diff options
| author | Noah Misch <noah@leadboat.com> | 2019-04-03 17:03:46 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2019-04-03 17:03:46 -0700 |
| commit | 2f932f71d9f2963bbd201129d7b971c8f5f077fd (patch) | |
| tree | a9647622166d61e3b7668eca618f37c47d864f5f /src/include | |
| parent | af052daec5aa282eab2d22fa3b24d6109a30c2f3 (diff) | |
Consistently test for in-use shared memory.
postmaster startup scrutinizes any shared memory segment recorded in
postmaster.pid, exiting if that segment matches the current data
directory and has an attached process. When the postmaster.pid file was
missing, a starting postmaster used weaker checks. Change to use the
same checks in both scenarios. This increases the chance of a startup
failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1
postmaster.pid` && rm postmaster.pid && pg_ctl -w start". A postmaster
will no longer recycle segments pertaining to other data directories.
That's good for production, but it's bad for integration tests that
crash a postmaster and immediately delete its data directory. Such a
test now leaks a segment indefinitely. No "make check-world" test does
that. win32_shmem.c already avoided all these problems. In 9.6 and
later, enhance PostgresNode to facilitate testing. Back-patch to 9.4
(all supported versions).
Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.
Discussion: https://postgr.es/m/20130911033341.GD225735@tornado.leadboat.com
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/storage/ipc.h | 2 | ||||
| -rw-r--r-- | src/include/storage/pg_shmem.h | 6 |
2 files changed, 4 insertions, 4 deletions
diff --git a/src/include/storage/ipc.h b/src/include/storage/ipc.h index 0660252faf2..e9b243fe7d4 100644 --- a/src/include/storage/ipc.h +++ b/src/include/storage/ipc.h @@ -76,6 +76,6 @@ extern void on_exit_reset(void); /* ipci.c */ extern PGDLLIMPORT shmem_startup_hook_type shmem_startup_hook; -extern void CreateSharedMemoryAndSemaphores(bool makePrivate, int port); +extern void CreateSharedMemoryAndSemaphores(int port); #endif /* IPC_H */ diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h index 57d3107a89f..50bf9f06f0f 100644 --- a/src/include/storage/pg_shmem.h +++ b/src/include/storage/pg_shmem.h @@ -30,7 +30,7 @@ typedef struct PGShmemHeader /* standard header for all Postgres shmem */ { int32 magic; /* magic # to identify Postgres segments */ #define PGShmemMagic 679834894 - pid_t creatorPID; /* PID of creating process */ + pid_t creatorPID; /* PID of creating process (set but unread) */ Size totalsize; /* total size of segment */ Size freeoffset; /* offset to first free space */ dsm_handle dsm_control; /* ID of dynamic shared memory control seg */ @@ -81,8 +81,8 @@ extern void PGSharedMemoryReAttach(void); extern void PGSharedMemoryNoReAttach(void); #endif -extern PGShmemHeader *PGSharedMemoryCreate(Size size, bool makePrivate, - int port, PGShmemHeader **shim); +extern PGShmemHeader *PGSharedMemoryCreate(Size size, int port, + PGShmemHeader **shim); extern bool PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2); extern void PGSharedMemoryDetach(void); |