Skip to content

Commit 07c6e51

Browse files
anarazelanarazel
committed
Remove volatile qualifiers from shm_mq.c.
Since commit 0709b7e, spinlock primitives include a compiler barrier so it is no longer necessary to access either spinlocks or the memory they protect through pointer-to-volatile. Like earlier commits e93b629, d53e3d5, 430008b, 8f6bb85, df4077c. Author: Thomas Munro Discussion: https://postgr.es/m/CAEepm=204T37SxcHo4=xw5btho9jQ-=ZYYrVdcKyz82XYzMoqg@mail.gmail.com
1 parent 8ecdc2f commit 07c6e51

File tree

1 file changed

+27
-33
lines changed

1 file changed

+27
-33
lines changed

‎src/backend/storage/ipc/shm_mq.c

Lines changed: 27 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -146,15 +146,15 @@ static shm_mq_result shm_mq_send_bytes(shm_mq_handle *mq, Size nbytes,
146146
const void *data, bool nowait, Size *bytes_written);
147147
static shm_mq_result shm_mq_receive_bytes(shm_mq *mq, Size bytes_needed,
148148
bool nowait, Size *nbytesp, void **datap);
149-
static bool shm_mq_counterparty_gone(volatile shm_mq *mq,
149+
static bool shm_mq_counterparty_gone(shm_mq *mq,
150150
BackgroundWorkerHandle *handle);
151-
static bool shm_mq_wait_internal(volatile shm_mq *mq, PGPROC *volatile *ptr,
151+
static bool shm_mq_wait_internal(shm_mq *mq, PGPROC **ptr,
152152
BackgroundWorkerHandle *handle);
153-
static uint64 shm_mq_get_bytes_read(volatile shm_mq *mq, bool *detached);
154-
static void shm_mq_inc_bytes_read(volatile shm_mq *mq, Size n);
155-
static uint64 shm_mq_get_bytes_written(volatile shm_mq *mq, bool *detached);
156-
static void shm_mq_inc_bytes_written(volatile shm_mq *mq, Size n);
157-
static shm_mq_result shm_mq_notify_receiver(volatile shm_mq *mq);
153+
static uint64 shm_mq_get_bytes_read(shm_mq *mq, bool *detached);
154+
static void shm_mq_inc_bytes_read(shm_mq *mq, Size n);
155+
static uint64 shm_mq_get_bytes_written(shm_mq *mq, bool *detached);
156+
static void shm_mq_inc_bytes_written(shm_mq *mq, Size n);
157+
static shm_mq_result shm_mq_notify_receiver(shm_mq *mq);
158158
static void shm_mq_detach_callback(dsm_segment *seg, Datum arg);
159159

160160
/* Minimum queue size is enough for header and at least one chunk of data. */
@@ -198,13 +198,12 @@ shm_mq_create(void *address, Size size)
198198
void
199199
shm_mq_set_receiver(shm_mq *mq, PGPROC *proc)
200200
{
201-
volatile shm_mq *vmq = mq;
202201
PGPROC *sender;
203202

204203
SpinLockAcquire(&mq->mq_mutex);
205-
Assert(vmq->mq_receiver == NULL);
206-
vmq->mq_receiver = proc;
207-
sender = vmq->mq_sender;
204+
Assert(mq->mq_receiver == NULL);
205+
mq->mq_receiver = proc;
206+
sender = mq->mq_sender;
208207
SpinLockRelease(&mq->mq_mutex);
209208

210209
if (sender != NULL)
@@ -217,13 +216,12 @@ shm_mq_set_receiver(shm_mq *mq, PGPROC *proc)
217216
void
218217
shm_mq_set_sender(shm_mq *mq, PGPROC *proc)
219218
{
220-
volatile shm_mq *vmq = mq;
221219
PGPROC *receiver;
222220

223221
SpinLockAcquire(&mq->mq_mutex);
224-
Assert(vmq->mq_sender == NULL);
225-
vmq->mq_sender = proc;
226-
receiver = vmq->mq_receiver;
222+
Assert(mq->mq_sender == NULL);
223+
mq->mq_sender = proc;
224+
receiver = mq->mq_receiver;
227225
SpinLockRelease(&mq->mq_mutex);
228226

229227
if (receiver != NULL)
@@ -236,11 +234,10 @@ shm_mq_set_sender(shm_mq *mq, PGPROC *proc)
236234
PGPROC *
237235
shm_mq_get_receiver(shm_mq *mq)
238236
{
239-
volatile shm_mq *vmq = mq;
240237
PGPROC *receiver;
241238

242239
SpinLockAcquire(&mq->mq_mutex);
243-
receiver = vmq->mq_receiver;
240+
receiver = mq->mq_receiver;
244241
SpinLockRelease(&mq->mq_mutex);
245242

