X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=stdin.c;h=a66ad469c2d648a875d4e8f1ce6917606a18967d;hp=cecdcb77521964b7303423f564d04117233a3d1b;hb=b0d2b25210ac347ab95dfa176d133f6629f0b123;hpb=2290d9be0703d3f83f38c2f100b1b41ec0790bb3 diff --git a/stdin.c b/stdin.c index cecdcb77..a66ad469 100644 --- a/stdin.c +++ b/stdin.c @@ -1,48 +1,120 @@ +/* + * Copyright (C) 2006-2014 Andre Noll + * + * Licensed under the GPL v2. For licencing details see COPYING. + */ + +/** \file stdin.c Functions that deal with reading from stdin. */ + +#include +#include + #include "para.h" -#include "string.h" #include "list.h" #include "sched.h" #include "fd.h" #include "error.h" #include "stdin.h" +#include "buffer_tree.h" +#include "string.h" -void stdin_pre_select(struct sched *s, struct task *t) +/* + * If there is space left in the buffer of the stdin task add STDIN_FILENO to + * the read fd set of s. + */ +static void stdin_pre_select(struct sched *s, void *context) { - struct stdin_task *sit = t->private_data; - if (sit->loaded < sit->bufsize) - para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); - t->ret = 1; /* success */ + struct stdin_task *sit = context; + int ret; + + ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); + if (ret < 0) + sched_min_delay(s); + if (ret <= 0) + return; + if (btr_pool_unused(sit->btrp) > 0) + return para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); + sched_request_timeout_ms(100, s); } -void stdin_post_select(struct sched *s, struct task *t) +/* + * This function checks if STDIN_FILENO was included by in the read fd set of s + * during the previous pre_select call. If so, and if STDIN_FILENO is readable, + * data is read from stdin and fed into the buffer tree. + */ +static int stdin_post_select(struct sched *s, void *context) { - struct stdin_task *sit = t->private_data; + struct stdin_task *sit = context; ssize_t ret; + size_t sz, n; + char *buf = NULL; - t->ret = 1; - if (sit->loaded >= sit->bufsize) - return; - if (!FD_ISSET(STDIN_FILENO, &s->rfds)) - return; - ret = read(STDIN_FILENO, sit->buf + sit->loaded, sit->bufsize - sit->loaded); + ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); if (ret < 0) - t->ret = -E_STDIN_READ; - else { - sit->loaded += ret; - t->ret = ret; + goto err; + if (ret == 0) + return 0; + sz = btr_pool_get_buffer(sit->btrp, &buf); + if (sz == 0) + return 0; + if (sit->must_set_nonblock_flag) { + ret = mark_fd_nonblocking(STDIN_FILENO); + if (ret < 0) + goto err; + sit->must_set_nonblock_flag = false; } - sprintf(t->status, - "%p stdin reader: loaded = %d, ret = %d", - sit, sit->loaded, t->ret); + /* + * Do not use the maximal size to avoid having only a single buffer + * reference for the whole pool. This is bad because if that single + * reference can not be freed, we're stuck. + */ + sz = PARA_MIN(sz, btr_pool_size(sit->btrp) / 2); + ret = read_nonblock(STDIN_FILENO, buf, sz, &s->rfds, &n); + if (n > 0) + btr_add_output_pool(sit->btrp, n, sit->btrn); + if (ret >= 0) + return 0; +err: + btr_remove_node(&sit->btrn); + /* Revert to blocking mode if necessary. */ + fcntl(STDIN_FILENO, F_SETFL, sit->fd_flags); + //btr_pool_free(sit->btrp); + return ret; } -#if 0 -void stdin_init(struct stdin_task *sit) +/** + * Register a stdin task structure. + * + * \param sit The stdin task structure to register. + * \param s The task will be added to this scheduler's task list. + * + * This allocates a buffer tree pool for I/O, sets up \a sit and registers a + * task with \a sit as context pointer. + */ +void stdin_task_register(struct stdin_task *sit, struct sched *s) { - sit->task.private_data = sit; - sit->task.pre_select = stdin_pre_select; - sit->task.post_select = stdin_post_select; - sit->task.flags = POST_EOF_IS_ERROR; - sprintf(sit->task.status, "%p stdin reader: initialized", &sit->task); + int ret; + struct task_info ti = { + .name = "stdin", + .pre_select = stdin_pre_select, + .post_select = stdin_post_select, + .context = sit, + }; + + sit->btrp = btr_pool_new("stdin", 128 * 1024); + /* + * Both STDIN_FILENO and STDOUT_FILENO may refer to the same open file + * description (the terminal), and thus share the same file status + * flags. In order to not interfere with the stdout task, we only get + * the file status flags for STDIN here and save a copy. The nonblock + * flag is set later on the first read. + */ + ret = fcntl(STDIN_FILENO, F_GETFL); + if (ret < 0) { + PARA_EMERG_LOG("F_GETFL: %s\n", strerror(errno)); + exit(EXIT_FAILURE); + } + sit->fd_flags = ret; + sit->must_set_nonblock_flag = (sit->fd_flags & O_NONBLOCK) == 0; + sit->task = task_register(&ti, s); } -#endif