[libvirt] [go PATCH 24/37] nwfilter: fix error reporting thread safety

[Daniel P. Berrangé]

Create wrapper functions for each nwfilter C API that accepts a
virErrorPtr parameter. This avoids accessing a thread local from a
goroutine which may race with other goroutines doing native API calls in
the same OS thread.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 nwfilter.go         | 35 ++++++++++--------
 nwfilter_wrapper.go | 88 +++++++++++++++++++++++++++++++++++++++++++++
 nwfilter_wrapper.h  | 33 +++++++++++++++++
 3 files changed, 142 insertions(+), 14 deletions(-)

diff --git a/nwfilter.go b/nwfilter.go
index 441fcca..0b55c41 100644
--- a/nwfilter.go
+++ b/nwfilter.go
@@ -43,36 +43,40 @@ type NWFilter struct {
 
 // See also https://libvirt.org/html/libvirt-libvirt-nwfilter.html#virNWFilterFree
 func (f *NWFilter) Free() error {
-	ret := C.virNWFilterFree(f.ptr)
+	var err C.virError
+	ret := C.virNWFilterFreeWrapper(f.ptr, &err)
 	if ret == -1 {
-		return GetLastError()
+		return makeError(&err)
 	}
 	return nil
 }
 
 // See also https://libvirt.org/html/libvirt-libvirt-nwfilter.html#virNWFilterRef
 func (c *NWFilter) Ref() error {
-	ret := C.virNWFilterRef(c.ptr)
+	var err C.virError
+	ret := C.virNWFilterRefWrapper(c.ptr, &err)
 	if ret == -1 {
-		return GetLastError()
+		return makeError(&err)
 	}
 	return nil
 }
 
 // See also https://libvirt.org/html/libvirt-libvirt-nwfilter.html#virNWFilterGetName
 func (f *NWFilter) GetName() (string, error) {
-	name := C.virNWFilterGetName(f.ptr)
+	var err C.virError
+	name := C.virNWFilterGetNameWrapper(f.ptr, &err)
 	if name == nil {
-		return "", GetLastError()
+		return "", makeError(&err)
 	}
 	return C.GoString(name), nil
 }
 
 // See also https://libvirt.org/html/libvirt-libvirt-nwfilter.html#virNWFilterUndefine
 func (f *NWFilter) Undefine() error {
-	result := C.virNWFilterUndefine(f.ptr)
+	var err C.virError
+	result := C.virNWFilterUndefineWrapper(f.ptr, &err)
 	if result == -1 {
-		return GetLastError()
+		return makeError(&err)
 	}
 	return nil
 }
@@ -81,9 +85,10 @@ func (f *NWFilter) Undefine() error {
 func (f *NWFilter) GetUUID() ([]byte, error) {
 	var cUuid [C.VIR_UUID_BUFLEN](byte)
 	cuidPtr := unsafe.Pointer(&cUuid)
-	result := C.virNWFilterGetUUID(f.ptr, (*C.uchar)(cuidPtr))
+	var err C.virError
+	result := C.virNWFilterGetUUIDWrapper(f.ptr, (*C.uchar)(cuidPtr), &err)
 	if result != 0 {
-		return []byte{}, GetLastError()
+		return []byte{}, makeError(&err)
 	}
 	return C.GoBytes(cuidPtr, C.VIR_UUID_BUFLEN), nil
 }
@@ -92,18 +97,20 @@ func (f *NWFilter) GetUUID() ([]byte, error) {
 func (f *NWFilter) GetUUIDString() (string, error) {
 	var cUuid [C.VIR_UUID_STRING_BUFLEN](C.char)
 	cuidPtr := unsafe.Pointer(&cUuid)
-	result := C.virNWFilterGetUUIDString(f.ptr, (*C.char)(cuidPtr))
+	var err C.virError
+	result := C.virNWFilterGetUUIDStringWrapper(f.ptr, (*C.char)(cuidPtr), &err)
 	if result != 0 {
-		return "", GetLastError()
+		return "", makeError(&err)
 	}
 	return C.GoString((*C.char)(cuidPtr)), nil
 }
 
