From: Martin Mares <mj@ucw.cz>
Date: Tue, 2 Sep 2008 20:07:18 +0000 (+0200)
Subject: Automatic tying of fastbufs to resources.
X-Git-Tag: v5.0~74^2~42
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=a45646a634b71708f5bc4277868c60e80daaa84c;p=libucw.git

Automatic tying of fastbufs to resources.
---

diff --git a/ucw/Makefile b/ucw/Makefile
index 4ff774e4..6f076ed7 100644
--- a/ucw/Makefile
+++ b/ucw/Makefile
@@ -34,7 +34,7 @@ LIBUCW_MODS= \
 	bbuf gary \
 	getopt \
 	strtonum \
-	respool trans
+	respool trans res-fd res-mem
 
 LIBUCW_MAIN_INCLUDES= \
 	lib.h log.h threads.h \
diff --git a/ucw/doc/fastbuf.txt b/ucw/doc/fastbuf.txt
index d94fffe9..86ab55d9 100644
--- a/ucw/doc/fastbuf.txt
+++ b/ucw/doc/fastbuf.txt
@@ -18,6 +18,12 @@ inbetween and remember that the file position reported by @btell() points after
 the flushed buffer, which is not necessarily the same as after the data you've
 really read.
 
+Most fastbuf back-ends also participate in the libucw resource management system.
+If you have a resource pool active, newly created fastbufs are automatically tied
+to resources in the pool, so when the pool gets cleaned up, the fastbufs are
+freed, too. The bclose() function is still available and it removes the tie
+as needed.
+
 .Back-ends:
 - <<fbparam,Files (parametrized)>>
 - <<fbfile,Regular files>>
diff --git a/ucw/fastbuf.c b/ucw/fastbuf.c
index 9ba01ef4..de38b277 100644
--- a/ucw/fastbuf.c
+++ b/ucw/fastbuf.c
@@ -9,6 +9,7 @@
 
 #include "ucw/lib.h"
 #include "ucw/fastbuf.h"
+#include "ucw/respool.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,6 +21,8 @@ void bclose(struct fastbuf *f)
       bflush(f);
       if (f->close)
 	f->close(f);
+      if (f->res)
+	res_drop(f->res);
     }
 }
 
@@ -202,3 +205,40 @@ bfilesize(struct fastbuf *f)
   bsetpos(f, pos);
   return len;
 }
+
+/* Resources */
+
+static void
+fb_res_detach(struct resource *r)
+{
+  struct fastbuf *f = r->priv;
+  f->res = NULL;
+}
+
+static void
+fb_res_free(struct resource *r)
+{
+  struct fastbuf *f = r->priv;
+  f->res = NULL;
+  bclose(f);
+}
+
+static void
+fb_res_dump(struct resource *r)
+{
+  struct fastbuf *f = r->priv;
+  printf(" name=%s", f->name);
+}
+
+static const struct res_class fb_res_class = {
+  .name = "fastbuf",
+  .detach = fb_res_detach,
+  .dump = fb_res_dump,
+  .free = fb_res_free,
+};
+
+void
+fb_tie(struct fastbuf *f)
+{
+  f->res = res_new(&fb_res_class, f);
+}
diff --git a/ucw/fastbuf.h b/ucw/fastbuf.h
index 2c1c1a10..6e3b2626 100644
--- a/ucw/fastbuf.h
+++ b/ucw/fastbuf.h
@@ -139,13 +139,18 @@ struct fastbuf {
   void (*close)(struct fastbuf *);		/* Close the stream */
   int (*config)(struct fastbuf *, uns, int);	/* Configure the stream */
   int can_overwrite_buffer;			/* Can the buffer be altered? 0=never, 1=temporarily, 2=permanently */
+  struct resource *res;				/* The fastbuf can be tied to a resource pool */
 };
 
+void fb_tie(struct fastbuf *b);			/* Tie fastbuf to a resource if there is an active pool */
+
 /***
  * === Fastbuf on files [[fbparam]]
  *
  * If you want to use fastbufs to access files, you can choose one of several
  * back-ends and set their parameters.
+ *
+ * All file fastbufs are tied to resources automatically.
  ***/
 
 /**
@@ -292,6 +297,8 @@ void bclose_file_helper(struct fastbuf *f, int fd, int is_temp_file);
  *
  * The `fblim` back-end reads from a file handle, but at most a given
  * number of bytes. This is frequently used for reading from sockets.
+ *
+ * All such fastbufs are tied to resources automatically.
  ***/
 
 struct fastbuf *bopen_limited_fd(int fd, uns bufsize, uns limit); /** Create a fastbuf which reads at most @limit bytes from @fd. **/
@@ -306,6 +313,8 @@ struct fastbuf *bopen_limited_fd(int fd, uns bufsize, uns limit); /** Create a f
  * First, you use @fbmem_create() to create the stream and the fastbuf
  * used for writing to it. Then you can call @fbmem_clone_read() to get
  * an arbitrary number of fastbuf for reading from the stream.
+ *
+ * All in-memory fastbufs are tied to resources automatically.
  ***/
 
 struct fastbuf *fbmem_create(uns blocksize);		/** Create stream and return its writing fastbuf. **/
@@ -327,7 +336,8 @@ struct fastbuf *fbmem_clone_read(struct fastbuf *f);	/** Given a writing fastbuf
  * of the buffer temporarily. In this case, set @can_overwrite as described
  * in <<internal,Internals>>. If you do not care, keep @can_overwrite zero.
  *
- * It is not possible to close this fastbuf.
+ * It is not possible to close this fastbuf. This implies that no tying to
+ * resources takes place.
  */
 void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size, uns can_overwrite);
 
