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-rw-r--r--libusb/os/threads_windows.c207
1 files changed, 207 insertions, 0 deletions
diff --git a/libusb/os/threads_windows.c b/libusb/os/threads_windows.c
new file mode 100644
index 0000000..f0704b2
--- /dev/null
+++ b/libusb/os/threads_windows.c
@@ -0,0 +1,207 @@
+/*
+ * libusb synchronization on Microsoft Windows
+ *
+ * Copyright (C) 2010 Michael Plante <michael.plante@gmail.com>
+ *
+ * This library 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 library 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <config.h>
+#include <objbase.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#include "libusb.h"
+#include "libusbi.h"
+
+
+int usbi_mutex_init(usbi_mutex_t *mutex,
+ const usbi_mutexattr_t *attr) {
+ if(! mutex) return ((errno=EINVAL));
+ *mutex = CreateMutex(NULL, FALSE, NULL);
+ if(!*mutex) return ((errno=ENOMEM));
+ return 0;
+}
+int usbi_mutex_destroy(usbi_mutex_t *mutex) {
+ // It is not clear if CloseHandle failure is due to failure to unlock.
+ // If so, this should be errno=EBUSY.
+ if(!mutex || !CloseHandle(*mutex)) return ((errno=EINVAL));
+ *mutex = NULL;
+ return 0;
+}
+int usbi_mutex_trylock(usbi_mutex_t *mutex) {
+ DWORD result;
+ if(!mutex) return ((errno=EINVAL));
+ result = WaitForSingleObject(*mutex, 0);
+ if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+ return 0; // acquired (ToDo: check that abandoned is ok)
+ if(result == WAIT_TIMEOUT)
+ return ((errno=EBUSY));
+ return ((errno=EINVAL)); // don't know how this would happen
+ // so don't know proper errno
+}
+int usbi_mutex_lock(usbi_mutex_t *mutex) {
+ DWORD result;
+ if(!mutex) return ((errno=EINVAL));
+ result = WaitForSingleObject(*mutex, INFINITE);
+ if(result == WAIT_OBJECT_0 || result == WAIT_ABANDONED)
+ return 0; // acquired (ToDo: check that abandoned is ok)
+ return ((errno=EINVAL)); // don't know how this would happen
+ // so don't know proper errno
+}
+int usbi_mutex_unlock(usbi_mutex_t *mutex) {
+ if(!mutex) return ((errno=EINVAL));
+ if(!ReleaseMutex(mutex)) return ((errno=EPERM ));
+ return 0;
+}
+
+int usbi_mutex_static_lock(usbi_mutex_static_t *mutex) {
+ if(!mutex) return ((errno=EINVAL));
+ while (InterlockedExchange((LONG *)mutex, 1) == 1) {
+ SleepEx(0, TRUE);
+ }
+ return 0;
+}
+int usbi_mutex_static_unlock(usbi_mutex_static_t *mutex) {
+ if(!mutex) return ((errno=EINVAL));
+ *mutex = 0;
+ return 0;
+}
+
+
+
+int usbi_cond_init(usbi_cond_t *cond,
+ const usbi_condattr_t *attr) {
+ if(!cond) return ((errno=EINVAL));
+ list_init(&cond->waiters );
+ list_init(&cond->not_waiting);
+ return 0;
+}
+int usbi_cond_destroy(usbi_cond_t *cond) {
+ // This assumes no one is using this anymore. The check MAY NOT BE safe.
+ struct usbi_cond_perthread *pos, *prev_pos = NULL;
+ if(!cond) return ((errno=EINVAL));
+ if(!list_empty(&cond->waiters)) return ((errno=EBUSY )); // (!see above!)
+ list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+ free(prev_pos);
+ list_del(&pos->list);
+ prev_pos = pos;
+ }
+ free(prev_pos);
+ prev_pos = pos = NULL;
+
+ return 0;
+}
+
+int usbi_cond_broadcast(usbi_cond_t *cond) {
+ // Assumes mutex is locked; this is not in keeping with POSIX spec, but
+ // libusb does this anyway, so we simplify by not adding more sync
+ // primitives to the CV definition!
