Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Add calls to sqlite3_log() when sqlite3_mutex_enter() takes more than 100,000 CPU cycles. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | debug |
| Files: | files | file ages | folders |
| SHA1: |
33c7ef7aca69f9b714bc25b2af5ae2a1 |
| User & Date: | drh 2016-07-29 14:10:43.773 |
Context
|
2016-07-29
| ||
| 14:23 | Use __sync_synchronous(), when available, instead of a mutex when a memory barrier is needed. (check-in: 7d4562e9d5 user: drh tags: debug) | |
| 14:10 | Add calls to sqlite3_log() when sqlite3_mutex_enter() takes more than 100,000 CPU cycles. (check-in: 33c7ef7aca user: drh tags: debug) | |
|
2016-07-16
| ||
| 11:47 | Temporarily add extra sqlite3_log() calls to this version to help with debugging a performance problem. (check-in: 613c1ceaf4 user: dan tags: debug) | |
Changes
Changes to src/mutex_unix.c.
| ︙ | ︙ | |||
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 |
static void pthreadMutexFree(sqlite3_mutex *p){
assert( p->nRef==0 );
assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
pthread_mutex_destroy(&p->mutex);
sqlite3_free(p);
}
/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread. In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter. If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
static void pthreadMutexEnter(sqlite3_mutex *p){
assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );
#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
/* If recursive mutexes are not available, then we have to grow
** our own. This implementation assumes that pthread_equal()
** is atomic - that it cannot be deceived into thinking self
** and p->owner are equal if p->owner changes between two values
| > > > > > > > > | 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 |
static void pthreadMutexFree(sqlite3_mutex *p){
assert( p->nRef==0 );
assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
pthread_mutex_destroy(&p->mutex);
sqlite3_free(p);
}
#include "hwtime.h"
#ifdef SQLITE_MUTEX_NREF
# define MUTEX_ID(p) (p->id)
#else
# define MUTEX_ID(p) 0
#endif
/*
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can
** be entered multiple times by the same thread. In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter. If the same thread tries to enter any other kind of mutex
** more than once, the behavior is undefined.
*/
static void pthreadMutexEnter(sqlite3_mutex *p){
sqlite3_uint64 iTimer = sqlite3Hwtime();
assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );
#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
/* If recursive mutexes are not available, then we have to grow
** our own. This implementation assumes that pthread_equal()
** is atomic - that it cannot be deceived into thinking self
** and p->owner are equal if p->owner changes between two values
|
| ︙ | ︙ | |||
241 242 243 244 245 246 247 248 249 250 251 252 253 254 |
*/
pthread_mutex_lock(&p->mutex);
#if SQLITE_MUTEX_NREF
assert( p->nRef>0 || p->owner==0 );
p->owner = pthread_self();
p->nRef++;
#endif
#endif
#ifdef SQLITE_DEBUG
if( p->trace ){
printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
}
#endif
| > > > > > | 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 |
*/
pthread_mutex_lock(&p->mutex);
#if SQLITE_MUTEX_NREF
assert( p->nRef>0 || p->owner==0 );
p->owner = pthread_self();
p->nRef++;
#endif
iTimer = sqlite3Hwtime() - iTimer;
if( iTimer>100000 ){
sqlite3_log(SQLITE_NOTICE, "slow mutex: %lld cycles on %d/%p",
iTimer, MUTEX_ID(p), p);
}
#endif
#ifdef SQLITE_DEBUG
if( p->trace ){
printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
}
#endif
|
| ︙ | ︙ |