* Initialize a read/write lock
*
* Returns: 0 on success
- * errno on failure
+ * errno on failure
*/
-int rwl_init(rwlock_t *rwl)
+int rwl_init(brwlock_t *rwl)
{
int stat;
-
+
rwl->r_active = rwl->w_active = 0;
rwl->r_wait = rwl->w_wait = 0;
if ((stat = pthread_mutex_init(&rwl->mutex, NULL)) != 0) {
* Destroy a read/write lock
*
* Returns: 0 on success
- * errno on failure
+ * errno on failure
*/
-int rwl_destroy(rwlock_t *rwl)
+int rwl_destroy(brwlock_t *rwl)
{
int stat, stat1, stat2;
if ((stat = pthread_mutex_unlock(&rwl->mutex)) != 0) {
return stat;
}
- stat = pthread_mutex_destroy(&rwl->mutex);
+ stat = pthread_mutex_destroy(&rwl->mutex);
stat1 = pthread_cond_destroy(&rwl->read);
stat2 = pthread_cond_destroy(&rwl->write);
return (stat != 0 ? stat : (stat1 != 0 ? stat1 : stat2));
*/
static void rwl_read_release(void *arg)
{
- rwlock_t *rwl = (rwlock_t *)arg;
+ brwlock_t *rwl = (brwlock_t *)arg;
rwl->r_wait--;
pthread_mutex_unlock(&rwl->mutex);
*/
static void rwl_write_release(void *arg)
{
- rwlock_t *rwl = (rwlock_t *)arg;
+ brwlock_t *rwl = (brwlock_t *)arg;
rwl->w_wait--;
pthread_mutex_unlock(&rwl->mutex);
/*
* Lock for read access, wait until locked (or error).
*/
-int rwl_readlock(rwlock_t *rwl)
+int rwl_readlock(brwlock_t *rwl)
{
int stat;
return stat;
}
if (rwl->w_active) {
- rwl->r_wait++; /* indicate that we are waiting */
+ rwl->r_wait++; /* indicate that we are waiting */
pthread_cleanup_push(rwl_read_release, (void *)rwl);
while (rwl->w_active) {
- stat = pthread_cond_wait(&rwl->read, &rwl->mutex);
- if (stat != 0) {
- break; /* error, bail out */
- }
+ stat = pthread_cond_wait(&rwl->read, &rwl->mutex);
+ if (stat != 0) {
+ break; /* error, bail out */
+ }
}
pthread_cleanup_pop(0);
- rwl->r_wait--; /* we are no longer waiting */
+ rwl->r_wait--; /* we are no longer waiting */
}
if (stat == 0) {
- rwl->r_active++; /* we are running */
+ rwl->r_active++; /* we are running */
}
pthread_mutex_unlock(&rwl->mutex);
return stat;
/*
* Attempt to lock for read access, don't wait
*/
-int rwl_readtrylock(rwlock_t *rwl)
+int rwl_readtrylock(brwlock_t *rwl)
{
int stat, stat2;
if (rwl->w_active) {
stat = EBUSY;
} else {
- rwl->r_active++; /* we are running */
+ rwl->r_active++; /* we are running */
}
stat2 = pthread_mutex_unlock(&rwl->mutex);
return (stat == 0 ? stat2 : stat);
/*
* Unlock read lock
*/
-int rwl_readunlock(rwlock_t *rwl)
+int rwl_readunlock(brwlock_t *rwl)
{
int stat, stat2;
* Lock for write access, wait until locked (or error).
* Multiple nested write locking is permitted.
