1 |
24 |
jeremybenn |
/*
|
2 |
|
|
* (c) Copyright 1990-1996 OPEN SOFTWARE FOUNDATION, INC.
|
3 |
|
|
* (c) Copyright 1990-1996 HEWLETT-PACKARD COMPANY
|
4 |
|
|
* (c) Copyright 1990-1996 DIGITAL EQUIPMENT CORPORATION
|
5 |
|
|
* (c) Copyright 1991, 1992 Siemens-Nixdorf Information Systems
|
6 |
|
|
* To anyone who acknowledges that this file is provided "AS IS" without
|
7 |
|
|
* any express or implied warranty: permission to use, copy, modify, and
|
8 |
|
|
* distribute this file for any purpose is hereby granted without fee,
|
9 |
|
|
* provided that the above copyright notices and this notice appears in
|
10 |
|
|
* all source code copies, and that none of the names listed above be used
|
11 |
|
|
* in advertising or publicity pertaining to distribution of the software
|
12 |
|
|
* without specific, written prior permission. None of these organizations
|
13 |
|
|
* makes any representations about the suitability of this software for
|
14 |
|
|
* any purpose.
|
15 |
|
|
*/
|
16 |
|
|
/*
|
17 |
|
|
*
|
18 |
|
|
* Header file for thread synchrounous I/O
|
19 |
|
|
*/
|
20 |
|
|
|
21 |
|
|
#ifndef CMA_THREAD_IO
|
22 |
|
|
#define CMA_THREAD_IO
|
23 |
|
|
|
24 |
|
|
/*
|
25 |
|
|
* INCLUDE FILES
|
26 |
|
|
*/
|
27 |
|
|
|
28 |
|
|
#include <cma_config.h>
|
29 |
|
|
#include <sys/file.h>
|
30 |
|
|
#include <cma.h>
|
31 |
|
|
#include <sys/types.h>
|
32 |
|
|
#include <sys/time.h>
|
33 |
|
|
#include <cma_init.h>
|
34 |
|
|
#include <cma_errors.h>
|
35 |
|
|
|
36 |
|
|
/*
|
37 |
|
|
* CONSTANTS
|
38 |
|
|
*/
|
39 |
|
|
|
40 |
|
|
|
41 |
|
|
|
42 |
|
|
/*
|
43 |
|
|
* Maximum number of files (ie, max_fd+1)
|
44 |
|
|
*/
|
45 |
|
|
#define cma__c_mx_file FD_SETSIZE
|
46 |
|
|
|
47 |
|
|
/*
|
48 |
|
|
* Number of bits per file descriptor bit mask (ie number of bytes * bits/byte)
|
49 |
|
|
*/
|
50 |
|
|
#define cma__c_nbpm NFDBITS
|
51 |
|
|
|
52 |
|
|
/*
|
53 |
|
|
* TYPE DEFINITIONS
|
54 |
|
|
*/
|
55 |
|
|
|
56 |
|
|
typedef enum CMA__T_IO_TYPE {
|
57 |
|
|
cma__c_io_read = 0,
|
58 |
|
|
cma__c_io_write = 1,
|
59 |
|
|
cma__c_io_except = 2
|
60 |
|
|
} cma__t_io_type;
|
61 |
|
|
#define cma__c_max_io_type 2
|
62 |
|
|
|
63 |
|
|
/*
|
64 |
|
|
* From our local <sys/types.h>:
|
65 |
|
|
*
|
66 |
|
|
* typedef long fd_mask;
|
67 |
|
|
*
|
68 |
|
|
* typedef struct fd_set {
|
69 |
|
|
* fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
|
70 |
|
|
* } fd_set;
|
71 |
|
|
*
|
72 |
|
|
*/
|
73 |
|
|
typedef fd_mask cma__t_mask;
|
74 |
|
|
typedef fd_set cma__t_file_mask;
|
75 |
|
|
|
76 |
|
|
|
77 |
|
|
|
78 |
|
|
/*
|
79 |
|
|
* GLOBAL DATA
|
80 |
|
|
*/
|
81 |
|
|
|
82 |
|
|
/*
|
83 |
|
|
* Maximum number of files (ie, max_fd+1) as determined by getdtablesize().
