diff options
Diffstat (limited to 'examples/c/ex_file_system.c')
-rw-r--r-- | examples/c/ex_file_system.c | 132 |
1 files changed, 78 insertions, 54 deletions
diff --git a/examples/c/ex_file_system.c b/examples/c/ex_file_system.c index f51cad328c3..56869171558 100644 --- a/examples/c/ex_file_system.c +++ b/examples/c/ex_file_system.c @@ -29,35 +29,49 @@ * demonstrates how to use the custom file system interface */ -/* - * Include WiredTiger internal functions: we need architecture portable locking - * in this example, and we use the TAILQ_XXX functions to keep the code simple. - * - * Application-writers SHOULD NOT INCLUDE "wt_internal.h", the public WiredTiger - * include files should be used instead: - * - * #include <wiredtiger.h> - * #include <wiredtiger_ext.h> - */ -#include "wt_internal.h" +#include <assert.h> +#include <errno.h> +#include <inttypes.h> +#include <queue.h> +#include <stdlib.h> +#include <string.h> + +#ifndef _WIN32 +#include <pthread.h> +#else +#include "windows_shim.h" +#endif + +#include <wiredtiger.h> +#include <wiredtiger_ext.h> /* - * This example code uses internal WiredTiger functions for portable locking. - * We use #defines to clarify the meaning and ignore errors to simplify the - * code. - * - * Application writers SHOULD NOT COPY THIS LOCKING CODE, it's special-case code - * to make this example portable across platforms. + * This example code uses pthread functions for portable locking, we ignore + * errors for simplicity. */ -#define ALLOCATE_FILE_SYSTEM_LOCK(demo_fs) \ - (void)__wt_spin_init(NULL, &(demo_fs)->lock, "demo file handle lock") -#define DESTROY_FILE_SYSTEM_LOCK(wt_session, demo_fs) \ - __wt_spin_destroy((WT_SESSION_IMPL *)(wt_session), &(demo_fs)->lock) -#define LOCK_FILE_SYSTEM(wt_session, demo_fs) \ - __wt_spin_lock((WT_SESSION_IMPL *)(wt_session), &(demo_fs)->lock) -#define UNLOCK_FILE_SYSTEM(wt_session, demo_fs) \ - __wt_spin_unlock( \ - (WT_SESSION_IMPL *)(wt_session), &(demo_fs)->lock) +static void +allocate_file_system_lock(pthread_rwlock_t *lockp) +{ + assert(pthread_rwlock_init(lockp, NULL) == 0); +} + +static void +destroy_file_system_lock(pthread_rwlock_t *lockp) +{ + assert(pthread_rwlock_destroy(lockp) == 0); +} + +static void +lock_file_system(pthread_rwlock_t *lockp) +{ + assert(pthread_rwlock_wrlock(lockp) == 0); +} + +static void +unlock_file_system(pthread_rwlock_t *lockp) +{ + assert(pthread_rwlock_unlock(lockp) == 0); +} /* * Example file system implementation, using memory buffers to represent files. @@ -72,7 +86,7 @@ typedef struct { * might require finer granularity, for example, a single lock for the * file system handle list and per-handle locks serializing I/O. */ - WT_SPINLOCK lock; /* Lock */ + pthread_rwlock_t lock; /* Lock */ int opened_file_count; int opened_unique_file_count; @@ -239,7 +253,7 @@ demo_file_system_create(WT_CONNECTION *conn, WT_CONFIG_ARG *config) goto err; } - ALLOCATE_FILE_SYSTEM_LOCK(demo_fs); + allocate_file_system_lock(&demo_fs->lock); /* Initialize the in-memory jump table. */ file_system->fs_directory_list = demo_fs_directory_list; @@ -288,7 +302,7 @@ demo_fs_open(WT_FILE_SYSTEM *file_system, WT_SESSION *session, demo_fh = NULL; wtext = demo_fs->wtext; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); ++demo_fs->opened_file_count; /* @@ -308,7 +322,7 @@ demo_fs_open(WT_FILE_SYSTEM *file_system, WT_SESSION *session, *file_handlep = (WT_FILE_HANDLE *)demo_fh; - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (0); } @@ -366,7 +380,7 @@ err: free(demo_fh->buf); free(demo_fh); } - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (ret); } @@ -386,6 +400,8 @@ demo_fs_directory_list(WT_FILE_SYSTEM *file_system, int ret = 0; char *name, **entries; + (void)session; /* Unused */ + demo_fs = (DEMO_FILE_SYSTEM *)file_system; *dirlistp = NULL; @@ -396,7 +412,7 @@ demo_fs_directory_list(WT_FILE_SYSTEM *file_system, len = strlen(directory); prefix_len = prefix == NULL ? 