[Kernel] Add signal implementation.

1. Add signal implementation;
2. Change the 'rt_uint8_t' of cmd to 'int';

1 files changed, 382 insertions, 0 deletions

diff --git a/src/signal.c b/src/signal.c
new file mode 100644
index 0000000000..d70d25087b
--- /dev/null
+++ b/src/signal.c
@@ -0,0 +1,382 @@
+/*
+ * File      : signal.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2017, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2017/10/5      Bernard      the first version
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <rthw.h>
+#include <rtthread.h>
+
+#ifdef RT_USING_SIGNALS
+
+#ifndef RT_SIG_INFO_MAX
+#define RT_SIG_INFO_MAX	32
+#endif
+
+// #define DBG_ENABLE
+#define DBG_SECTION_NAME    "[SIGN]"
+#define DBG_COLOR
+#define DBG_LEVEL           DBG_LOG
+#include <rtdbg.h>
+
+#define sig_mask(sig_no)    (1u << sig_no)
+#define sig_valid(sig_no)   (sig_no >= 0 && sig_no < RT_SIG_MAX)
+
+struct siginfo_node
+{
+    struct siginfo si;
+    struct rt_slist_node list;
+};
+
+static struct rt_mempool *_rt_siginfo_pool;
+static void _signal_deliver(rt_thread_t tid);
+void rt_thread_handle_sig(rt_bool_t clean_state);
+
+static void _signal_default_handler(int signo)
+{
+    dbg_log(DBG_INFO, "handled signo[%d] with default action.\n", signo);
+    return ;
+}
+
+static void _signal_entry(void* parameter)
+{
+    rt_thread_t tid = rt_thread_self();
+
+    dbg_enter;
+
+    /* handle signal */
+    rt_thread_handle_sig(RT_FALSE);
+
+	/* never come back... */
+	rt_hw_interrupt_disable();
+    /* return to thread */
+    tid->sp = tid->sig_ret;
+    tid->sig_ret = RT_NULL;
+
+    dbg_log(DBG_LOG, "switch back to: 0x%08x\n", tid->sp);
+    tid->stat &= ~RT_THREAD_STAT_SIGNAL;
+
+    rt_hw_context_switch_to((rt_uint32_t)&(tid->sp));
+}
+
+static void _signal_deliver(rt_thread_t tid)
+{
+    rt_ubase_t level;
+
+    /* thread is not interested in pended signals */
+    if (!(tid->sig_pending & tid->sig_mask)) return;
+
+    level = rt_hw_interrupt_disable();
+    if (tid->stat == RT_THREAD_SUSPEND)
+    {
+        /* resume thread to handle signal */
+        rt_thread_resume(tid);
+		/* add signal state */
+		tid->stat |= RT_THREAD_STAT_SIGNAL;
+
+        rt_hw_interrupt_enable(level);
+
+        /* re-schedule */
+        rt_schedule();
+    }
+    else
+    {
+        if (tid == rt_thread_self())
+        {
+			/* add signal state */
+			tid->stat |= RT_THREAD_STAT_SIGNAL;
+            rt_hw_interrupt_enable(level);
+
+            /* do signal action in self thread context */
+            rt_thread_handle_sig(RT_TRUE);
+        }
+        else if (!(tid->stat & RT_THREAD_STAT_SIGNAL))
+        {
+            tid->stat |= RT_THREAD_STAT_SIGNAL;
+            /* point to the signal handle entry */
+            tid->sig_ret = tid->sp;
+            tid->sp = rt_hw_stack_init((void*)_signal_entry, RT_NULL, 
+                (void *)((char *)tid->sig_ret - 32), RT_NULL);
+
+            rt_hw_interrupt_enable(level);
+            dbg_log(DBG_LOG, "signal stack pointer @ 0x%08x\n", tid->sp);
+
+            /* re-schedule */
+            rt_schedule();
+        }
+        else
+        {
