thread.h

/* FreeTDS - Library of routines accessing Sybase and Microsoft databases
 *
 * Copyright (C) 2005 Liam Widdowson
 * Copyright (C) 2010-2012 Frediano Ziglio
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
 
#ifndef _tdsguard_cIfZP7JZiHtLLfanwl7ubP_
#define _tdsguard_cIfZP7JZiHtLLfanwl7ubP_
 
#undef TDS_HAVE_MUTEX
 
#if defined(_THREAD_SAFE) && defined(TDS_HAVE_PTHREAD_MUTEX)
 
#include <tds_sysdep_public.h>
#include <freetds/sysdep_private.h>
#include <pthread.h>
#include <errno.h>
 
#include <freetds/pushvis.h>
 
typedef pthread_mutex_t tds_raw_mutex;
#define TDS_RAW_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
 
static inline void tds_raw_mutex_lock(tds_raw_mutex *mtx)
{
    pthread_mutex_lock(mtx);
}
 
static inline int tds_raw_mutex_trylock(tds_raw_mutex *mtx)
{
    return pthread_mutex_trylock(mtx);
}
 
static inline void tds_raw_mutex_unlock(tds_raw_mutex *mtx)
{
    pthread_mutex_unlock(mtx);
}
 
static inline int tds_raw_mutex_init(tds_raw_mutex *mtx)
{
    return pthread_mutex_init(mtx, NULL);
}
 
static inline void tds_raw_mutex_free(tds_raw_mutex *mtx)
{
    pthread_mutex_destroy(mtx);
}
 
typedef pthread_cond_t tds_condition;
 
int tds_raw_cond_init(tds_condition *cond);
static inline int tds_raw_cond_destroy(tds_condition *cond)
{
    return pthread_cond_destroy(cond);
}
static inline int tds_raw_cond_signal(tds_condition *cond)
{
    return pthread_cond_signal(cond);
}
static inline int tds_raw_cond_wait(tds_condition *cond, tds_raw_mutex *mtx)
{
    return pthread_cond_wait(cond, mtx);
}
int tds_raw_cond_timedwait(tds_condition *cond, tds_raw_mutex *mtx, int timeout_sec);
 
#define TDS_HAVE_MUTEX 1
 
typedef pthread_t tds_thread;
typedef pthread_t tds_thread_id;
typedef void *(*tds_thread_proc)(void *arg);
#define TDS_THREAD_PROC_DECLARE(name, arg) \
    void *name(void *arg)
#define TDS_THREAD_RESULT(n) ((void*)(TDS_INTPTR)(n))
 
static inline int tds_thread_create(tds_thread *ret, tds_thread_proc proc, void *arg)
{
    return pthread_create(ret, NULL, proc, arg);
}
 
static inline int tds_thread_create_detached(tds_thread_proc proc, void *arg)
{
    tds_thread th;
    int ret = pthread_create(&th, NULL, proc, arg);
    if (!ret)
        pthread_detach(th);
    return ret;
}
 
static inline int tds_thread_join(tds_thread th, void **ret)
{
    return pthread_join(th, ret);
}
 
static inline tds_thread_id tds_thread_get_current_id(void)
{
    return pthread_self();
}
 
static inline int tds_thread_is_current(tds_thread_id th)
{
    return pthread_equal(th, pthread_self());
}
 
#include <freetds/popvis.h>
 
#elif defined(_WIN32)
 
#include <freetds/windows.h>
#include <errno.h>
 
/* old version of Windows do not define this constant */
#ifndef ETIMEDOUT
#define ETIMEDOUT 138
#endif
 
struct ptw32_mcs_node_t_;
 
typedef struct {
    struct ptw32_mcs_node_t_ *lock;
    LONG done;
    DWORD thread_id;
    CRITICAL_SECTION crit;
} tds_raw_mutex;
 
#define TDS_RAW_MUTEX_INITIALIZER { NULL, 0, 0 }
 
static inline int
tds_raw_mutex_init(tds_raw_mutex *mtx)
{
    mtx->lock = NULL;
    mtx->done = 0;
    mtx->thread_id = 0;
    return 0;
}
 
void tds_win_mutex_lock(tds_raw_mutex *mutex);
 
static inline void tds_raw_mutex_lock(tds_raw_mutex *mtx)
{
    if (mtx->done) {
        EnterCriticalSection(&mtx->crit);
        mtx->thread_id = GetCurrentThreadId();
    } else {
        tds_win_mutex_lock(mtx);
    }
}
 
int tds_raw_mutex_trylock(tds_raw_mutex *mtx);
 
static inline void tds_raw_mutex_unlock(tds_raw_mutex *mtx)
{
    mtx->thread_id = 0;
    LeaveCriticalSection(&mtx->crit);
}
 
static inline void tds_raw_mutex_free(tds_raw_mutex *mtx)
{
    if (mtx->done) {
        DeleteCriticalSection(&mtx->crit);
        mtx->done = 0;
    }
}
 
