Bool
MXUser_TryAcquireExclLock(MXUserExclLock *lock) // IN/OUT:
{
Bool success;
ASSERT(lock);
MXUserValidateHeader(&lock->header, MXUSER_TYPE_EXCL);
if (MXUserTryAcquireFail(lock->header.name)) {
return FALSE;
}
success = MXRecLockTryAcquire(&lock->recursiveLock);
if (success) {
MXUserAcquisitionTracking(&lock->header, FALSE);
if (vmx86_debug && (MXRecLockCount(&lock->recursiveLock) > 1)) {
MXUserDumpAndPanic(&lock->header,
"%s: Acquire on an acquired exclusive lock\n",
__FUNCTION__);
}
}
if (vmx86_stats) {
MXUserStats *stats = Atomic_ReadPtr(&lock->statsMem);
if (LIKELY(stats != NULL)) {
MXUserAcquisitionSample(&stats->acquisitionStats, success, !success,
0ULL);
}
}
return success;
}
Bool
MXUser_TryDownSemaphore(MXUserSemaphore *sema) // IN/OUT:
{
int err;
Bool downOccurred = FALSE;
ASSERT(sema);
MXUserValidateHeader(&sema->header, MXUSER_TYPE_SEMA);
Atomic_Inc(&sema->activeUserCount);
err = MXUserTryDown(&sema->nativeSemaphore, &downOccurred);
if (UNLIKELY(err != 0)) {
MXUserDumpAndPanic(&sema->header, "%s: Internal error (%d)\n",
__FUNCTION__, err);
}
if (vmx86_stats) {
MXUserAcquireStats *acquireStats;
acquireStats = Atomic_ReadPtr(&sema->acquireStatsMem);
if (LIKELY(acquireStats != NULL)) {
MXUserAcquisitionSample(&acquireStats->data, downOccurred,
!downOccurred, 0ULL);
}
}
Atomic_Dec(&sema->activeUserCount);
return downOccurred;
}
void
MXUser_DownSemaphore(MXUserSemaphore *sema) // IN/OUT:
{
int err;
ASSERT(sema);
MXUserValidateHeader(&sema->header, MXUSER_TYPE_SEMA);
Atomic_Inc(&sema->activeUserCount);
MXUserAcquisitionTracking(&sema->header, TRUE); // rank checking
if (vmx86_stats) {
VmTimeType start = 0;
Bool tryDownSuccess = FALSE;
MXUserAcquireStats *acquireStats;
acquireStats = Atomic_ReadPtr(&sema->acquireStatsMem);
if (LIKELY(acquireStats != NULL)) {
start = Hostinfo_SystemTimerNS();
}
err = MXUserTryDown(&sema->nativeSemaphore, &tryDownSuccess);
if (LIKELY(err == 0)) {
if (!tryDownSuccess) {
err = MXUserDown(&sema->nativeSemaphore);
}
}
if (LIKELY((err == 0) && (acquireStats != NULL))) {
MXUserHisto *histo;
VmTimeType value = Hostinfo_SystemTimerNS() - start;
MXUserAcquisitionSample(&acquireStats->data, TRUE,
!tryDownSuccess, value);
histo = Atomic_ReadPtr(&acquireStats->histo);
if (UNLIKELY(histo != NULL)) {
MXUserHistoSample(histo, value, GetReturnAddress());
}
}
} else {
err = MXUserDown(&sema->nativeSemaphore);
}
if (UNLIKELY(err != 0)) {
MXUserDumpAndPanic(&sema->header, "%s: Internal error (%d)\n",
__FUNCTION__, err);
}
MXUserReleaseTracking(&sema->header);
Atomic_Dec(&sema->activeUserCount);
}
void
MXUser_AcquireRecLock(MXUserRecLock *lock) // IN/OUT:
{
ASSERT(lock);
MXUserValidateHeader(&lock->header, MXUSER_TYPE_REC);
ASSERT(Atomic_Read(&lock->refCount) > 0);
if (UNLIKELY(lock->vmmLock != NULL)) {
ASSERT(MXUserMX_LockRec);
(*MXUserMX_LockRec)(lock->vmmLock);
} else {
/* Rank checking is only done on the first acquisition */
MXUserAcquisitionTracking(&lock->header, TRUE);
if (vmx86_stats) {
VmTimeType value = 0;
MXUserAcquireStats *acquireStats;
acquireStats = Atomic_ReadPtr(&lock->acquireStatsMem);
MXRecLockAcquire(&lock->recursiveLock,
(acquireStats == NULL) ? NULL : &value);
if (LIKELY(acquireStats != NULL)) {
if (MXRecLockCount(&lock->recursiveLock) == 1) {
MXUserHeldStats *heldStats;
MXUserHisto *histo;
MXUserAcquisitionSample(&acquireStats->data, TRUE,
value > acquireStats->data.contentionDurationFloor,
value);
histo = Atomic_ReadPtr(&acquireStats->histo);
if (UNLIKELY(histo != NULL)) {
MXUserHistoSample(histo, value, GetReturnAddress());
}
heldStats = Atomic_ReadPtr(&lock->heldStatsMem);
if (UNLIKELY(heldStats != NULL)) {
heldStats->holdStart = Hostinfo_SystemTimerNS();
}
}
}
} else {
MXRecLockAcquire(&lock->recursiveLock,
NULL); // non-stats