+            rt_hw_interrupt_enable(level);
+        }
+    }
+}
+
+rt_sighandler_t rt_signal_install(int signo, rt_sighandler_t handler)
+{
+    rt_sighandler_t old;
+    rt_thread_t tid = rt_thread_self();
+
+	if (!sig_valid(signo)) return SIG_ERR;
+
+    rt_enter_critical();
+    if (tid->sig_vectors == RT_NULL)
+    {
+        rt_thread_alloc_sig(tid);
+    }
+
+    if (tid->sig_vectors)
+    {
+        old = tid->sig_vectors[signo];
+
+        if (handler == SIG_IGN) tid->sig_vectors[signo] = RT_NULL;
+        else if (handler == SIG_DFL) tid->sig_vectors[signo] = _signal_default_handler;
+        else tid->sig_vectors[signo] = handler;
+    }
+    rt_exit_critical();
+
+    return old;
+}
+
+void rt_signal_mask(int signo)
+{
+    rt_base_t level;
+    rt_thread_t tid = rt_thread_self();
+
+    level = rt_hw_interrupt_disable();
+
+    tid->sig_mask &= ~sig_mask(signo);
+
+    rt_hw_interrupt_enable(level);
+}
+
+void rt_signal_unmask(int signo)
+{
+    rt_base_t level;
+    rt_thread_t tid = rt_thread_self();
+
+    level = rt_hw_interrupt_disable();
+
+    tid->sig_mask |= sig_mask(signo);
+
+    /* let thread handle pended signals */
+    if (tid->sig_mask & tid->sig_pending)
+    {
+        rt_hw_interrupt_enable(level);
+        _signal_deliver(tid);
+    }
+    else 
+    {
+        rt_hw_interrupt_enable(level);
+    }
+}
+
+void rt_thread_handle_sig(rt_bool_t clean_state)
+{
+	rt_base_t level;
+
+    rt_thread_t tid = rt_thread_self();
+    struct siginfo_node *si_node;
+
+	level = rt_hw_interrupt_disable();
+    while (tid->sig_pending & tid->sig_mask)
+    {
+        int signo, error;
+        rt_sighandler_t handler;
+
+		si_node = (struct siginfo_node *)tid->si_list;
+		if (!si_node) break;
+
+		/* remove this sig info node from list */
+        if (si_node->list.next == RT_NULL)
+            tid->si_list = RT_NULL;
+        else
+            tid->si_list = (void*)rt_slist_entry(si_node->list.next, struct siginfo_node, list);
+
+        signo   = si_node->si.si_signo;
+        handler = tid->sig_vectors[signo];
+		rt_hw_interrupt_enable(level);
+
+        dbg_log(DBG_LOG, "handle signal: %d, handler 0x%08x\n", signo, handler);
+        if (handler) handler(signo);
+
+		level = rt_hw_interrupt_disable();
+        tid->sig_pending &= ~sig_mask(signo);
+        error = si_node->si.si_errno;
+
+        rt_mp_free(si_node); /* release this siginfo node */
+        /* set errno in thread tcb */
+        tid->error = error;
+    }
+
+	/* whether clean signal status */
+	if (clean_state == RT_TRUE) tid->stat &= ~RT_THREAD_STAT_SIGNAL;
+
+	rt_hw_interrupt_enable(level);
+}
+
+void rt_thread_alloc_sig(rt_thread_t tid)
+{
+    int index;
+    rt_base_t level;
+    rt_sighandler_t *vectors;
+
+    vectors = (rt_sighandler_t *)RT_KERNEL_MALLOC(sizeof(rt_sighandler_t) * RT_SIG_MAX);
+    RT_ASSERT(vectors != RT_NULL);
+
+    for (index = 0; index < RT_SIG_MAX; index ++)
+    {
+        vectors[index] = _signal_default_handler;
+    }
+
+    level = rt_hw_interrupt_disable();
+    tid->sig_vectors = vectors;
+    rt_hw_interrupt_enable(level);
+}
+
+void rt_thread_free_sig(rt_thread_t tid)
