X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=stdin.c;h=9408235a045a6767e2acf443208d95196990d379;hp=79a9a3231d8a675c94f49ee6e0c0a98069ae6d0c;hb=4643fd6eeee81acc0e82e47e7895a3111775bbba;hpb=f42b5eccb6ec3364dc0500ffeffbe9d9ecab07bd diff --git a/stdin.c b/stdin.c index 79a9a323..9408235a 100644 --- a/stdin.c +++ b/stdin.c @@ -1,14 +1,7 @@ -/* - * Copyright (C) 2006-2009 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 2006 Andre Noll , see file COPYING. */ /** \file stdin.c Functions that deal with reading from stdin. */ -#include /* readdir() */ -#include -#include #include #include "para.h" @@ -20,22 +13,15 @@ #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. */ -static void stdin_pre_select(struct sched *s, struct task *t) +static void stdin_pre_select(struct sched *s, void *context) { - struct stdin_task *sit = container_of(t, struct stdin_task, task); + struct stdin_task *sit = context; int ret; - t->error = 0; ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); if (ret < 0) sched_min_delay(s); @@ -46,76 +32,85 @@ static void stdin_pre_select(struct sched *s, struct task *t) 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 - * appears to be readable, data is read from stdin and fed into the buffer - * tree. +/* + * 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 void stdin_post_select(struct sched *s, struct task *t) +static int stdin_post_select(struct sched *s, void *context) { - struct stdin_task *sit = container_of(t, struct stdin_task, task); + struct stdin_task *sit = context; ssize_t ret; - size_t sz; + size_t sz, n; char *buf = NULL; - t->error = 0; ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); if (ret < 0) goto err; if (ret == 0) - return; - if (!FD_ISSET(STDIN_FILENO, &s->rfds)) - return; + return 0; sz = btr_pool_get_buffer(sit->btrp, &buf); if (sz == 0) - return; + 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(STDIN_FILENO, buf, sz); - if (ret < 0) - ret = -ERRNO_TO_PARA_ERROR(errno); - if (ret == 0) - ret = -E_STDIN_EOF; - if (ret < 0) - goto err; - btr_add_output_pool(sit->btrp, ret, sit->btrn); - return; + 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); + btr_remove_node(&sit->btrn); + /* Revert to blocking mode if necessary. */ + fcntl(STDIN_FILENO, F_SETFL, sit->fd_flags); //btr_pool_free(sit->btrp); - t->error = ret; + 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 pointers of the task structure - * given by \a sit. Moreover, the stdin file desctiptor is set to nonblocking - * mode, and a buffer tree is created. + * 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) { int ret; + struct task_info ti = { + .name = "stdin", + .pre_select = stdin_pre_select, + .post_select = stdin_post_select, + .context = sit, + }; - sit->task.pre_select = stdin_pre_select; - sit->task.post_select = stdin_post_select; - sit->btrp = btr_pool_new("stdin", 64 * 1024); - sprintf(sit->task.status, "stdin reader"); - ret = mark_fd_nonblocking(STDIN_FILENO); - if (ret >= 0) - return; - PARA_EMERG_LOG("%s\n", para_strerror(-ret)); - exit(EXIT_FAILURE); + 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 + && !isatty(STDIN_FILENO); + sit->task = task_register(&ti, s); }