}
}
}
void
MXUser_AcquireExclLock(MXUserExclLock *lock) // IN/OUT:
{
ASSERT(lock);
MXUserValidateHeader(&lock->header, MXUSER_TYPE_EXCL);
MXUserAcquisitionTracking(&lock->header, TRUE);
if (vmx86_stats) {
VmTimeType value = 0;
MXUserStats *stats = Atomic_ReadPtr(&lock->statsMem);
MXRecLockAcquire(&lock->recursiveLock, (stats == NULL) ? NULL : &value);
if (LIKELY(stats != NULL)) {
MXUserHisto *histo;
MXUserAcquisitionSample(&stats->acquisitionStats, TRUE, value != 0,
value);
histo = Atomic_ReadPtr(&stats->acquisitionHisto);
if (UNLIKELY(histo != NULL)) {
MXUserHistoSample(histo, value, GetReturnAddress());
}
stats->holdStart = Hostinfo_SystemTimerNS();
}
} else {
MXRecLockAcquire(&lock->recursiveLock,
NULL); // non-stats
}
if (vmx86_debug && (MXRecLockCount(&lock->recursiveLock) > 1)) {
MXUserDumpAndPanic(&lock->header,
"%s: Acquire on an acquired exclusive lock\n",
__FUNCTION__);
}
}
Bool
MXUser_TryAcquireRecLock(MXUserRecLock *lock) // IN/OUT:
{
Bool success;
ASSERT(lock);
MXUserValidateHeader(&lock->header, MXUSER_TYPE_REC);
ASSERT(Atomic_Read(&lock->refCount) > 0);
if (UNLIKELY(lock->vmmLock != NULL)) {
ASSERT(MXUserMX_TryLockRec);
success = (*MXUserMX_TryLockRec)(lock->vmmLock);
} else {
if (MXUserTryAcquireFail(lock->header.name)) {
success = FALSE;
goto bail;
}
success = MXRecLockTryAcquire(&lock->recursiveLock);
if (success) {
MXUserAcquisitionTracking(&lock->header, FALSE);
}
if (vmx86_stats) {
MXUserAcquireStats *acquireStats;
acquireStats = Atomic_ReadPtr(&lock->acquireStatsMem);
if (LIKELY(acquireStats != NULL)) {
MXUserAcquisitionSample(&acquireStats->data, success, !success,
0ULL);
}
}
}
bail:
return success;
}
static INLINE void
MXUserAcquisition(MXUserRWLock *lock, // IN/OUT:
Bool forRead) // IN:
{
HolderContext *myContext;
ASSERT(lock);
MXUserValidateHeader(&lock->header, MXUSER_TYPE_RW);
MXUserAcquisitionTracking(&lock->header, TRUE);
myContext = MXUserGetHolderContext(lock);
if (UNLIKELY(myContext->state != RW_UNLOCKED)) {
MXUserDumpAndPanic(&lock->header,
"%s: AcquireFor%s after AcquireFor%s\n",
__FUNCTION__,
forRead ? "Read" : "Write",
(myContext->state == RW_LOCKED_FOR_READ) ? "Read" :
"Write");
}
if (vmx86_stats) {
VmTimeType value;
MXUserStats *stats = Atomic_ReadPtr(&lock->statsMem);
if (lock->useNative) {
int err = 0;
Bool contended;
VmTimeType begin = Hostinfo_SystemTimerNS();
contended = MXUserNativeRWAcquire(&lock->nativeLock, forRead, &err);
value = contended ? Hostinfo_SystemTimerNS() - begin : 0;
if (UNLIKELY(err != 0)) {
MXUserDumpAndPanic(&lock->header, "%s: Error %d: contended %d\n",
__FUNCTION__, err, contended);
}
} else {
value = 0;
MXRecLockAcquire(&lock->recursiveLock,
(stats == NULL) ? NULL : &value);
}
if (LIKELY(stats != NULL)) {
MXUserHisto *histo;
/*
* The statistics are not atomically safe so protect them when
* necessary.
*/
if (forRead && lock->useNative) {
MXRecLockAcquire(&lock->recursiveLock,
NULL); // non-stats
}
MXUserAcquisitionSample(&stats->acquisitionStats, TRUE, value != 0,
value);
histo = Atomic_ReadPtr(&stats->acquisitionHisto);
if (UNLIKELY(histo != NULL)) {
MXUserHistoSample(histo, value, GetReturnAddress());
}
if (forRead && lock->useNative) {
MXRecLockRelease(&lock->recursiveLock);
}
myContext->holdStart = Hostinfo_SystemTimerNS();
}
} else {
if (LIKELY(lock->useNative)) {
int err = 0;
MXUserNativeRWAcquire(&lock->nativeLock, forRead, &err);
if (UNLIKELY(err != 0)) {
MXUserDumpAndPanic(&lock->header, "%s: Error %d\n",
__FUNCTION__, err);
}
} else {
MXRecLockAcquire(&lock->recursiveLock,
NULL); // non-stats
}
}
if (!forRead || !lock->useNative) {
ASSERT(Atomic_Read(&lock->holderCount) == 0);
}
Atomic_Inc(&lock->holderCount);
myContext->state = forRead ? RW_LOCKED_FOR_READ : RW_LOCKED_FOR_WRITE;
}