|
84 |
|
|
*/
|
85 |
|
|
extern int cma__g_mx_file;
|
86 |
|
|
|
87 |
|
|
/*
|
88 |
|
|
* Number of submasks (ie "int" sized chunks) per file descriptor mask as
|
89 |
|
|
* determined by getdtablesize().
|
90 |
|
|
*/
|
91 |
|
|
extern int cma__g_nspm;
|
92 |
|
|
|
93 |
|
|
/*
|
94 |
|
|
* MACROS
|
95 |
|
|
*/
|
96 |
|
|
|
97 |
|
|
/*
|
98 |
|
|
* Define a constant for the errno value which indicates that the requested
|
99 |
|
|
* operation was not performed because it would block the process.
|
100 |
|
|
*/
|
101 |
|
|
# define cma__is_blocking(s) \
|
102 |
|
|
((s == EAGAIN) || (s == EWOULDBLOCK) || (s == EINPROGRESS) || \
|
103 |
|
|
(s == EALREADY) || (s == EDEADLK))
|
104 |
|
|
|
105 |
|
|
/*
|
106 |
|
|
* It is necessary to issue an I/O function, before calling cma__io_wait()
|
107 |
|
|
* in the following cases:
|
108 |
|
|
*
|
109 |
|
|
* * This file descriptor has been set non-blocking by CMA
|
110 |
|
|
* * This file descriptor has been set non-blocking by the user.
|
111 |
|
|
*/
|
112 |
|
|
|
113 |
|
|
#define cma__issue_io_call(fd) \
|
114 |
|
|
( (cma__g_file[fd]->non_blocking) || \
|
115 |
|
|
(cma__g_file[fd]->user_fl.user_non_blocking) )
|
116 |
|
|
|
117 |
|
|
|
118 |
|
|
#define cma__set_user_nonblocking(flags) \
|
119 |
|
|
|
120 |
|
|
/*
|
121 |
|
|
* Determine if the file is open
|
122 |
|
|
*/
|
123 |
|
|
/*
|
124 |
|
|
* If the file gets closed while waiting for the mutex cma__g_file[rfd]
|
125 |
|
|
* gets set to null. This results in a crash if NDEBUG is set to 0
|
126 |
|
|
* since cma__int_lock tries to dereference it to set the mutex ownership
|
127 |
|
|
* after it gets the mutex. The following will still set the ownership
|
128 |
|
|
* in cma__int_lock so we'll set it back to noone if cma__g_file is null
|
129 |
|
|
* when we come back just in case it matters. It shouldn't since its no
|
130 |
|
|
* longer in use but.....
|
131 |
|
|
* Callers of this should recheck cma__g_file after the reservation to
|
132 |
|
|
* make sure continueing makes sense.
|
133 |
|
|
*/
|
134 |
|
|
#define cma__fd_reserve(rfd) \
|
135 |
|
|
{ \
|
136 |
|
|
cma__t_int_mutex *__mutex__; \
|
137 |
|
|
__mutex__ = cma__g_file[rfd]->mutex; \
|
138 |
|
|
cma__int_lock (__mutex__); \
|
139 |
|
|
if(cma__g_file[rfd] == (cma__t_file_obj *)cma_c_null_ptr) \
|
140 |
|
|
cma__int_unlock(__mutex__); \
|
141 |
|
|
}
|
142 |
|
|
|
143 |
|
|
|
144 |
|
|
/*
|
145 |
|
|
* Unreserve a file descriptor
|
146 |
|
|
*/
|
147 |
|
|
#define cma__fd_unreserve(ufd) cma__int_unlock (cma__g_file[ufd]->mutex)
|
148 |
|
|
|
149 |
|
|
/*
|
150 |
|
|
* AND together two select file descriptor masks
|
151 |
|
|
*/
|
152 |
|
|
#define cma__fdm_and(target,a,b) \
|
153 |
|
|
{ \
|
154 |
|
|
int __i__ = cma__g_nspm; \
|
155 |
|
|
while (__i__--) \
|
156 |
|
|
(target)->fds_bits[__i__] = \
|
157 |
|
|
(a)->fds_bits[__i__] & (b)->fds_bits[__i__]; \
|
158 |
|
|
}
|
159 |
|
|
|
160 |
|
|
/*
|
161 |
|
|
* Clear a bit in a select file descriptor mask
|
162 |
|
|
*
|
163 |
|
|
* FD_CLR(n, p) := ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
|
164 |
|
|
*/
|
165 |
|
|
#define cma__fdm_clr_bit(n,p) FD_CLR (n, p)
|
166 |
|
|
|
167 |
|
|
/*
|
168 |
|
|
* Copy the contents of one file descriptor mask into another. If the
|
169 |
|
|
* destination operand is null, do nothing; if the source operand is null,
|
170 |
|
|
* simply zero the destination.