0 : strlen(prefix); - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); TAILQ_FOREACH(demo_fh, &demo_fs->fileq, q) { name = demo_fh->iface.name; if (strncmp(name, directory, len) != 0 || @@ -424,7 +440,7 @@ demo_fs_directory_list(WT_FILE_SYSTEM *file_system, *dirlistp = entries; *countp = count; -err: UNLOCK_FILE_SYSTEM(session, demo_fs); +err: unlock_file_system(&demo_fs->lock); if (ret == 0) return (0); @@ -466,11 +482,13 @@ demo_fs_exist(WT_FILE_SYSTEM *file_system, { DEMO_FILE_SYSTEM *demo_fs; + (void)session; /* Unused */ + demo_fs = (DEMO_FILE_SYSTEM *)file_system; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); *existp = demo_handle_search(file_system, name) != NULL; - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (0); } @@ -487,15 +505,16 @@ demo_fs_remove(WT_FILE_SYSTEM *file_system, DEMO_FILE_HANDLE *demo_fh; int ret = 0; - (void)flags; /* Unused */ + (void)session; /* Unused */ + (void)flags; /* Unused */ demo_fs = (DEMO_FILE_SYSTEM *)file_system; ret = ENOENT; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); if ((demo_fh = demo_handle_search(file_system, name)) != NULL) ret = demo_handle_remove(session, demo_fh); - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (ret); } @@ -513,11 +532,12 @@ demo_fs_rename(WT_FILE_SYSTEM *file_system, char *copy; int ret = 0; - (void)flags; /* Unused */ + (void)session; /* Unused */ + (void)flags; /* Unused */ demo_fs = (DEMO_FILE_SYSTEM *)file_system; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); if ((demo_fh = demo_handle_search(file_system, from)) == NULL) ret = ENOENT; else if ((copy = strdup(to)) == NULL) @@ -526,7 +546,7 @@ demo_fs_rename(WT_FILE_SYSTEM *file_system, free(demo_fh->iface.name); demo_fh->iface.name = copy; } - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (ret); } @@ -545,10 +565,10 @@ demo_fs_size(WT_FILE_SYSTEM *file_system, demo_fs = (DEMO_FILE_SYSTEM *)file_system; ret = ENOENT; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); if ((demo_fh = demo_handle_search(file_system, name)) != NULL) ret = demo_file_size((WT_FILE_HANDLE *)demo_fh, session, sizep); - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (ret); } @@ -578,7 +598,7 @@ demo_fs_terminate(WT_FILE_SYSTEM *file_system, WT_SESSION *session) printf("\t%d reads, %d writes\n", demo_fs->read_ops, demo_fs->write_ops); - DESTROY_FILE_SYSTEM_LOCK(session, demo_fs); + destroy_file_system_lock(&demo_fs->lock); free(demo_fs); return (ret); @@ -594,13 +614,15 @@ demo_file_close(WT_FILE_HANDLE *file_handle, WT_SESSION *session) DEMO_FILE_HANDLE *demo_fh; DEMO_FILE_SYSTEM *demo_fs; + (void)session; /* Unused */ + demo_fh = (DEMO_FILE_HANDLE *)file_handle; demo_fs = demo_fh->demo_fs; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); if (--demo_fh->ref == 0) ++demo_fs->closed_file_count; - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (0); } @@ -638,7 +660,7 @@ demo_file_read(WT_FILE_HANDLE *file_handle, wtext = demo_fs->wtext; off = (size_t)offset; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); ++demo_fs->read_ops; if (off < demo_fh->size) { if (len > demo_fh->size - off) @@ -646,7 +668,7 @@ demo_file_read(WT_FILE_HANDLE *file_handle, memcpy(buf, (uint8_t *)demo_fh->buf + off, len); } else ret = EIO; /* EOF */ - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); if (ret == 0) return (0); @@ -667,12 +689,14 @@ demo_file_size( DEMO_FILE_HANDLE *demo_fh; DEMO_FILE_SYSTEM *demo_fs; + (void)session; /* Unused */ + demo_fh = (DEMO_FILE_HANDLE *)file_handle; demo_fs = demo_fh->demo_fs; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); *sizep = (wt_off_t)demo_fh->size; - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (0); } @@ -739,10 +763,10 @@ demo_file_truncate( demo_fh = (DEMO_FILE_HANDLE *)file_handle; demo_fs = demo_fh->demo_fs; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); if ((ret = demo_buffer_resize(session, demo_fh, offset)) == 0) demo_fh->size = (size_t)offset; - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); return (ret); } @@ -765,7 +789,7 @@ demo_file_write(WT_FILE_HANDLE *file_handle, WT_SESSION *session, wtext = demo_fs->wtext; off = (size_t)offset; - LOCK_FILE_SYSTEM(session, demo_fs); + lock_file_system(&demo_fs->lock); ++demo_fs->write_ops; if ((ret = demo_buffer_resize(session, demo_fh, offset + (wt_off_t)(len + DEMO_FILE_SIZE_INCREMENT))) == 0) { @@ -773,7 +797,7 @@ demo_file_write(WT_FILE_HANDLE *file_handle, WT_SESSION *session, if (off + len > demo_fh->size) demo_fh->size = off + len; } - UNLOCK_FILE_SYSTEM(session, demo_fs); + unlock_file_system(&demo_fs->lock); if (ret == 0) return (0); |