/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1997,2008 Oracle. All rights reserved. * * $Id: os.h,v 12.31 2008/03/26 04:11:34 david Exp $ */ #ifndef _DB_OS_H_ #define _DB_OS_H_ #if defined(__cplusplus) extern "C" { #endif /* Number of times to retry system calls that return EINTR or EBUSY. */ #define DB_RETRY 100 #ifdef __TANDEM /* * OSS Tandem problem: fsync can return a Guardian file system error of 70, * which has no symbolic name in OSS. HP says to retry the fsync. [#12957] */ #define RETRY_CHK(op, ret) do { \ int __retries, __t_ret; \ for ((ret) = 0, __retries = DB_RETRY;;) { \ if ((op) == 0) \ break; \ (ret) = __os_get_syserr(); \ if (((__t_ret = __os_posix_err(ret)) == EAGAIN || \ __t_ret == EBUSY || __t_ret == EINTR || \ __t_ret == EIO || __t_ret == 70) && --__retries > 0)\ continue; \ break; \ } \ } while (0) #else #define RETRY_CHK(op, ret) do { \ int __retries, __t_ret; \ for ((ret) = 0, __retries = DB_RETRY;;) { \ if ((op) == 0) \ break; \ (ret) = __os_get_syserr(); \ if (((__t_ret = __os_posix_err(ret)) == EAGAIN || \ __t_ret == EBUSY || __t_ret == EINTR || \ __t_ret == EIO) && --__retries > 0) \ continue; \ break; \ } \ } while (0) #endif #define RETRY_CHK_EINTR_ONLY(op, ret) do { \ int __retries; \ for ((ret) = 0, __retries = DB_RETRY;;) { \ if ((op) == 0) \ break; \ (ret) = __os_get_syserr(); \ if (__os_posix_err(ret) == EINTR && --__retries > 0) \ continue; \ break; \ } \ } while (0) /* * Flags understood by __os_open. */ #define DB_OSO_ABSMODE 0x0001 /* Absolute mode specified. */ #define DB_OSO_CREATE 0x0002 /* POSIX: O_CREAT */ #define DB_OSO_DIRECT 0x0004 /* Don't buffer the file in the OS. */ #define DB_OSO_DSYNC 0x0008 /* POSIX: O_DSYNC. */ #define DB_OSO_EXCL 0x0010 /* POSIX: O_EXCL */ #define DB_OSO_RDONLY 0x0020 /* POSIX: O_RDONLY */ #define DB_OSO_REGION 0x0040 /* Opening a region file. */ #define DB_OSO_SEQ 0x0080 /* Expected sequential access. */ #define DB_OSO_TEMP 0x0100 /* Remove after last close. */ #define DB_OSO_TRUNC 0x0200 /* POSIX: O_TRUNC */ /* * File modes. */ #define DB_MODE_400 (S_IRUSR) #define DB_MODE_600 (S_IRUSR|S_IWUSR) #define DB_MODE_660 (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) #define DB_MODE_666 (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH) #define DB_MODE_700 (S_IRUSR|S_IWUSR|S_IXUSR) /* * We group certain seek/write calls into a single function so that we * can use pread(2)/pwrite(2) where they're available. */ #define DB_IO_READ 1 #define DB_IO_WRITE 2 /* * Make a last "panic" check. Imagine a thread of control running in Berkeley * DB, going to sleep. Another thread of control decides to run recovery * because the environment is broken. The first thing recovery does is panic * the existing environment, but we only check the panic flag when crossing the * public API. If the sleeping thread wakes up and writes something, we could * have two threads of control writing the log files at the same time. So, * before reading or writing, make a last panic check. Obviously, there's still * a window, but it's very, very small. */ #define LAST_PANIC_CHECK_BEFORE_IO(env) \ PANIC_CHECK(env); /* DB filehandle. */ struct __fh_t { /* * Linked list of DB_FH's, linked from the DB_ENV, used to keep track * of all open file handles for resource cleanup. */ TAILQ_ENTRY(__fh_t) q; /* * The file-handle mutex is only used to protect the handle/fd * across seek and read/write pairs, it does not protect the * the reference count, or any other fields in the structure. */ db_mutex_t mtx_fh; /* Mutex to lock. */ int ref; /* Reference count. */ #ifdef HAVE_BREW IFile *ifp; /* IFile pointer */ #endif #if defined(DB_WIN32) HANDLE handle; /* Windows/32 file handle. */ HANDLE trunc_handle; /* Handle for truncate calls. */ #endif int fd; /* POSIX file descriptor. */ char *name; /* File name at open. */ /* * Last seek statistics, used for zero-filling on filesystems * that don't support it directly. */ db_pgno_t pgno; u_int32_t pgsize; u_int32_t offset; #ifdef HAVE_STATISTICS u_int32_t seek_count; /* I/O statistics */ u_int32_t read_count; u_int32_t write_count; #endif #define DB_FH_ENVLINK 0x01 /* We're linked on the DB_ENV. */ #define DB_FH_NOSYNC 0x02 /* Handle doesn't need to be sync'd. */ #define DB_FH_OPENED 0x04 /* Handle is valid. */ #define DB_FH_UNLINK 0x08 /* Unlink on close */ #define DB_FH_REGION 0x10 /* Opened to contain a region */ u_int8_t flags; }; /* Standard buffer size for ctime/ctime_r function calls. */ #define CTIME_BUFLEN 26 /* * VxWorks requires we cast (const char *) variables to (char *) in order to * pass them to system calls like stat, read and write. */ #ifdef HAVE_VXWORKS #define CHAR_STAR_CAST (char *) #else #define CHAR_STAR_CAST #endif #if defined(__cplusplus) } #endif #include "dbinc_auto/os_ext.h" #endif /* !_DB_OS_H_ */