*/
-int rwl_writelock(rwlock_t *rwl)
+int rwl_writelock(brwlock_t *rwl)
{
int stat;
return 0;
}
if (rwl->w_active || rwl->r_active > 0) {
- rwl->w_wait++; /* indicate that we are waiting */
+ rwl->w_wait++; /* indicate that we are waiting */
pthread_cleanup_push(rwl_write_release, (void *)rwl);
while (rwl->w_active || rwl->r_active > 0) {
- if ((stat = pthread_cond_wait(&rwl->write, &rwl->mutex)) != 0) {
- break; /* error, bail out */
- }
+ if ((stat = pthread_cond_wait(&rwl->write, &rwl->mutex)) != 0) {
+ break; /* error, bail out */
+ }
}
pthread_cleanup_pop(0);
- rwl->w_wait--; /* we are no longer waiting */
+ rwl->w_wait--; /* we are no longer waiting */
}
if (stat == 0) {
- rwl->w_active = 1; /* we are running */
+ rwl->w_active = 1; /* we are running */
rwl->writer_id = pthread_self(); /* save writer thread's id */
}
pthread_mutex_unlock(&rwl->mutex);
/*
* Attempt to lock for write access, don't wait
*/
-int rwl_writetrylock(rwlock_t *rwl)
+int rwl_writetrylock(brwlock_t *rwl)
{
int stat, stat2;
if (rwl->w_active || rwl->r_active > 0) {
stat = EBUSY;
} else {
- rwl->w_active = 1; /* we are running */
+ rwl->w_active = 1; /* we are running */
rwl->writer_id = pthread_self(); /* save writer thread's id */
}
stat2 = pthread_mutex_unlock(&rwl->mutex);
* Unlock write lock
* Start any waiting writers in preference to waiting readers
*/
-int rwl_writeunlock(rwlock_t *rwl)
+int rwl_writeunlock(brwlock_t *rwl)
{
int stat, stat2;
Emsg0(M_ABORT, 0, "rwl_writeunlock by non-owner.\n");
}
if (rwl->w_active > 0) {
- stat = 0; /* writers still active */
+ stat = 0; /* writers still active */
} else {
/* No more writers, awaken someone */
- if (rwl->r_wait > 0) { /* if readers waiting */
- stat = pthread_cond_broadcast(&rwl->read);
+ if (rwl->r_wait > 0) { /* if readers waiting */
+ stat = pthread_cond_broadcast(&rwl->read);
} else if (rwl->w_wait > 0) {
- stat = pthread_cond_signal(&rwl->write);
+ stat = pthread_cond_signal(&rwl->write);
}
}
stat2 = pthread_mutex_unlock(&rwl->mutex);
* Read/write lock and shared data.
*/
typedef struct data_tag {
- rwlock_t lock;
+ brwlock_t lock;
int data;
int writes;
} data_t;
* lock).
*/
if ((iteration % self->interval) == 0) {
- status = rwl_writelock(&data[element].lock);
- if (status != 0) {
+ status = rwl_writelock(&data[element].lock);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Write lock failed. ERR=%s\n", strerror(status));
- }
- data[element].data = self->thread_num;
- data[element].writes++;
- self->writes++;
- status = rwl_writeunlock(&data[element].lock);
- if (status != 0) {
+ }
+ data[element].data = self->thread_num;
+ data[element].writes++;
+ self->writes++;
+ status = rwl_writeunlock(&data[element].lock);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Write unlock failed. ERR=%s\n", strerror(status));
- }
+ }
} else {
- /*
- * Look at the current data element to see whether
- * the current thread last updated it. Count the
- * times to report later.
- */
- status = rwl_readlock(&data[element].lock);
- if (status != 0) {
+ /*
+ * Look at the current data element to see whether
+ * the current thread last updated it. Count the
+ * times to report later.
+ */
+ status = rwl_readlock(&data[element].lock);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Read lock failed. ERR=%s\n", strerror(status));
- }
- self->reads++;
- if (data[element].data == self->thread_num)
- repeats++;
- status = rwl_readunlock(&data[element].lock);
- if (status != 0) {
+ }
+ self->reads++;
+ if (data[element].data == self->thread_num)
+ repeats++;
+ status = rwl_readunlock(&data[element].lock);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Read unlock failed. ERR=%s\n", strerror(status));
- }
+ }
}
element++;
if (element >= DATASIZE) {
- element = 0;
+ element = 0;
}
}
if (repeats > 0) {
Dmsg2(000, "Thread %d found unchanged elements %d times\n",
- self->thread_num, repeats);
+ self->thread_num, repeats);
}
return NULL;
}
* Initialize the shared data.
