Skip to content
New issue

Have a question about this project? # for a free GitHub account to open an issue and contact its maintainers and the community.

#

By clicking “#”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? # to your account

Use butil::ThreadLocal to store keytable #2645

Merged
merged 8 commits into from
Jul 7, 2024
+87 −35
Merged

Use butil::ThreadLocal to store keytable #2645

Show file tree
Hide file tree
Changes from 6 commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
b339a7b
update
MJY-HUST May 22, 2024
c707aa3
update by comments
MJY-HUST May 26, 2024
ddb253f
update
MJY-HUST May 27, 2024
0fb0655
fix
MJY-HUST May 28, 2024
d279324
update test for using_pool
MJY-HUST May 28, 2024
c2bc88b
fix format
MJY-HUST May 29, 2024
98edccf
format
MJY-HUST Jun 5, 2024
efcaba7
Change KeyTableList from class to struct
MJY-HUST Jun 11, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
100 changes: 74 additions & 26 deletions src/bthread/key.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@
#include <pthread.h>
#include "butil/macros.h"
#include "butil/atomicops.h"
#include "butil/thread_key.h"
#include "bvar/passive_status.h"
#include "bthread/errno.h" // EAGAIN
#include "bthread/task_group.h" // TaskGroup
Expand Down Expand Up @@ -204,14 +205,57 @@ class BAIDU_CACHELINE_ALIGNMENT KeyTable {
SubKeyTable* _subs[KEY_1STLEVEL_SIZE];
};

class KeyTableList {
public:
KeyTableList() {
keytable = NULL;
}
~KeyTableList() {
bthread::TaskGroup* g = bthread::tls_task_group;
bthread::KeyTable* old_kt = bthread::tls_bls.keytable;
while (keytable) {
bthread::KeyTable* kt = keytable;
keytable = kt->next;
bthread::tls_bls.keytable = kt;
if (g) {
g->current_task()->local_storage.keytable = kt;
}
delete kt;
if (old_kt == kt) {
old_kt = NULL;
}
g = bthread::tls_task_group;
}
bthread::tls_bls.keytable = old_kt;
if(g) {
g->current_task()->local_storage.keytable = old_kt;
}
}
KeyTable* keytable;
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

class 类型不建议直接把成员暴露成public，要么改成struct，要么封装成getter/setter

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

改成了struct

};

static KeyTable* borrow_keytable(bthread_keytable_pool_t* pool) {
if (pool != NULL && pool->free_keytables) {
BAIDU_SCOPED_LOCK(pool->mutex);
KeyTable* p = (KeyTable*)pool->free_keytables;
if (p) {
pool->free_keytables = p->next;
if (pool != NULL && (pool->list || pool->free_keytables)) {
KeyTable* p;
pthread_rwlock_rdlock(&pool->rwlock);
auto list = (butil::ThreadLocal<bthread::KeyTableList>*)pool->list;
if (list && list->get()->keytable) {
p = list->get()->keytable;
list->get()->keytable = p->next;
pthread_rwlock_unlock(&pool->rwlock);
return p;
}
pthread_rwlock_unlock(&pool->rwlock);
if (pool->free_keytables) {
pthread_rwlock_wrlock(&pool->rwlock);
p = (KeyTable*)pool->free_keytables;
if (p) {
pool->free_keytables = p->next;
pthread_rwlock_unlock(&pool->rwlock);
return p;
}
pthread_rwlock_unlock(&pool->rwlock);
}
}
return NULL;
}
Expand All @@ -226,14 +270,16 @@ void return_keytable(bthread_keytable_pool_t* pool, KeyTable* kt) {
delete kt;
return;
}
std::unique_lock<pthread_mutex_t> mu(pool->mutex);
pthread_rwlock_rdlock(&pool->rwlock);
if (pool->destroyed) {
mu.unlock();
pthread_rwlock_unlock(&pool->rwlock);
delete kt;
return;
}
kt->next = (KeyTable*)pool->free_keytables;
pool->free_keytables = kt;
auto list = (butil::ThreadLocal<bthread::KeyTableList>*)pool->list;
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

全局free_keytables里的kt一旦被借走就永远还不回去free_keytables了吗？这样keytables的复用率会降低吧，如果线程数很多，可能会占用更多的内存

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

是不会返回给free_keytables了。free_keytables的大小是根据server.option的reserved_thread_local_data变量设置的，默认为0。
不过这里的线程指的应该只是一个bthread_keytable_pool_t pool所对应的server的brpc_worker threads，而不是普通的pthread。
所以相比使用单链表管理，如果brpc_worker thread是公平调度的话，内部的butil::ThreadLocal维护的链表长度应该是比使用一个单链表来说要短，但是性能会更好，因为同样存在回收机制，内存不会多太多。

kt->next = list->get()->keytable;
list->get()->keytable = kt;
pthread_rwlock_unlock(&pool->rwlock);
}

static void cleanup_pthread(void* arg) {
Expand Down Expand Up @@ -279,7 +325,8 @@ int bthread_keytable_pool_init(bthread_keytable_pool_t* pool) {
LOG(ERROR) << "Param[pool] is NULL";
return EINVAL;
}
pthread_mutex_init(&pool->mutex, NULL);
pthread_rwlock_init(&pool->rwlock, NULL);
pool->list = new butil::ThreadLocal<bthread::KeyTableList>();
pool->free_keytables = NULL;
pool->destroyed = 0;
return 0;
Expand All @@ -291,33 +338,32 @@ int bthread_keytable_pool_destroy(bthread_keytable_pool_t* pool) {
return EINVAL;
}
bthread::KeyTable* saved_free_keytables = NULL;
{
BAIDU_SCOPED_LOCK(pool->mutex);
if (pool->free_keytables) {
saved_free_keytables = (bthread::KeyTable*)pool->free_keytables;
pool->free_keytables = NULL;
}
pool->destroyed = 1;
}
pthread_rwlock_wrlock(&pool->rwlock);
pool->destroyed = 1;
delete (butil::ThreadLocal<bthread::KeyTableList>*)pool->list;
saved_free_keytables = (bthread::KeyTable*)pool->free_keytables;
pool->list = NULL;
pool->free_keytables = NULL;
pthread_rwlock_unlock(&pool->rwlock);

