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os_io.c
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os_io.c
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/* File: "os_io.c" */
/* Copyright (c) 1994-2012 by Marc Feeley, All Rights Reserved. */
/*
* This module implements the operating system specific routines
* related to I/O.
*/
#define ___INCLUDED_FROM_OS_IO
#define ___VERSION 406004
#include "gambit.h"
#include "os_base.h"
#include "os_io.h"
#include "os_tty.h"
#include "os_files.h"
#include "setup.h"
#include "c_intf.h"
/*---------------------------------------------------------------------------*/
___io_module ___io_mod =
{
0,
0
#ifdef ___IO_MODULE_INIT
___IO_MODULE_INIT
#endif
};
/*---------------------------------------------------------------------------*/
/* Device groups. */
___SCMOBJ ___device_group_setup
___P((___device_group **dgroup),
(dgroup)
___device_group **dgroup;)
{
___SCMOBJ e;
___device_group *g;
g = ___CAST(___device_group*,
___alloc_mem (sizeof (___device_group)));
if (g == NULL)
return ___FIX(___HEAP_OVERFLOW_ERR);
g->list = NULL;
*dgroup = g;
return ___FIX(___NO_ERR);
}
void ___device_group_cleanup
___P((___device_group *dgroup),
(dgroup)
___device_group *dgroup;)
{
while (dgroup->list != NULL)
if (___device_cleanup (dgroup->list) != ___FIX(___NO_ERR))
break;
___free_mem (dgroup);
}
void ___device_add_to_group
___P((___device_group *dgroup,
___device *dev),
(dgroup,
dev)
___device_group *dgroup;
___device *dev;)
{
___device *head = dgroup->list;
dev->group = dgroup;
if (head == NULL)
{
dev->next = dev;
dev->prev = dev;
dgroup->list = dev;
}
else
{
___device *tail = head->prev;
dev->next = head;
dev->prev = tail;
tail->next = dev;
head->prev = dev;
}
}
void ___device_remove_from_group
___P((___device *dev),
(dev)
___device *dev;)
{
___device_group *dgroup = dev->group;
___device *prev = dev->prev;
___device *next = dev->next;
if (prev == dev)
dgroup->list = NULL;
else
{
if (dgroup->list == dev)
dgroup->list = next;
prev->next = next;
next->prev = prev;
dev->next = dev;
dev->prev = dev;
}
dev->group = NULL;
}
___device_group *___global_device_group ___PVOID
{
return ___io_mod.dgroup;
}
/*---------------------------------------------------------------------------*/
/* Nonblocking pipes */
#ifdef USE_PUMPS
___HIDDEN ___SCMOBJ ___nonblocking_pipe_setup
___P((___nonblocking_pipe *pipe,
int size),
(pipe,
size)
___nonblocking_pipe *pipe;
int size;)
{
___U8 *buffer;
HANDLE mutex;
HANDLE revent;
HANDLE wevent;
buffer = ___CAST(___U8*,
___alloc_mem (size));
if (buffer == NULL)
return ___FIX(___HEAP_OVERFLOW_ERR);
mutex = CreateMutex (NULL, /* can't inherit */
FALSE, /* unlocked */
NULL); /* no name */
if (mutex == NULL)
{
___SCMOBJ e = err_code_from_GetLastError ();
___free_mem (buffer);
return e;
}
revent = CreateEvent (NULL, /* can't inherit */
TRUE, /* manual reset */
FALSE, /* not signaled */
NULL); /* no name */
if (revent == NULL)
{
___SCMOBJ e = err_code_from_GetLastError ();
CloseHandle (mutex); /* ignore error */
___free_mem (buffer);
return e;
}
wevent = CreateEvent (NULL, /* can't inherit */
TRUE, /* manual reset */
FALSE, /* not signaled */
NULL); /* no name */
if (wevent == NULL)
{
