tal_stack

[ccan] / ccan / tal / stack / _info

diff --git a/ccan/tal/stack/_info b/ccan/tal/stack/_info
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+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * tal/stack - stack of tal contextes (inspired by talloc_stack)
+ *
+ * Implement a stack of tal contexts. A new (empty) context is pushed on top
+ * of the stack using tal_newframe and it is popped/freed using tal_free().
+ * tal_curframe() can be used to get the stack's top context.
+ *
+ * tal_stack can be used to implement per-function temporary allocation context
+ * to help mitigating memory leaks, but unlike the plain tal approach it does not
+ * require the caller to pass a destination context for returning allocated
+ * values. Instead, allocated values are moved to the parent context using
+ * tal_steal(tal_parent(tmp_ctx), ptr).
+ *
+ * Example:
+ *     #include <assert.h>
+ *     #include <ccan/tal/stack/stack.h>
+ *
+ *     static int *do_work(void)
+ *     {
+ *             int *retval = NULL;
+ *             tal_t *tmp_ctx = tal_newframe();
+ *
+ *             int *val = talz(tmp_ctx, int);
+ *             assert(val != NULL);
+ *
+ *             // ... do something with val ...
+ *
+ *             if (retval >= 0) {
+ *                     // steal to parent cxt so it survives tal_free()
+ *                     tal_steal(tal_parent(tmp_ctx), val);
+ *                     retval = val;
+ *             }
+ *             tal_free(tmp_ctx);
+ *             return retval;
+ *     }
+ *
+ *     int main(int argc, char *argv[])
+ *     {
+ *             tal_t *tmp_ctx = tal_newframe();
+ *             int *val = do_work();
+ *             if (val) {
+ *                     // ... do something with val ...
+ *             }
+ *             // val is eventually freed
+ *             tal_free(tmp_ctx);
+ *             return 0;
+ *     }
+ *
+ * License: BSD-MIT
+ * Author: Delio Brignoli <brignoli.delio@gmail.com>
+ */
+int main(int argc, char *argv[])
+{
+       /* Expect exactly one argument */
+       if (argc != 2)
+               return 1;
+
+       if (strcmp(argv[1], "depends") == 0) {
+               printf("ccan/tal\n");
+               return 0;
+       }
+
+       return 1;
+}