#include "db_config.h"
#include "db_int.h"
#define LOAD_ACTUAL_MUTEX_CODE
#include "dbinc/mutex_int.h"
#undef MUTEX_DIAG
static _TCHAR hex_digits[] = _T("0123456789abcdef");
static SECURITY_DESCRIPTOR null_sd;
static SECURITY_ATTRIBUTES all_sa;
static int security_initialized = 0;
static __inline int get_handle(env, mutexp, eventp)
ENV *env;
DB_MUTEX *mutexp;
HANDLE *eventp;
{
_TCHAR idbuf[] = _T("db.m00000000");
_TCHAR *p = idbuf + 12;
int ret = 0;
u_int32_t id;
for (id = (mutexp)->id; id != 0; id >>= 4)
*--p = hex_digits[id & 0xf];
#ifndef DB_WINCE
if (!security_initialized) {
InitializeSecurityDescriptor(&null_sd,
SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl(&null_sd, TRUE, 0, FALSE);
all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
all_sa.bInheritHandle = FALSE;
all_sa.lpSecurityDescriptor = &null_sd;
security_initialized = 1;
}
#endif
if ((*eventp = CreateEvent(&all_sa, FALSE, FALSE, idbuf)) == NULL) {
ret = __os_get_syserr();
__db_syserr(env, ret, "Win32 create event failed");
}
return (ret);
}
int
__db_win32_mutex_init(env, mutex, flags)
ENV *env;
db_mutex_t mutex;
u_int32_t flags;
{
DB_MUTEX *mutexp;
DB_MUTEXMGR *mtxmgr;
DB_MUTEXREGION *mtxregion;
mtxmgr = env->mutex_handle;
mtxregion = mtxmgr->reginfo.primary;
mutexp = MUTEXP_SET(mutex);
mutexp->id = ((getpid() & 0xffff) << 16) ^ P_TO_UINT32(mutexp);
return (0);
}
int
__db_win32_mutex_lock(env, mutex)
ENV *env;
db_mutex_t mutex;
{
DB_ENV *dbenv;
DB_MUTEX *mutexp;
DB_MUTEXMGR *mtxmgr;
DB_MUTEXREGION *mtxregion;
HANDLE event;
u_int32_t nspins;
int ms, ret;
#ifdef MUTEX_DIAG
LARGE_INTEGER now;
#endif
#ifdef DB_WINCE
volatile db_threadid_t tmp_tid;
#endif
dbenv = env->dbenv;
if (!MUTEX_ON(env) || F_ISSET(dbenv, DB_ENV_NOLOCKING))
return (0);
mtxmgr = env->mutex_handle;
mtxregion = mtxmgr->reginfo.primary;
mutexp = MUTEXP_SET(mutex);
CHECK_MTX_THREAD(env, mutexp);
event = NULL;
ms = 50;
ret = 0;
loop:
for (nspins =
mtxregion->stat.st_mutex_tas_spins; nspins > 0; --nspins) {
#ifdef DB_WINCE
tmp_tid = mutexp->tid;
mutexp->tid = tmp_tid;
#endif
if (mutexp->tas || !MUTEX_SET(&mutexp->tas)) {
#ifdef MUTEX_PAUSE
MUTEX_PAUSE
#endif
continue;
}
#ifdef DIAGNOSTIC
if (F_ISSET(mutexp, DB_MUTEX_LOCKED)) {
char buf[DB_THREADID_STRLEN];
__db_errx(env,
"Win32 lock failed: mutex already locked by %s",
dbenv->thread_id_string(dbenv,
mutexp->pid, mutexp->tid, buf));
return (__env_panic(env, EACCES));
}
#endif
F_SET(mutexp, DB_MUTEX_LOCKED);
dbenv->thread_id(dbenv, &mutexp->pid, &mutexp->tid);
#ifdef HAVE_STATISTICS
if (event == NULL)
++mutexp->mutex_set_nowait;
else
++mutexp->mutex_set_wait;
#endif
if (event != NULL) {
CloseHandle(event);
InterlockedDecrement(&mutexp->nwaiters);
#ifdef MUTEX_DIAG
if (ret != WAIT_OBJECT_0) {
QueryPerformanceCounter(&now);
printf("[%I64d]: Lost signal on mutex %p, "
"id %d, ms %d\n",
now.QuadPart, mutexp, mutexp->id, ms);
}
#endif
}
#ifdef DIAGNOSTIC
if (F_ISSET(dbenv, DB_ENV_YIELDCPU))
__os_yield(env, 0, 0);
#endif
return (0);
}
if (event == NULL) {
#ifdef MUTEX_DIAG
QueryPerformanceCounter(&now);
printf("[%I64d]: Waiting on mutex %p, id %d\n",
now.QuadPart, mutexp, mutexp->id);
#endif
InterlockedIncrement(&mutexp->nwaiters);
if ((ret = get_handle(env, mutexp, &event)) != 0)
goto err;
}
if ((ret = WaitForSingleObject(event, ms)) == WAIT_FAILED) {
ret = __os_get_syserr();
goto err;
}
if ((ms <<= 1) > MS_PER_SEC)
ms = MS_PER_SEC;
PANIC_CHECK(env);
goto loop;
err: __db_syserr(env, ret, "Win32 lock failed");
return (__env_panic(env, __os_posix_err(ret)));
}
int
__db_win32_mutex_unlock(env, mutex)
ENV *env;
db_mutex_t mutex;
{
DB_ENV *dbenv;
DB_MUTEX *mutexp;
DB_MUTEXMGR *mtxmgr;
DB_MUTEXREGION *mtxregion;
HANDLE event;
int ret;
#ifdef MUTEX_DIAG
LARGE_INTEGER now;
#endif
dbenv = env->dbenv;
if (!MUTEX_ON(env) || F_ISSET(dbenv, DB_ENV_NOLOCKING))
return (0);
mtxmgr = env->mutex_handle;
mtxregion = mtxmgr->reginfo.primary;
mutexp = MUTEXP_SET(mutex);
#ifdef DIAGNOSTIC
if (!mutexp->tas || !F_ISSET(mutexp, DB_MUTEX_LOCKED)) {
__db_errx(env, "Win32 unlock failed: lock already unlocked");
return (__env_panic(env, EACCES));
}
#endif
F_CLR(mutexp, DB_MUTEX_LOCKED);
MUTEX_UNSET(&mutexp->tas);
if (mutexp->nwaiters > 0) {
if ((ret = get_handle(env, mutexp, &event)) != 0)
goto err;
#ifdef MUTEX_DIAG
QueryPerformanceCounter(&now);
printf("[%I64d]: Signalling mutex %p, id %d\n",
now.QuadPart, mutexp, mutexp->id);
#endif
if (!PulseEvent(event)) {
ret = __os_get_syserr();
CloseHandle(event);
goto err;
}
CloseHandle(event);
}
return (0);
err: __db_syserr(env, ret, "Win32 unlock failed");
return (__env_panic(env, __os_posix_err(ret)));
}
int
__db_win32_mutex_destroy(env, mutex)
ENV *env;
db_mutex_t mutex;
{
return (0);
}