@@ -339,7 +349,8 @@ void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size, uns can_overwrit
  * Data are written directly into the buffer, so it is not necessary to call @bflush()
  * at any moment.
  *
- * It is not possible to close this fastbuf.
+ * It is not possible to close this fastbuf. This implies that no tying to
+ * resources takes place.
  */
 void fbbuf_init_write(struct fastbuf *f, byte *buffer, uns size);
 
@@ -356,6 +367,8 @@ static inline uns fbbuf_count_written(struct fastbuf *f) /** Calculates, how man
  * size and it is expanded to accomodate all data.
  *
  * At every moment, you can use `fastbuf->buffer` to gain access to the stream.
+ *
+ * All fastbufs of this type are tied to resources automatically.
  ***/
 
 struct fastbuf *fbgrow_create(unsigned basic_size);	/** Create the growing buffer pre-allocated to @basic_size bytes. **/
@@ -376,7 +389,8 @@ struct fbpool { /** Structure for fastbufs & mempools. **/
 };
 
 /**
- * Initialize a new `fbpool`. The structure is allocated by the caller.
+ * Initialize a new `fbpool`. The structure is allocated by the caller,
+ * so bclose() should not be called and no resource tying takes place.
  **/
 void fbpool_init(struct fbpool *fb);	/** Initialize a new mempool fastbuf. **/
 /**
@@ -411,6 +425,8 @@ void *fbpool_end(struct fbpool *fb);
  *
  * Please note that initialization of the clones is not thread-safe,
  * so you have to serialize it yourself.
+ *
+ * The atomic fastbufs are tied to resources automatically.
  ***/
 
 struct fb_atomic {
diff --git a/ucw/fb-atomic.c b/ucw/fb-atomic.c
index 32c9ca9b..2283cee5 100644
--- a/ucw/fb-atomic.c
+++ b/ucw/fb-atomic.c
@@ -129,6 +129,7 @@ fbatomic_open(const char *name, struct fastbuf *master, uns bufsize, int record_
   f->name = af->name;
   f->spout = fbatomic_spout;
   f->close = fbatomic_close;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-direct.c b/ucw/fb-direct.c
index 1e2dfd89..71e7351b 100644
--- a/ucw/fb-direct.c
+++ b/ucw/fb-direct.c
@@ -308,6 +308,7 @@ fbdir_open_fd_internal(int fd, const char *name, struct asio_queue *q, uns buffe
   f->close = fbdir_close;
   f->config = fbdir_config;
   f->can_overwrite_buffer = 2;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-file.c b/ucw/fb-file.c
index 3eb2996f..fff44378 100644
--- a/ucw/fb-file.c
+++ b/ucw/fb-file.c
@@ -244,6 +244,7 @@ bfdopen_internal(int fd, const char *name, uns buflen)
   f->close = bfd_close;
   f->config = bfd_config;
   f->can_overwrite_buffer = 2;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-grow.c b/ucw/fb-grow.c
index e1da0107..7d4a8f84 100644
--- a/ucw/fb-grow.c
+++ b/ucw/fb-grow.c
@@ -80,6 +80,7 @@ fbgrow_create(unsigned basic_size)
   b->seek = fbgrow_seek;
   b->close = fbgrow_close;
   b->can_overwrite_buffer = 1;
+  fb_tie(b);
   return b;
 }
 
diff --git a/ucw/fb-limfd.c b/ucw/fb-limfd.c
index 7e30f6a2..4e7d406b 100644
--- a/ucw/fb-limfd.c
+++ b/ucw/fb-limfd.c
@@ -55,6 +55,7 @@ bopen_limited_fd(int fd, uns buflen, uns limit)
   f->refill = bfl_refill;
   f->close = bfl_close;
   f->can_overwrite_buffer = 2;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-mem.c b/ucw/fb-mem.c
index 1acb38f6..a100d481 100644
--- a/ucw/fb-mem.c
+++ b/ucw/fb-mem.c
@@ -162,6 +162,7 @@ fbmem_create(unsigned blocksize)
   f->name = "<fbmem-write>";
   f->spout = fbmem_spout;
   f->close = fbmem_close;
+  fb_tie(f);
   return f;
 }
 
@@ -180,6 +181,7 @@ fbmem_clone_read(struct fastbuf *b)
   f->seek = fbmem_seek;
   f->close = fbmem_close;
   f->can_overwrite_buffer = 1;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-mmap.c b/ucw/fb-mmap.c
index 747b4286..25209721 100644
--- a/ucw/fb-mmap.c
+++ b/ucw/fb-mmap.c
@@ -189,6 +189,7 @@ bfmmopen_internal(int fd, const char *name, uns mode)
   f->seek = bfmm_seek;
   f->close = bfmm_close;
   f->config = bfmm_config;
+  fb_tie(f);
   return f;
 }
 
diff --git a/ucw/fb-socket.c b/ucw/fb-socket.c
index dce8fffd..d90f7e7c 100644
--- a/ucw/fb-socket.c
+++ b/ucw/fb-socket.c
@@ -125,6 +125,7 @@ fbsock_create(struct fbsock_params *p)
   f->spout = fbs_spout;
   f->close = fbs_close;
   f->can_overwrite_buffer = 1;
+  fb_tie(f);
   return f;
 }