|
171 |
|
|
*/
|
172 |
|
|
#define cma__fdm_copy(src,dst,nfds) { \
|
173 |
|
|
if (dst) \
|
174 |
|
|
if (src) { \
|
175 |
|
|
cma__t_mask *__s__ = (cma__t_mask *)(src); \
|
176 |
|
|
cma__t_mask *__d__ = (cma__t_mask *)(dst); \
|
177 |
|
|
int __i__; \
|
178 |
|
|
for (__i__ = 0; __i__ < (nfds); __i__ += cma__c_nbpm) \
|
179 |
|
|
*__d__++ = *__s__++; \
|
180 |
|
|
} \
|
181 |
|
|
else \
|
182 |
|
|
cma__fdm_zero (dst); \
|
183 |
|
|
}
|
184 |
|
|
|
185 |
|
|
/*
|
186 |
|
|
* To increment count for each bit set in fd - mask
|
187 |
|
|
*/
|
188 |
|
|
#define cma__fdm_count_bits(map,count) \
|
189 |
|
|
{ \
|
190 |
|
|
int __i__ = cma__g_nspm; \
|
191 |
|
|
while (__i__--) { \
|
192 |
|
|
cma__t_mask __tm__; \
|
193 |
|
|
__tm__ = (map)->fds_bits[__i__]; \
|
194 |
|
|
while(__tm__) { \
|
195 |
|
|
(count)++; \
|
196 |
|
|
__tm__ &= ~(__tm__ & (-__tm__)); /* Assumes 2's comp */ \
|
197 |
|
|
} \
|
198 |
|
|
} \
|
199 |
|
|
}
|
200 |
|
|
|
201 |
|
|
/*
|
202 |
|
|
* Test if a bit is set in a select file descriptor mask
|
203 |
|
|
*
|
204 |
|
|
* FD_ISSET(n,p) := ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
|
205 |
|
|
*/
|
206 |
|
|
#define cma__fdm_is_set(n,p) FD_ISSET (n, p)
|
207 |
|
|
|
208 |
|
|
/*
|
209 |
|
|
* OR together two select file descriptor masks
|
210 |
|
|
*/
|
211 |
|
|
#define cma__fdm_or(target,a,b) \
|
212 |
|
|
{ \
|
213 |
|
|
int __i__ = cma__g_nspm; \
|
214 |
|
|
while (__i__--) \
|
215 |
|
|
(target)->fds_bits[__i__] = \
|
216 |
|
|
(a)->fds_bits[__i__] | (b)->fds_bits[__i__]; \
|
217 |
|
|
}
|
218 |
|
|
|
219 |
|
|
/*
|
220 |
|
|
* Set a bit in a select file descriptor mask
|
221 |
|
|
*
|
222 |
|
|
* FD_SET(n,p) := ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
|
223 |
|
|
*/
|
224 |
|
|
#define cma__fdm_set_bit(n,p) FD_SET (n, p)
|
225 |
|
|
|
226 |
|
|
/*
|
227 |
|
|
* Clear a select file descriptor mask.