#define TDS_HAVE_MUTEX 1
 
/* easy way, only single signal supported */
typedef void *TDS_CONDITION_VARIABLE;
typedef union {
    HANDLE ev;
    TDS_CONDITION_VARIABLE cv;
} tds_condition;
 
extern int (*tds_raw_cond_init)(tds_condition *cond);
extern int (*tds_raw_cond_destroy)(tds_condition *cond);
extern int (*tds_raw_cond_signal)(tds_condition *cond);
extern int (*tds_raw_cond_timedwait)(tds_condition *cond, tds_raw_mutex *mtx, int timeout_sec);
static inline int tds_raw_cond_wait(tds_condition *cond, tds_raw_mutex *mtx)
{
    return tds_raw_cond_timedwait(cond, mtx, -1);
}
 
typedef HANDLE tds_thread;
typedef DWORD  tds_thread_id;
typedef DWORD (WINAPI *tds_thread_proc)(void *arg);
#define TDS_THREAD_PROC_DECLARE(name, arg) \
    DWORD WINAPI name(void *arg)
#define TDS_THREAD_RESULT(n) ((DWORD)(int)(n))
 
static inline int tds_thread_create(tds_thread *ret, tds_thread_proc proc, void *arg)
{
    *ret = CreateThread(NULL, 0, proc, arg, 0, NULL);
    return *ret != NULL ? 0 : 11 /* EAGAIN */;
}
 
static inline int tds_thread_create_detached(tds_thread_proc proc, void *arg)
{
    HANDLE h = CreateThread(NULL, 0, proc, arg, 0, NULL);
    if (!h)
        return 11 /* EAGAIN */;
 
    /* Avoids leaking the handle - Thread continues to run */
    CloseHandle(h);
    return 0;
}
 
static inline int tds_thread_join(tds_thread th, void **ret)
{
    if (WaitForSingleObject(th, INFINITE) == WAIT_OBJECT_0) {
        if (ret) {
            DWORD r;
            if (!GetExitCodeThread(th, &r))
                r = 0xffffffffu;
            *ret = (void*) (((char*)0) + r);
        }
 
        CloseHandle(th);
        return 0;
    }
    CloseHandle(th);
    return 22 /* EINVAL */;
}
 
static inline tds_thread_id tds_thread_get_current_id(void)
{
    return GetCurrentThreadId();
}
 
static inline int tds_thread_is_current(tds_thread_id th)
{
    return th == GetCurrentThreadId();
}
 
#else
 
#include <tds_sysdep_public.h>
 
/* define noops as "successful" */
typedef struct {
    char dummy[0]; /* compiler compatibility */
} tds_raw_mutex;
 
#define TDS_RAW_MUTEX_INITIALIZER {}
 
static inline void tds_raw_mutex_lock(tds_raw_mutex *mtx)
{
}
 
static inline int tds_raw_mutex_trylock(tds_raw_mutex *mtx)
{
    return 0;
}
 
static inline void tds_raw_mutex_unlock(tds_raw_mutex *mtx)
{
}
 
static inline int tds_raw_mutex_init(tds_raw_mutex *mtx)
{
    return 0;
}
 
static inline void tds_raw_mutex_free(tds_raw_mutex *mtx)
{
}
 
typedef struct {
    char dummy[0]; /* compiler compatibility */
} tds_condition;
 
static inline int tds_raw_cond_init(tds_condition *cond)
{
    return 0;
}
static inline int tds_raw_cond_destroy(tds_condition *cond)
{
    return 0;
}
#define tds_raw_cond_signal(cond) \
    FreeTDS_Condition_not_compiled
 
