diff options
Diffstat (limited to 'kit/shared_mutex.h')
| -rw-r--r-- | kit/shared_mutex.h | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/kit/shared_mutex.h b/kit/shared_mutex.h deleted file mode 100644 index ad83418..0000000 --- a/kit/shared_mutex.h +++ /dev/null @@ -1,176 +0,0 @@ -// Shared mutex can be used in shared memory for interprocess -// synchronization. -// - -#ifndef KIT_SHARED_MUTEX_H -#define KIT_SHARED_MUTEX_H - -#include "atomic.h" -#include "threads.h" - -#include <assert.h> -#include <string.h> - -#ifdef __cplusplus -extern "C" { -#endif - -#if defined(__GNUC__) || defined(__clang__) -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wunused-function" -# pragma GCC diagnostic ignored "-Wunknown-pragmas" -# pragma GCC push_options -# pragma GCC optimize("O3") -#endif - -enum { - KIT_SHARED_MUTEX_READY = 1, - KIT_SHARED_MUTEX_LOCKED, - KIT_SHARED_MUTEX_WRITER -}; - -typedef union { - struct { - i8 _Atomic state; - i32 readers; - }; - struct { - u8 _pad[16]; - }; -} kit_shared_mutex_t; - -static void kit_shared_mutex_init(kit_shared_mutex_t *m) { - assert(m != NULL); - memset(m, 0, sizeof *m); - - atomic_store_explicit(&m->state, KIT_SHARED_MUTEX_READY, - memory_order_relaxed); -} - -static b8 kit_shared_try_lock(kit_shared_mutex_t *m) { - assert(m != NULL); - - for (;;) { - i8 prev_state = KIT_SHARED_MUTEX_READY; - if (atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_LOCKED, - memory_order_seq_cst, memory_order_seq_cst)) - break; - if (prev_state == KIT_SHARED_MUTEX_WRITER) - return 0; - // FIXME - // Check performance - thrd_yield(); - } - - assert(m->readers >= 0); - ++m->readers; - - i8 prev_state = KIT_SHARED_MUTEX_LOCKED; - if (!atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_READY, - memory_order_seq_cst, memory_order_seq_cst)) - assert(0); - - return 1; -} - -static void kit_shared_lock(kit_shared_mutex_t *m) { - assert(m != NULL); - - while (!kit_shared_try_lock(m)) - // FIXME - // Check performance - thrd_yield(); -} - -static void kit_shared_unlock(kit_shared_mutex_t *m) { - assert(m != NULL); - - for (;;) { - i8 prev_state = KIT_SHARED_MUTEX_READY; - if (atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_LOCKED, - memory_order_seq_cst, memory_order_seq_cst)) - break; - // FIXME - // Check performance - thrd_yield(); - } - - assert(m->readers > 0); - m->readers--; - - i8 prev_state = KIT_SHARED_MUTEX_LOCKED; - if (!atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_READY, - memory_order_seq_cst, memory_order_seq_cst)) - assert(0); -} - -static b8 kit_unique_try_lock(kit_shared_mutex_t *m) { - assert(m != NULL); - - i8 prev_state = KIT_SHARED_MUTEX_READY; - if (!atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_WRITER, - memory_order_seq_cst, memory_order_seq_cst)) - return 0; - - i8 is_locked = (m->readers == 0); - - prev_state = KIT_SHARED_MUTEX_WRITER; - if (!is_locked && - !atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_READY, - memory_order_seq_cst, memory_order_seq_cst)) - assert(0); - - return is_locked; -} - -static void kit_unique_lock(kit_shared_mutex_t *m) { - assert(m != NULL); - - while (!kit_unique_try_lock(m)) - // FIXME - // Check performance - thrd_yield(); -} - -static void kit_unique_unlock(kit_shared_mutex_t *m) { - assert(m != NULL); - - i8 prev_state = KIT_SHARED_MUTEX_WRITER; - if (!atomic_compare_exchange_strong_explicit( - &m->state, &prev_state, KIT_SHARED_MUTEX_READY, - memory_order_seq_cst, memory_order_seq_cst)) - assert(0); -} - -#if defined(__GNUC__) || defined(__clang__) -# pragma GCC pop_options -# pragma GCC diagnostic pop -#endif - -#ifdef __cplusplus -} -#endif - -#define shared_mutex_t kit_shared_mutex_t -#define shared_mutex_init kit_shared_mutex_init -#define shared_try_lock kit_shared_try_lock -#define shared_lock kit_shared_lock -#define shared_unlock kit_shared_unlock -#define unique_try_lock kit_unique_try_lock -#define unique_lock kit_unique_lock -#define unique_unlock kit_unique_unlock -#define shared_mutex_init kit_shared_mutex_init -#define shared_try_lock kit_shared_try_lock -#define shared_lock kit_shared_lock -#define shared_unlock kit_shared_unlock -#define unique_try_lock kit_unique_try_lock -#define unique_lock kit_unique_lock -#define unique_unlock kit_unique_unlock - -#endif |