2fe8fb192f
There is important information about booting non-ack images in docs/UPDATING. ack/aout-format images can't be built any more, and booting clang/ELF-format ones is a little different. Updating to the new boot monitor is recommended. Changes in this commit: . drop boot monitor -> allowing dropping ack support . facility to copy ELF boot files to /boot so that old boot monitor can still boot fairly easily, see UPDATING . no more ack-format libraries -> single-case libraries . some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases . drop several ack toolchain commands, but not all support commands (e.g. aal is gone but acksize is not yet). . a few libc files moved to netbsd libc dir . new /bin/date as minix date used code in libc/ . test compile fix . harmonize includes . /usr/lib is no longer special: without ack, /usr/lib plays no kind of special bootstrapping role any more and bootstrapping is done exclusively through packages, so releases depend even less on the state of the machine making them now. . rename nbsd_lib* to lib* . reduce mtree
61 lines
1.5 KiB
C
61 lines
1.5 KiB
C
/* asyn_read() Author: Kees J. Bot
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* 7 Jul 1997
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*/
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#include "asyn.h"
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#include <signal.h>
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ssize_t asyn_read(asynchio_t *asyn, int fd, void *buf, size_t len)
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/* Asynchronous read(). Try if a read can be done, if not then set a flag
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* indicating that select(2) should look out for it. Returns like a normal
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* read or returns -1 with errno set to EAGAIN.
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*/
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{
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asynfd_t *afd;
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/* Asyn_wait() may block if this counter equals zero indicating that
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* all of the asyn_* functions are "in progress".
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*/
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asyn->asyn_more++;
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if ((unsigned) fd >= FD_SETSIZE) { errno= EBADF; return -1; }
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afd= &asyn->asyn_afd[fd];
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/* If this is the first async call on this filedescriptor then
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* remember its file flags.
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*/
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if (!afd->afd_seen) {
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if ((afd->afd_flags= fcntl(fd, F_GETFL)) < 0) return -1;
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afd->afd_seen= 1;
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}
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/* Try to read if I/O is pending. */
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if (afd->afd_state[SEL_READ] == PENDING) {
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sigset_t mask;
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ssize_t result;
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int err;
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sigemptyset(&mask);
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if (sigprocmask(SIG_SETMASK, &mask, &mask) < 0) return -1;
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(void) fcntl(fd, F_SETFL, afd->afd_flags | O_NONBLOCK);
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/* Try the actual read. */
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result= read(fd, buf, len);
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err= errno;
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(void) fcntl(fd, F_SETFL, afd->afd_flags);
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(void) sigprocmask(SIG_SETMASK, &mask, nil);
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errno= err;
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if (result != -1 || errno != EAGAIN) {
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afd->afd_state[SEL_READ]= IDLE;
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return result;
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}
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}
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/* Record this read as "waiting". */
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afd->afd_state[SEL_READ]= WAITING;
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FD_SET(fd, &asyn->asyn_fdset[SEL_READ]);
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errno= EAGAIN;
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asyn->asyn_more--;
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return -1;
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}
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