+ int fail = 0;
+ struct usbi_cond_perthread *pos;
+ if(!cond) return ((errno=EINVAL));
+ list_for_each_entry(pos, &cond->waiters, list, struct usbi_cond_perthread) {
+ if(!SetEvent(pos->event))
+ fail = 1;
+ }
+ // The wait function will remove its respective item from the list.
+ return fail ? ((errno=EINVAL)) : 0;
+}
+int usbi_cond_signal(usbi_cond_t *cond) {
+ // Assumes mutex is locked; this is not in keeping with POSIX spec, but
+ // libusb does this anyway, so we simplify by not adding more sync
+ // primitives to the CV definition!
+ struct usbi_cond_perthread *pos;
+ if(!cond) return ((errno=EINVAL));
+ if(list_empty(&cond->waiters)) return 0; // no one to wakeup.
+ pos = list_entry(&cond->waiters.next, struct usbi_cond_perthread, list);
+ // The wait function will remove its respective item from the list.
+ return SetEvent(pos->event) ? 0 : ((errno=EINVAL));
+}
+static int __inline usbi_cond_intwait(usbi_cond_t *cond,
+ usbi_mutex_t *mutex,
+ DWORD timeout_ms) {
+ struct usbi_cond_perthread *pos;
+ int found = 0, r;
+ DWORD r2,tid = GetCurrentThreadId();
+ if(!cond || !mutex) return ((errno=EINVAL));
+ list_for_each_entry(pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
+ if(tid == pos->tid) {
+ found = 1;
+ break;
+ }
+ }
+ if(!found) {
+ pos = malloc(sizeof(struct usbi_cond_perthread));
+ if(!pos) return ((errno=ENOMEM)); // This errno is not POSIX-allowed.
+ pos->tid = tid;
+ pos->event = CreateEvent(NULL, FALSE, FALSE, NULL); // auto-reset.
+ if(!pos->event) {
+ free(pos);
+ return ((errno=ENOMEM));
+ }
+ list_add(&pos->list, &cond->not_waiting);
+ }
+
+ list_del(&pos->list); // remove from not_waiting list.
+ list_add(&pos->list, &cond->waiters);
+
+ r = usbi_mutex_unlock(mutex);
+ if(r) return r;
+ r2 = WaitForSingleObject(pos->event, timeout_ms);
+ r = usbi_mutex_lock(mutex);
+ if(r) return r;
+
+ list_del(&pos->list);
+ list_add(&pos->list, &cond->not_waiting);
+
+ if(r2 == WAIT_TIMEOUT) return ((errno=ETIMEDOUT));
+
+ return 0;
+}
+// N.B.: usbi_cond_*wait() can also return ENOMEM, even though pthread_cond_*wait cannot!
+int usbi_cond_wait(usbi_cond_t *cond, usbi_mutex_t *mutex) {
+ return usbi_cond_intwait(cond, mutex, INFINITE);
+}
+int usbi_cond_timedwait(usbi_cond_t *cond,
+ usbi_mutex_t *mutex,
+ const struct timespec *abstime) {
+ FILETIME ftime;
+ ULARGE_INTEGER rtime;
+ struct timeval targ_time, cur_time, delta_time;
+ struct timespec cur_time_ns;
+ DWORD millis;
+ extern const uint64_t epoch_time;
+
+ GetSystemTimeAsFileTime(&ftime);
+ rtime.LowPart = ftime.dwLowDateTime;
+ rtime.HighPart = ftime.dwHighDateTime;
+ rtime.QuadPart -= epoch_time;
+ cur_time_ns.tv_sec = (long)(rtime.QuadPart / 10000000);
+ cur_time_ns.tv_nsec = (long)((rtime.QuadPart % 10000000)*100);
+ TIMESPEC_TO_TIMEVAL(&cur_time, &cur_time_ns);
+
+ TIMESPEC_TO_TIMEVAL(&targ_time, abstime);
+ timersub(&targ_time, &cur_time, &delta_time);
+ if(delta_time.tv_sec <= 0) // abstime already passed?
+ millis = 0;
+ else {
+ millis = delta_time.tv_usec/1000;
+ millis += delta_time.tv_sec *1000;
+ }
+
+ return usbi_cond_intwait(cond, mutex, millis);
+}
+
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