c语言put_msg方法,MSG结构,

MSG结构体在Windows程序中用于保存消息,包括窗口句柄(hwnd)、消息类型(message)、附加信息(wParam和lParam)、消息时间(time)和鼠标位置(pt)。消息类型如WM_LBUTTONDOWN、WM_KEYDOWN等,wParam和lParam的含义随消息变化,如在WM_SIZE消息中,lParam表示客户区大小。

MSG结构,

MSG是Windows程序中的结构体,用于保存windows消息,

定义:

typedef structtagMSG {

HWND hwnd;//该消息所属的窗口句柄

UINT message; //指定消息的类型

WPARAM wParam; //用于指定消息的附加信息,根据消息不同,代表不同意思

LPARAM lParam; //用于指定消息的附加信息,根据消息不同,代表不同意思

DWORD time; //该消息投递到消息列队当中的时间

POINT pt; //该消息投递到消息列队当时,鼠标的当前位置

} MSG, *PMSG, NEAR *NPMSG, FAR *LPMSG;

第一个参数:hwnd

hwnd是一个窗口句柄,用于区别该消息属于哪一个窗口,可以说是一个窗口的编号。

一个消息一般都与某个窗口相关联,比如鼠标移动到某个窗口中按下鼠标左键,

该窗口就会收到一个“WM_LBUTTONDOWND”的消息,而应用程序就是利用消息中的hwnd值来

确定该消息到底是属于众多窗口中的哪一个窗口的。

第二个参数:message

为消息类型,该值为一个数值,不同的数值表示不同的消息,为了便于记忆,windows

为不同的消息定义了不同的宏,WM_XXX。(WM是windows message的缩写),例如

WM_LBUTTONDOWN 消息  按下鼠标左键的消息是

WM_KEYDOWN 消息 表示按下键盘上的某个键等等。

第三个参数:wParam

WPARAM类型 根据不同的消息 代表不同的意思:例如

当收到 WM_LBUTTONDOWN 消息时,wParam 鼠标按钮、Shift和Ctrl键的状态。

第四个参数:lParam

LPARAM类型 WPARAM类型

/* * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1 * as published by the Free Software Foundation * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <sys/types.h> #include <sys/socket.h> #include <unistd.h> #include <fcntl.h> #include <libubox/blob.h> #include <libubox/blobmsg.h> #include "libubus.h" #include "libubus-internal.h" #include "ubusmsg.h" const char *__ubus_strerror[__UBUS_STATUS_LAST] = { [UBUS_STATUS_OK] = "Success", [UBUS_STATUS_INVALID_COMMAND] = "Invalid command", [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument", [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found", [UBUS_STATUS_NOT_FOUND] = "Not found", [UBUS_STATUS_NO_DATA] = "No response", [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied", [UBUS_STATUS_TIMEOUT] = "Request timed out", [UBUS_STATUS_NOT_SUPPORTED] = "Operation not supported", [UBUS_STATUS_UNKNOWN_ERROR] = "Unknown error", [UBUS_STATUS_CONNECTION_FAILED] = "Connection failed", [UBUS_STATUS_NO_MEMORY] = "Out of memory", [UBUS_STATUS_PARSE_ERROR] = "Parsing message data failed", [UBUS_STATUS_SYSTEM_ERROR] = "System error", }; struct blob_buf b __hidden = {}; struct ubus_pending_msg { struct list_head list; struct ubus_msghdr_buf hdr; }; static int ubus_cmp_id(const void *k1, const void *k2, void *ptr) { const uint32_t *id1 = k1, *id2 = k2; if (*id1 < *id2) return -1; else return *id1 > *id2; } const char *ubus_strerror(int error) { static char err[32]; if (error < 0 || error >= __UBUS_STATUS_LAST) goto out; if (!__ubus_strerror[error]) goto out; return __ubus_strerror[error]; out: sprintf(err, "Unknown error: %d", error); return err; } static void ubus_queue_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf) { struct ubus_pending_msg *pending; void *data; pending = calloc_a(sizeof(*pending), &data, blob_raw_len(buf->data)); pending->hdr.data = data; memcpy(&pending->hdr.hdr, &buf->hdr, sizeof(buf->hdr)); memcpy(data, buf->data, blob_raw_len(buf->data)); list_add_tail(&pending->list, &ctx->pending); if (ctx->sock.registered) uloop_timeout_set(&ctx->pending_timer, 1); } void __hidden ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd) { switch(buf->hdr.type) { case UBUS_MSG_STATUS: case UBUS_MSG_DATA: ubus_process_req_msg(ctx, buf, fd); break; case UBUS_MSG_UNSUBSCRIBE: case UBUS_MSG_NOTIFY: if (ubus_context_is_channel(ctx)) break; /* fallthrough */ case UBUS_MSG_INVOKE: if (ctx->stack_depth) { ubus_queue_msg(ctx, buf); break; } ctx->stack_depth++; ubus_process_obj_msg(ctx, buf, fd); ctx->stack_depth--; break; case UBUS_MSG_MONITOR: if (ubus_context_is_channel(ctx)) break; if (ctx->monitor_cb) ctx->monitor_cb(ctx, buf->hdr.seq, buf->data); break; } } static void ubus_process_pending_msg(struct uloop_timeout *timeout) { struct ubus_context *ctx = container_of(timeout, struct ubus_context, pending_timer); struct ubus_pending_msg *pending; while (!list_empty(&ctx->pending)) { if (ctx->stack_depth) break; pending = list_first_entry(&ctx->pending, struct ubus_pending_msg, list); list_del(&pending->list); ubus_process_msg(ctx, &pending->hdr, -1); free(pending); } } struct ubus_lookup_request { struct ubus_request req; ubus_lookup_handler_t cb; }; static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg) { struct ubus_lookup_request *req; struct ubus_object_data obj = {}; struct blob_attr **attr; req = container_of(ureq, struct ubus_lookup_request, req); attr = ubus_parse_msg(msg, blob_raw_len(msg)); if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] || !attr[UBUS_ATTR_OBJTYPE]) return; obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]); obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]); obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]); obj.signature = attr[UBUS_ATTR_SIGNATURE]; req->cb(ureq->ctx, &obj, ureq->priv); } int ubus_lookup(struct ubus_context *ctx, const char *path, ubus_lookup_handler_t cb, void *priv) { struct ubus_lookup_request lookup; if (ubus_context_is_channel(ctx)) return UBUS_STATUS_INVALID_ARGUMENT; blob_buf_init(&b, 0); if (path) blob_put_string(&b, UBUS_ATTR_OBJPATH, path); if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0) return UBUS_STATUS_INVALID_ARGUMENT; lookup.req.raw_data_cb = ubus_lookup_cb; lookup.req.priv = priv; lookup.cb = cb; return ubus_complete_request(ctx, &lookup.req, 0); } static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg) { struct blob_attr **attr; uint32_t *id = req->priv; attr = ubus_parse_msg(msg, blob_raw_len(msg)); if (!attr[UBUS_ATTR_OBJID]) return; *id = blob_get_u32(attr[UBUS_ATTR_OBJID]); } int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id) { struct ubus_request req; if (ubus_context_is_channel(ctx)) return UBUS_STATUS_INVALID_ARGUMENT; blob_buf_init(&b, 0); if (path) blob_put_string(&b, UBUS_ATTR_OBJPATH, path); if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0) return UBUS_STATUS_INVALID_ARGUMENT; req.raw_data_cb = ubus_lookup_id_cb; req.priv = id; return ubus_complete_request(ctx, &req, 0); } static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj, struct ubus_request_data *req, const char *method, struct blob_attr *msg) { struct ubus_event_handler *ev; ev = container_of(obj, struct ubus_event_handler, obj); ev->cb(ctx, ev, method, msg); return 0; } static const struct ubus_method event_method = { .name = NULL, .handler = ubus_event_cb, }; int ubus_register_event_handler(struct ubus_context *ctx, struct ubus_event_handler *ev, const char *pattern) { struct ubus_object *obj = &ev->obj; struct blob_buf b2 = {}; int ret; if (ubus_context_is_channel(ctx)) return UBUS_STATUS_INVALID_ARGUMENT; if (!obj->id) { obj->methods = &event_method; obj->n_methods = 1; if (!!obj->name ^ !!obj->type) return UBUS_STATUS_INVALID_ARGUMENT; ret = ubus_add_object(ctx, obj); if (ret) return ret; } /* use a second buffer, ubus_invoke() overwrites the primary one */ blob_buf_init(&b2, 0); blobmsg_add_u32(&b2, "object", obj->id); if (pattern) blobmsg_add_string(&b2, "pattern", pattern); ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head, NULL, NULL, 0); blob_buf_free(&b2); return ret; } int ubus_send_event(struct ubus_context *ctx, const char *id, struct blob_attr *data) { struct ubus_request req; void *s; blob_buf_init(&b, 0); blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT); blob_put_string(&b, UBUS_ATTR_METHOD, "send"); s = blob_nest_start(&b, UBUS_ATTR_DATA); blobmsg_add_string(&b, "id", id); blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data)); blob_nest_end(&b, s); if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0) return UBUS_STATUS_INVALID_ARGUMENT; return ubus_complete_request(ctx, &req, 0); } static void ubus_default_connection_lost(struct ubus_context *ctx) { if (ctx->sock.registered) uloop_end(); } static int __ubus_ctx_init(struct ubus_context *ctx) { uloop_init(); memset(ctx, 0, sizeof(*ctx)); ctx->sock.fd = -1; ctx->sock.cb = ubus_handle_data; ctx->connection_lost = ubus_default_connection_lost; ctx->pending_timer.cb = ubus_process_pending_msg; ctx->msgbuf.data = calloc(1, UBUS_MSG_CHUNK_SIZE); if (!ctx->msgbuf.data) return -1; ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE; INIT_LIST_HEAD(&ctx->requests); INIT_LIST_HEAD(&ctx->pending); avl_init(&ctx->objects, ubus_cmp_id, false, NULL); return 0; } int ubus_connect_ctx(struct ubus_context *ctx, const char *path) { if (__ubus_ctx_init(ctx)) return -1; INIT_LIST_HEAD(&ctx->auto_subscribers); if (ubus_reconnect(ctx, path)) { free(ctx->msgbuf.data); ctx->msgbuf.data = NULL; return -1; } return 0; } int ubus_channel_connect(struct ubus_context *ctx, int fd, ubus_handler_t handler) { if (__ubus_ctx_init(ctx)) return -1; if (ctx->sock.fd >= 0) { if (ctx->sock.registered) uloop_fd_delete(&ctx->sock); close(ctx->sock.fd); } ctx->sock.eof = false; ctx->sock.error = false; ctx->sock.fd = fd; ctx->local_id = UBUS_CLIENT_ID_CHANNEL; ctx->request_handler = handler; fcntl(ctx->sock.fd, F_SETFL, fcntl(ctx->sock.fd, F_GETFL) | O_NONBLOCK | O_CLOEXEC); return 0; } int ubus_channel_create(struct ubus_context *ctx, int *remote_fd, ubus_handler_t handler) { int sfd[2]; if (socketpair(AF_UNIX, SOCK_STREAM, 0, sfd)) return -1; if (ubus_channel_connect(ctx, sfd[0], handler) < 0) { close(sfd[0]); close(sfd[1]); return -1; } *remote_fd = sfd[1]; return 0; } static void ubus_auto_reconnect_cb(struct uloop_timeout *timeout) { struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer); if (!ubus_reconnect(&conn->ctx, conn->path)) ubus_add_uloop(&conn->ctx); else uloop_timeout_set(timeout, 1000); } static void ubus_auto_disconnect_cb(struct ubus_context *ctx) { struct ubus_auto_conn *conn = container_of(ctx, struct ubus_auto_conn, ctx); conn->timer.cb = ubus_auto_reconnect_cb; uloop_timeout_set(&conn->timer, 1000); } static void ubus_auto_connect_cb(struct uloop_timeout *timeout) { struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer); if (ubus_connect_ctx(&conn->ctx, conn->path)) { uloop_timeout_set(timeout, 1000); fprintf(stderr, "failed to connect to ubus\n"); return; } conn->ctx.connection_lost = ubus_auto_disconnect_cb; if (conn->cb) conn->cb(&conn->ctx); ubus_add_uloop(&conn->ctx); } void ubus_auto_connect(struct ubus_auto_conn *conn) { conn->timer.cb = ubus_auto_connect_cb; ubus_auto_connect_cb(&conn->timer); } struct ubus_context *ubus_connect(const char *path) { struct ubus_context *ctx; ctx = calloc(1, sizeof(*ctx)); if (!ctx) return NULL; if (ubus_connect_ctx(ctx, path)) { free(ctx); ctx = NULL; } return ctx; } void ubus_shutdown(struct ubus_context *ctx) { blob_buf_free(&b); if (!ctx) return; uloop_fd_delete(&ctx->sock); close(ctx->sock.fd); uloop_timeout_cancel(&ctx->pending_timer); free(ctx->msgbuf.data); } void ubus_free(struct ubus_context *ctx) { ubus_shutdown(ctx); free(ctx); } 解读为主
最新发布
08-22
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