stdin: Use buffer pools.

This introduces a memory leak to be fixed in a subsequent patch (the
buffer pool can not be freed in post_select() because there might
still be references to its area).

diff --git a/stdin.c b/stdin.c
index abe69cafd4270ddf0e82ed9d2b30d3cf3603f43a..4329e144a04ae2921a710bd28a3faae710f6b17f 100644 (file)
--- a/stdin.c
+++ b/stdin.c
@@ -95,11 +95,11 @@ static void stdin_post_select(struct sched *s, struct task *t)
                t->error = -E_STDIN_EOF;
 }
 
-#define STDIN_INPUT_BUFFER_SIZE (1024 * 32)
 static void stdin_post_select_btr(struct sched *s, struct task *t)
 {
        struct stdin_task *sit = container_of(t, struct stdin_task, task);
        ssize_t ret;
+       size_t sz;
        char *buf = NULL;
 
        t->error = 0;
@@ -110,21 +110,29 @@ static void stdin_post_select_btr(struct sched *s, struct task *t)
                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);
+       sz = btr_pool_get_buffer(sit->btrp, &buf);
+       ret = -E_STDIN_OVERRUN;
+       if (sz == 0)
+               goto err;
+       /*
+        * 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);
        //PARA_CRIT_LOG("read ret: %d\n", ret);
-       if (ret <= 0) {
-               if (ret < 0)
-                       ret = -ERRNO_TO_PARA_ERROR(errno);
-               else
-                       ret = -E_STDIN_EOF;
+       if (ret < 0)
+               ret = -ERRNO_TO_PARA_ERROR(errno);
+       if (ret == 0)
+               ret = -E_STDIN_EOF;
+       if (ret < 0)
                goto err;
-       }
-       btr_add_output(buf, ret, sit->btrn);
+       btr_add_output_pool(sit->btrp, ret, sit->btrn);
        return;
 err:
-       free(buf);
        btr_remove_node(sit->btrn);
+       //btr_pool_free(sit->btrp);
        t->error = ret;
 }
 
@@ -135,7 +143,7 @@ err:
  *
  * 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).
+ * mode and \a bufsize is initialized (but no buffer is allocated).
  */
 void stdin_set_defaults(struct stdin_task *sit)
 {
@@ -145,6 +153,7 @@ void stdin_set_defaults(struct stdin_task *sit)
        if (sit->btrn) {
                sit->task.pre_select = stdin_pre_select_btr;
                sit->task.post_select = stdin_post_select_btr;
+               sit->btrp = btr_pool_new("stdin", 64 * 1024);
        } else {
                sit->task.pre_select = stdin_pre_select;
                sit->task.post_select = stdin_post_select;

diff --git a/stdin.h b/stdin.h
index 8e5b3ce5bfc16e4c4659a819677213341723c103..2b87f760d9caacc2dc69ae211016f8b85b7e141e 100644 (file)
--- a/stdin.h
+++ b/stdin.h
@@ -22,6 +22,7 @@ struct stdin_task {
        struct task task;
        /** Non-null if buffer tree API should be used. */
        struct btr_node *btrn;
+       struct btr_pool *btrp;
 };
 
 void stdin_set_defaults(struct stdin_task *sit);