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authorsanine <sanine.not@pm.me>2022-08-27 23:52:56 -0500
committersanine <sanine.not@pm.me>2022-08-27 23:52:56 -0500
commita4dd0ad63c00f4dee3b86dfd3075d1d61b2b3180 (patch)
tree13bd5bfa15e6fea2a12f176bae79adf9c6fd0933 /3rdparty/plibsys/src/prwlock-general.c
parentbde3e4f1bb7b8f8abca0884a7d994ee1c17a66b1 (diff)
add plibsys
Diffstat (limited to '3rdparty/plibsys/src/prwlock-general.c')
-rw-r--r--3rdparty/plibsys/src/prwlock-general.c326
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
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--- /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)
+{
+}