___SCMOBJ e = err_code_from_GetLastError ();
CloseHandle (revent); /* ignore error */
CloseHandle (mutex); /* ignore error */
___free_mem (buffer);
return e;
}
pipe->mutex = mutex;
pipe->revent = revent;
pipe->wevent = wevent;
pipe->rerr = ___FIX(___NO_ERR);
pipe->werr = ___FIX(___NO_ERR);
pipe->oob = 0;
pipe->rd = 0;
pipe->wr = 0;
pipe->size = size;
pipe->buffer = buffer;
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_cleanup
___P((___nonblocking_pipe *pipe),
(pipe)
___nonblocking_pipe *pipe;)
{
CloseHandle (pipe->wevent); /* ignore error */
CloseHandle (pipe->revent); /* ignore error */
CloseHandle (pipe->mutex); /* ignore error */
___free_mem (pipe->buffer);
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_set_reader_err
___P((___nonblocking_pipe *pipe,
___SCMOBJ err),
(pipe,
err)
___nonblocking_pipe *pipe;
___SCMOBJ err;)
{
if (WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
/* note: the reader error indicator may get overwritten */
pipe->rerr = err;
SetEvent (pipe->wevent); /* ignore error */
if (pipe->werr == ___FIX(___NO_ERR))
ResetEvent (pipe->revent); /* ignore error */
ReleaseMutex (pipe->mutex); /* ignore error */
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_set_writer_err
___P((___nonblocking_pipe *pipe,
___SCMOBJ err),
(pipe,
err)
___nonblocking_pipe *pipe;
___SCMOBJ err;)
{
if (WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
/* note: the writer error indicator may get overwritten */
pipe->werr = err;
SetEvent (pipe->revent); /* ignore error */
if (pipe->rerr == ___FIX(___NO_ERR))
ResetEvent (pipe->wevent); /* ignore error */
ReleaseMutex (pipe->mutex); /* ignore error */
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_write_oob
___P((___nonblocking_pipe *pipe,
___nonblocking_pipe_oob_msg *oob_msg),
(pipe,
oob_msg)
___nonblocking_pipe *pipe;
___nonblocking_pipe_oob_msg *oob_msg;)
{
if (WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
if (pipe->werr != ___FIX(___NO_ERR) || pipe->oob)
{
ReleaseMutex (pipe->mutex); /* ignore error */
return ___ERR_CODE_EAGAIN;
}
pipe->oob = 1;
pipe->oob_msg = *oob_msg;
if (pipe->rerr == ___FIX(___NO_ERR))
{
SetEvent (pipe->revent); /* ignore error */
ResetEvent (pipe->wevent); /* ignore error */
}
ReleaseMutex (pipe->mutex); /* ignore error */
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_read_ready_wait
___P((___nonblocking_pipe *pipe),
(pipe)
___nonblocking_pipe *pipe;)
{
___SCMOBJ werr;
if (WaitForSingleObject (pipe->revent, INFINITE) == WAIT_FAILED ||
WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
werr = pipe->werr;
if (werr != ___FIX(___NO_ERR))
{
pipe->werr = ___FIX(___NO_ERR);
if (pipe->rerr != ___FIX(___NO_ERR) ||
(pipe->rd == pipe->wr && !pipe->oob))
ResetEvent (pipe->revent); /* ignore error */
}
ReleaseMutex (pipe->mutex); /* ignore error */
return werr;
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_write_ready_wait
___P((___nonblocking_pipe *pipe),
(pipe)
___nonblocking_pipe *pipe;)
{
___SCMOBJ rerr;
if (WaitForSingleObject (pipe->wevent, INFINITE) == WAIT_FAILED ||
WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
rerr = pipe->rerr;
if (rerr != ___FIX(___NO_ERR))
{
pipe->rerr = ___FIX(___NO_ERR);
ResetEvent (pipe->wevent); /* ignore error */