*/
for (data_count = 0; data_count < DATASIZE; data_count++) {
- data[data_count].data = 0;
- data[data_count].writes = 0;
- status = rwl_init (&data[data_count].lock);
- if (status != 0) {
+ data[data_count].data = 0;
+ data[data_count].writes = 0;
+ status = rwl_init (&data[data_count].lock);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Init rwlock failed. ERR=%s\n", strerror(status));
- }
+ }
}
/*
* Create THREADS threads to access shared data.
*/
for (count = 0; count < THREADS; count++) {
- threads[count].thread_num = count + 1;
- threads[count].writes = 0;
- threads[count].reads = 0;
- threads[count].interval = rand_r (&seed) % 71;
- status = pthread_create (&threads[count].thread_id,
- NULL, thread_routine, (void*)&threads[count]);
- if (status != 0) {
+ threads[count].thread_num = count + 1;
+ threads[count].writes = 0;
+ threads[count].reads = 0;
+ threads[count].interval = rand_r (&seed) % 71;
+ status = pthread_create (&threads[count].thread_id,
+ NULL, thread_routine, (void*)&threads[count]);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Create thread failed. ERR=%s\n", strerror(status));
- }
+ }
}
/*
* statistics.
*/
for (count = 0; count < THREADS; count++) {
- status = pthread_join (threads[count].thread_id, NULL);
- if (status != 0) {
+ status = pthread_join (threads[count].thread_id, NULL);
+ if (status != 0) {
Emsg1(M_ABORT, 0, "Join thread failed. ERR=%s\n", strerror(status));
- }
- thread_writes += threads[count].writes;
+ }
+ thread_writes += threads[count].writes;
printf ("%02d: interval %d, writes %d, reads %d\n",
- count, threads[count].interval,
- threads[count].writes, threads[count].reads);
+ count, threads[count].interval,
+ threads[count].writes, threads[count].reads);
}
/*
* Collect statistics for the data.
*/
for (data_count = 0; data_count < DATASIZE; data_count++) {
- data_writes += data[data_count].writes;
+ data_writes += data[data_count].writes;
printf ("data %02d: value %d, %d writes\n",
- data_count, data[data_count].data, data[data_count].writes);
- rwl_destroy (&data[data_count].lock);
+ data_count, data[data_count].data, data[data_count].writes);
+ rwl_destroy (&data[data_count].lock);
}
printf ("Total: %d thread writes, %d data writes\n",
- thread_writes, data_writes);
+ thread_writes, data_writes);
return 0;
}
#ifdef TEST_RW_TRY_LOCK
/*
- * rwlock_try_main.c
+ * brwlock_try_main.c
*
* Demonstrate use of non-blocking read-write locks.
*
#include "rwlock.h"
#include "errors.h"
-#define THREADS 5
-#define ITERATIONS 1000
-#define DATASIZE 15
+#define THREADS 5
+#define ITERATIONS 1000
+#define DATASIZE 15
/*
* Keep statistics for each thread.
