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Ignore whitespace Rev 2429 → Rev 2430

/branches/rcu/kernel/test/synch/rcu1.c
27,6 → 27,10
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
 
 
/* This is RCU thorough test. It should provide basic guidelines on how to use
this implementation of RCU */
 
#include <synch/rcu.h>
#include <print.h>
#include <test.h>
37,14 → 41,19
#include <preemption.h>
#include <proc/thread.h>
 
 
#define RCU_MAX_I 1000
//number of nodes in the list. The sum of the list will grow up to RCU_MAX_I^2
#define RCU_MAX_I 500
//number of reader and writer threads in the test
#define READER_THREADS 10
#define WRITER_THREADS 10
#define THREADS_SLEEP_LENGTH (uint32_t)50
//a sleep separates iterations of reading
#define THREADS_SLEEP_LENGTH 50
 
//shared flag specifying whether we should be quiet
bool gquiet;
volatile bool finished;
//count of finished threads
volatile int cfinished;
//the list we will manage with RCU
typedef struct data_struc {
int number;
struct data_struc* next;
54,7 → 63,7
SPINLOCK_INITIALIZE(write_lock);
 
 
 
/** this thread will try to read from the list */
static void reader(void* a)
{
a = (a);
62,20 → 71,22
int i = 0;
while (true)
{
i = 0;
//entering read critical section
rcu_read_lock();
for (cur = rcu_dereference_pointer(first).next; cur != first; cur = cur->next) {
i += rcu_dereference_pointer(cur).number;
//proper dereferencing
i = rcu_dereference_pointer(first).number;
for (cur = rcu_dereference_pointer(first).next; cur != NULL; cur = cur->next) {
i += cur->number;
}
rcu_read_unlock();
thread_usleep(THREADS_SLEEP_LENGTH);
if (i>RCU_MAX_I || finished)
if (i>RCU_MAX_I*RCU_MAX_I || cfinished>0)
{
printf("@");
break;
}
thread_usleep(THREADS_SLEEP_LENGTH);
}
finished = true;
cfinished++;
}
 
static void writer(void* a)
82,70 → 93,70
{
a = (a);
data_t* cur;
data_t* newdata, *oldata;
data_t* newdata;
data_t* oldata;
rcu_callback_list_t* rcudata;
int i = 0;
printf("a1 ");
rcudata = malloc(sizeof(rcu_callback_list_t),0);
while (true)
{
//we must allocate the rcu structure each time, because it gets freed after the callback
//we allocate it outside any critical section, as it could block
rcudata = malloc(sizeof(rcu_callback_list_t),0);
rcu_read_lock();
i = rcu_dereference_pointer(first).number;
rcu_read_lock();
printf("a2 ");
for (cur = rcu_dereference_pointer(first).next; cur != first; cur = rcu_dereference_pointer(cur).next) {
i += rcu_dereference_pointer(cur).number;
for (cur = rcu_dereference_pointer(first).next; cur != NULL; cur = cur->next) {
i += cur->number;
}
rcu_read_unlock();
if (!gquiet)
printf("i%d ",i);
if (i>RCU_MAX_I || finished)
if (i>RCU_MAX_I*RCU_MAX_I || cfinished>0)
{
printf("!");
break;
}
printf("a2b ");
thread_usleep(THREADS_SLEEP_LENGTH);
 
printf("a3 ");
//insert a new member
newdata = malloc(sizeof(data_t),0);
printf("a4 ");
newdata->number = (i/(RCU_MAX_I/2))+1;
rcu_read_lock();
//prepend a new member
//we have to acquire the lock for writing to the structure
spinlock_lock(&write_lock);
printf("a5 ");
newdata->number = (i/10)+1;
oldata = first;
newdata->next = first;
//rcu_assign_pointer takes care of the necessary write barriers
rcu_assign_pointer(first, newdata);
printf("a6 ");
rcu_sync_callback(&rcu_callback_free, oldata, rcudata);
if (!gquiet)
printf("prepending:%x,n:%d ", newdata, newdata->number);
spinlock_unlock(&write_lock);
printf("a7 ");
rcu_read_unlock();
thread_usleep(THREADS_SLEEP_LENGTH);
printf("a8 ");
if (!gquiet)
printf(".",i);
 
