lib/context.c

   1 /*
   2  * context.c
   3  *
   4  * Babeltrace Library
   5  *
   6  * Copyright 2011-2012 EfficiOS Inc. and Linux Foundation
   7  *
   8  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *         Julien Desfossez <julien.desfossez@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  */
  21
  22 #include <babeltrace/babeltrace.h>
  23 #include <babeltrace/context.h>
  24 #include <stdlib.h>
  25
  26 struct bt_context *bt_context_create(struct trace_collection *tc)
  27 {
  28         struct bt_context *ctx;
  29
  30         ctx = calloc(1, sizeof(struct bt_context));
  31         if (ctx == NULL) {
  32                 perror("allocating context");
  33                 goto error;
  34         }
  35
  36         ctx->tc = tc;
  37         ctx->refcount = 1;
  38
  39         return ctx;
  40
  41 error:
  42         return NULL;
  43 }
  44
  45 int bt_context_destroy(struct bt_context *ctx)
  46 {
  47         if (ctx) {
  48                 if (ctx->refcount >= 1)
  49                         goto ctx_used;
  50
  51                 free(ctx);
  52         }
  53         return 0;
  54
  55 ctx_used:
  56         return -1;
  57 }
  58
  59 int bt_context_get(struct bt_context *ctx)
  60 {
  61         if (!ctx)
  62                 return -1;
  63         ctx->refcount++;
  64         return 0;
  65 }
  66
  67 int bt_context_put(struct bt_context *ctx)
  68 {
  69         if (!ctx)
  70                 return -1;
  71
  72         ctx->refcount--;
  73         if (ctx->refcount == 0)
  74                 return bt_context_destroy(ctx);
  75         return 0;
  76 }