}
ReleaseMutex (pipe->mutex); /* ignore error */
return rerr;
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_read
___P((___nonblocking_pipe *pipe,
___U8 *buf,
___stream_index len,
___stream_index *len_done,
___nonblocking_pipe_oob_msg *oob_msg),
(pipe,
buf,
len,
len_done,
oob_msg)
___nonblocking_pipe *pipe;
___U8 *buf;
___stream_index len;
___stream_index *len_done;
___nonblocking_pipe_oob_msg *oob_msg;)
{
___SCMOBJ rerr;
___SCMOBJ werr;
DWORD rd;
DWORD wr;
___U8 *p;
DWORD end;
DWORD n;
DWORD i;
if (len <= 0)
return ___FIX(___UNKNOWN_ERR);
if (WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
rerr = pipe->rerr;
werr = pipe->werr;
rd = pipe->rd;
wr = pipe->wr;
if (rerr != ___FIX(___NO_ERR))
{
/* there is a reader error */
if (werr == ___FIX(___NO_ERR))
werr = ___ERR_CODE_EAGAIN;
else
{
pipe->werr = ___FIX(___NO_ERR);
ResetEvent (pipe->revent); /* ignore error */
}
ReleaseMutex (pipe->mutex); /* ignore error */
return werr;
}
/* there is no reader error */
if (rd == wr)
{
/* no bytes in FIFO buffer */
if (pipe->oob)
{
/* out-of-band present */
*oob_msg = pipe->oob_msg;
pipe->oob = 0;
if (werr == ___FIX(___NO_ERR))
{
ResetEvent (pipe->revent); /* ignore error */
#if 0
/******************zzzzzzzzzzzzzz****/
SetEvent (pipe->wevent); /* ignore error */
#endif
}
ReleaseMutex (pipe->mutex); /* ignore error */
*len_done = 0;
return ___FIX(___NO_ERR);
}
/* out-of-band not present */
if (werr != ___FIX(___NO_ERR))
{
/* there is a writer error */
pipe->werr = ___FIX(___NO_ERR);
ResetEvent (pipe->revent); /* ignore error */
ReleaseMutex (pipe->mutex); /* ignore error */
return werr;
}
/* there is no writer error */
SetEvent (pipe->wevent); /* ignore error */
ReleaseMutex (pipe->mutex); /* ignore error */
return ___ERR_CODE_EAGAIN;
}
/* at least one byte in FIFO buffer */
end = pipe->size - rd; /* number of bytes from rd to end */
n = wr + end; /* number of bytes available */
if (n >= pipe->size)
n -= pipe->size;
if (n > ___CAST(DWORD,len)) /* don't transfer more than len */
n = len;
*len_done = n;
p = pipe->buffer + rd; /* prepare transfer source */
rd = rd + n;
if (rd >= pipe->size)
rd -= pipe->size;
pipe->rd = rd;
if (werr == ___FIX(___NO_ERR) && !pipe->oob)
{
/* there is no writer error and out-of-band not present */
if (rd == wr) /* the FIFO will be empty? */
ResetEvent (pipe->revent); /* ignore error */
/* the FIFO will not be full */
SetEvent (pipe->wevent); /* ignore error */
}
if (n <= end)
{
/* only need to transfer n bytes starting from original rd */
for (i=n; i>0; i--)
*buf++ = *p++;
}
else
{
/* need to transfer end bytes starting from original rd */
for (i=end; i>0; i--)
*buf++ = *p++;
/* and to transfer n-end bytes starting from 0 */
p = pipe->buffer;
for (i=n-end; i>0; i--)
*buf++ = *p++;
}
ReleaseMutex (pipe->mutex); /* ignore error */
return ___FIX(___NO_ERR);
}
___HIDDEN ___SCMOBJ ___nonblocking_pipe_write
___P((___nonblocking_pipe *pipe,
___U8 *buf,
___stream_index len,
___stream_index *len_done),
(pipe,
buf,
len,
len_done)
___nonblocking_pipe *pipe;
___U8 *buf;
___stream_index len;
___stream_index *len_done;)
{
___SCMOBJ rerr;
___SCMOBJ werr;
DWORD rd;
DWORD wr;
___U8 *p;
DWORD end;
DWORD n;
DWORD i;