 // See also https://libvirt.org/html/libvirt-libvirt-nwfilter.html#virNWFilterGetXMLDesc
 func (f *NWFilter) GetXMLDesc(flags uint32) (string, error) {
-	result := C.virNWFilterGetXMLDesc(f.ptr, C.uint(flags))
+	var err C.virError
+	result := C.virNWFilterGetXMLDescWrapper(f.ptr, C.uint(flags), &err)
 	if result == nil {
-		return "", GetLastError()
+		return "", makeError(&err)
 	}
 	xml := C.GoString(result)
 	C.free(unsafe.Pointer(result))
diff --git a/nwfilter_wrapper.go b/nwfilter_wrapper.go
index 78d0487..809e527 100644
--- a/nwfilter_wrapper.go
+++ b/nwfilter_wrapper.go
@@ -30,5 +30,93 @@ package libvirt
 #include <assert.h>
 #include "nwfilter_wrapper.h"
 
+
+int
+virNWFilterFreeWrapper(virNWFilterPtr nwfilter,
+                       virErrorPtr err)
+{
+    int ret = virNWFilterFree(nwfilter);
+    if (ret < 0) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+const char *
+virNWFilterGetNameWrapper(virNWFilterPtr nwfilter,
+                          virErrorPtr err)
+{
+    const char * ret = virNWFilterGetName(nwfilter);
+    if (!ret) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+int
+virNWFilterGetUUIDWrapper(virNWFilterPtr nwfilter,
+                          unsigned char *uuid,
+                          virErrorPtr err)
+{
+    int ret = virNWFilterGetUUID(nwfilter, uuid);
+    if (ret < 0) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+int
+virNWFilterGetUUIDStringWrapper(virNWFilterPtr nwfilter,
+                                char *buf,
+                                virErrorPtr err)
+{
+    int ret = virNWFilterGetUUIDString(nwfilter, buf);
+    if (ret < 0) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+char *
+virNWFilterGetXMLDescWrapper(virNWFilterPtr nwfilter,
+                             unsigned int flags,
+                             virErrorPtr err)
+{
+    char * ret = virNWFilterGetXMLDesc(nwfilter, flags);
+    if (!ret) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+int
+virNWFilterRefWrapper(virNWFilterPtr nwfilter,
+                      virErrorPtr err)
+{
+    int ret = virNWFilterRef(nwfilter);
+    if (ret < 0) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
+int
+virNWFilterUndefineWrapper(virNWFilterPtr nwfilter,
+                           virErrorPtr err)
+{
+    int ret = virNWFilterUndefine(nwfilter);
+    if (ret < 0) {
+        virCopyLastError(err);
+    }
+    return ret;
+}
+
+
 */
 import "C"
diff --git a/nwfilter_wrapper.h b/nwfilter_wrapper.h
index c470366..9a0651c 100644
--- a/nwfilter_wrapper.h
+++ b/nwfilter_wrapper.h
@@ -29,4 +29,37 @@
 #include <libvirt/libvirt.h>
 #include <libvirt/virterror.h>
 
+
+int
+virNWFilterFreeWrapper(virNWFilterPtr nwfilter,
+                       virErrorPtr err);
+
+const char *
+virNWFilterGetNameWrapper(virNWFilterPtr nwfilter,
+                          virErrorPtr err);
+
+int
+virNWFilterGetUUIDWrapper(virNWFilterPtr nwfilter,
+                          unsigned char *uuid,
+                          virErrorPtr err);
+
+int
+virNWFilterGetUUIDStringWrapper(virNWFilterPtr nwfilter,
+                                char *buf,
+                                virErrorPtr err);
+
+char *
+virNWFilterGetXMLDescWrapper(virNWFilterPtr nwfilter,
+                             unsigned int flags,
+                             virErrorPtr err);
+
+int
+virNWFilterRefWrapper(virNWFilterPtr nwfilter,
+                      virErrorPtr err);
+
+int
+virNWFilterUndefineWrapper(virNWFilterPtr nwfilter,
+                           virErrorPtr err);
+
+
 #endif /* LIBVIRT_GO_NWFILTER_WRAPPER_H__ */
-- 
2.17.1