WalSndShmemInit函数由postmaster的CreateSharedMemoryAndSemaphores函数调用(src/backend/storage/ipc/ipci.c)。首先调用ShmemInitStruct函数为WALSndCtlData申请内存,如果是第一次申请,则调用SHMQueueInit初始化SyncRepQueue成员槽,然后调用SpinLockInit函数初始化walsnd结构体的mutex成员。 voidWalSndShmemInit(void){boolfou...
ReleaseSemaphores函数释放信号量,主要在数据库关闭或shmem重新初始化时调用。主要是对所有信号量调用PosixSemaphoreKill函数。 /* Release semaphores at shutdown or shmem reinitialization (called as an on_shmem_exit callback, hence funny argument list) */ staticvoidReleaseSemaphores(intstatus,Datumarg) { in...
InternalIpcMemoryCreate函数通过指定的key尝试创建新的共享内存段,如果内存段存在则调用失败返回NULL;如果成功,将内存段attach到当前进程,然后返回其attached地址,最后将回调函数注册到on_shmem_exit,当detach或delete该共享内存时,on_shmem_exit会调用该回调函数。 typedefkey_tIpcMemoryKey;/* shared memory key passed ...
然后根据情况ProcSignalInit为辅助进程分配ProcSignalSlot,调用InitBufferPoolBackbend方法,在其中调用on_shmem_exit注册共享内存退出清理缓存相关资源要调用的函数AtProcExit_Buffers。然后把进程设回通常模式。根据传入参数调用StartupProcessMain,设置合适的信号处理句柄,然后调用StartupXLOG方法,这个方法有约1000行,搞完退出,...
config.status: linking src/backend/port/sysv_shmem.c to src/backend/port/pg_shmem.c config.status: linking src/include/port/linux.h to src/include/pg_config_os.h config.status: linking src/makefiles/Makefile.linux to src/Makefile.port ...
现在在$PGDATA/postgresql.conf中设置参数huge_pages为"on"并重启服务器。 $cat /proc/meminfo | grep -i hugeAnonHugePages:0 kBShmemHugePages:0 kBHugePages_Total:88HugePages_Free:81HugePages_Rsvd:64HugePages_Surp:0Hugepagesize:2048 kB
backup_label base pg_clog pg_dynshmem pg_ident.conf pg_logical pg_notify pg_serial pg_stat pg_subtrans pg_twophase pg_xlog postgresql.conf tablespace_map.old 创建本地基础备份并打包压缩,并存储到/home/postgres/2021-12-06 [postgres]# pg_basebackup -U repl -Ft -z -P -D /home/postgres/...
BufferBlocks = (char *) ShmemInitStruct("Buffer Blocks", NBuffers * (Size) BLCKSZ, &foundBufs); 3锁 这几把锁都在是共享内存中的。 3.1 Buffer Table Locks BufMappingLock 哈希表的分区锁,分s/e 3.2 Desc锁 content_lock 读写PAGE的轻量锁,分s/e e模式出现在以下情况下 插入page、修改tuple的...
$ psql -h 127.0.0.1 -d postgres postgres=# CREATE DATABASE sampledb OWNER perrynzhou; CREATE DATABASE postgres=# GRANT ALL PRIVILEGES ON DATABASE sampledb to perrynzhou; GRANT postgres=# select oid, datname from pg_database ; oid | datname ---+--- 12974 | postgres 1 | template...
immediate quit without complete shutdown; will lead to recovery on restart Allowed signal namesforkill: ABRT HUP INT KILL QUIT TERM USR1 USR2 Report bugs to <pgsql-bugs@lists.postgresql.org>. PostgreSQL home page: <https://www.postgresql.org/> ...