if (len <= 0)
return ___FIX(___UNKNOWN_ERR);
if (WaitForSingleObject (pipe->mutex, INFINITE) == WAIT_FAILED)
return err_code_from_GetLastError ();
rerr = pipe->rerr;
werr = pipe->werr;
rd = pipe->rd;
wr = pipe->wr;
if (werr != ___FIX(___NO_ERR))
{
/* there is a writer error */
if (rerr == ___FIX(___NO_ERR))
rerr = ___ERR_CODE_EAGAIN;
else
{
pipe->rerr = ___FIX(___NO_ERR);
ResetEvent (pipe->wevent); /* ignore error */
}
ReleaseMutex (pipe->mutex); /* ignore error */
return rerr;
}
/* there is no writer error */
if (rerr != ___FIX(___NO_ERR))
{
/* there is a reader error */
pipe->rerr = ___FIX(___NO_ERR);
if (rd != wr || pipe->oob) /* FIFO is not empty */
SetEvent (pipe->revent); /* ignore error */
ResetEvent (pipe->wevent); /* ignore error */
ReleaseMutex (pipe->mutex); /* ignore error */
return rerr;
}
/* there is no reader error */
if (wr + 1 - rd == 0 || wr + 1 - rd == pipe->size || pipe->oob)
{
/* FIFO buffer is full or out-of-band present */
ReleaseMutex (pipe->mutex); /* ignore error */
return ___ERR_CODE_EAGAIN;
}
/* FIFO buffer is not full and out-of-band not present */
end = pipe->size - wr; /* number of bytes from wr to end */
n = rd + end - 1; /* number of bytes available */
if (n >= pipe->size)
n -= pipe->size;
if (n > ___CAST(DWORD,len)) /* don't transfer more than len */
n = len;
*len_done = n;
p = pipe->buffer + wr; /* prepare transfer source */
wr = wr + n;
if (wr >= pipe->size)
wr -= pipe->size;
pipe->wr = wr;
if (wr + 1 - rd == 0 || wr + 1 - rd == pipe->size) /* FIFO will be full? */
ResetEvent (pipe->wevent); /* ignore error */
/* FIFO will not be empty */
SetEvent (pipe->revent); /* ignore error */
if (n <= end)
{
/* only need to transfer n bytes starting from original wr */
for (i=n; i>0; i--)
*p++ = *buf++;
}
else
{
/* need to transfer end bytes starting from original wr */
for (i=end; i>0; i--)
*p++ = *buf++;
/* and to transfer n-end bytes starting from 0 */
p = pipe->buffer;
for (i=n-end; i>0; i--)
*p++ = *buf++;
}
ReleaseMutex (pipe->mutex); /* ignore error */
return ___FIX(___NO_ERR);
}
#endif
/*---------------------------------------------------------------------------*/
/* Operations on I/O devices. */
/* Miscellaneous utility functions. */
#ifdef USE_POSIX
#ifdef USE_sigaction
typedef sigset_t sigset_type;
#else
typedef int sigset_type;
#endif
___HIDDEN sigset_type block_signal
___P((int signum),
(signum)
int signum;)
{
sigset_type oldmask;
#ifdef USE_sigaction
sigset_type toblock;
sigemptyset (&toblock);
sigaddset (&toblock, signum);
sigprocmask (SIG_BLOCK, &toblock, &oldmask);
#endif
#ifdef USE_signal
oldmask = sigblock (sigmask (signum));
#endif
return oldmask;
}
___HIDDEN void restore_sigmask
___P((sigset_type oldmask),
(oldmask)
sigset_type oldmask;)
{
#ifdef USE_sigaction
sigprocmask (SIG_SETMASK, &oldmask, 0);
#endif
#ifdef USE_signal
sigsetmask (oldmask);
#endif
}
/*
* Some system calls can be interrupted by a signal and fail with
* errno == EINTR. The following functions are wrappers for system
* calls which may be interrupted. They simply ignore the EINTR and
* retry the operation.
*
* TODO: add wrappers for all the system calls which can fail
* with EINTR. Also, move these functions to a central place.
