458 lines
13 KiB
C
458 lines
13 KiB
C
|
/*
|
|||
|
|
* (c) Copyright 1990-1996 OPEN SOFTWARE FOUNDATION, INC.
|
|||
|
|
* (c) Copyright 1990-1996 HEWLETT-PACKARD COMPANY
|
|||
|
|
* (c) Copyright 1990-1996 DIGITAL EQUIPMENT CORPORATION
|
|||
|
|
* (c) Copyright 1991, 1992 Siemens-Nixdorf Information Systems
|
|||
|
|
* To anyone who acknowledges that this file is provided "AS IS" without
|
|||
|
|
* any express or implied warranty: permission to use, copy, modify, and
|
|||
|
|
* distribute this file for any purpose is hereby granted without fee,
|
|||
|
|
* provided that the above copyright notices and this notice appears in
|
|||
|
|
* all source code copies, and that none of the names listed above be used
|
|||
|
|
* in advertising or publicity pertaining to distribution of the software
|
|||
|
|
* without specific, written prior permission. None of these organizations
|
|||
|
|
* makes any representations about the suitability of this software for
|
|||
|
|
* any purpose.
|
|||
|
|
*/
|
|||
|
|
/*
|
|||
|
|
* Header file for thread synchrounous I/O
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#ifndef CMA_THREAD_IO
|
|||
|
|
#define CMA_THREAD_IO
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* INCLUDE FILES
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#include <cma_config.h>
|
|||
|
|
#include <sys/file.h>
|
|||
|
|
#include <cma.h>
|
|||
|
|
#include <sys/types.h>
|
|||
|
|
#include <sys/time.h>
|
|||
|
|
#include <cma_init.h>
|
|||
|
|
#include <cma_errors.h>
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* CONSTANTS
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Define symbols which indicate whether to compile code for obsolete
|
|||
|
|
* "non-blocking mode" flags: FNDELAY and FNBLOCK. If the obsolete
|
|||
|
|
* symbols are defined, and if their replacement symbols are defined
|
|||
|
|
* and are different or if they are undefined, then define a symbol
|
|||
|
|
* that says to compile the code in; otherwise no code will be compiled
|
|||
|
|
* for these obsolete symbols.
|
|||
|
|
*/
|
|||
|
|
#ifdef FNDELAY
|
|||
|
|
# ifdef O_NDELAY
|
|||
|
|
# if O_NDELAY != FNDELAY
|
|||
|
|
# define _CMA_FNDELAY_
|
|||
|
|
# endif
|
|||
|
|
# else
|
|||
|
|
# define _CMA_FNDELAY_
|
|||
|
|
# endif
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
#ifdef FNBLOCK
|
|||
|
|
# ifdef O_NONBLOCK
|
|||
|
|
# if O_NONBLOCK != FNBLOCK
|
|||
|
|
# define _CMA_FNBLOCK_
|
|||
|
|
# endif
|
|||
|
|
# else
|
|||
|
|
# define _CMA_FNBLOCK_
|
|||
|
|
# endif
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
|
|||
|
|
extern cma_t_boolean cma_is_open(int);
|
|||
|
|
/*
|
|||
|
|
* Maximum number of files (ie, max_fd+1)
|
|||
|
|
*/
|
|||
|
|
#define cma__c_mx_file FD_SETSIZE
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Number of bits per file descriptor bit mask (ie number of bytes * bits/byte)
|
|||
|
|
*/
|
|||
|
|
#define cma__c_nbpm NFDBITS
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* TYPE DEFINITIONS
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
typedef enum CMA__T_IO_TYPE {
|
|||
|
|
cma__c_io_read = 0,
|
|||
|
|
cma__c_io_write = 1,
|
|||
|
|
cma__c_io_except = 2
|
|||
|
|
} cma__t_io_type;
|
|||
|
|
#define cma__c_max_io_type 2
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* From our local <sys/types.h>:
|
|||
|
|
*
|
|||
|
|
* typedef long fd_mask;
|
|||
|
|
*
|
|||
|
|
* typedef struct fd_set {
|
|||
|
|
* fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
|
|||
|
|
* } fd_set;
|
|||
|
|
*
|
|||
|
|
*/
|
|||
|
|
typedef fd_mask cma__t_mask;
|
|||
|
|
typedef fd_set cma__t_file_mask;
|
|||
|
|
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* GLOBAL DATA
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Maximum number of files (ie, max_fd+1) as determined by getdtablesize().
