From cf4076dba99c227abb293529a447371e1f20f76d Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Mon, 20 Apr 2015 09:56:35 +0200
Subject: [PATCH] test-tool: Make it possible to disable memory caching

Disable memory caching in libiscsi if the environment variable
LIBISCSI_CACHE_ALLOCATIONS has been set to zero. This makes
Valgrind reports more meaningful.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
---
 include/iscsi.h           |  2 ++
 lib/init.c                | 39 ++++++++++++++++++++++++++++-----------
 lib/libiscsi.def          |  1 +
 lib/libiscsi.syms         |  1 +
 test-tool/iscsi-test-cu.c |  5 +++++
 5 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/include/iscsi.h b/include/iscsi.h
index a36f5aa..c8f41bb 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -51,6 +51,8 @@ struct sockaddr;
   "<host>[:<port>]\""
 
 
+EXTERN void iscsi_set_cache_allocations(int ca);
+
 /*
  * The following three functions are used to integrate libiscsi in an event
  * system.
diff --git a/lib/init.c b/lib/init.c
index a9885b1..ea9c5f5 100644
--- a/lib/init.c
+++ b/lib/init.c
@@ -33,6 +33,17 @@
 #include "iscsi-private.h"
 #include "slist.h"
 
+int cache_allocations = 1;
+
+/**
+ * Whether or not the internal memory allocator caches allocations. Disable
+ * memory allocation caching to improve the accuracy of Valgrind reports.
+ */
+void iscsi_set_cache_allocations(int ca)
+{
+	cache_allocations = ca;
+}
+
 void* iscsi_malloc(struct iscsi_context *iscsi, size_t size) {
 	void * ptr = malloc(size);
 	if (ptr != NULL) iscsi->mallocs++;
@@ -94,19 +105,25 @@ void iscsi_sfree(struct iscsi_context *iscsi, void* ptr) {
 	if (ptr == NULL) {
 		return;
 	}
-	if (iscsi->smalloc_free == SMALL_ALLOC_MAX_FREE) {
-		int i;
-		/* SMALL_ALLOC_MAX_FREE should be adjusted that this happens rarely */
-		ISCSI_LOG(iscsi, 6, "smalloc free == SMALLOC_MAX_FREE");
-		/* remove oldest half of free pointers and copy
-		 * upper half to lower half */
-		iscsi->smalloc_free >>= 1;
-		for (i = 0; i < iscsi->smalloc_free; i++) {
-			iscsi_free(iscsi, iscsi->smalloc_ptrs[i]);
-			iscsi->smalloc_ptrs[i] = iscsi->smalloc_ptrs[i + iscsi->smalloc_free];
+	if (cache_allocations) {
+		if (iscsi->smalloc_free == SMALL_ALLOC_MAX_FREE) {
+			int i;
+			/* SMALL_ALLOC_MAX_FREE should be adjusted that this */
+			/* happens rarely */
+			ISCSI_LOG(iscsi, 6, "smalloc free == SMALLOC_MAX_FREE");
+			/* remove oldest half of free pointers and copy
+			 * upper half to lower half */
+			iscsi->smalloc_free >>= 1;
+			for (i = 0; i < iscsi->smalloc_free; i++) {
+				iscsi_free(iscsi, iscsi->smalloc_ptrs[i]);
+				iscsi->smalloc_ptrs[i] =
+				  iscsi->smalloc_ptrs[i + iscsi->smalloc_free];
+			}
 		}
+		iscsi->smalloc_ptrs[iscsi->smalloc_free++] = ptr;
+	} else {
+		iscsi_free(iscsi, ptr);
 	}
-	iscsi->smalloc_ptrs[iscsi->smalloc_free++] = ptr;
 }
 
 struct iscsi_context *
diff --git a/lib/libiscsi.def b/lib/libiscsi.def
index 080c142..fa37fc2 100644
--- a/lib/libiscsi.def
+++ b/lib/libiscsi.def
@@ -76,6 +76,7 @@ iscsi_sanitize_crypto_erase_sync
 iscsi_sanitize_crypto_erase_task
 iscsi_sanitize_exit_failure_mode_sync
 iscsi_sanitize_exit_failure_mode_task
+iscsi_set_cache_allocations
 iscsi_set_noautoreconnect
 iscsi_set_reconnect_max_retries
 iscsi_set_timeout
diff --git a/lib/libiscsi.syms b/lib/libiscsi.syms
index 471e06d..5ca3acf 100644
--- a/lib/libiscsi.syms
+++ b/lib/libiscsi.syms
@@ -74,6 +74,7 @@ iscsi_sanitize_crypto_erase_sync
 iscsi_sanitize_crypto_erase_task
 iscsi_sanitize_exit_failure_mode_sync
 iscsi_sanitize_exit_failure_mode_task
+iscsi_set_cache_allocations
 iscsi_set_noautoreconnect
 iscsi_set_reconnect_max_retries
 iscsi_set_timeout
diff --git a/test-tool/iscsi-test-cu.c b/test-tool/iscsi-test-cu.c
index ae236b2..7aa90f1 100644
--- a/test-tool/iscsi-test-cu.c
+++ b/test-tool/iscsi-test-cu.c
@@ -971,6 +971,11 @@ main(int argc, char *argv[])
 	};
 	int i, c;
 	int opt_idx = 0;
+	char *ca;
+
+	ca = getenv("LIBISCSI_CACHE_ALLOCATIONS");
+	if (ca && atoi(ca) == 0)
+		iscsi_set_cache_allocations(0);
 
 	sd = malloc(sizeof(struct scsi_device));
 	memset(sd, '\0', sizeof(struct scsi_device));