diff options
Diffstat (limited to '3rdparty/plibsys/src/prwlock-general.c')
| -rw-r--r-- | 3rdparty/plibsys/src/prwlock-general.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/3rdparty/plibsys/src/prwlock-general.c b/3rdparty/plibsys/src/prwlock-general.c new file mode 100644 index 0000000..5d79ed1 --- /dev/null +++ b/3rdparty/plibsys/src/prwlock-general.c @@ -0,0 +1,326 @@ +/* + * The MIT License + * + * Copyright (C) 2016 Alexander Saprykin <saprykin.spb@gmail.com> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * 'Software'), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +#include "pmem.h" +#include "pmutex.h" +#include "pcondvariable.h" +#include "prwlock.h" + +#include <stdlib.h> + +#define P_RWLOCK_SET_READERS(lock, readers) (((lock) & (~0x00007FFF)) | (readers)) +#define P_RWLOCK_READER_COUNT(lock) ((lock) & 0x00007FFF) +#define P_RWLOCK_SET_WRITERS(lock, writers) (((lock) & (~0x3FFF8000)) | ((writers) << 15)) +#define P_RWLOCK_WRITER_COUNT(lock) (((lock) & 0x3FFF8000) >> 15) + +struct PRWLock_ { + PMutex *mutex; + PCondVariable *read_cv; + PCondVariable *write_cv; + puint32 active_threads; + puint32 waiting_threads; +}; + +P_LIB_API PRWLock * +p_rwlock_new (void) +{ + PRWLock *ret; + + if (P_UNLIKELY ((ret = p_malloc0 (sizeof (PRWLock))) == NULL)) { + P_ERROR ("PRWLock::p_rwlock_new: failed to allocate memory"); + return NULL; + } + + if (P_UNLIKELY ((ret->mutex = p_mutex_new ()) == NULL)) { + P_ERROR ("PRWLock::p_rwlock_new: failed to allocate mutex"); + p_free (ret); + } + + if (P_UNLIKELY ((ret->read_cv = p_cond_variable_new ()) == NULL)) { + P_ERROR ("PRWLock::p_rwlock_new: failed to allocate condition variable for read"); + p_mutex_free (ret->mutex); + p_free (ret); + } + + if (P_UNLIKELY ((ret->write_cv = p_cond_variable_new ()) == NULL)) { + P_ERROR ("PRWLock::p_rwlock_new: failed to allocate condition variable for write"); + p_cond_variable_free (ret->read_cv); + p_mutex_free (ret->mutex); + p_free (ret); + } + + return ret; +} + +P_LIB_API pboolean +p_rwlock_reader_lock (PRWLock *lock) +{ + pboolean wait_ok; + + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_lock: p_mutex_lock() failed"); + return FALSE; + } + + wait_ok = TRUE; + + if (P_RWLOCK_WRITER_COUNT (lock->active_threads)) { + lock->waiting_threads = P_RWLOCK_SET_READERS (lock->waiting_threads, + P_RWLOCK_READER_COUNT (lock->waiting_threads) + 1); + + while (P_RWLOCK_WRITER_COUNT (lock->active_threads)) { + wait_ok = p_cond_variable_wait (lock->read_cv, lock->mutex); + + if (P_UNLIKELY (wait_ok == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_lock: p_cond_variable_wait() failed"); + break; + } + } + + lock->waiting_threads = P_RWLOCK_SET_READERS (lock->waiting_threads, + P_RWLOCK_READER_COUNT (lock->waiting_threads) - 1); + } + + if (P_LIKELY (wait_ok == TRUE)) + lock->active_threads = P_RWLOCK_SET_READERS (lock->active_threads, + P_RWLOCK_READER_COUNT (lock->active_threads) + 1); + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_lock: p_mutex_unlock() failed"); + return FALSE; + } + + return wait_ok; +} + +P_LIB_API pboolean +p_rwlock_reader_trylock (PRWLock *lock) +{ + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_trylock: p_mutex_lock() failed"); + return FALSE; + } + + if (P_RWLOCK_WRITER_COUNT (lock->active_threads)) { + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) + P_ERROR ("PRWLock::p_rwlock_reader_trylock: p_mutex_unlock() failed(1)"); + + return FALSE; + } + + lock->active_threads = P_RWLOCK_SET_READERS (lock->active_threads, + P_RWLOCK_READER_COUNT (lock->active_threads) + 1); + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_trylock: p_mutex_unlock() failed(2)"); + return FALSE; + } + + return TRUE; +} + +P_LIB_API pboolean +p_rwlock_reader_unlock (PRWLock *lock) +{ + puint32 reader_count; + pboolean signal_ok; + + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_unlock: p_mutex_lock() failed"); + return