|
|||
|
|
*/
|
|||
|
|
extern int cma__g_mx_file;
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Number of submasks (ie "int" sized chunks) per file descriptor mask as
|
|||
|
|
* determined by getdtablesize().
|
|||
|
|
*/
|
|||
|
|
extern int cma__g_nspm;
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* MACROS
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Define a constant for the errno value which indicates that the requested
|
|||
|
|
* operation was not performed because it would block the process.
|
|||
|
|
*/
|
|||
|
|
# define cma__is_blocking(s) \
|
|||
|
|
((s == EAGAIN) || (s == EWOULDBLOCK) || (s == EINPROGRESS) || \
|
|||
|
|
(s == EALREADY) || (s == EDEADLK))
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* It is necessary to issue an I/O function, before calling cma__io_wait()
|
|||
|
|
* in the following cases:
|
|||
|
|
*
|
|||
|
|
* * This file descriptor has been set non-blocking by CMA
|
|||
|
|
* * This file descriptor has been set non-blocking by the user.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define cma__issue_io_call(fd) \
|
|||
|
|
( (cma__g_file[fd]->non_blocking) || \
|
|||
|
|
(cma__g_file[fd]->user_fl.user_non_blocking) )
|
|||
|
|
|
|||
|
|
|
|||
|
|
#define cma__set_user_nonblocking(flags) \
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Determine if the file is open
|
|||
|
|
*/
|
|||
|
|
/*
|
|||
|
|
* If the file gets closed while waiting for the mutex cma__g_file[rfd]
|
|||
|
|
* gets set to null. This results in a crash if NDEBUG is set to 0
|
|||
|
|
* since cma__int_lock tries to dereference it to set the mutex ownership
|
|||
|
|
* after it gets the mutex. The following will still set the ownership
|
|||
|
|
* in cma__int_lock so we'll set it back to noone if cma__g_file is null
|
|||
|
|
* when we come back just in case it matters. It shouldn't since its no
|
|||
|
|
* longer in use but.....
|
|||
|
|
* Callers of this should recheck cma__g_file after the reservation to
|
|||
|
|
* make sure continueing makes sense.
|
|||
|
|
*/
|
|||
|
|
#define cma__fd_reserve(rfd) \
|
|||
|
|
{ \
|
|||
|
|
cma__t_int_mutex *__mutex__; \
|
|||
|
|
__mutex__ = cma__g_file[rfd]->mutex; \
|
|||
|
|
cma__int_lock (__mutex__); \
|
|||
|
|
if(cma__g_file[rfd] == (cma__t_file_obj *)cma_c_null_ptr) \
|
|||
|
|
cma__int_unlock(__mutex__); \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Unreserve a file descriptor
|
|||
|
|
*/
|
|||
|
|
#define cma__fd_unreserve(ufd) cma__int_unlock (cma__g_file[ufd]->mutex)
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* AND together two select file descriptor masks
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_and(target,a,b) \
|
|||
|
|
{ \
|
|||
|
|
int __i__ = cma__g_nspm; \
|
|||
|
|
while (__i__--) \
|
|||
|
|
(target)->fds_bits[__i__] = \
|
|||
|
|
(a)->fds_bits[__i__] & (b)->fds_bits[__i__]; \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Clear a bit in a select file descriptor mask
|
|||
|
|
*
|
|||
|
|
* FD_CLR(n, p) := ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_clr_bit(n,p) FD_CLR (n, p)
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Copy the contents of one file descriptor mask into another. If the
|
|||
|
|
* destination operand is null, do nothing; if the source operand is null,
|
|||
|
|
* simply zero the destination.
