Re: [Qemu-devel] [PATCH] migration: Use g_new() & friends where that makes obvious sense

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>

On 2015/9/14 19:51, Markus Armbruster wrote:
> g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
> for two reasons.  One, it catches multiplication overflowing size_t.
> Two, it returns T * rather than void *, which lets the compiler catch
> more type errors.
>
> This commit only touches allocations with size arguments of the form
> sizeof(T).  Same Coccinelle semantic patch as in commit b45c03f.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   migration/migration.c       |  2 +-
>   migration/qemu-file-buf.c   |  2 +-
>   migration/qemu-file-stdio.c |  4 ++--
>   migration/qemu-file-unix.c  |  4 ++--
>   migration/qemu-file.c       |  2 +-
>   migration/rdma.c            | 17 ++++++++---------
>   migration/savevm.c          | 12 ++++++------
>   7 files changed, 21 insertions(+), 22 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 662e77e..e0ce401 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -86,7 +86,7 @@ MigrationIncomingState *migration_incoming_get_current(void)
>
>   MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
>   {
> -    mis_current = g_malloc0(sizeof(MigrationIncomingState));
> +    mis_current = g_new0(MigrationIncomingState, 1);
>       mis_current->file = f;
>       QLIST_INIT(&mis_current->loadvm_handlers);
>
> diff --git a/migration/qemu-file-buf.c b/migration/qemu-file-buf.c
> index 2de9330..7adec46 100644
> --- a/migration/qemu-file-buf.c
> +++ b/migration/qemu-file-buf.c
> @@ -439,7 +439,7 @@ QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input)
>           return NULL;
>       }
>
> -    s = g_malloc0(sizeof(QEMUBuffer));
> +    s = g_new0(QEMUBuffer, 1);
>       s->qsb = input;
>
>       if (s->qsb == NULL) {
> diff --git a/migration/qemu-file-stdio.c b/migration/qemu-file-stdio.c
> index 285068b..079caee 100644
> --- a/migration/qemu-file-stdio.c
> +++ b/migration/qemu-file-stdio.c
> @@ -143,7 +143,7 @@ QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
>           return NULL;
>       }
>
> -    s = g_malloc0(sizeof(QEMUFileStdio));
> +    s = g_new0(QEMUFileStdio, 1);
>
>       s->stdio_file = stdio_file;
>
> @@ -175,7 +175,7 @@ QEMUFile *qemu_fopen(const char *filename, const char *mode)
>           return NULL;
>       }
>
> -    s = g_malloc0(sizeof(QEMUFileStdio));
> +    s = g_new0(QEMUFileStdio, 1);
>
>       s->stdio_file = fopen(filename, mode);
>       if (!s->stdio_file) {
> diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c
> index bfbc086..7d80a54 100644
> --- a/migration/qemu-file-unix.c
> +++ b/migration/qemu-file-unix.c
> @@ -192,7 +192,7 @@ QEMUFile *qemu_fdopen(int fd, const char *mode)
>           return NULL;
>       }
>
> -    s = g_malloc0(sizeof(QEMUFileSocket));
> +    s = g_new0(QEMUFileSocket, 1);
>       s->fd = fd;
>
>       if (mode[0] == 'r') {
> @@ -226,7 +226,7 @@ QEMUFile *qemu_fopen_socket(int fd, const char *mode)
>           return NULL;
>       }
>
> -    s = g_malloc0(sizeof(QEMUFileSocket));
> +    s = g_new0(QEMUFileSocket, 1);
>       s->fd = fd;
>       if (mode[0] == 'w') {
>           qemu_set_block(s->fd);
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index 6bb3dc1..6162e7e 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -60,7 +60,7 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
>   {
>       QEMUFile *f;
>
> -    f = g_malloc0(sizeof(QEMUFile));
> +    f = g_new0(QEMUFile, 1);
>
>       f->opaque = opaque;
>       f->ops = ops;
> diff --git a/migration/rdma.c b/migration/rdma.c
> index 9424834..8886fa2 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -541,7 +541,7 @@ static int rdma_add_block(RDMAContext *rdma, const char *block_name,
>       RDMALocalBlock *block;
>       RDMALocalBlock *old = local->block;
>
> -    local->block = g_malloc0(sizeof(RDMALocalBlock) * (local->nb_blocks + 1));
> +    local->block = g_new0(RDMALocalBlock, local->nb_blocks + 1);
>
>       if (local->nb_blocks) {
>           int x;
> @@ -572,7 +572,7 @@ static int rdma_add_block(RDMAContext *rdma, const char *block_name,
>       bitmap_clear(block->transit_bitmap, 0, block->nb_chunks);
>       block->unregister_bitmap = bitmap_new(block->nb_chunks);
>       bitmap_clear(block->unregister_bitmap, 0, block->nb_chunks);
> -    block->remote_keys = g_malloc0(block->nb_chunks * sizeof(uint32_t));
> +    block->remote_keys = g_new0(uint32_t, block->nb_chunks);
>
>       block->is_ram_block = local->init ? false : true;