*/
typedef struct thread_tag {
- int thread_num;
- pthread_t thread_id;
- int r_collisions;
- int w_collisions;
- int updates;
- int interval;
+ int thread_num;
+ pthread_t thread_id;
+ int r_collisions;
+ int w_collisions;
+ int updates;
+ int interval;
} thread_t;
/*
* Read-write lock and shared data
*/
typedef struct data_tag {
- rwlock_t lock;
- int data;
- int updates;
+ brwlock_t lock;
+ int data;
+ int updates;
} data_t;
thread_t threads[THREADS];
int element;
int status;
- element = 0; /* Current data element */
+ element = 0; /* Current data element */
for (iteration = 0; iteration < ITERATIONS; iteration++) {
- if ((iteration % self->interval) == 0) {
- status = rwl_writetrylock (&data[element].lock);
- if (status == EBUSY)
- self->w_collisions++;
- else if (status == 0) {
- data[element].data++;
- data[element].updates++;
- self->updates++;
- rwl_writeunlock (&data[element].lock);
- } else
+ if ((iteration % self->interval) == 0) {
+ status = rwl_writetrylock (&data[element].lock);
+ if (status == EBUSY)
+ self->w_collisions++;
+ else if (status == 0) {
+ data[element].data++;
+ data[element].updates++;
+ self->updates++;
+ rwl_writeunlock (&data[element].lock);
+ } else
err_abort (status, "Try write lock");
- } else {
- status = rwl_readtrylock (&data[element].lock);
- if (status == EBUSY)
- self->r_collisions++;
- else if (status != 0) {
+ } else {
+ status = rwl_readtrylock (&data[element].lock);
+ if (status == EBUSY)
+ self->r_collisions++;
+ else if (status != 0) {
err_abort (status, "Try read lock");
- } else {
- if (data[element].data != data[element].updates)
+ } else {
+ if (data[element].data != data[element].updates)
printf ("%d: data[%d] %d != %d\n",
- self->thread_num, element,
- data[element].data, data[element].updates);
- rwl_readunlock (&data[element].lock);
- }
- }
-
- element++;
- if (element >= DATASIZE)
- element = 0;
+ self->thread_num, element,
+ data[element].data, data[element].updates);
+ rwl_readunlock (&data[element].lock);
+ }
+ }
+
+ element++;
+ if (element >= DATASIZE)
+ element = 0;
}
return NULL;
}
* Initialize the shared data.
*/
for (data_count = 0; data_count < DATASIZE; data_count++) {
- data[data_count].data = 0;
- data[data_count].updates = 0;
- rwl_init (&data[data_count].lock);
+ data[data_count].data = 0;
+ data[data_count].updates = 0;
+ rwl_init (&data[data_count].lock);
}
/*
* Create THREADS threads to access shared data.
*/
for (count = 0; count < THREADS; count++) {
- threads[count].thread_num = count;
- threads[count].r_collisions = 0;
- threads[count].w_collisions = 0;
- threads[count].updates = 0;
- threads[count].interval = rand_r (&seed) % ITERATIONS;
- status = pthread_create (&threads[count].thread_id,
- NULL, thread_routine, (void*)&threads[count]);
- if (status != 0)
+ threads[count].thread_num = count;
+ threads[count].r_collisions = 0;
+ threads[count].w_collisions = 0;
+ threads[count].updates = 0;
+ threads[count].interval = rand_r (&seed) % ITERATIONS;
+ status = pthread_create (&threads[count].thread_id,
+ NULL, thread_routine, (void*)&threads[count]);
+ if (status != 0)
err_abort (status, "Create thread");
}
* statistics.
*/
for (count = 0; count < THREADS; count++) {
- status = pthread_join (threads[count].thread_id, NULL);
- if (status != 0)
+ status = pthread_join (threads[count].thread_id, NULL);
+ if (status != 0)
err_abort (status, "Join thread");
- thread_updates += threads[count].updates;
+ thread_updates += threads[count].updates;
printf ("%02d: interval %d, updates %d, "
"r_collisions %d, w_collisions %d\n",
- count, threads[count].interval,
- threads[count].updates,
- threads[count].r_collisions, threads[count].w_collisions);
+ count, threads[count].interval,
+ threads[count].updates,
+ threads[count].r_collisions, threads[count].w_collisions);
}
/*
* Collect statistics for the data.
*/
for (data_count = 0; data_count < DATASIZE; data_count++) {
- data_updates += data[data_count].updates;
+ data_updates += data[data_count].updates;
printf ("data %02d: value %d, %d updates\n",
- data_count, data[data_count].data, data[data_count].updates);
- rwl_destroy (&data[data_count].lock);
+ data_count, data[data_count].data, data[data_count].updates);
+ rwl_destroy (&data[data_count].lock);
}
return 0;
projects / bacula / bacula / commitdiff