|
228 |
|
|
*/
|
229 |
|
|
#define cma__fdm_zero(n) \
|
230 |
|
|
cma__memset ((char *) n, 0, cma__g_nspm * sizeof(cma__t_mask))
|
231 |
|
|
|
232 |
|
|
|
233 |
|
|
|
234 |
|
|
|
235 |
|
|
|
236 |
|
|
/*
|
237 |
|
|
* CMA "thread-synchronous" I/O read/write operations
|
238 |
|
|
*/
|
239 |
|
|
|
240 |
|
|
/*
|
241 |
|
|
* Since all CMA "thread-synchronous" I/O (read or write) operations on
|
242 |
|
|
* U*ix follow the exact same structure, the wrapper routines have been
|
243 |
|
|
* condensed into a macro.
|
244 |
|
|
*
|
245 |
|
|
* The steps performed are as follows:
|
246 |
|
|
* 1. Check that the file descriptor is a legitimate value.
|
247 |
|
|
* 2. Check that the entry in the CMA file "database" which corresponds to
|
248 |
|
|
* the file descriptor indicates that the "file" was "opened" by CMA.
|
249 |
|
|
* 3. Reserve the file, to serialized access to files. This not only
|
250 |
|
|
* simplifies things, but also defends against non-reentrancy.
|
251 |
|
|
* 4. If the "file" is "set" for non-blocking I/O, check if we
|
252 |
|
|
* have actually set the file non-blocking yet, and if not do so.
|
253 |
|
|
* Then, issue the I/O operantion.
|
254 |
|
|
* Success or failure is returned immediately, after unreserving the
|
255 |
|
|
* file. If the error indicates that the operation would have caused
|
256 |
|
|
* the process to block, continue to the next step.
|
257 |
|
|
* 5. The I/O prolog adds this "file" to the global bit mask, which
|
258 |
|
|
* represents all "files" which have threads waiting to perform I/O on
|
259 |
|
|
* them, and causes the thread to block on the condition variable for
|
260 |
|
|
* this "file". Periodically, a select is done on this global bit
|
261 |
|
|
* mask, and the condition variables corresponding to "files" which
|
262 |
|
|
* are ready for I/O are signaled, releasing those waiting threads to
|
263 |
|
|
* perform their I/O.
|
264 |
|
|
* 6. When the thread returns from the I/O prolog, it can (hopefully)
|
265 |
|
|
* perform its operation without blocking the process.
|
266 |
|
|
* 7. The I/O epilog clears the bit in the global mask and/or signals the
|
267 |
|
|
* the next thread waiting for this "file", as appropriate.
|
268 |
|
|
* 8. If the I/O failed, continue to loop.
|
269 |
|
|
* 9. Finally, the "file" is unreserved, as we're done with it, and the
|
270 |
|
|
* result of the operation is returned.
|
271 |
|
|
*
|
272 |
|
|
*
|
273 |
|
|
* Note: currently, we believe that timeslicing which is based on the
|
274 |
|
|
* virtual-time timer does not cause system calls to return EINTR.
|
275 |
|
|
* Threfore, any EINTR returns are relayed directly to the caller.
|
276 |
|
|
* On platforms which do not support a virtual-time timer, the code
|
277 |
|
|
* should probably catch EINTR returns and restart the system call.
|
278 |
|
|
*/
|
279 |
|
|
|
280 |
|
|
/*
|
281 |
|
|
* This macro is used for both read-type and write-type functions.
|
282 |
|
|
*
|
283 |
|
|
* Note: the second call to "func" may require being bracketed in a
|
284 |
|
|
* cma__interrupt_disable/cma__interrupt_enable pair, but we'll
|
285 |
|
|
* wait and see if this is necessary.
