqueue_notify_all (&lock->waiting_readers);
+ }
+ }
+ LeaveCriticalSection (&lock->lock);
+ return 0;
+}
+
+int
+glwthread_timedrwlock_destroy (glwthread_timedrwlock_t *lock)
+{
+ if (!lock->guard.done)
+ return EINVAL;
+ if (lock->runcount != 0)
+ return EBUSY;
+ DeleteCriticalSection (&lock->lock);
+ lock->guard.done = 0;
+ return 0;
+}
--
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