[lwP] Add light weight process component.

2 files changed, 125 insertions, 16 deletions

diff --git a/components/dfs/include/dfs.h b/components/dfs/include/dfs.h
index 91ef42ab56..f17458bd69 100644
--- a/components/dfs/include/dfs.h
+++ b/components/dfs/include/dfs.h
@@ -95,6 +95,12 @@ struct dirent
     char d_name[DFS_PATH_MAX];   /* The null-terminated file name */
 };
 
+struct dfs_fdtable
+{
+    uint32_t maxfd;
+    struct dfs_fd **fds;
+};
+
 /* Initialization of dfs */
 int dfs_init(void);
 
@@ -110,6 +116,8 @@ struct dfs_fd *fd_get(int fd);
 void fd_put(struct dfs_fd *fd);
 int fd_is_open(const char *pathname);
 
+struct dfs_fdtable* dfs_fdtable_get(void);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/dfs/src/dfs.c b/components/dfs/src/dfs.c
index 858399fd13..f613168a4c 100644
--- a/components/dfs/src/dfs.c
+++ b/components/dfs/src/dfs.c
@@ -21,12 +21,16 @@
  * Date           Author       Notes
  * 2005-02-22     Bernard      The first version.
  * 2017-12-11     Bernard      Use rt_free to instead of free in fd_is_open().
+ * 2018-03-20     Heyuanjie    dynamic allocation FD
  */
 
 #include <dfs.h>
 #include <dfs_fs.h>
 #include <dfs_file.h>
 #include "dfs_private.h"
+#ifdef RT_USING_LWP
+#include <lwp.h>
+#endif
 
 /* Global variables */
 const struct dfs_filesystem_ops *filesystem_operation_table[DFS_FILESYSTEM_TYPES_MAX];
@@ -39,7 +43,8 @@ static struct rt_mutex fslock;
 char working_directory[DFS_PATH_MAX] = {"/"};
 #endif
 
-struct dfs_fd fd_table[DFS_FD_MAX];
+static struct dfs_fdtable _fdtab;
+static int  fd_alloc(struct dfs_fdtable *fdt, int startfd);
 
 /**
  * @addtogroup DFS
@@ -57,7 +62,7 @@ int dfs_init(void)
     /* clear filesystem table */
     memset(filesystem_table, 0, sizeof(filesystem_table));
     /* clean fd table */
-    memset(fd_table, 0, sizeof(fd_table));
+    memset(&_fdtab, 0, sizeof(_fdtab));
 
     /* create device filesystem lock */
     rt_mutex_init(&fslock, "fslock", RT_IPC_FLAG_FIFO);
@@ -90,9 +95,13 @@ INIT_PREV_EXPORT(dfs_init);
  */
 void dfs_lock(void)
 {
-    rt_err_t result;
+    rt_err_t result = -RT_EBUSY;
+
+    while (result == -RT_EBUSY)
+    {
+        result = rt_mutex_take(&fslock, RT_WAITING_FOREVER);
+    }
 
-    result = rt_mutex_take(&fslock, RT_WAITING_FOREVER);
     if (result != RT_EOK)
     {
         RT_ASSERT(0);
@@ -109,6 +118,54 @@ void dfs_unlock(void)
     rt_mutex_release(&fslock);
 }
 
+static int fd_alloc(struct dfs_fdtable *fdt, int startfd)
+{
+    int idx;
+
+    /* find an empty fd entry */
+    for (idx = startfd; idx < fdt->maxfd; idx++)
+    {
+        if (fdt->fds[idx] == RT_NULL)
+            break;
+        if (fdt->fds[idx]->ref_count == 0)
+            break;
+    }
+
+    /* allocate a larger FD container */
+    if (idx == fdt->maxfd && fdt->maxfd < DFS_FD_MAX)
+    {
+        int cnt, index;
+        struct dfs_fd **fds;
+
+        /* increase the number of FD with 4 step length */
+        cnt = fdt->maxfd + 4;
+        cnt = cnt > DFS_FD_MAX? DFS_FD_MAX : cnt;
+
+        fds = rt_realloc(fdt->fds, cnt * sizeof(struct dfs_fd *));
+        if (fds == NULL) goto __out; /* return fdt->maxfd */
+
+        /* clean the new allocated fds */
+        for (index = fdt->maxfd; index < cnt; index ++)
+        {
+            fds[index] = NULL;
+        }
+
+        fdt->fds   = fds;
+        fdt->maxfd = cnt;
+    }
+
+    /* allocate  'struct dfs_fd' */
+    if (idx < fdt->maxfd &&fdt->fds[idx] == RT_NULL)
+    {
+        fdt->fds[idx] = rt_malloc(sizeof(struct dfs_fd));
+        if (fdt->fds[idx] == RT_NULL)
+            idx = fdt->maxfd;
+    }
+
+__out:
+    return idx;
+}
+
 /**
  * @ingroup Fd
  * This function will allocate a file descriptor.
@@ -119,21 +176,23 @@ int fd_new(void)
 {
     struct dfs_fd *d;
     int idx;
+    struct dfs_fdtable *fdt;
 