>
> @@ -617,8 +617,8 @@ static int qemu_rdma_init_ram_blocks(RDMAContext *rdma)
>       memset(local, 0, sizeof *local);
>       qemu_ram_foreach_block(qemu_rdma_init_one_block, rdma);
>       trace_qemu_rdma_init_ram_blocks(local->nb_blocks);
> -    rdma->dest_blocks = (RDMADestBlock *) g_malloc0(sizeof(RDMADestBlock) *
> -                        rdma->local_ram_blocks.nb_blocks);
> +    rdma->dest_blocks = g_new0(RDMADestBlock,
> +                               rdma->local_ram_blocks.nb_blocks);
>       local->init = true;
>       return 0;
>   }
> @@ -677,8 +677,7 @@ static int rdma_delete_block(RDMAContext *rdma, RDMALocalBlock *block)
>
>       if (local->nb_blocks > 1) {
>
> -        local->block = g_malloc0(sizeof(RDMALocalBlock) *
> -                                    (local->nb_blocks - 1));
> +        local->block = g_new0(RDMALocalBlock, local->nb_blocks - 1);
>
>           if (block->index) {
>               memcpy(local->block, old, sizeof(RDMALocalBlock) * block->index);
> @@ -1164,7 +1163,7 @@ static int qemu_rdma_register_and_get_keys(RDMAContext *rdma,
>
>       /* allocate memory to store chunk MRs */
>       if (!block->pmr) {
> -        block->pmr = g_malloc0(block->nb_chunks * sizeof(struct ibv_mr *));
> +        block->pmr = g_new0(struct ibv_mr *, block->nb_chunks);
>       }
>
>       /*
> @@ -2494,7 +2493,7 @@ static void *qemu_rdma_data_init(const char *host_port, Error **errp)
>       InetSocketAddress *addr;
>
>       if (host_port) {
> -        rdma = g_malloc0(sizeof(RDMAContext));
> +        rdma = g_new0(RDMAContext, 1);
>           rdma->current_index = -1;
>           rdma->current_chunk = -1;
>
> @@ -3399,7 +3398,7 @@ static void *qemu_fopen_rdma(RDMAContext *rdma, const char *mode)
>           return NULL;
>       }
>
> -    r = g_malloc0(sizeof(QEMUFileRDMA));
> +    r = g_new0(QEMUFileRDMA, 1);
>       r->rdma = rdma;
>
>       if (mode[0] == 'w') {
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 33e55fe..7914f86 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -480,7 +480,7 @@ int register_savevm_live(DeviceState *dev,
>   {
>       SaveStateEntry *se;
>
> -    se = g_malloc0(sizeof(SaveStateEntry));
> +    se = g_new0(SaveStateEntry, 1);
>       se->version_id = version_id;
>       se->section_id = savevm_state.global_section_id++;
>       se->ops = ops;
> @@ -498,7 +498,7 @@ int register_savevm_live(DeviceState *dev,
>               pstrcat(se->idstr, sizeof(se->idstr), "/");
>               g_free(id);
>
> -            se->compat = g_malloc0(sizeof(CompatEntry));
> +            se->compat = g_new0(CompatEntry, 1);
>               pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), idstr);
>               se->compat->instance_id = instance_id == -1 ?
>                            calculate_compat_instance_id(idstr) : instance_id;
> @@ -526,7 +526,7 @@ int register_savevm(DeviceState *dev,
>                       LoadStateHandler *load_state,
>                       void *opaque)
>   {
> -    SaveVMHandlers *ops = g_malloc0(sizeof(SaveVMHandlers));
> +    SaveVMHandlers *ops = g_new0(SaveVMHandlers, 1);
>       ops->save_state = save_state;
>       ops->load_state = load_state;
>       return register_savevm_live(dev, idstr, instance_id, version_id,
> @@ -568,7 +568,7 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
>       /* If this triggers, alias support can be dropped for the vmsd. */
>       assert(alias_id == -1 || required_for_version >= vmsd->minimum_version_id);
>
> -    se = g_malloc0(sizeof(SaveStateEntry));
> +    se = g_new0(SaveStateEntry, 1);
>       se->version_id = vmsd->version_id;
>       se->section_id = savevm_state.global_section_id++;
>       se->opaque = opaque;
> @@ -582,7 +582,7 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
>               pstrcat(se->idstr, sizeof(se->idstr), "/");
>               g_free(id);
>
> -            se->compat = g_malloc0(sizeof(CompatEntry));
> +            se->compat = g_new0(CompatEntry, 1);
>               pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
>               se->compat->instance_id = instance_id == -1 ?
>                            calculate_compat_instance_id(vmsd->name) : instance_id;
> @@ -1544,7 +1544,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
>           return;
>       }
>
> -    available_snapshots = g_malloc0(sizeof(int) * nb_sns);
> +    available_snapshots = g_new0(int, nb_sns);
>       total = 0;
>       for (i = 0; i < nb_sns; i++) {
>           sn = &sn_tab[i];
>