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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
| commit | 46651ce6fe013220ed397add242004d764fc0153 (patch) | |
| tree | 6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/storage/dsm_impl.h | |
| parent | Initial commit. (diff) | |
| download | postgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip | |
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/storage/dsm_impl.h')
| -rw-r--r-- | src/include/storage/dsm_impl.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/src/include/storage/dsm_impl.h b/src/include/storage/dsm_impl.h new file mode 100644 index 0000000..ff72f7b --- /dev/null +++ b/src/include/storage/dsm_impl.h @@ -0,0 +1,76 @@ +/*------------------------------------------------------------------------- + * + * dsm_impl.h + * low-level dynamic shared memory primitives + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/storage/dsm_impl.h + * + *------------------------------------------------------------------------- + */ +#ifndef DSM_IMPL_H +#define DSM_IMPL_H + +/* Dynamic shared memory implementations. */ +#define DSM_IMPL_POSIX 1 +#define DSM_IMPL_SYSV 2 +#define DSM_IMPL_WINDOWS 3 +#define DSM_IMPL_MMAP 4 + +/* + * Determine which dynamic shared memory implementations will be supported + * on this platform, and which one will be the default. + */ +#ifdef WIN32 +#define USE_DSM_WINDOWS +#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE DSM_IMPL_WINDOWS +#else +#ifdef HAVE_SHM_OPEN +#define USE_DSM_POSIX +#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE DSM_IMPL_POSIX +#endif +#define USE_DSM_SYSV +#ifndef DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE +#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE DSM_IMPL_SYSV +#endif +#define USE_DSM_MMAP +#endif + +/* GUC. */ +extern int dynamic_shared_memory_type; +extern int min_dynamic_shared_memory; + +/* + * Directory for on-disk state. + * + * This is used by all implementations for crash recovery and by the mmap + * implementation for storage. + */ +#define PG_DYNSHMEM_DIR "pg_dynshmem" +#define PG_DYNSHMEM_MMAP_FILE_PREFIX "mmap." + +/* A "name" for a dynamic shared memory segment. */ +typedef uint32 dsm_handle; + +/* All the shared-memory operations we know about. */ +typedef enum +{ + DSM_OP_CREATE, + DSM_OP_ATTACH, + DSM_OP_DETACH, + DSM_OP_DESTROY +} dsm_op; + +/* Create, attach to, detach from, resize, or destroy a segment. */ +extern bool dsm_impl_op(dsm_op op, dsm_handle handle, Size request_size, + void **impl_private, void **mapped_address, Size *mapped_size, + int elevel); + +/* Implementation-dependent actions required to keep segment until shutdown. */ +extern void dsm_impl_pin_segment(dsm_handle handle, void *impl_private, + void **impl_private_pm_handle); +extern void dsm_impl_unpin_segment(dsm_handle handle, void **impl_private); + +#endif /* DSM_IMPL_H */ |