 
//replace a random member
rcu_read_lock();
for (cur = rcu_dereference_pointer(first).next; rcu_dereference_pointer(cur).number % 5 != 4 && cur != first; cur = rcu_dereference_pointer(cur).next) {
//we have to lock the spinlock now, because we'll use the cur pointer later
//RCU doesn't provide guarantee that cur->next will point to a member of the list
//note that read critical section DOES guarantee that the *cur will be allocated space
//with current or past version of some member of the list
//However, that is not sufficient as we would be changing old version, which would be freed later on
spinlock_lock(&write_lock);
for (cur = first; cur->next != NULL && cur->next->number >= (i/(RCU_MAX_I/2)); cur = rcu_dereference_pointer(cur).next) {
}
if (cur != first){
//delete the cur->next
spinlock_lock(&write_lock);
oldata = rcu_dereference_pointer(cur).next;
newdata->next = rcu_dereference_pointer(rcu_dereference_pointer(cur).next).next;
rcu_assign_pointer(rcu_dereference_pointer(cur).next, newdata);
if (cur->next != NULL) {
newdata = malloc(sizeof(data_t),0);
//the change of number member could be done atomically, its here just to simulate some real work
newdata->number = (i/(RCU_MAX_I/2))+5;
newdata->next = cur->next->next;
oldata = cur->next;
if (!gquiet)
printf("free:%x,n:%d ", cur->next, cur->next->number);
rcu_assign_pointer(cur->next, newdata);
//free the old member when it is safe (i.e. no references are held)
rcu_sync_callback(&rcu_callback_free, oldata, rcudata);
spinlock_unlock(&write_lock);
if (!gquiet)
printf(", ",i);
 
}
rcu_read_unlock();
thread_usleep(THREADS_SLEEP_LENGTH);
rcu_read_unlock();
}
finished = true;
cfinished++;
}
 
char * test_rcu1(bool quiet)
154,29 → 165,39
data_t* cur, *oldata;
int i;
thread_t* t;
thread_t** threads;
 
//allocate and initialize the list
first = malloc(sizeof(data_t),0);
first->number = 10;
first->next = first;
threads = malloc(sizeof(thread_t*),0);
finished = false;
first->number = 0;
cur = first;
for (i=1;i<RCU_MAX_I;i++) {
cur->next = malloc(sizeof(data_t),0);
cur = cur->next;
cur->number = i;
}
cur->next = NULL;
 
//initialize the counter of finished threads
cfinished=0;
 
//start the writers
for(i = 0; i< WRITER_THREADS; i++) {
threads[i]=t=thread_create(writer,NULL, TASK, 0, "writerthread", false );
t=thread_create(writer,NULL, TASK, 0, "writerthread", false );
if (t != NULL)
thread_ready(t);
}
 
//start the readers
for(i = 0; i< READER_THREADS; i++) {
threads[WRITER_THREADS+i]=t=thread_create(reader,NULL, TASK, 0, "readerthread", false );
t=thread_create(reader,NULL, TASK, 0, "readerthread", false );
if (t != NULL)
thread_ready(t);
}
 
for (i=0;i<WRITER_THREADS+READER_THREADS;i++)
thread_join(threads[i]);
 
for(cur=first->next;cur->next!=first;) {
//wait for completion
while (cfinished<WRITER_THREADS+READER_THREADS);
printf("\nfinished all threads!\n");
//free the list
for(cur=first->next;cur!=NULL;) {
oldata = cur->next;
free(cur);
cur = oldata;
/branches/rcu/kernel/test/synch/rcu1.def
1,6 → 1,6
{
"rcu1",
"RCU test (very basic)",
"RCU test",
&test_rcu1,
true
},