+    fdt = dfs_fdtable_get();
     /* lock filesystem */
     dfs_lock();
 
     /* find an empty fd entry */
-    for (idx = 0; idx < DFS_FD_MAX && fd_table[idx].ref_count > 0; idx++);
+    idx = fd_alloc(fdt, 0);
 
     /* can't find an empty fd entry */
-    if (idx == DFS_FD_MAX)
+    if (idx == fdt->maxfd)
     {
         idx = -(1 + DFS_FD_OFFSET);
         goto __result;
     }
 
-    d = &(fd_table[idx]);
+    d = fdt->fds[idx];
     d->ref_count = 1;
     d->magic = DFS_FD_MAGIC;
 
@@ -154,13 +213,15 @@ __result:
 struct dfs_fd *fd_get(int fd)
 {
     struct dfs_fd *d;
+    struct dfs_fdtable *fdt;
 
+    fdt = dfs_fdtable_get();
     fd = fd - DFS_FD_OFFSET;
-    if (fd < 0 || fd >= DFS_FD_MAX)
+    if (fd < 0 || fd >= fdt->maxfd)
         return NULL;
 
     dfs_lock();
-    d = &fd_table[fd];
+    d = fdt->fds[fd];
 
     /* check dfs_fd valid or not */
     if (d->magic != DFS_FD_MAGIC)
@@ -186,12 +247,25 @@ void fd_put(struct dfs_fd *fd)
     RT_ASSERT(fd != NULL);
 
     dfs_lock();
+
     fd->ref_count --;
 
     /* clear this fd entry */
     if (fd->ref_count == 0)
     {
-        memset(fd, 0, sizeof(struct dfs_fd));
+        int index;
+        struct dfs_fdtable *fdt;
+
+        fdt = dfs_fdtable_get();
+        for (index = 0; index < fdt->maxfd; index ++)
+        {
+            if (fdt->fds[index] == fd)
+            {
+                rt_free(fd);
+                fdt->fds[index] = 0;
+                break;
+            }
+        }
     }
     dfs_unlock();
 }
@@ -211,7 +285,9 @@ int fd_is_open(const char *pathname)
     unsigned int index;
     struct dfs_filesystem *fs;
     struct dfs_fd *fd;
+    struct dfs_fdtable *fdt;
 
+    fdt = dfs_fdtable_get();
     fullpath = dfs_normalize_path(NULL, pathname);
     if (fullpath != NULL)
     {
@@ -233,11 +309,10 @@ int fd_is_open(const char *pathname)
 
         dfs_lock();
 
-        for (index = 0; index < DFS_FD_MAX; index++)
+        for (index = 0; index < fdt->maxfd; index++)
         {
-            fd = &(fd_table[index]);
-            if (fd->fops == NULL)
-                continue;
+            fd = fdt->fds[index];
+            if (fd == NULL) continue;
 
             if (fd->fops == fs->ops->fops && strcmp(fd->path, mountpath) == 0)
             {
@@ -414,17 +489,43 @@ up_one:
     return fullpath;
 }
 RTM_EXPORT(dfs_normalize_path);
+
+/**
+ * This function will get the file descriptor table of current process.
+ */
+struct dfs_fdtable* dfs_fdtable_get(void)
+{
+    struct dfs_fdtable *fdt;
+#ifdef RT_USING_LWP
+	struct rt_lwp *lwp;
+
+	lwp = (struct rt_lwp *)rt_thread_self()->user_data;
+    if (lwp)
+		fdt = &lwp->fdt;
+	else
+		fdt = &_fdtab;
+#else
+    fdt = &_fdtab;
+#endif
+
+    return fdt;
+}
+
 #ifdef RT_USING_FINSH
 #include <finsh.h>
 int list_fd(void)
 {
     int index;
+    struct dfs_fdtable *fd_table;
+    
+    fd_table = dfs_fdtable_get();
+    if (!fd_table) return -1;
 
     rt_enter_critical();
 
-    for (index = 0; index < DFS_FD_MAX; index ++)
+    for (index = 0; index < fd_table->maxfd; index ++)
     {
-        struct dfs_fd *fd = &(fd_table[index]);
+        struct dfs_fd *fd = fd_table->fds[index];
 
         if (fd->fops)
         {