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_copy(src,dst,nfds) { \
|
|||
|
|
if (dst) \
|
|||
|
|
if (src) { \
|
|||
|
|
cma__t_mask *__s__ = (cma__t_mask *)(src); \
|
|||
|
|
cma__t_mask *__d__ = (cma__t_mask *)(dst); \
|
|||
|
|
int __i__; \
|
|||
|
|
for (__i__ = 0; __i__ < (nfds); __i__ += cma__c_nbpm) \
|
|||
|
|
*__d__++ = *__s__++; \
|
|||
|
|
} \
|
|||
|
|
else \
|
|||
|
|
cma__fdm_zero (dst); \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* To increment count for each bit set in fd - mask
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_count_bits(map,count) \
|
|||
|
|
{ \
|
|||
|
|
int __i__ = cma__g_nspm; \
|
|||
|
|
while (__i__--) { \
|
|||
|
|
cma__t_mask __tm__; \
|
|||
|
|
__tm__ = (map)->fds_bits[__i__]; \
|
|||
|
|
while(__tm__) { \
|
|||
|
|
(count)++; \
|
|||
|
|
__tm__ &= ~(__tm__ & (-__tm__)); /* Assumes 2's comp */ \
|
|||
|
|
} \
|
|||
|
|
} \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Test if a bit is set in a select file descriptor mask
|
|||
|
|
*
|
|||
|
|
* FD_ISSET(n,p) := ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_is_set(n,p) FD_ISSET (n, p)
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* OR together two select file descriptor masks
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_or(target,a,b) \
|
|||
|
|
{ \
|
|||
|
|
int __i__ = cma__g_nspm; \
|
|||
|
|
while (__i__--) \
|
|||
|
|
(target)->fds_bits[__i__] = \
|
|||
|
|
(a)->fds_bits[__i__] | (b)->fds_bits[__i__]; \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Set a bit in a select file descriptor mask
|
|||
|
|
*
|
|||
|
|
* FD_SET(n,p) := ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_set_bit(n,p) FD_SET (n, p)
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Clear a select file descriptor mask.
|
|||
|
|
*/
|
|||
|
|
#define cma__fdm_zero(n) \
|
|||
|
|
cma__memset ((char *) n, 0, cma__g_nspm * sizeof(cma__t_mask))
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* CMA "thread-synchronous" I/O read/write operations
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Since all CMA "thread-synchronous" I/O (read or write) operations on
|
|||
|
|
* U*ix follow the exact same structure, the wrapper routines have been
|
|||
|
|
* condensed into a macro.
|
|||
|
|
*
|
|||
|
|
* The steps performed are as follows:
|
|||
|
|
* 1. Check that the file descriptor is a legitimate value.
|
|||
|
|
* 2. Check that the entry in the CMA file "database" which corresponds to
|
|||
|
|
* the file descriptor indicates that the "file" was "opened" by CMA.
|
|||
|
|
* 3. Reserve the file, to serialized access to files. This not only
|
|||
|
|
* simplifies things, but also defends against non-reentrancy.
|
|||
|
|
* 4. If the "file" is "set" for non-blocking I/O, check if we
|
|||
|
|
* have actually set the file non-blocking yet, and if not do so.
|
|||
|
|
* Then, issue the I/O operantion.
|
|||
|
|
* Success or failure is returned immediately, after unreserving the
|
|||
|
|
* file. If the error indicates that the operation would have caused
|
|||
|
|
* the process to block, continue to the next step.
|
|||
|
|
* 5. The I/O prolog adds this "file" to the global bit mask, which
|
|||
|
|
* represents all "files" which have threads waiting to perform I/O on
|
|||
|
|
* them, and causes the thread to block on the condition variable for
|
|||
|
|
* this "file". Periodically, a select is done on this global bit
|
|||
|
|
* mask, and the condition variables corresponding to "files" which
|
|||
|
|
* are ready for I/O are signaled, releasing those waiting threads to
|
|||
|
|
* perform their I/O.
|
|||
|
|
* 6. When the thread returns from the I/O prolog, it can (hopefully)
|
|||
|
|
* perform its operation without blocking the process.
|
|||
|
|
* 7. The I/O epilog clears the bit in the global mask and/or signals the
|
|||
|
|
* the next thread waiting for this "file", as appropriate.
|
|||
|
|
* 8. If the I/O failed, continue to loop.
|
|||
|
|
* 9. Finally, the "file" is unreserved, as we're done with it, and the
|
|||
|
|
* result of the operation is returned.
|
|||
|
|
*
|
|||
|
|
*
|
|||
|
|
* Note: currently, we believe that timeslicing which is based on the
|
|||
|
|
* virtual-time timer does not cause system calls to return EINTR.
