X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=stdin.c;h=20b9250e9b7fbf3c252e20dff8891bfeeb5112dd;hp=d080e2165b169ec3fd03bf0c669ac6ec05188985;hb=63abcd1b2f6de6ce53d82962f5a2100c5a57e5d3;hpb=aa05cb41dd2f031935507e89b56b1e6096b846db diff --git a/stdin.c b/stdin.c index d080e216..20b9250e 100644 --- a/stdin.c +++ b/stdin.c @@ -1,14 +1,12 @@ /* - * Copyright (C) 2006-2009 Andre Noll + * Copyright (C) 2006-2013 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ /** \file stdin.c Functions that deal with reading from stdin. */ -#include /* readdir() */ #include -#include #include #include "para.h" @@ -33,38 +31,16 @@ static void stdin_pre_select(struct sched *s, struct task *t) { struct stdin_task *sit = container_of(t, struct stdin_task, task); + int ret; - if (sit->output_error && *sit->output_error < 0) { - t->error = *sit->output_error; - return; - } - t->error = 0; - sit->check_fd = 0; - if (sit->loaded >= sit->bufsize) - return; - sit->check_fd = 1; - para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); -} - -#define STDIN_MAX_PENDING (1024 * 1024) - -static void stdin_pre_select_btr(struct sched *s, struct task *t) -{ - struct stdin_task *sit = container_of(t, struct stdin_task, task); - - if (btr_no_children(sit->btrn)) { - t->error = -E_STDIN_NO_CHILD; - btr_del_node(sit->btrn); - sit->btrn = NULL; + ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); + if (ret < 0) + sched_min_delay(s); + if (ret <= 0) return; - } - t->error = 0; - if (btr_bytes_pending(sit->btrn) > STDIN_MAX_PENDING) - sit->check_fd = 0; - else { - sit->check_fd = 1; - para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); - } + if (btr_pool_unused(sit->btrp) > 0) + return para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno); + sched_request_timeout_ms(100, s); } /** @@ -75,63 +51,47 @@ static void stdin_pre_select_btr(struct sched *s, struct task *t) * * 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 into the buffer of the - * stdin task. + * appears to be readable, data is read from stdin and fed into the buffer + * tree. */ -static void stdin_post_select(struct sched *s, struct task *t) -{ - struct stdin_task *sit = container_of(t, struct stdin_task, task); - ssize_t ret; - - if (sit->output_error && *sit->output_error < 0) { - t->error = *sit->output_error; - return; - } - t->error = 0; - 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); - if (ret < 0) - t->error = ERRNO_TO_PARA_ERROR(errno); - else if (ret > 0) - sit->loaded += ret; - else - t->error = -E_STDIN_EOF; -} - -#define STDIN_INPUT_BUFFER_SIZE 4000 -static void stdin_post_select_btr(struct sched *s, struct task *t) +static int stdin_post_select(struct sched *s, struct task *t) { struct stdin_task *sit = container_of(t, struct stdin_task, task); ssize_t ret; + size_t sz, n; char *buf = NULL; - t->error = -E_STDIN_NO_CHILD; - if (btr_no_children(sit->btrn)) - goto err; - - t->error = 0; - if (!sit->check_fd) - return; - if (!FD_ISSET(STDIN_FILENO, &s->rfds)) - return; - - buf = para_malloc(STDIN_INPUT_BUFFER_SIZE); - ret = read(STDIN_FILENO, buf, STDIN_INPUT_BUFFER_SIZE); + ret = btr_node_status(sit->btrn, 0, BTR_NT_ROOT); if (ret < 0) - t->error = -ERRNO_TO_PARA_ERROR(errno); - if (ret == 0) - t->error = -E_STDIN_EOF; - if (t->error < 0) goto err; - btr_add_output(buf, ret, sit->btrn); - return; + 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: - free(buf); - btr_del_node(sit->btrn); - sit->btrn = NULL; + 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; } /** @@ -140,26 +100,28 @@ err: * \param sit The stdin task structure. * * 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 bufsize is initialized to 16 KB (but no buffer is allocated). + * given by \a sit and creates a buffer tree for I/O. */ void stdin_set_defaults(struct stdin_task *sit) { int ret; - sit->bufsize = 32 * 1024; - if (sit->btrn) { - sit->task.pre_select = stdin_pre_select_btr; - sit->task.post_select = stdin_post_select_btr; - } else { - sit->task.pre_select = stdin_pre_select; - sit->task.post_select = stdin_post_select; - } + sit->task.pre_select = stdin_pre_select; + sit->task.post_select = stdin_post_select; + sit->btrp = btr_pool_new("stdin", 128 * 1024); sprintf(sit->task.status, "stdin reader"); - ret = mark_fd_nonblocking(STDIN_FILENO); - if (ret >= 0) - return; - sit->output_error = NULL; - PARA_EMERG_LOG("%s\n", para_strerror(-ret)); - exit(EXIT_FAILURE); + /* + * 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; }