|
286 |
|
|
*/
|
287 |
|
|
#define cma__ts_func(func,fd,arglist,type,post_process) { \
|
288 |
|
|
cma_t_integer __res__; \
|
289 |
|
|
cma_t_boolean __done__ = cma_c_false; \
|
290 |
|
|
if ((fd < 0) || (fd >= cma__g_mx_file)) return (cma__set_errno (EBADF), -1); \
|
291 |
|
|
if (!cma__is_open(fd)) return (cma__set_errno (EBADF), -1); \
|
292 |
|
|
cma__fd_reserve (fd); \
|
293 |
|
|
if (!cma__is_open(fd)) return (cma__set_errno (EBADF), -1); \
|
294 |
|
|
if (cma__issue_io_call(fd)) {\
|
295 |
|
|
if ((!cma__g_file[fd]->set_non_blocking) && \
|
296 |
|
|
(cma__g_file[fd]->non_blocking == cma_c_true)) \
|
297 |
|
|
cma__set_nonblocking(fd); \
|
298 |
|
|
cma__interrupt_disable (0); \
|
299 |
|
|
TRY { \
|
300 |
|
|
__res__ = func arglist; \
|
301 |
|
|
} \
|
302 |
|
|
CATCH_ALL { \
|
303 |
|
|
cma__interrupt_enable (0); \
|
304 |
|
|
cma__fd_unreserve (fd); \
|
305 |
|
|
RERAISE; \
|
306 |
|
|
} \
|
307 |
|
|
ENDTRY \
|
308 |
|
|
cma__interrupt_enable (0); \
|
309 |
|
|
if ((__res__ != -1) \
|
310 |
|
|
|| (!cma__is_blocking (errno)) \
|
311 |
|
|
|| (cma__g_file[fd]->user_fl.user_non_blocking)) \
|
312 |
|
|
__done__ = cma_c_true; \
|
313 |
|
|
} \
|
314 |
|
|
if (__done__) { \
|
315 |
|
|
cma__fd_unreserve (fd); \
|
316 |
|
|
} \
|
317 |
|
|
else { \
|
318 |
|
|
TRY { \
|
319 |
|
|
cma__io_prolog (type, fd); \
|
320 |
|
|
while (!__done__) { \
|
321 |
|
|
cma__io_wait (type, fd); \
|
322 |
|
|
__res__ = func arglist; \
|
323 |
|
|
if ((__res__ != -1) \
|
324 |
|
|
|| (!cma__is_blocking (errno)) \
|
325 |
|
|
|| (cma__g_file[fd]->user_fl.user_non_blocking)) \
|
326 |
|
|
__done__ = cma_c_true; \
|
327 |
|
|
} \
|
328 |
|
|
} \
|
329 |
|
|
FINALLY { \
|
330 |
|
|
cma__io_epilog (type, fd); \
|
331 |
|
|
cma__fd_unreserve (fd); \
|
332 |
|
|
} \
|
333 |
|
|
ENDTRY \
|
334 |
|
|
} \
|
335 |
|
|
if (__res__ != -1) post_process; \
|
336 |
|
|
return __res__; \
|
337 |
|
|
}
|
338 |
|
|
|
339 |
|
|
/*
|
340 |
|
|
* Since most CMA "thread-synchronous" I/O ("open"-type) operations on
|
341 |
|
|
* U*ix follow the exact same structure, the wrapper routines have been
|
342 |
|
|
* condensed into a macro.
|
343 |
|
|
*
|
344 |
|
|
* The steps performed are as follows:
|
345 |
|
|
* 1. Issue the open function.
|
346 |
|
|
* 2. If the value returned indicates an error, return it to the caller.
|
347 |
|
|
* 3. If the file descriptor returned is larger than what we think is the
|
348 |
|
|
* maximum value (ie if it is too big for our database) then bugcheck.
|
349 |
|
|
* 4. "Open" the "file" in the CMA file database.
|
350 |
|
|
* 5. Return the file descriptor value to the caller.
|
351 |
|
|
*
|
352 |
|
|
* FIX-ME: for the time being, if the I/O operation returns EINTR, we
|
353 |
|
|
* simply return it to the caller; eventually, we should catch this
|
354 |
|
|
* and "do the right thing" (if we can figure out what that is).
|
355 |
|
|
*/
|
356 |
|
|
|
357 |
|
|
/*
|
358 |
|
|
* This macro is used for all "open"-type functions which return a single file
|
359 |
|
|
* desciptor by immediate value.
