Implemented mreserve() for reserving/trimming in fdsets.

refs #1291, #1582

src/common/fdset_epoll.c

@@ -27,7 +27,6 @@
 #include "skip-list.h"
 
 #define OS_FDS_CHUNKSIZE 8   /*!< Number of pollfd structs in a chunk. */
-#define OS_FDS_KEEPCHUNKS 32 /*!< Will attempt to free memory when reached. */
 
 struct fdset_t {
 	fdset_base_t _base;
@@ -76,23 +75,8 @@ int fdset_epoll_add(fdset_t *fdset, int fd, int events)
 	}
 
 	/* Realloc needed. */
-	if (fdset->nfds == fdset->reserved) {
-		const size_t chunk = OS_FDS_CHUNKSIZE;
-		const size_t nsize = (fdset->reserved + chunk) *
-				     sizeof(struct epoll_event);
-		struct epoll_event *events_n = malloc(nsize);
-		if (!events_n) {
-			return -1;
-		}
-
-		/* Clear and copy old fdset data. */
-		memset(events_n, 0, nsize);
-		memcpy(events_n, fdset->events,
-		       fdset->nfds * sizeof(struct epoll_event));
-		free(fdset->events);
-		fdset->events = events_n;
-		fdset->reserved += chunk;
-	}
+	mreserve(&fdset->events, sizeof(struct epoll_event), fdset->nfds + 1,
+	         OS_FDS_CHUNKSIZE, &fdset->reserved);
 
 	/* Add to epoll set. */
 	struct epoll_event ev;
@@ -123,7 +107,10 @@ int fdset_epoll_remove(fdset_t *fdset, int fd)
 	/* Overwrite current item. */
 	--fdset->nfds;
 
-	/*! \todo Return memory if unused (issue #1582). */
+	/* Trim excessive memory if possible (retval is not interesting). */
+	mreserve(&fdset->events, sizeof(struct epoll_event), fdset->nfds,
+	         OS_FDS_CHUNKSIZE, &fdset->reserved);
+	
 	return 0;
 }
 

src/common/fdset_kqueue.c

@@ -37,6 +37,7 @@ struct fdset_t {
 	struct kevent *revents;
 	size_t nfds;
 	size_t reserved;
+	size_t rreserved;
 	size_t polled;
 };
 
@@ -76,24 +77,6 @@ int fdset_kqueue_destroy(fdset_t * fdset)
 	return 0;
 }
 
-int fdset_kqueue_realloc(struct kevent **old, size_t oldsize, size_t nsize)
-{
-	void *nmem = malloc(nsize);
-	if (!nmem) {
-		return -1;
-	}
-
-	/* Clear and copy old fdset data. */
-	memset(nmem, 0, nsize);
-	if (oldsize > 0) {
-		memcpy(nmem, *old, oldsize);
-		free(*old);
-	}
-	
-	*old = nmem;
-	return 0;
-}
-
 int fdset_kqueue_add(fdset_t *fdset, int fd, int events)
 {
 	if (!fdset || fd < 0 || events <= 0) {
@@ -101,20 +84,13 @@ int fdset_kqueue_add(fdset_t *fdset, int fd, int events)
 	}
 
 	/* Realloc needed. */
-	if (fdset->nfds == fdset->reserved) {
-		size_t chunk = OS_FDS_CHUNKSIZE;
-		size_t nsize = (fdset->reserved + chunk) *
-				     sizeof(struct kevent);
-		size_t oldsize = fdset->nfds * sizeof(struct kevent);
-		
-		if (fdset_kqueue_realloc(&fdset->events, oldsize, nsize) < 0) {
-			return -1;
-		}
-		
-		if (fdset_kqueue_realloc(&fdset->revents, oldsize, nsize) < 0) {
-			return -1;
-		}
-
+	int ret = 0;
+	ret += mreserve(&fdset->events, sizeof(struct kevent), fdset->nfds + 1,
+	                OS_FDS_CHUNKSIZE, &fdset->reserved);
+	ret += mreserve(&fdset->revents, sizeof(struct kevent), fdset->nfds + 1,
+	                OS_FDS_CHUNKSIZE, &fdset->rreserved);
+	if (ret != 0) {
+		return ret;
 	}
 
 	/* Add to kqueue set. */
@@ -156,7 +132,12 @@ int fdset_kqueue_remove(fdset_t *fdset, int fd)
 	/* Overwrite current item. */
 	--fdset->nfds;
 
-	/*! \todo Return memory if unused (issue #1582). */
+	/* Trim excessive memory if possible (retval is not interesting). */
+	mreserve(&fdset->events, sizeof(struct epoll_event), fdset->nfds,
+	         OS_FDS_CHUNKSIZE, &fdset->reserved);
+	mreserve(&fdset->revents, sizeof(struct epoll_event), fdset->nfds,
+	         OS_FDS_CHUNKSIZE, &fdset->rreserved);
+
 	return 0;
 }
 

src/common/fdset_poll.c

@@ -26,7 +26,6 @@
 #include "common/fdset_poll.h"
 
 #define OS_FDS_CHUNKSIZE 8   /*!< Number of pollfd structs in a chunk. */
-#define OS_FDS_KEEPCHUNKS 32 /*!< Will attempt to free memory when reached. */
 
 struct fdset_t {
 	fdset_base_t _base;
@@ -68,20 +67,9 @@ int fdset_poll_add(fdset_t *fdset, int fd, int events)
 	}
 
 	/* Realloc needed. */
-	if (fdset->nfds == fdset->reserved) {
-		const size_t chunk = OS_FDS_CHUNKSIZE;
-		const size_t nsize = sizeof(struct pollfd) * (fdset->reserved + chunk);
-		struct pollfd *fds_n = malloc(nsize);
-		if (!fds_n) {
-			return -1;
-		}
-
-		/* Clear and copy old fdset data. */
-		memset(fds_n, 0, nsize);
-		memcpy(fds_n, fdset->fds, fdset->nfds * sizeof(struct pollfd));
-		free(fdset->fds);
-		fdset->fds = fds_n;
-		fdset->reserved += chunk;
+	if (mreserve(&fdset->fds, sizeof(struct pollfd), fdset->nfds + 1,
+	             OS_FDS_CHUNKSIZE, &fdset->reserved) < 0) {
+		return -1;
 	}
 
 	/* Append. */
@@ -118,7 +106,10 @@ int fdset_poll_remove(fdset_t *fdset, int fd)
 	memmove(fdset->fds + pos, fdset->fds + (pos + 1), remaining);
 	--fdset->nfds;
 
-	/*! \todo Return memory if unused (issue #1582). */
+	/* Trim excessive memory if possible (retval is not interesting). */
+	mreserve(&fdset->fds, sizeof(struct pollfd), fdset->nfds,
+	         OS_FDS_CHUNKSIZE, &fdset->reserved);
+	
 	return 0;
 }