Switch flow memuse counter to the atomic api.

src/flow-hash.c

@@ -305,7 +305,7 @@ static Flow *FlowGetNew(Packet *p) {
          * 2- by emergency mode timeouts
          * 3- by last time seen
          */
-        if (flow_memuse + sizeof(Flow) > flow_config.memcap) {
+        if (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) > flow_config.memcap) {
             uint32_t not_released = 0;
 
             SCLogDebug("We need to prune some flows(1)");

src/flow-private.h

@@ -27,6 +27,7 @@
 #include "flow-hash.h"
 #include "flow-queue.h"
 
+#include "util-atomic.h"
 
 /* global flow flags */
 
@@ -96,8 +97,8 @@ FlowConfig flow_config;
 
 uint8_t flow_flags;
 
-uint32_t flow_memuse;
-SCMutex flow_memuse_mutex;
+/** flow memuse counter (atomic), for enforcing memcap limit */
+SC_ATOMIC_DECLARE(unsigned int, flow_memuse);
 
 //#define FLOWBITS_STATS
 #ifdef FLOWBITS_STATS

src/flow-util.c

@@ -42,21 +42,16 @@ Flow *FlowAlloc(void)
 {
     Flow *f;
 
-    SCMutexLock(&flow_memuse_mutex);
-    if (flow_memuse + sizeof(Flow) > flow_config.memcap) {
-        SCMutexUnlock(&flow_memuse_mutex);
+    if (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) > flow_config.memcap) {
         return NULL;
     }
-    SCMutexUnlock(&flow_memuse_mutex);
 
     f = SCMalloc(sizeof(Flow));
     if (f == NULL) {
         return NULL;
     }
 
-    SCMutexLock(&flow_memuse_mutex);
-    flow_memuse += sizeof(Flow);
-    SCMutexUnlock(&flow_memuse_mutex);
+    SC_ATOMIC_ADD(flow_memuse, sizeof(Flow));
 
     SCMutexInit(&f->m, NULL);
     f->lnext = NULL;
@@ -71,12 +66,10 @@ Flow *FlowAlloc(void)
 /** free the memory of a flow */
 void FlowFree(Flow *f)
 {
-    SCMutexLock(&flow_memuse_mutex);
-    flow_memuse -= sizeof(Flow);
-    SCMutexUnlock(&flow_memuse_mutex);
-
     SCMutexDestroy(&f->m);
     SCFree(f);
+
+    SC_ATOMIC_SUB(flow_memuse, sizeof(Flow));
 }
 
 /**

src/flow.c

@@ -703,7 +703,7 @@ void FlowInitConfig (char quiet)
         SCLogInfo("initializing flow engine...");
 
     memset(&flow_config,  0, sizeof(flow_config));
-    flow_memuse = 0;
+    SC_ATOMIC_INIT(flow_memuse);
 
     int ifq = 0;
     FlowQueueInit(&flow_spare_q);
@@ -712,7 +712,6 @@ void FlowInitConfig (char quiet)
         FlowQueueInit(&flow_est_q[ifq]);
         FlowQueueInit(&flow_close_q[ifq]);
     }
-    SCMutexInit(&flow_memuse_mutex, NULL);
 
     unsigned int seed = RandomTimePreseed();
     /* set defaults */
@@ -782,25 +781,23 @@ void FlowInitConfig (char quiet)
     memset(flow_hash, 0, flow_config.hash_size * sizeof(FlowBucket));
     for (i = 0; i < flow_config.hash_size; i++)
         SCSpinInit(&flow_hash[i].s, 0);
-    flow_memuse += (flow_config.hash_size * sizeof(FlowBucket));
+    SC_ATOMIC_ADD(flow_memuse, (flow_config.hash_size * sizeof(FlowBucket)));
 
     if (quiet == FALSE)
         SCLogInfo("allocated %" PRIu32 " bytes of memory for the flow hash... "
                   "%" PRIu32 " buckets of size %" PRIuMAX "",
-                  flow_memuse, flow_config.hash_size,
+                  SC_ATOMIC_GET(flow_memuse), flow_config.hash_size,
                   (uintmax_t)sizeof(FlowBucket));
 
     /* pre allocate flows */
     for (i = 0; i < flow_config.prealloc; i++) {
-        if (flow_memuse + sizeof(Flow) > flow_config.memcap) {
-            SCMutexUnlock(&flow_memuse_mutex);
+        if (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) > flow_config.memcap) {
             printf("ERROR: FlowAlloc failed (max flow memcap reached): %s\n", strerror(errno));
             exit(1);
         }
 
         Flow *f = FlowAlloc();
         if (f == NULL) {
-            SCMutexUnlock(&flow_memuse_mutex);
             printf("ERROR: FlowAlloc failed: %s\n", strerror(errno));
             exit(1);
         }
@@ -811,7 +808,7 @@ void FlowInitConfig (char quiet)
         SCLogInfo("preallocated %" PRIu32 " flows of size %" PRIuMAX "",
                 flow_spare_q.len, (uintmax_t)sizeof(Flow));
         SCLogInfo("flow memory usage: %" PRIu32 " bytes, maximum: %" PRIu32 "",
-                flow_memuse, flow_config.memcap);
+                SC_ATOMIC_GET(flow_memuse), flow_config.memcap);
     }
 
     FlowInitFlowProto();
@@ -902,7 +899,7 @@ void FlowShutdown(void) {
         SCFree(flow_hash);
         flow_hash = NULL;
     }
-    flow_memuse -= flow_config.hash_size * sizeof(FlowBucket);
+    SC_ATOMIC_SUB(flow_memuse, flow_config.hash_size * sizeof(FlowBucket));
 
     int ifq = 0;
     FlowQueueDestroy(&flow_spare_q);
@@ -911,8 +908,6 @@ void FlowShutdown(void) {
         FlowQueueDestroy(&flow_est_q[ifq]);
         FlowQueueDestroy(&flow_close_q[ifq]);
     }
-
-    SCMutexDestroy(&flow_memuse_mutex);
 }
 
 /** \brief Thread that manages the various queue's and removes timed out flows.
@@ -1790,7 +1785,7 @@ static int FlowTest07 (void) {
     UTHBuildPacketOfFlows(ini, end, 0);
 
     /* And now let's try to reach the memcap val */
-    while (flow_memuse + sizeof(Flow) < flow_config.memcap) {
+    while (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) < flow_config.memcap) {
         ini = end + 1;
         end = end + 2;
         UTHBuildPacketOfFlows(ini, end, 0);
@@ -1836,7 +1831,7 @@ static int FlowTest08 (void) {
     UTHBuildPacketOfFlows(ini, end, 0);
 
     /* And now let's try to reach the memcap val */
-    while (flow_memuse + sizeof(Flow) < flow_config.memcap) {
+    while (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) < flow_config.memcap) {
         ini = end + 1;
         end = end + 2;
         UTHBuildPacketOfFlows(ini, end, 0);
@@ -1883,7 +1878,7 @@ static int FlowTest09 (void) {
     UTHBuildPacketOfFlows(ini, end, 0);
 
     /* And now let's try to reach the memcap val */
-    while (flow_memuse + sizeof(Flow) < flow_config.memcap) {
+    while (SC_ATOMIC_GET(flow_memuse) + sizeof(Flow) < flow_config.memcap) {
         ini = end + 1;
         end = end + 2;
         UTHBuildPacketOfFlows(ini, end, 0);