From fd209cb880f6d2d39b6265c09727182b55446bdf Mon Sep 17 00:00:00 2001
From: heyuanjie <heyuanjie>
Date: Sun, 12 Aug 2018 20:26:16 +0800
Subject: [PATCH 1/4] =?UTF-8?q?[lwp]=E6=B7=BB=E5=8A=A0select=E7=B3=BB?=
 =?UTF-8?q?=E7=BB=9F=E8=B0=83=E7=94=A8?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 components/dfs/src/select.c  | 19 ++++++++++++++++---
 components/lwp/lwp_syscall.c |  6 +++++-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/components/dfs/src/select.c b/components/dfs/src/select.c
index c727763991..8b4e417f28 100644
--- a/components/dfs/src/select.c
+++ b/components/dfs/src/select.c
@@ -28,6 +28,19 @@
 #include <dfs_poll.h>
 #include <dfs_select.h>
 
+static void fdzero(fd_set *set, int nfds)
+{
+    fd_mask *m;
+    int n;
+
+    m = (fd_mask*)set;
+    for (n = 0; n < nfds; n += sizeof(fd_mask))
+    {
+        rt_memset(m, 0, sizeof(fd_mask));
+        m ++;
+    }
+}
+
 int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
 {
     int fd;
@@ -113,17 +126,17 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struc
     /* Now set up the return values */
     if (readfds)
     {
-        memset(readfds, 0, sizeof(fd_set));
+        fdzero(readfds, nfds);
     }
 
     if (writefds)
     {
-        memset(writefds, 0, sizeof(fd_set));
+        fdzero(writefds, nfds);
     }
 
     if (exceptfds)
     {
-        memset(exceptfds, 0, sizeof(fd_set));
+        fdzero(exceptfds, nfds);
     }
 
     /* Convert the poll descriptor list back into selects 3 bitsets */
diff --git a/components/lwp/lwp_syscall.c b/components/lwp/lwp_syscall.c
index 1b5aa411aa..0150e50b62 100644
--- a/components/lwp/lwp_syscall.c
+++ b/components/lwp/lwp_syscall.c
@@ -27,6 +27,8 @@
 #include <lwp_syscall.h>
 
 #include <dfs_poll.h>
+#include <dfs_select.h>
+
 #if (defined(RT_USING_SAL) && defined(SAL_USING_POSIX))
 #include <sys/socket.h>
 
@@ -235,7 +237,7 @@ const static void* func_table[] =
 
     (void *)sys_gettimeofday,   // 0x0b
     (void *)sys_settimeofday,   // 0x0c
-        
+
     (void *)sys_malloc,         // 0x0d
     (void *)sys_free,           // 0x0e
     (void *)sys_realloc,      //0x0f
@@ -256,6 +258,8 @@ const static void* func_table[] =
     SYSCALL_NET(send),       // 0x1d
     SYSCALL_NET(sendto),     // 0x1e
     SYSCALL_NET(socket),     // 0x1f
+
+    select,                  // 0x20
 };
 
 const void *lwp_get_sys_api(rt_uint32_t number)

From d948dba42a7b2a219508ac28cf78e6e44f835dcf Mon Sep 17 00:00:00 2001
From: heyuanjie87 <sc943313837@gmail.com>
Date: Sun, 12 Aug 2018 20:41:56 +0800
Subject: [PATCH 2/4] update select.c

---
 components/dfs/src/select.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/dfs/src/select.c b/components/dfs/src/select.c
index 8b4e417f28..3c83ac109c 100644
--- a/components/dfs/src/select.c
+++ b/components/dfs/src/select.c
@@ -34,7 +34,7 @@ static void fdzero(fd_set *set, int nfds)
     int n;
 
     m = (fd_mask*)set;
-    for (n = 0; n < nfds; n += sizeof(fd_mask))
+    for (n = 0; n < nfds; n += (sizeof(fd_mask) * 8))
     {
         rt_memset(m, 0, sizeof(fd_mask));
         m ++;

From c90b449dac29e3e5a46a20988b043d283d3405d6 Mon Sep 17 00:00:00 2001
From: heyuanjie87 <sc943313837@gmail.com>
Date: Mon, 13 Aug 2018 22:42:09 +0800
Subject: [PATCH 3/4] Update select.c

---
 components/dfs/src/select.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/components/dfs/src/select.c b/components/dfs/src/select.c
index 3c83ac109c..339d506c7f 100644
--- a/components/dfs/src/select.c
+++ b/components/dfs/src/select.c
@@ -32,7 +32,11 @@ static void fdzero(fd_set *set, int nfds)
 {
     fd_mask *m;
     int n;
-
+    
+    /*
+      The 'sizeof(fd_set)' of the system space may differ from user space,
+      so the actual size of the 'fd_set' is determined here with the parameter 'nfds'
+    */
     m = (fd_mask*)set;
     for (n = 0; n < nfds; n += (sizeof(fd_mask) * 8))
     {

From 18510fa80fef9751228935ef31e0b9fab9e3cdcc Mon Sep 17 00:00:00 2001
From: heyuanjie87 <sc943313837@gmail.com>
Date: Tue, 14 Aug 2018 09:33:22 +0800
Subject: [PATCH 4/4] Update select.c

---
 components/dfs/src/select.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/components/dfs/src/select.c b/components/dfs/src/select.c
index 339d506c7f..cbbd159557 100644
--- a/components/dfs/src/select.c
+++ b/components/dfs/src/select.c
@@ -28,7 +28,7 @@
 #include <dfs_poll.h>
 #include <dfs_select.h>
 
-static void fdzero(fd_set *set, int nfds)
+static void fdszero(fd_set *set, int nfds)
 {
     fd_mask *m;
     int n;
@@ -130,17 +130,17 @@ int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struc
     /* Now set up the return values */
     if (readfds)
     {
-        fdzero(readfds, nfds);
+        fdszero(readfds, nfds);
     }
 
     if (writefds)
     {
-        fdzero(writefds, nfds);
+        fdszero(writefds, nfds);
     }
 
     if (exceptfds)
     {
-        fdzero(exceptfds, nfds);
+        fdszero(exceptfds, nfds);
     }
 
     /* Convert the poll descriptor list back into selects 3 bitsets */