+{
+    rt_base_t level;
+    struct siginfo_node *si_list;
+    rt_sighandler_t *sig_vectors;
+
+    level = rt_hw_interrupt_disable();
+    si_list = (struct siginfo_node*)tid->si_list;
+    tid->si_list = RT_NULL;
+    
+    sig_vectors = tid->sig_vectors;
+    tid->sig_vectors = RT_NULL;
+    rt_hw_interrupt_enable(level);
+
+    if (si_list)
+    {
+        struct rt_slist_node *node;
+        struct siginfo_node  *si_node;
+
+        dbg_log(DBG_LOG, "free signal info list\n");
+        node = &(si_list->list);
+        do {
+            si_node = rt_slist_entry(node, struct siginfo_node, list);
+            rt_mp_free(si_node);
+
+            node = node->next;
+        } while (node);
+    }
+
+    if (sig_vectors)
+    {
+        RT_KERNEL_FREE(sig_vectors);
+    }
+}
+
+int rt_thread_kill(rt_thread_t tid, int sig)
+{
+    siginfo_t si;
+	rt_base_t level;
+	struct siginfo_node *si_node;
+
+    RT_ASSERT(tid != RT_NULL);
+    if (!sig_valid(sig)) return -RT_EINVAL;
+
+    dbg_log(DBG_INFO, "send signal: %d\n", sig);
+    si.si_errno = RT_EINTR;
+    si.si_signo = sig;
+    si.si_code  = SI_USER;
+    si.si_value.sival_ptr = RT_NULL;
+
+	level = rt_hw_interrupt_disable();
+    if (tid->sig_pending & sig_mask(sig))
+    {
+        /* whether already emits this signal? */
+        struct rt_slist_node *node;
+        struct siginfo_node  *entry;
+
+		node = (struct rt_slist_node *)tid->si_list;
+		rt_hw_interrupt_enable(level);
+
+		/* update sig infor */
+		rt_enter_critical();
+        for (; (node) != RT_NULL; node = node->next)
+        {
+            entry = rt_slist_entry(node, struct siginfo_node, list);
+            if (entry->si.si_signo == sig)
+            {
+                memcpy(&(entry->si), &si, sizeof(siginfo_t));
+				rt_exit_critical();
+                return 0;
+            }
+        }
+		rt_exit_critical();
+
+		/* disable interrupt to protect tcb */
+		level = rt_hw_interrupt_disable();
+    }
+	else
+	{
+		/* a new signal */
+	    tid->sig_pending |= sig_mask(sig);
+	}
+	rt_hw_interrupt_enable(level);
+
+    si_node = (struct siginfo_node*) rt_mp_alloc(_rt_siginfo_pool, 0);
+    if (si_node)
+    {
+        rt_slist_init(&(si_node->list));
+        memcpy(&(si_node->si), &si, sizeof(siginfo_t));
+
+		level = rt_hw_interrupt_disable();
+        if (!tid->si_list) tid->si_list = si_node;
+        else 
+        {
+        	struct siginfo_node *si_list;
+
+            si_list = (struct siginfo_node*)tid->si_list;
+            rt_slist_append(&(si_list->list), &(si_node->list));
+        }
+		rt_hw_interrupt_enable(level);
+    }
+    else
+    {
+        dbg_log(DBG_ERROR, "The allocation of signal infor node failed.\n");
+    }
+
+    /* deliver signal to this thread */
+    _signal_deliver(tid);
+
+    return RT_EOK;
+}
+
+int rt_system_signal_init(void)
+{
+    _rt_siginfo_pool = rt_mp_create("signal", RT_SIG_INFO_MAX, sizeof(struct siginfo_node));
+    if (_rt_siginfo_pool == RT_NULL)
+    {
+        dbg_log(DBG_ERROR, "create memory pool for signal info failed.\n");
+        RT_ASSERT(0);
+    }
+
+    return 0;
+}
+
+#endif
+