-/*
- * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file stdin.c Functions that deal with reading from stdin. */
-#include <dirent.h> /* readdir() */
-#include <assert.h>
-#include <stdbool.h>
#include <regex.h>
#include "para.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.
*/
-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);
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);
}