[libvirt] [PATCH v3 01/10] driver: allow override of connection for secondary drivers

[Daniel P. Berrangé]

When the test suite is running, we don't want to be triggering the
startup of daemons for the secondary drivers. Thus we must provide a way
to set a custom connection for the secondary drivers, to override the
default logic which opens a new connection.

This will also be useful for code where we have a whole set of separate
functions calls all needing the secret driver. Currently the connection
to the secret driver is opened & closed many times in quick
succession. This will allow us to pre-open a connection temporarily,
improving the performance of startup.

Reviewed-by: John Ferlan <jferlan at redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/driver.c             | 184 +++++++++++++++++++++++++++++++++++++++++++++--
 src/driver.h             |   7 ++
 src/libvirt_private.syms |   6 ++
 3 files changed, 191 insertions(+), 6 deletions(-)

diff --git a/src/driver.c b/src/driver.c
index a6a7ff925a..52e1ae345a 100644
--- a/src/driver.c
+++ b/src/driver.c
@@ -28,6 +28,7 @@
 #include "viralloc.h"
 #include "virfile.h"
 #include "virlog.h"
+#include "virthread.h"
 #include "configmake.h"
 
 VIR_LOG_INIT("driver");
@@ -168,32 +169,203 @@ virDriverLoadModule(const char *name,
 
 /* XXX unload modules, but we can't until we can unregister libvirt drivers */
 
+virThreadLocal connectInterface;
+virThreadLocal connectNetwork;
+virThreadLocal connectNWFilter;
+virThreadLocal connectNodeDev;
+virThreadLocal connectSecret;
+virThreadLocal connectStorage;
+
+static int
+virConnectCacheOnceInit(void)
+{
+    if (virThreadLocalInit(&connectInterface, NULL) < 0)
+        return -1;
+    if (virThreadLocalInit(&connectNetwork, NULL) < 0)
+        return -1;
+    if (virThreadLocalInit(&connectNWFilter, NULL) < 0)
+        return -1;
+    if (virThreadLocalInit(&connectNodeDev, NULL) < 0)
+        return -1;
+    if (virThreadLocalInit(&connectSecret, NULL) < 0)
+        return -1;
+    if (virThreadLocalInit(&connectStorage, NULL) < 0)
+        return -1;
+    return 0;
+}
+
+VIR_ONCE_GLOBAL_INIT(virConnectCache);
+
 virConnectPtr virGetConnectInterface(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "interface:///system" : "interface:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectInterface);
+    if (conn) {
+        VIR_DEBUG("Return cached interface connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "interface:///system" : "interface:///session");
+        VIR_DEBUG("Opened new interface connection %p", conn);
+    }
+    return conn;
 }
 
 virConnectPtr virGetConnectNetwork(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "network:///system" : "network:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectNetwork);
+    if (conn) {
+        VIR_DEBUG("Return cached network connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "network:///system" : "network:///session");
+        VIR_DEBUG("Opened new network connection %p", conn);
+    }
+    return conn;
 }
 
 virConnectPtr virGetConnectNWFilter(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "nwfilter:///system" : "nwfilter:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectNWFilter);
+    if (conn) {
+        VIR_DEBUG("Return cached nwfilter connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "nwfilter:///system" : "nwfilter:///session");
+        VIR_DEBUG("Opened new nwfilter connection %p", conn);
+    }
+    return conn;
 }
 
 virConnectPtr virGetConnectNodeDev(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "nodedev:///system" : "nodedev:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectNodeDev);
+    if (conn) {
+        VIR_DEBUG("Return cached nodedev connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "nodedev:///system" : "nodedev:///session");
+        VIR_DEBUG("Opened new nodedev connection %p", conn);
+    }
+    return conn;
 }
 
 virConnectPtr virGetConnectSecret(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "secret:///system" : "secret:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectSecret);
+    if (conn) {
+        VIR_DEBUG("Return cached secret connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "secret:///system" : "secret:///session");
+        VIR_DEBUG("Opened new secret connection %p", conn);
+    }
+    return conn;
 }
 
 virConnectPtr virGetConnectStorage(void)
 {
-    return virConnectOpen(geteuid() == 0 ? "storage:///system" : "storage:///session");
+    virConnectPtr conn;
+
+    if (virConnectCacheInitialize() < 0)
+        return NULL;
+
+    conn = virThreadLocalGet(&connectStorage);
+    if (conn) {
+        VIR_DEBUG("Return cached storage connection %p", conn);
+        virObjectRef(conn);
+    } else {
+        conn = virConnectOpen(geteuid() == 0 ? "storage:///system" : "storage:///session");
+        VIR_DEBUG("Opened new storage connection %p", conn);
+    }
+    return conn;
+}
+
+
+int
+virSetConnectInterface(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override interface connection with %p", conn);
+    return virThreadLocalSet(&connectInterface, conn);
+}
+
+
+int
+virSetConnectNetwork(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override network connection with %p", conn);
+    return virThreadLocalSet(&connectNetwork, conn);
+}
+
+
+int
+virSetConnectNWFilter(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override nwfilter connection with %p", conn);
+    return virThreadLocalSet(&connectNWFilter, conn);
+}
+
+
+int
+virSetConnectNodeDev(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override nodedev connection with %p", conn);
+    return virThreadLocalSet(&connectNodeDev, conn);
+}
+
+
+int
+virSetConnectSecret(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override secret connection with %p", conn);
+    return virThreadLocalSet(&connectSecret, conn);
+}
+
+
+int
+virSetConnectStorage(virConnectPtr conn)
+{
+    if (virConnectCacheInitialize() < 0)
+        return -1;
+
+    VIR_DEBUG("Override storage connection with %p", conn);
+    return virThreadLocalSet(&connectStorage, conn);
 }
diff --git a/src/driver.h b/src/driver.h
index fe0cec0923..c86da85481 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -112,4 +112,11 @@ virConnectPtr virGetConnectNodeDev(void);
 virConnectPtr virGetConnectSecret(void);
 virConnectPtr virGetConnectStorage(void);
 
+int virSetConnectInterface(virConnectPtr conn);
+int virSetConnectNetwork(virConnectPtr conn);
+int virSetConnectNWFilter(virConnectPtr conn);
+int virSetConnectNodeDev(virConnectPtr conn);
+int virSetConnectSecret(virConnectPtr conn);
+int virSetConnectStorage(virConnectPtr conn);
+
 #endif /* __VIR_DRIVER_H__ */
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 3b14d7d158..7b05e4418f 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1202,6 +1202,12 @@ virGetConnectNodeDev;
 virGetConnectNWFilter;
 virGetConnectSecret;
 virGetConnectStorage;
+virSetConnectInterface;
+virSetConnectNetwork;
+virSetConnectNodeDev;
+virSetConnectNWFilter;
+virSetConnectSecret;
+virSetConnectStorage;
 
 
 # libvirt_internal.h
-- 
2.14.3