From 9a48a8553a8dd4a92039b582113339cdb48a9359 Mon Sep 17 00:00:00 2001
From: Sears Russell <sears.russell@gmail.com>
Date: Mon, 25 Apr 2011 15:30:11 +0000
Subject: [PATCH] implement deinit for concurrent ringbuffer

---
 src/stasis/util/ringbuffer.c | 41 +++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/src/stasis/util/ringbuffer.c b/src/stasis/util/ringbuffer.c
index 784f96f..375fb72 100644
--- a/src/stasis/util/ringbuffer.c
+++ b/src/stasis/util/ringbuffer.c
@@ -46,6 +46,8 @@ struct stasis_ringbuffer_t {
   pthread_cond_t read_done;
   pthread_cond_t write_done;
 
+  int fd;
+
   // If non-zero, all read requests act as though size is
   // RING_NEXT until the read frontier is greater than flush.
   lsn_t flush;
@@ -115,12 +117,12 @@ lsn_t stasis_ringbuffer_consume_bytes(stasis_ringbuffer_t * ring, lsn_t* sz, lsn
   lsn_t orig_sz = *sz;
 
   if(ring->flush > ring->rf) {
-    pthread_mutex_unlock(&ring->mut);
-    struct timespec tv;
-    tv.tv_sec = 0;
-    tv.tv_nsec = 100000;
-    nanosleep(&tv, 0);
-    pthread_mutex_lock(&ring->mut);
+//    pthread_mutex_unlock(&ring->mut);
+//    struct timespec tv;
+//    tv.tv_sec = 0;
+//    tv.tv_nsec = 100000;
+//    nanosleep(&tv, 0);
+//    pthread_mutex_lock(&ring->mut);
     if(ring->flush > ring->rf) { *sz = RING_NEXT; }
   }
   if(ring->shutdown) {
@@ -259,8 +261,8 @@ stasis_ringbuffer_t * stasis_ringbuffer_init(intptr_t base, lsn_t initial_offset
   // Allocate the memory region using mmap black magic.
 
   char* name = strdup("/dev/shm/stasis-ringbuffer-XXXXXX");
-  int fd = mkstemp(name);
-  if(fd == -1) { perror("Couldn't mkstemp\n"); abort(); }
+  ring->fd = mkstemp(name);
+  if(ring->fd == -1) { perror("Couldn't mkstemp\n"); abort(); }
 
   int err;
 
@@ -272,7 +274,7 @@ stasis_ringbuffer_t * stasis_ringbuffer_init(intptr_t base, lsn_t initial_offset
 
   ring->mask = (1 << base) - 1;
   lsn_t size = ring->mask+1;
-  err = ftruncate(fd, size);
+  err = ftruncate(ring->fd, size);
 
   if(err == -1) { perror("Couldn't ftruncate file"); }
 
@@ -280,11 +282,11 @@ stasis_ringbuffer_t * stasis_ringbuffer_init(intptr_t base, lsn_t initial_offset
 
   if(ring->mem == MAP_FAILED) { perror("Couldn't mmap anonymous region"); abort(); }
 
-  void * errp = mmap(ring->mem, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0);
+  void * errp = mmap(ring->mem, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, ring->fd, 0);
 
   if(errp == MAP_FAILED) { perror("Couldn't mmap temp region"); abort(); }
 
-  errp = mmap(((char*)ring->mem)+size, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0);
+  errp = mmap(((char*)ring->mem)+size, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, ring->fd, 0);
 
   if(errp == MAP_FAILED) { perror("Couldn't mmap temp region the second time."); abort(); }
 
@@ -325,5 +327,20 @@ void stasis_ringbuffer_shutdown(stasis_ringbuffer_t * ring) {
   } while (ring->rt < ring->wf);
 
   pthread_mutex_unlock(&ring->mut);
-  // XXX free resources.
+
+  lsn_t size = ring->mask+1;
+  int err = munmap(((char*)ring->mem), size * 2);
+  if(err == -1) { perror("could not munmap first half of ringbuffer"); }
+  munmap(((char*)ring->mem)+size, size);
+  if(err == -1) { perror("could not munmap second half of ringbuffer"); }
+  munmap(((char*)ring->mem), size);
+  if(err == -1) { perror("could not munmap hidden backing region of ringbuffer"); }
+
+  stasis_aggregate_min_deinit(ring->min_reader);
+  stasis_aggregate_min_deinit(ring->min_writer);
+  pthread_mutex_destroy(&ring->mut);
+  pthread_cond_destroy(&ring->read_done);
+  pthread_cond_destroy(&ring->write_done);
+  close(ring->fd);
+  free(ring);
 }