246243
return receiver;
@@ -252,11 +249,10 @@ shm_mq_get_receiver(shm_mq *mq)
252249
PGPROC *
253250
shm_mq_get_sender(shm_mq *mq)
254251
{
255-
volatile shm_mq *vmq = mq;
256252
PGPROC *sender;
257253

258254
SpinLockAcquire(&mq->mq_mutex);
259-
sender = vmq->mq_sender;
255+
sender = mq->mq_sender;
260256
SpinLockRelease(&mq->mq_mutex);
261257

262258
return sender;
@@ -806,18 +802,17 @@ shm_mq_detach(shm_mq_handle *mqh)
806802
static void
807803
shm_mq_detach_internal(shm_mq *mq)
808804
{
809-
volatile shm_mq *vmq = mq;
810805
PGPROC *victim;
811806

812807
SpinLockAcquire(&mq->mq_mutex);
813-
if (vmq->mq_sender == MyProc)
814-
victim = vmq->mq_receiver;
808+
if (mq->mq_sender == MyProc)
809+
victim = mq->mq_receiver;
815810
else
816811
{
817-
Assert(vmq->mq_receiver == MyProc);
818-
victim = vmq->mq_sender;
812+
Assert(mq->mq_receiver == MyProc);
813+
victim = mq->mq_sender;
819814
}
820-
vmq->mq_detached = true;
815+
mq->mq_detached = true;
821816
SpinLockRelease(&mq->mq_mutex);
822817

823818
if (victim != NULL)
@@ -1035,7 +1030,7 @@ shm_mq_receive_bytes(shm_mq *mq, Size bytes_needed, bool nowait,
10351030
* Test whether a counterparty who may not even be alive yet is definitely gone.
10361031
*/
10371032
static bool
1038-
shm_mq_counterparty_gone(volatile shm_mq *mq, BackgroundWorkerHandle *handle)
1033+
shm_mq_counterparty_gone(shm_mq *mq, BackgroundWorkerHandle *handle)
10391034
{
10401035
bool detached;
10411036
pid_t pid;
@@ -1082,8 +1077,7 @@ shm_mq_counterparty_gone(volatile shm_mq *mq, BackgroundWorkerHandle *handle)
10821077
* non-NULL when our counterpart attaches to the queue.
10831078
*/
10841079
static bool
1085-
shm_mq_wait_internal(volatile shm_mq *mq, PGPROC *volatile *ptr,
1086-
BackgroundWorkerHandle *handle)
1080+
shm_mq_wait_internal(shm_mq *mq, PGPROC **ptr, BackgroundWorkerHandle *handle)
10871081
{
10881082
bool result = false;
10891083

@@ -1137,7 +1131,7 @@ shm_mq_wait_internal(volatile shm_mq *mq, PGPROC *volatile *ptr,
11371131
* the count of bytes read, but the sender must.
11381132
*/
11391133
static uint64
1140-
shm_mq_get_bytes_read(volatile shm_mq *mq, bool *detached)
1134+
shm_mq_get_bytes_read(shm_mq *mq, bool *detached)
11411135
{
11421136
uint64 v;
11431137

@@ -1153,7 +1147,7 @@ shm_mq_get_bytes_read(volatile shm_mq *mq, bool *detached)
11531147
* Increment the number of bytes read.
11541148
*/
11551149
static void
1156-
shm_mq_inc_bytes_read(volatile shm_mq *mq, Size n)
1150+
shm_mq_inc_bytes_read(shm_mq *mq, Size n)
11571151
{
11581152
PGPROC *sender;
11591153

@@ -1172,7 +1166,7 @@ shm_mq_inc_bytes_read(volatile shm_mq *mq, Size n)
11721166
* the count of bytes written, but the receiver must.
11731167
*/
11741168
static uint64
1175-
shm_mq_get_bytes_written(volatile shm_mq *mq, bool *detached)
1169+
shm_mq_get_bytes_written(shm_mq *mq, bool *detached)
11761170
{
11771171
uint64 v;
11781172

@@ -1188,7 +1182,7 @@ shm_mq_get_bytes_written(volatile shm_mq *mq, bool *detached)
11881182
* Increment the number of bytes written.
11891183
*/
11901184
static void
1191-
shm_mq_inc_bytes_written(volatile shm_mq *mq, Size n)
1185+
shm_mq_inc_bytes_written(shm_mq *mq, Size n)
11921186
{
11931187
SpinLockAcquire(&mq->mq_mutex);
11941188
mq->mq_bytes_written += n;
@@ -1199,7 +1193,7 @@ shm_mq_inc_bytes_written(volatile shm_mq *mq, Size n)
11991193
* Set receiver's latch, unless queue is detached.
12001194
*/
12011195
static shm_mq_result
1202-
shm_mq_notify_receiver(volatile shm_mq *mq)
1196+
shm_mq_notify_receiver(shm_mq *mq)
12031197
{
12041198
PGPROC *receiver;
12051199
bool detached;

0 commit comments

Comments
 (0)
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy