diff options
Diffstat (limited to 'src/osd/modules/sync/sync_windows.cpp')
-rw-r--r-- | src/osd/modules/sync/sync_windows.cpp | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/osd/modules/sync/sync_windows.cpp b/src/osd/modules/sync/sync_windows.cpp index c744f345e6f..9439d68b72c 100644 --- a/src/osd/modules/sync/sync_windows.cpp +++ b/src/osd/modules/sync/sync_windows.cpp @@ -23,6 +23,8 @@ //============================================================ #define DEBUG_SLOW_LOCKS 0 +#define USE_SCALABLE_LOCKS (0) + //============================================================ @@ -31,6 +33,11 @@ typedef BOOL (WINAPI *try_enter_critical_section_ptr)(LPCRITICAL_SECTION lpCriticalSection); +struct osd_lock +{ + CRITICAL_SECTION critsect; +}; + struct osd_event { void * ptr; @@ -42,6 +49,113 @@ struct osd_thread { void *param; }; +struct osd_scalable_lock +{ +#if USE_SCALABLE_LOCKS + struct + { + volatile INT32 haslock; // do we have the lock? + INT32 filler[64/4-1]; // assumes a 64-byte cache line + } slot[WORK_MAX_THREADS]; // one slot per thread + volatile INT32 nextindex; // index of next slot to use +#else + CRITICAL_SECTION section; +#endif +}; + + +//============================================================ +// GLOBAL VARIABLES +//============================================================ + +static try_enter_critical_section_ptr try_enter_critical_section = nullptr; +static int checked_for_try_enter = FALSE; + + + +//============================================================ +// osd_lock_alloc +//============================================================ + +osd_lock *osd_lock_alloc(void) +{ + osd_lock *lock = (osd_lock *)malloc(sizeof(*lock)); + if (lock == nullptr) + return nullptr; + InitializeCriticalSection(&lock->critsect); + return lock; +} + + +//============================================================ +// osd_lock_acquire +//============================================================ + +void osd_lock_acquire(osd_lock *lock) +{ +#if DEBUG_SLOW_LOCKS + osd_ticks_t ticks = osd_ticks(); +#endif + + // block until we can acquire the lock + EnterCriticalSection(&lock->critsect); + +#if DEBUG_SLOW_LOCKS + // log any locks that take more than 1ms + ticks = osd_ticks() - ticks; + if (ticks > osd_ticks_per_second() / 1000) osd_printf_debug("Blocked %d ticks on lock acquire\n", (int)ticks); +#endif +} + + +//============================================================ +// osd_lock_try +//============================================================ + +int osd_lock_try(osd_lock *lock) +{ + int result = TRUE; + + // if we haven't yet checked for the TryEnter API, do it now + if (!checked_for_try_enter) + { + // see if we can use TryEnterCriticalSection + HMODULE library = LoadLibrary(TEXT("kernel32.dll")); + if (library != nullptr) + try_enter_critical_section = (try_enter_critical_section_ptr)GetProcAddress(library, "TryEnterCriticalSection"); + checked_for_try_enter = TRUE; + } + + // if we have it, use it, otherwise just block + if (try_enter_critical_section != nullptr) + result = (*try_enter_critical_section)(&lock->critsect); + else + EnterCriticalSection(&lock->critsect); + return result; +} + + +//============================================================ +// osd_lock_release +//============================================================ + +void osd_lock_release(osd_lock *lock) +{ + LeaveCriticalSection(&lock->critsect); +} + + +//============================================================ +// osd_lock_free +//============================================================ + +void osd_lock_free(osd_lock *lock) +{ + DeleteCriticalSection(&lock->critsect); + free(lock); +} + + //============================================================ // win_compare_exchange32 //============================================================ @@ -203,3 +317,66 @@ int osd_thread_cpu_affinity(osd_thread *thread, UINT32 mask) { return TRUE; } + +//============================================================ +// Scalable Locks +//============================================================ + +osd_scalable_lock *osd_scalable_lock_alloc(void) +{ + osd_scalable_lock *lock; + + lock = (osd_scalable_lock *)calloc(1, sizeof(*lock)); + if (lock == nullptr) + return nullptr; + + memset(lock, 0, sizeof(*lock)); +#if USE_SCALABLE_LOCKS + lock->slot[0].haslock = TRUE; +#else + InitializeCriticalSection(&lock->section); +#endif + return lock; +} + + +INT32 osd_scalable_lock_acquire(osd_scalable_lock *lock) +{ +#if USE_SCALABLE_LOCKS + INT32 myslot = (atomic_increment32(&lock->nextindex) - 1) & (WORK_MAX_THREADS - 1); + INT32 backoff = 1; + + while (!lock->slot[myslot].haslock) + { + INT32 backcount; + for (backcount = 0; backcount < backoff; backcount++) + osd_yield_processor(); + backoff <<= 1; + } + lock->slot[myslot].haslock = FALSE; + return myslot; +#else + EnterCriticalSection(&lock->section); + return 0; +#endif +} + + +void osd_scalable_lock_release(osd_scalable_lock *lock, INT32 myslot) +{ +#if USE_SCALABLE_LOCKS + atomic_exchange32(&lock->slot[(myslot + 1) & (WORK_MAX_THREADS - 1)].haslock, TRUE); +#else + LeaveCriticalSection(&lock->section); +#endif +} + + +void osd_scalable_lock_free(osd_scalable_lock *lock) +{ +#if USE_SCALABLE_LOCKS +#else + DeleteCriticalSection(&lock->section); +#endif + free(lock); +} |