diff options
| author |   Florin Coras <fcoras@cisco.com> | 2018-01-23 18:17:44 -0800 |
|---|---|---|
| committer |   Dave Barach <openvpp@barachs.net> | 2018-01-25 23:54:22 +0000 |
| commit | 1f9600e50f3317e8a9abd5ac38734010ca08e246 (patch) | |
| tree | ae67853e5073565b8a59cc2a56b6368b14e57929 /src/vppinfra | |
| parent | b384b543313b6b47a277c903e9d4fcd4343054fa (diff) | |
vppinfra: add readers-writer lock
Change-Id: I606fd89c410369cbd9ce9dcaaaa9dc58796e7c0e
Signed-off-by: Florin Coras <fcoras@cisco.com>
Diffstat (limited to 'src/vppinfra')
| -rw-r--r-- | src/vppinfra/lock.h | 112 |
1 files changed, 98 insertions, 14 deletions
diff --git a/src/vppinfra/lock.h b/src/vppinfra/lock.h index 7d241675b12..0ffb0455be0 100644 --- a/src/vppinfra/lock.h +++ b/src/vppinfra/lock.h @@ -18,6 +18,30 @@ #include <vppinfra/clib.h> +#if __x86_64__ +#define CLIB_PAUSE() __builtin_ia32_pause () +#else +#define CLIB_PAUSE() +#endif + +#if CLIB_DEBUG > 1 +#define CLIB_LOCK_DBG(_p) \ +do { \ + (*_p)->frame_address = __builtin_frame_address (0); \ + (*_p)->pid = getpid (); \ + (*_p)->thread_index = os_get_thread_index (); \ +} while (0) +#define CLIB_LOCK_DBG_CLEAR(_p) \ +do { \ + (*_p)->frame_address = 0; \ + (*_p)->pid = 0; \ + (*_p)->thread_index = 0; \ +} while (0) +#else +#define CLIB_LOCK_DBG(_p) +#define CLIB_LOCK_DBG_CLEAR(_p) +#endif + typedef struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); @@ -50,15 +74,8 @@ static_always_inline void clib_spinlock_lock (clib_spinlock_t * p) { while (__sync_lock_test_and_set (&(*p)->lock, 1)) -#if __x86_64__ - __builtin_ia32_pause () -#endif - ; -#if CLIB_DEBUG > 0 - (*p)->frame_address = __builtin_frame_address (0); - (*p)->pid = getpid (); - (*p)->thread_index = os_get_thread_index (); -#endif + CLIB_PAUSE (); + CLIB_LOCK_DBG (p); } static_always_inline void @@ -71,11 +88,7 @@ clib_spinlock_lock_if_init (clib_spinlock_t * p) static_always_inline void clib_spinlock_unlock (clib_spinlock_t * p) { -#if CLIB_DEBUG > 0 - (*p)->frame_address = 0; - (*p)->pid = 0; - (*p)->thread_index = 0; -#endif + CLIB_LOCK_DBG_CLEAR (p); /* Make sure all writes are complete before releasing the lock */ CLIB_MEMORY_BARRIER (); (*p)->lock = 0; @@ -88,6 +101,77 @@ clib_spinlock_unlock_if_init (clib_spinlock_t * p) clib_spinlock_unlock (p); } +/* + * Readers-Writer Lock + */ + +typedef struct clib_rw_lock_ +{ + CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); + volatile u32 n_readers; + volatile u32 writer_lock; +#if CLIB_DEBUG > 0 + pid_t pid; + uword thread_index; + void *frame_address; +#endif +} *clib_rwlock_t; + +always_inline void +clib_rwlock_init (clib_rwlock_t * p) +{ + *p = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES, CLIB_CACHE_LINE_BYTES); + memset ((void *) *p, 0, CLIB_CACHE_LINE_BYTES); +} + +always_inline void +clib_rwlock_free (clib_rwlock_t * p) +{ + if (*p) + { + clib_mem_free ((void *) *p); + *p = 0; + } +} + +always_inline void +clib_rwlock_reader_lock (clib_rwlock_t * p) +{ + if (__sync_fetch_and_add (&(*p)->n_readers, 1) == 0) + { + while (__sync_lock_test_and_set (&(*p)->writer_lock, 1)) + CLIB_PAUSE (); + } + CLIB_LOCK_DBG (p); +} + +always_inline void +clib_rwlock_reader_unlock (clib_rwlock_t * p) +{ + CLIB_LOCK_DBG_CLEAR (p); + if (__sync_fetch_and_sub (&(*p)->n_readers, 1) == 1) + { + CLIB_MEMORY_BARRIER (); + (*p)->writer_lock = 0; + } +} + +always_inline void +clib_rwlock_writer_lock (clib_rwlock_t * p) +{ + while (__sync_lock_test_and_set (&(*p)->writer_lock, 1)) + CLIB_PAUSE (); + CLIB_LOCK_DBG (p); +} + +always_inline void +clib_rwlock_writer_unlock (clib_rwlock_t * p) +{ + CLIB_LOCK_DBG_CLEAR (p); + CLIB_MEMORY_BARRIER (); + (*p)->writer_lock = 0; +} + #endif /* |