X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=stdin.c;h=e5c40bcb092a1faa59a91a33bd2d7b1975f1f3e7;hp=d9f9bd936590985bf32a8351738bbf875c4a5478;hb=67808e59c9d94d3cf68733e94d4afaa1eecb7e8c;hpb=471684761a2039bbc89aa1e3c33c62de6bef86cf diff --git a/stdin.c b/stdin.c index d9f9bd93..e5c40bcb 100644 --- a/stdin.c +++ b/stdin.c @@ -1,98 +1,119 @@ /* - * Copyright (C) 2006 Andre Noll + * Copyright (C) 2006 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file stdin.c functions that deal with reading from stdin */ +/** \file stdin.c Functions that deal with reading from stdin. */ + +#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" -/** - * the pre_select function of the stdin task - * - * \param s the scheduler this task was registered to - * \param t the task structure of the stdin task - * - * This function is always successful. If there is space left in the - * buffer of the stdin task, it adds \p STDIN_FILENO to the read fd set - * of \a s. +/* + * If there is space left in the buffer of the stdin task add STDIN_FILENO to + * the read fd set of s. */ -void stdin_pre_select(struct sched *s, struct task *t) +static void stdin_pre_select(struct sched *s, void *context) { - struct stdin_task *sit = t->private_data; - t->ret = 1; - sit->check_fd = 0; - if (sit->loaded >= sit->bufsize) - return; - sit->check_fd = 1; - para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); -} + struct stdin_task *sit = context; + int ret; -static void stdin_default_event_handler(struct task *t) -{ - PARA_NOTICE_LOG("%p: %s\n", t, PARA_STRERROR(-t->ret)); - unregister_task(t); + 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); } -/** - * the post select function of the stdin task - * - * \param s the scheduler this task was registered to - * \param t the task structure of the stdin task - * - * This function checks if \p STDIN_FILENO was included by in the read fd set - * of \a s during the previous pre_select call. If yes, and \p STDIN_FILENO - * appeears to be readable, data is read from stdin into the buffer of the - * stdin task. +/* + * 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. */ -void stdin_post_select(struct sched *s, struct task *t) +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->check_fd) - 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 if (ret > 0) { - sit->loaded += ret; - t->ret = ret; - } else - t->ret = -E_STDIN_EOF; - if (t->ret < 0) - sit->eof = 1; + 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; + } + /* + * 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; } /** - * initialize a stdin task structure with default values + * Register a stdin task structure. * - * \param sit the 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 fills in the pre/post select function poinzters of the task structure - * given by \a sot. It also sets up a default error handler which unregisters - * the task. Moreover, \a loaded and \a eof are set to zero and \a bufsize is - * initialized to 16 KB (but no buffer is allocated). + * 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_set_defaults(struct stdin_task *sit) +void stdin_task_register(struct stdin_task *sit, struct sched *s) { - sit->bufsize = 16 * 1024, - sit->loaded = 0, - sit->eof = 0, - sit->task.pre_select = stdin_pre_select; - sit->task.post_select = stdin_post_select; - sit->task.event_handler = stdin_default_event_handler; - sit->task.private_data = sit; - mark_fd_nonblock(STDIN_FILENO); - sprintf(sit->task.status, "stdin reader"); + 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); }