#define tds_raw_cond_wait(cond, mtx) \
    FreeTDS_Condition_not_compiled
 
#define tds_raw_cond_timedwait(cond, mtx, timeout_sec) \
    FreeTDS_Condition_not_compiled
 
typedef struct {
    char dummy[0]; /* compiler compatibility */
} tds_thread;
typedef int tds_thread_id;
 
typedef void *(*tds_thread_proc)(void *arg);
#define TDS_THREAD_PROC_DECLARE(name, arg) \
    void *name(void *arg)
#define TDS_THREAD_RESULT(n) ((void*)(TDS_INTPTR)(n))
 
#define tds_thread_create(ret, proc, arg) \
    FreeTDS_Thread_not_compiled
 
#define tds_thread_create_detached(proc, arg) \
    FreeTDS_Thread_not_compiled
 
#define tds_thread_join(th, ret) \
    FreeTDS_Thread_not_compiled
 
static inline tds_thread_id tds_thread_get_current_id(void)
{
    return 0;
}
 
static inline int tds_thread_is_current(tds_thread_id th)
{
    return 1;
}
 
#endif
 
#  define tds_cond_init tds_raw_cond_init
#  define tds_cond_destroy tds_raw_cond_destroy
#  define tds_cond_signal tds_raw_cond_signal
#  if !ENABLE_EXTRA_CHECKS || !defined(TDS_HAVE_MUTEX)
#    define TDS_MUTEX_INITIALIZER TDS_RAW_MUTEX_INITIALIZER
#    define tds_mutex tds_raw_mutex
#    define tds_mutex_lock tds_raw_mutex_lock
#    define tds_mutex_trylock tds_raw_mutex_trylock
#    define tds_mutex_unlock tds_raw_mutex_unlock
#    define tds_mutex_check_owned(mtx) do {} while(0)
#    define tds_mutex_init tds_raw_mutex_init
#    define tds_mutex_free tds_raw_mutex_free
#    define tds_cond_wait tds_raw_cond_wait
#    define tds_cond_timedwait tds_raw_cond_timedwait
#  else
#    include <assert.h>
 
typedef struct tds_mutex
{
    tds_raw_mutex mtx;
    volatile int locked;
    volatile tds_thread_id locked_by;
} tds_mutex;
 
#   define TDS_MUTEX_INITIALIZER { TDS_RAW_MUTEX_INITIALIZER, 0 }
 
static inline void tds_mutex_lock(tds_mutex *mtx)
{
    assert(mtx);
    tds_raw_mutex_lock(&mtx->mtx);
    assert(!mtx->locked);
    mtx->locked = 1;
    mtx->locked_by = tds_thread_get_current_id();
}
 
static inline int tds_mutex_trylock(tds_mutex *mtx)
{
    int ret;
    assert(mtx);
    ret = tds_raw_mutex_trylock(&mtx->mtx);
    if (!ret) {
        assert(!mtx->locked);
        mtx->locked = 1;
        mtx->locked_by = tds_thread_get_current_id();
    }
    return ret;
}
 
static inline void tds_mutex_unlock(tds_mutex *mtx)
{
    assert(mtx && mtx->locked);
    mtx->locked = 0;
    tds_raw_mutex_unlock(&mtx->mtx);
}
 
static inline void tds_mutex_check_owned(tds_mutex *mtx)
{
    int ret;
    assert(mtx);
    ret = tds_raw_mutex_trylock(&mtx->mtx);
    assert(ret);
    assert(mtx->locked);
    assert(tds_thread_is_current(mtx->locked_by));
}
 
static inline int tds_mutex_init(tds_mutex *mtx)
{
    mtx->locked = 0;
    return tds_raw_mutex_init(&mtx->mtx);
}
 
static inline void tds_mutex_free(tds_mutex *mtx)
{
    assert(mtx && !mtx->locked);
    tds_raw_mutex_free(&mtx->mtx);
}
 
static inline int tds_cond_wait(tds_condition *cond, tds_mutex *mtx)
{
    int ret;
    assert(mtx && mtx->locked);
    mtx->locked = 0;
    ret = tds_raw_cond_wait(cond, &mtx->mtx);
    mtx->locked = 1;
    mtx->locked_by = tds_thread_get_current_id();
    return ret;
}
 
static inline int tds_cond_timedwait(tds_condition *cond, tds_mutex *mtx, int timeout_sec)
{
    int ret;
    assert(mtx && mtx->locked);
    mtx->locked = 0;
    ret = tds_raw_cond_timedwait(cond, &mtx->mtx, timeout_sec);
    mtx->locked = 1;
    mtx->locked_by = tds_thread_get_current_id();
    return ret;
}
 
#  endif
 
#endif