FALSE; + } + + reader_count = P_RWLOCK_READER_COUNT (lock->active_threads); + + if (P_UNLIKELY (reader_count == 0)) { + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) + P_ERROR ("PRWLock::p_rwlock_reader_unlock: p_mutex_unlock() failed(1)"); + + return TRUE; + } + + lock->active_threads = P_RWLOCK_SET_READERS (lock->active_threads, reader_count - 1); + + signal_ok = TRUE; + + if (reader_count == 1 && P_RWLOCK_WRITER_COUNT (lock->waiting_threads)) + signal_ok = p_cond_variable_signal (lock->write_cv); + + if (P_UNLIKELY (signal_ok == FALSE)) + P_ERROR ("PRWLock::p_rwlock_reader_unlock: p_cond_variable_signal() failed"); + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_reader_unlock: p_mutex_unlock() failed(2)"); + return FALSE; + } + + return signal_ok; +} + +P_LIB_API pboolean +p_rwlock_writer_lock (PRWLock *lock) +{ + pboolean wait_ok; + + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_lock: p_mutex_lock() failed"); + return FALSE; + } + + wait_ok = TRUE; + + if (lock->active_threads) { + lock->waiting_threads = P_RWLOCK_SET_WRITERS (lock->waiting_threads, + P_RWLOCK_WRITER_COUNT (lock->waiting_threads) + 1); + + while (lock->active_threads) { + wait_ok = p_cond_variable_wait (lock->write_cv, lock->mutex); + + if (P_UNLIKELY (wait_ok == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_lock: p_cond_variable_wait() failed"); + break; + } + } + + lock->waiting_threads = P_RWLOCK_SET_WRITERS (lock->waiting_threads, + P_RWLOCK_WRITER_COUNT (lock->waiting_threads) - 1); + } + + if (P_LIKELY (wait_ok == TRUE)) + lock->active_threads = P_RWLOCK_SET_WRITERS (lock->active_threads, 1); + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_lock: p_mutex_unlock() failed"); + return FALSE; + } + + return wait_ok; +} + +P_LIB_API pboolean +p_rwlock_writer_trylock (PRWLock *lock) +{ + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_trylock: p_mutex_lock() failed"); + return FALSE; + } + + if (lock->active_threads) { + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) + P_ERROR ("PRWLock::p_rwlock_writer_trylock: p_mutex_unlock() failed(1)"); + + return FALSE; + } + + lock->active_threads = P_RWLOCK_SET_WRITERS (lock->active_threads, 1); + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_trylock: p_mutex_unlock() failed(2)"); + return FALSE; + } + + return TRUE; +} + +P_LIB_API pboolean +p_rwlock_writer_unlock (PRWLock *lock) +{ + pboolean signal_ok; + + if (P_UNLIKELY (lock == NULL)) + return FALSE; + + if (P_UNLIKELY (p_mutex_lock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_unlock: p_mutex_lock() failed"); + return FALSE; + } + + lock->active_threads = P_RWLOCK_SET_WRITERS (lock->active_threads, 0); + + signal_ok = TRUE; + + if (P_RWLOCK_WRITER_COUNT (lock->waiting_threads)) { + if (P_UNLIKELY (p_cond_variable_signal (lock->write_cv) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_unlock: p_cond_variable_signal() failed"); + signal_ok = FALSE; + } + } else if (P_RWLOCK_READER_COUNT (lock->waiting_threads)) { + if (P_UNLIKELY (p_cond_variable_broadcast (lock->read_cv) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_unlock: p_cond_variable_broadcast() failed"); + signal_ok = FALSE; + } + } + + if (P_UNLIKELY (p_mutex_unlock (lock->mutex) == FALSE)) { + P_ERROR ("PRWLock::p_rwlock_writer_unlock: p_mutex_unlock() failed"); + return FALSE; + } + + return signal_ok; +} + +P_LIB_API void +p_rwlock_free (PRWLock *lock) +{ + if (P_UNLIKELY (lock == NULL)) + return; + + if (P_UNLIKELY (lock->active_threads)) + P_WARNING ("PRWLock::p_rwlock_free: destroying while active threads are present"); + + if (P_UNLIKELY (lock->waiting_threads)) + P_WARNING ("PRWLock::p_rwlock_free: destroying while waiting threads are present"); + + p_mutex_free (lock->mutex); + p_cond_variable_free (lock->read_cv); + p_cond_variable_free (lock->write_cv); + + p_free (lock); +} + +void +p_rwlock_init (void) +{ +} + +void +p_rwlock_shutdown (void) +{ +} |