// Cheat get/setspecific and destroy the keytables.
bthread::TaskGroup* const g = bthread::tls_task_group;
bthread::TaskGroup* g = bthread::tls_task_group;
bthread::KeyTable* old_kt = bthread::tls_bls.keytable;
while (saved_free_keytables) {
while(saved_free_keytables) {
bthread::KeyTable* kt = saved_free_keytables;
saved_free_keytables = kt->next;
bthread::tls_bls.keytable = kt;
if (g) {
g->current_task()->local_storage.keytable = kt;
}
delete kt;
if (old_kt == kt) {
old_kt = NULL;
}
g = bthread::tls_task_group;
}
bthread::tls_bls.keytable = old_kt;
if (g) {
g->current_task()->local_storage.keytable = old_kt;
}
return 0;
// TODO: return_keytable may race with this function, we don't destroy
// the mutex right now.
// pthread_mutex_destroy(&pool->mutex);
Expand All @@ -330,11 +376,12 @@ int bthread_keytable_pool_getstat(bthread_keytable_pool_t* pool,
LOG(ERROR) << "Param[pool] or Param[stat] is NULL";
return EINVAL;
}
std::unique_lock<pthread_mutex_t> mu(pool->mutex);
pthread_rwlock_rdlock(&pool->rwlock);
size_t count = 0;
bthread::KeyTable* p = (bthread::KeyTable*)pool->free_keytables;
for (; p; p = p->next, ++count) {}
stat->nfree = count;
pthread_rwlock_unlock(&pool->rwlock);
return 0;
}

Expand Down Expand Up @@ -365,14 +412,15 @@ void bthread_keytable_pool_reserve(bthread_keytable_pool_t* pool,
kt->set_data(key, data);
} // else append kt w/o data.

std::unique_lock<pthread_mutex_t> mu(pool->mutex);
pthread_rwlock_wrlock(&pool->rwlock);
if (pool->destroyed) {
mu.unlock();
pthread_rwlock_unlock(&pool->rwlock);
delete kt;
break;
}
kt->next = (bthread::KeyTable*)pool->free_keytables;
pool->free_keytables = kt;
pthread_rwlock_unlock(&pool->rwlock);
if (data == NULL) {
break;
}
Expand Down
3 changes: 2 additions & 1 deletion src/bthread/types.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -84,7 +84,8 @@ inline std::ostream& operator<<(std::ostream& os, bthread_key_t key) {
#endif // __cplusplus

typedef struct {
pthread_mutex_t mutex;
pthread_rwlock_t rwlock;
void* list;
void* free_keytables;
int destroyed;
} bthread_keytable_pool_t;
Expand Down
23 changes: 14 additions & 9 deletions test/bthread_key_unittest.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -339,15 +339,18 @@ TEST(KeyTest, set_tls_before_creating_any_bthread) {

struct PoolData {
bthread_key_t key;
PoolData* expected_data;
PoolData* data;
int seq;
int end_seq;
};

bool use_same_keytable = false;

static void pool_thread_impl(PoolData* data) {
ASSERT_EQ(data->expected_data, (PoolData*)bthread_getspecific(data->key));
if (NULL == bthread_getspecific(data->key)) {
ASSERT_EQ(0, bthread_setspecific(data->key, data));
} else {
use_same_keytable = true;
}
};

Expand Down Expand Up @@ -385,19 +388,21 @@ TEST(KeyTest, using_pool) {
ASSERT_EQ(0, bthread_start_urgent(&bth, &attr, pool_thread, &bth_data));
ASSERT_EQ(0, bthread_join(bth, NULL));
ASSERT_EQ(0, bth_data.seq);
ASSERT_EQ(1, bthread_keytable_pool_size(&pool));

PoolData bth2_data = { key, &bth_data, 0, 3 };
PoolData bth2_data = { key, NULL, 0, 3 };
bthread_t bth2;
ASSERT_EQ(0, bthread_start_urgent(&bth2, &attr2, pool_thread, &bth2_data));
ASSERT_EQ(0, bthread_join(bth2, NULL));
ASSERT_EQ(0, bth2_data.seq);
ASSERT_EQ(1, bthread_keytable_pool_size(&pool));

ASSERT_EQ(0, bthread_keytable_pool_destroy(&pool));

EXPECT_EQ(bth_data.end_seq, bth_data.seq);
EXPECT_EQ(0, bth2_data.seq);
if (use_same_keytable) {
EXPECT_EQ(bth_data.end_seq, bth_data.seq);
EXPECT_EQ(0, bth2_data.seq);
} else {
EXPECT_EQ(bth_data.end_seq, bth_data.seq);
EXPECT_EQ(bth_data.end_seq, bth2_data.seq);
}

ASSERT_EQ(0, bthread_key_delete(key));
}
Expand All @@ -415,7 +420,7 @@ static void lid_dtor(void* tls) {

static void lid_worker_impl(bthread_key_t key) {
ASSERT_EQ(NULL, bthread_getspecific(key));
ASSERT_EQ(0, bthread_setspecific(key, (void*)seq.fetch_add(1)));
ASSERT_EQ(0, bthread_setspecific(key, (void*)lid_seq.fetch_add(1)));
}

static void* lid_worker(void* arg) {
Expand Down
Loading