|
|||
|
|
* Threfore, any EINTR returns are relayed directly to the caller.
|
|||
|
|
* On platforms which do not support a virtual-time timer, the code
|
|||
|
|
* should probably catch EINTR returns and restart the system call.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* This macro is used for both read-type and write-type functions.
|
|||
|
|
*
|
|||
|
|
* Note: the second call to "func" may require being bracketed in a
|
|||
|
|
* cma__interrupt_disable/cma__interrupt_enable pair, but we'll
|
|||
|
|
* wait and see if this is necessary.
|
|||
|
|
*/
|
|||
|
|
#define cma__ts_func(func,fd,arglist,type,post_process) { \
|
|||
|
|
cma_t_integer __res__; \
|
|||
|
|
cma_t_boolean __done__ = cma_c_false; \
|
|||
|
|
if ((fd < 0) || (fd >= cma__g_mx_file)) return (cma__set_errno (EBADF), -1); \
|
|||
|
|
if (!cma__is_open(fd)) return (cma__set_errno (EBADF), -1); \
|
|||
|
|
cma__fd_reserve (fd); \
|
|||
|
|
if (!cma__is_open(fd)) return (cma__set_errno (EBADF), -1); \
|
|||
|
|
if (cma__issue_io_call(fd)) {\
|
|||
|
|
if ((!cma__g_file[fd]->set_non_blocking) && \
|
|||
|
|
(cma__g_file[fd]->non_blocking == cma_c_true)) \
|
|||
|
|
cma__set_nonblocking(fd); \
|
|||
|
|
cma__interrupt_disable (0); \
|
|||
|
|
TRY { \
|
|||
|
|
__res__ = func arglist; \
|
|||
|
|
} \
|
|||
|
|
CATCH_ALL { \
|
|||
|
|
cma__interrupt_enable (0); \
|
|||
|
|
cma__fd_unreserve (fd); \
|
|||
|
|
RERAISE; \
|
|||
|
|
} \
|
|||
|
|
ENDTRY \
|
|||
|
|
cma__interrupt_enable (0); \
|
|||
|
|
if ((__res__ != -1) \
|
|||
|
|
|| (!cma__is_blocking (errno)) \
|
|||
|
|
|| (cma__g_file[fd]->user_fl.user_non_blocking)) \
|
|||
|
|
__done__ = cma_c_true; \
|
|||
|
|
} \
|
|||
|
|
if (__done__) { \
|
|||
|
|
cma__fd_unreserve (fd); \
|
|||
|
|
} \
|
|||
|
|
else { \
|
|||
|
|
TRY { \
|
|||
|
|
cma__io_prolog (type, fd); \
|
|||
|
|
while (!__done__) { \
|
|||
|
|
cma__io_wait (type, fd); \
|
|||
|
|
__res__ = func arglist; \
|
|||
|
|
if ((__res__ != -1) \
|
|||
|
|
|| (!cma__is_blocking (errno)) \
|
|||
|
|
|| (cma__g_file[fd]->user_fl.user_non_blocking)) \
|
|||
|
|
__done__ = cma_c_true; \
|
|||
|
|
} \
|
|||
|
|
} \
|
|||
|
|
FINALLY { \
|
|||
|
|
cma__io_epilog (type, fd); \
|
|||
|
|
cma__fd_unreserve (fd); \
|
|||
|
|
} \
|
|||
|
|
ENDTRY \
|
|||
|
|
} \
|
|||
|
|
if (__res__ != -1) post_process; \
|
|||
|
|
return __res__; \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Since most CMA "thread-synchronous" I/O ("open"-type) operations on
|
|||
|
|
* U*ix follow the exact same structure, the wrapper routines have been
|
|||
|
|
* condensed into a macro.
|
|||
|
|
*
|
|||
|
|
* The steps performed are as follows:
|
|||
|
|
* 1. Issue the open function.
|
|||
|
|
* 2. If the value returned indicates an error, return it to the caller.
|
|||
|
|
* 3. If the file descriptor returned is larger than what we think is the
|
|||
|
|
* maximum value (ie if it is too big for our database) then bugcheck.
|
|||
|
|
* 4. "Open" the "file" in the CMA file database.
|
|||
|
|
* 5. Return the file descriptor value to the caller.
|
|||
|
|
*
|
|||
|
|
* FIX-ME: for the time being, if the I/O operation returns EINTR, we
|
|||
|
|
* simply return it to the caller; eventually, we should catch this
|
|||
|
|
* and "do the right thing" (if we can figure out what that is).
