1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2009 Oracle. 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);
/* 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_ */
|
