From b469d2dd9c6770cbdce9304dbb0e2c7ed8304b2a Mon Sep 17 00:00:00 2001 From: Julien Desfossez Date: Wed, 25 Jan 2012 14:46:16 -0500 Subject: [PATCH] Add missing context.h/context.c Signed-off-by: Mathieu Desnoyers --- include/babeltrace/context.h | 76 ++++++++++++++++++++++++++++++++++++ lib/context.c | 76 ++++++++++++++++++++++++++++++++++++ 2 files changed, 152 insertions(+) create mode 100644 include/babeltrace/context.h create mode 100644 lib/context.c diff --git a/include/babeltrace/context.h b/include/babeltrace/context.h new file mode 100644 index 00000000..55fe2313 --- /dev/null +++ b/include/babeltrace/context.h @@ -0,0 +1,76 @@ +#ifndef _BABELTRACE_CONTEXT_H +#define _BABELTRACE_CONTEXT_H + +/* + * BabelTrace + * + * context header + * + * Copyright 2012 EfficiOS Inc. and Linux Foundation + * + * Author: Mathieu Desnoyers + * Julien Desfossez + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + */ + +struct trace_collection; + +/* + * The context represents the object in which a trace_collection is open. As + * long as this structure is allocated, the trace_collection is open and the + * traces it contains can be read and seeked by the iterators and callbacks. + * + * It has to be created with the bt_context_create() function and destroyed by + * bt_context_destroy() + */ +struct bt_context { + struct trace_collection *tc; + int refcount; +}; + +/* + * bt_context_create : create a Babeltrace context + * + * Allocate a new context and assign the trace_collection passed in + * parameter as the context trace_collection. The trace_collection + * must contain an array of valid trace_descriptors. The creation of + * the context sets the refcount to 1. + * + * Returns an allocated context on success and NULL on error + */ +struct bt_context *bt_context_create(struct trace_collection *tc); + +/* + * bt_context_destroy : destroy a context + * + * If the context is still in use (by an iterator or a callback), the + * destroy fails and returns -1, on success : return 0. + */ +int bt_context_destroy(struct bt_context *ctx); + +/* + * bt_context_get and bt_context_put : increments and decrement the refcount of + * the context + * + * These functions ensures that the context won't be destroyed when it is in + * use. The same number of get and put has to be done to be able to destroy a + * context. + * + * Return 0 on success, -1 if the context pointer is invalid. When the context + * refcount is decremented to 0 by a bt_context_put, it calls + * bt_context_destroy to free the context. In this case the return code of + * bt_context_destroy is returned. + */ +int bt_context_get(struct bt_context *ctx); +int bt_context_put(struct bt_context *ctx); + +#endif /* _BABELTRACE_CONTEXT_H */ diff --git a/lib/context.c b/lib/context.c new file mode 100644 index 00000000..36efc9d0 --- /dev/null +++ b/lib/context.c @@ -0,0 +1,76 @@ +/* + * context.c + * + * Babeltrace Library + * + * Copyright 2011-2012 EfficiOS Inc. and Linux Foundation + * + * Author: Mathieu Desnoyers + * Julien Desfossez + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + */ + +#include +#include +#include + +struct bt_context *bt_context_create(struct trace_collection *tc) +{ + struct bt_context *ctx; + + ctx = calloc(1, sizeof(struct bt_context)); + if (ctx == NULL) { + perror("allocating context"); + goto error; + } + + ctx->tc = tc; + ctx->refcount = 1; + + return ctx; + +error: + return NULL; +} + +int bt_context_destroy(struct bt_context *ctx) +{ + if (ctx) { + if (ctx->refcount >= 1) + goto ctx_used; + + free(ctx); + } + return 0; + +ctx_used: + return -1; +} + +int bt_context_get(struct bt_context *ctx) +{ + if (!ctx) + return -1; + ctx->refcount++; + return 0; +} + +int bt_context_put(struct bt_context *ctx) +{ + if (!ctx) + return -1; + + ctx->refcount--; + if (ctx->refcount == 0) + return bt_context_destroy(ctx); + return 0; +} -- 2.34.1