third_party/libusb/src/libusb/os/threads

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This source file includes following definitions.
usbi_mutex_init
usbi_mutex_destroy
usbi_mutex_trylock
usbi_mutex_lock
usbi_mutex_unlock
usbi_mutex_static_lock
usbi_mutex_static_unlock
usbi_cond_init
usbi_cond_destroy
usbi_cond_broadcast
usbi_cond_signal
usbi_cond_intwait
usbi_cond_wait
usbi_cond_timedwait
usbi_get_tid
/*
 * libusbx synchronization on Microsoft Windows
 *
 * Copyright © 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 "libusbi.h"

extern const uint64_t epoch_time;

int usbi_mutex_init(usbi_mutex_t *mutex,
                                        const usbi_mutexattr_t *attr) {
        UNUSED(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) {
        UNUSED(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, *next_pos = NULL;
        if(!cond) return ((errno=EINVAL));
        if(!list_empty(&cond->waiters)) return ((errno=EBUSY )); // (!see above!)
        list_for_each_entry_safe(pos, next_pos, &cond->not_waiting, list, struct usbi_cond_perthread) {
                CloseHandle(pos->event);
                list_del(&pos->list);
                free(pos);
        }

        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));
}
__inline static int 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      = (struct usbi_cond_perthread*) calloc(1, 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 filetime;
        ULARGE_INTEGER rtime;
        struct timeval targ_time, cur_time, delta_time;
        struct timespec cur_time_ns;
        DWORD millis;

        // GetSystemTimeAsFileTime() is not available on CE
        SYSTEMTIME st;
        GetSystemTime(&st);
        SystemTimeToFileTime(&st, &filetime);
        rtime.LowPart   = filetime.dwLowDateTime;
        rtime.HighPart  = filetime.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;
                if (delta_time.tv_usec % 1000) // round up to next millisecond
                        millis++;
        }

        return usbi_cond_intwait(cond, mutex, millis);
}

int usbi_get_tid(void) {
        return GetCurrentThreadId();
}
/* [<][>][^][v][top][bottom][index][help] */
root/third_party/libusb/src/libusb/os/threads_windows.c

DEFINITIONS