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* This macro is used for all "open"-type functions which return a single file
|
|||
|
|
* desciptor by immediate value.
|
|||
|
|
*/
|
|||
|
|
#define cma__ts_open(func,arglist,post_process) { \
|
|||
|
|
int __fd__; \
|
|||
|
|
TRY { \
|
|||
|
|
cma__int_init (); \
|
|||
|
|
cma__int_lock (cma__g_io_data_mutex); \
|
|||
|
|
__fd__ = func arglist; \
|
|||
|
|
cma__int_unlock (cma__g_io_data_mutex); \
|
|||
|
|
if (__fd__ >= 0 && __fd__ < cma__g_mx_file) \
|
|||
|
|
post_process; \
|
|||
|
|
} \
|
|||
|
|
CATCH_ALL \
|
|||
|
|
{ \
|
|||
|
|
cma__set_errno (EBADF); \
|
|||
|
|
__fd__ = -1; \
|
|||
|
|
} \
|
|||
|
|
ENDTRY \
|
|||
|
|
if (__fd__ >= cma__g_mx_file) \
|
|||
|
|
cma__bugcheck ("cma__ts_open: fd is too large"); \
|
|||
|
|
return __fd__; \
|
|||
|
|
}
|
|||
|
|
/*
|
|||
|
|
* This macro is used for all "open"-type functions which return a pair of file
|
|||
|
|
* desciptors by reference parameter.
|
|||
|
|
*/
|
|||
|
|
#define cma__ts_open2(func,fdpair,arglist,post_process) { \
|
|||
|
|
int __res__; \
|
|||
|
|
TRY { \
|
|||
|
|
cma__int_init (); \
|
|||
|
|
cma__int_lock (cma__g_io_data_mutex); \
|
|||
|
|
__res__ = func arglist; \
|
|||
|
|
cma__int_unlock (cma__g_io_data_mutex); \
|
|||
|
|
if (__res__ >= 0 && fdpair[0] < cma__g_mx_file \
|
|||
|
|
&& fdpair[1] < cma__g_mx_file) \
|
|||
|
|
post_process; \
|
|||
|
|
} \
|
|||
|
|
CATCH_ALL \
|
|||
|
|
{ \
|
|||
|
|
cma__set_errno (EBADF); \
|
|||
|
|
__res__ = -1; \
|
|||
|
|
} \
|
|||
|
|
ENDTRY \
|
|||
|
|
if ((fdpair[0] >= cma__g_mx_file) || (fdpair[1] >= cma__g_mx_file)) \
|
|||
|
|
cma__bugcheck ("cma__ts_open2: one of fd's is too large"); \
|
|||
|
|
return __res__; \
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* INTERNAL INTERFACES
|
|||
|
|
*/
|
|||
|
|
extern void cma__close_general (int);
|
|||
|
|
|
|||
|
|
extern void cma__init_thread_io (void);
|
|||
|
|
|
|||
|
|
extern cma_t_boolean cma__io_available (cma__t_io_type,int,struct timeval *);
|
|||
|
|
|
|||
|
|
extern void cma__io_epilog (cma__t_io_type,int);
|
|||
|
|
|
|||
|
|
extern void cma__io_prolog (cma__t_io_type,int);
|
|||
|
|
|
|||
|
|
extern void cma__io_wait (cma__t_io_type,int);
|
|||
|
|
|
|||
|
|
extern void cma__open_general (int);
|
|||
|
|
|
|||
|
|
extern void cma__reinit_thread_io (int);
|
|||
|
|
|
|||
|
|
extern void cma__set_nonblocking (int);
|
|||
|
|
|
|||
|
|
extern void cma__set_user_nonblock_flags (int,int);
|
|||
|
|
|
|||
|
|
extern cma_t_boolean cma__is_open (int);
|
|||
|
|
|
|||
|
|
|
|||
|
|
#endif
|