|
360 |
|
|
*/
|
361 |
|
|
#define cma__ts_open(func,arglist,post_process) { \
|
362 |
|
|
int __fd__; \
|
363 |
|
|
TRY { \
|
364 |
|
|
cma__int_init (); \
|
365 |
|
|
cma__int_lock (cma__g_io_data_mutex); \
|
366 |
|
|
__fd__ = func arglist; \
|
367 |
|
|
cma__int_unlock (cma__g_io_data_mutex); \
|
368 |
|
|
if (__fd__ >= 0 && __fd__ < cma__g_mx_file) \
|
369 |
|
|
post_process; \
|
370 |
|
|
} \
|
371 |
|
|
CATCH_ALL \
|
372 |
|
|
{ \
|
373 |
|
|
cma__set_errno (EBADF); \
|
374 |
|
|
__fd__ = -1; \
|
375 |
|
|
} \
|
376 |
|
|
ENDTRY \
|
377 |
|
|
if (__fd__ >= cma__g_mx_file) \
|
378 |
|
|
cma__bugcheck ("cma__ts_open: fd is too large"); \
|
379 |
|
|
return __fd__; \
|
380 |
|
|
}
|
381 |
|
|
/*
|
382 |
|
|
* This macro is used for all "open"-type functions which return a pair of file
|
383 |
|
|
* desciptors by reference parameter.
|
384 |
|
|
*/
|
385 |
|
|
#define cma__ts_open2(func,fdpair,arglist,post_process) { \
|
386 |
|
|
int __res__; \
|
387 |
|
|
TRY { \
|
388 |
|
|
cma__int_init (); \
|
389 |
|
|
cma__int_lock (cma__g_io_data_mutex); \
|
390 |
|
|
__res__ = func arglist; \
|
391 |
|
|
cma__int_unlock (cma__g_io_data_mutex); \
|
392 |
|
|
if (__res__ >= 0 && fdpair[0] < cma__g_mx_file \
|
393 |
|
|
&& fdpair[1] < cma__g_mx_file) \
|
394 |
|
|
post_process; \
|
395 |
|
|
} \
|
396 |
|
|
CATCH_ALL \
|
397 |
|
|
{ \
|
398 |
|
|
cma__set_errno (EBADF); \
|
399 |
|
|
__res__ = -1; \
|
400 |
|
|
} \
|
401 |
|
|
ENDTRY \
|
402 |
|
|
if ((fdpair[0] >= cma__g_mx_file) || (fdpair[1] >= cma__g_mx_file)) \
|
403 |
|
|
cma__bugcheck ("cma__ts_open2: one of fd's is too large"); \
|
404 |
|
|
return __res__; \
|
405 |
|
|
}
|
406 |
|
|
|
407 |
|
|
/*
|
408 |
|
|
* INTERNAL INTERFACES
|
409 |
|
|
*/
|
410 |
|
|
extern void cma__close_general (int);
|
411 |
|
|
|
412 |
|
|
extern void cma__init_thread_io (void);
|
413 |
|
|
|
414 |
|
|
extern cma_t_boolean cma__io_available (cma__t_io_type,int,struct timeval *);
|
415 |
|
|
|
416 |
|
|
extern void cma__io_epilog (cma__t_io_type,int);
|
417 |
|
|
|
418 |
|
|
extern void cma__io_prolog (cma__t_io_type,int);
|
419 |
|
|
|
420 |
|
|
extern void cma__io_wait (cma__t_io_type,int);
|
421 |
|
|
|
422 |
|
|
extern void cma__open_general (int);
|
423 |
|
|
|
424 |
|
|
extern void cma__reinit_thread_io (int);
|
425 |
|
|
|
426 |
|
|
extern void cma__set_nonblocking (int);
|
427 |
|
|
|
428 |
|
|
extern void cma__set_user_nonblock_flags (int,int);
|
429 |
|
|
|
430 |
|
|
extern cma_t_boolean cma__is_open (int);
|
431 |
|
|
|
432 |
|
|
#endif
|