signal: Add support for SIGEV_THREAD_ID and sigev_notify_thread_id

This patch added support for SIGEV_THREAD_ID and sigev_notify_thread_id.

Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
Signed-off-by: ligd <liguiding1@xiaomi.com>

include/signal.h

@@ -264,9 +264,11 @@
 #define SIGEV_NONE      0 /* No asynchronous notification is delivered */
 #define SIGEV_SIGNAL    1 /* Notify via signal,with an application-defined value */
 #ifdef CONFIG_SIG_EVTHREAD
-#  define SIGEV_THREAD  3 /* A notification function is called */
+#  define SIGEV_THREAD  2 /* A notification function is called */
 #endif
 
+#define SIGEV_THREAD_ID 4 /* Notify a specific thread via signal. */
+
 /* sigaltstack stack size */
 
 #define MINSIGSTKSZ     CONFIG_PTHREAD_STACK_MIN     /* Smallest signal stack size */
@@ -345,6 +347,8 @@ struct sigevent
   sigev_notify_function_t sigev_notify_function;      /* Notification function */
   FAR struct pthread_attr_s *sigev_notify_attributes; /* Notification attributes (not used) */
 #endif
+
+  pid_t        sigev_notify_thread_id; /* ID of thread to signal */
 };
 
 /* The following types is used to pass parameters to/from signal handlers */

sched/signal/sig_notification.c

@@ -110,11 +110,9 @@ int nxsig_notification(pid_t pid, FAR struct sigevent *event,
 
   /* Notify client via a signal? */
 
-  if (event->sigev_notify == SIGEV_SIGNAL)
+  if (event->sigev_notify & SIGEV_SIGNAL)
     {
-#ifdef CONFIG_SCHED_HAVE_PARENT
       FAR struct tcb_s *rtcb = this_task();
-#endif
       siginfo_t info;
 
       /* Yes.. Create the siginfo structure */
@@ -135,6 +133,23 @@ int nxsig_notification(pid_t pid, FAR struct sigevent *event,
 
       memcpy(&info.si_value, &event->sigev_value, sizeof(union sigval));
 
+      /* Used only by POSIX timer. Notice that it is UNSAFE, unless
+       * we GUARANTEE that event->sigev_notify_thread_id is valid.
+       */
+
+      if (event->sigev_notify & SIGEV_THREAD_ID)
+        {
+          rtcb = nxsched_get_tcb(event->sigev_notify_thread_id);
+          if (rtcb != NULL)
+            {
+              return nxsig_tcbdispatch(rtcb, &info);
+            }
+          else
+            {
+              return -ENOENT;
+            }
+        }
+
       /* Send the signal */
 
       return nxsig_dispatch(pid, &info);
@@ -143,7 +158,7 @@ int nxsig_notification(pid_t pid, FAR struct sigevent *event,
 #ifdef CONFIG_SIG_EVTHREAD
   /* Notify the client via a function call */
 
-  else if (event->sigev_notify == SIGEV_THREAD)
+  else if (event->sigev_notify & SIGEV_THREAD)
     {
       /* Initialize the work information */
 

sched/timer/timer_create.c

@@ -37,6 +37,7 @@
 #include <nuttx/kmalloc.h>
 #include <nuttx/spinlock.h>
 
+#include "sched/sched.h"
 #include "timer/timer.h"
 
 #ifndef CONFIG_DISABLE_POSIX_TIMERS
@@ -158,6 +159,7 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
                  FAR timer_t *timerid)
 {
   FAR struct posix_timer_s *ret;
+  FAR struct tcb_s *tcb = this_task();
 
   /* Sanity checks. */
 
@@ -181,7 +183,7 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
 
   ret->pt_clock = clockid;
   ret->pt_crefs = 1;
-  ret->pt_owner = nxsched_getpid();
+  ret->pt_owner = tcb->pid;
   ret->pt_delay = 0;
   ret->pt_expected = 0;
 
@@ -189,6 +191,25 @@ int timer_create(clockid_t clockid, FAR struct sigevent *evp,
 
   if (evp)
     {
+      FAR struct tcb_s *ntcb;
+
+      /* Check the SIGEV_THREAD_ID and validate the tid */
+
+      if (evp->sigev_notify & SIGEV_THREAD_ID)
+        {
+          /* Make sure that the notified thread is
+           * in same process with current thread.
+           */
+
+          ntcb = nxsched_get_tcb(evp->sigev_notify_thread_id);
+
+          if (ntcb == NULL || tcb->group != ntcb->group)
+            {
+              set_errno(EINVAL);
+              return ERROR;
+            }
+        }
+
       /* Yes, copy the entire struct sigevent content */
 
       memcpy(&ret->pt_event, evp, sizeof(struct sigevent));