*/
pid_t waitpid_no_EINTR
___P((pid_t pid,
int *stat_loc,
int options),
(pid,
stat_loc,
options)
pid_t pid;
int *stat_loc;
int options;)
{
pid_t result;
for (;;)
{
result = waitpid (pid, stat_loc, options);
if (result >= 0 || errno != EINTR)
break;
}
return result;
}
ssize_t read_no_EINTR
___P((int fd,
void *buf,
size_t len),
(fd,
buf,
len)
int fd;
void *buf;
size_t len;)
{
char *p = ___CAST(char*,buf);
ssize_t result = 0;
int n;
while (result < len)
{
n = read (fd, p+result, len-result);
if (n > 0)
result += n;
else if (n == 0)
break;
else if (errno != EINTR)
return n; /* this forgets that some bytes were transferred */
}
return result;
}
int close_no_EINTR
___P((int fd),
(fd)
int fd;)
{
int result;
for (;;)
{
result = close (fd);
if (result >= 0 || errno != EINTR)
break;
}
return result;
}
int dup_no_EINTR
___P((int fd),
(fd)
int fd;)
{
int result;
for (;;)
{
result = dup (fd);
if (result >= 0 || errno != EINTR)
break;
}
return result;
}
int dup2_no_EINTR
___P((int fd,
int fd2),
(fd,
fd2)
int fd;
int fd2;)
{
int result;
for (;;)
{
result = dup2 (fd, fd2);
if (result >= 0 || errno != EINTR)
break;
}
return result;
}
int set_fd_blocking_mode
___P((int fd,
___BOOL blocking),
(fd,
blocking)
int fd;
___BOOL blocking;)
{
int fl;
if ((fl = fcntl (fd, F_GETFL, 0)) >= 0)
fl = fcntl (fd,
F_SETFL,
blocking ? (fl & ~O_NONBLOCK) : (fl | O_NONBLOCK));
return fl;
}
#endif
/*---------------------------------------------------------------------------*/
/* Generic device operations. */
___SCMOBJ ___device_select
___P((___device **devs,
int nb_read_devs,
int nb_write_devs,
___time timeout),
(devs,
nb_read_devs,
nb_write_devs,
timeout)
___device **devs;
int nb_read_devs;
int nb_write_devs;
___time timeout;)
{
int nb_devs;
___device_select_state state;
int pass;
int dev_list;
int i;
int prev;
___time delta;
nb_devs = nb_read_devs + nb_write_devs;
state.devs = devs;
state.timeout = timeout;
state.relative_timeout = POS_INFINITY;
#ifdef USE_select
state.highest_fd_plus_1 = 0;
FD_ZERO(&state.readfds);
FD_ZERO(&state.writefds);
FD_ZERO(&state.exceptfds);
#endif
#ifdef USE_MsgWaitForMultipleObjects
state.message_queue_mask = 0;
state.message_queue_dev_pos = -1;
state.wait_objs_buffer[0] = ___io_mod.abort_select;
state.wait_objs_buffer[1] = ___time_mod.heartbeat_thread;
state.nb_wait_objs = 2;
#endif
if (nb_devs > 0)
{
state.devs_next[nb_devs-1] = -1;
for (i=nb_devs-2; i>=0; i--)
state.devs_next[i] = i+1;
dev_list = 0;
}
else
dev_list = -1;
pass = ___SELECT_PASS_1;
while (dev_list != -1)
{
i = dev_list;
prev = -1;
while (i != -1)
{
___SCMOBJ e;
___device *d = devs[i];
if ((e = ___device_select_virt
(d,
i>=nb_read_devs,
i,
pass,
&state))
== ___FIX(___NO_ERR))
{
prev = i;
i = state.devs_next[i];
}
else
{
int j;
if (e != ___FIX(___SELECT_SETUP_DONE))
return e;
j = state.devs_next[i];
if (prev == -1)
dev_list = j;
else
state.devs_next[prev] = j;
#ifdef USE_MsgWaitForMultipleObjects
state.devs_next[i] = -1;
#endif
i = j;
}
}
pass++;
}
___absolute_time_to_relative_time (state.timeout, &delta);
if (___time_less (state.relative_timeout, delta))
{
delta = state.relative_timeout;
state.timeout = ___time_mod.time_neg_infinity;
}
else
state.relative_timeout = NEG_INFINITY;
#ifdef USE_select
{
struct timeval delta_tv_struct;
struct timeval *delta_tv = &delta_tv_struct;
int result;
___absolute_time_to_nonnegative_timeval (delta, &delta_tv);
if (delta_tv != NULL &&
state.highest_fd_plus_1 == 0)
{
/*
* ___device_select is only being called for sleeping until a
* certain timeout or interrupt occurs. This is a case that
* can be optimized.
*/
if (delta_tv->tv_sec < 0 ||
(delta_tv->tv_sec == 0 &&
delta_tv->tv_usec == 0))
{
/*
* The timeout has already passed, so we don't need to
* sleep. This simple optimization avoids doing a system
* call to the select or nanosleep functions (which can be
* expensive on some operating systems).
*/
result = 0;
goto select_done;