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Diffstat (limited to 'src/dbinc/os.h')
| -rw-r--r-- | src/dbinc/os.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/dbinc/os.h b/src/dbinc/os.h new file mode 100644 index 00000000..2515e6ee --- /dev/null +++ b/src/dbinc/os.h @@ -0,0 +1,178 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1997, 2012 Oracle and/or its affiliates. All rights reserved. + * + * $Id$ + */ + +#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); \ + if (env != NULL && \ + F_ISSET((env)->dbenv, DB_ENV_NOFLUSH)) \ + return (0) \ + \ +/* 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. */ + +#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; + off_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 *) +#define VOID_STAR_CAST (void *) +#else +#define CHAR_STAR_CAST +#define VOID_STAR_CAST +#endif + +#if defined(__cplusplus) +} +#endif + +#include "dbinc_auto/os_ext.h" +#endif /* !_DB_OS_H_ */ |