modified: components/libc/posix/delay/delay.c Added comments for all functions in this file

modified:   components/libc/posix/signal/posix_signal.c		Add comments to the sigqueue function, although it does not have an internal implementation
modified:   components/libc/posix/signal/posix_signal.h		Added detailed explanation to all members of the rt_signal_value enumeration

components/libc/posix/delay/delay.c

@@ -12,36 +12,68 @@
 #include <rtthread.h>
 #include <rthw.h>
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of milliseconds.
+ *
+ * @param    msecs The number of milliseconds to sleep.
+ */
 void msleep(unsigned int msecs)
 {
     rt_thread_mdelay(msecs);
 }
 RTM_EXPORT(msleep);
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of seconds.
+ *
+ * @param    seconds The number of seconds to sleep.
+ */
 void ssleep(unsigned int seconds)
 {
     msleep(seconds * 1000);
 }
 RTM_EXPORT(ssleep);
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of milliseconds.
+ *
+ * @param    msecs The number of milliseconds to delay.
+ */
 void mdelay(unsigned long msecs)
 {
     rt_hw_us_delay(msecs * 1000);
 }
 RTM_EXPORT(mdelay);
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of microseconds.
+ *
+ * @param    usecs The number of microseconds to delay.
+ */
 void udelay(unsigned long usecs)
 {
     rt_hw_us_delay(usecs);
 }
 RTM_EXPORT(udelay);
 
+/**
+ * @brief    Delays the execution of the current thread for approximately one microsecond.
+ *
+ * @param    nsecs This parameter is ignored.
+ */
 void ndelay(unsigned long nsecs)
 {
     rt_hw_us_delay(1);
 }
 RTM_EXPORT(ndelay);
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of seconds.
+ *
+ * @param    seconds The number of seconds to sleep.
+ *
+ * @return   Returns 0 on success.
+ */
 unsigned int sleep(unsigned int seconds)
 {
     if (rt_thread_self() != RT_NULL)
@@ -61,6 +93,13 @@ unsigned int sleep(unsigned int seconds)
 }
 RTM_EXPORT(sleep);
 
+/**
+ * @brief    Delays the execution of the current thread for the specified number of microseconds.
+ *
+ * @param    usec The number of microseconds to sleep.
+ *
+ * @return   Returns 0 on success.
+ */
 int usleep(useconds_t usec)
 {
     if (rt_thread_self() != RT_NULL)

components/libc/posix/signal/posix_signal.c

@@ -229,6 +229,16 @@ int raise(int sig)
 }
 
 #include <sys/types.h>
+/**
+ * @brief    Sends a signal to the caller.
+ *
+ * This function sends the signal specified by @p sig to the caller.
+ *
+ * @param    sig The signal to be sent.
+ *           This should be one of the standard signal macros such as SIGUSR1, SIGUSR2, etc.
+ *
+ * @return   Returns 0 on success. If an error occurs, -1 is returned and errno is set appropriately.
+ */
 int sigqueue (pid_t pid, int signo, const union sigval value)
 {
     /* no support, signal queue */

components/libc/posix/signal/posix_signal.h

@@ -18,40 +18,40 @@ extern "C" {
 #include <sys/signal.h>
 
 enum rt_signal_value{
-    SIG1 = SIGHUP,
+    SIG1  = SIGHUP,  // Hangup detected on controlling terminal or death of controlling process
-    SIG2 = SIGINT,
+    SIG2  = SIGINT,  // Interrupt from keyboard
-    SIG3 = SIGQUIT,
+    SIG3  = SIGQUIT, // Quit from keyboard
-    SIG4 = SIGILL,
+    SIG4  = SIGILL,  // Illegal instruction
-    SIG5 = SIGTRAP,
+    SIG5  = SIGTRAP, // Trace trap
-    SIG6 = SIGABRT,
+    SIG6  = SIGABRT, // Abort signal from abort(3)
-    SIG7 = SIGEMT,
+    SIG7  = SIGEMT,  // Emulator trap
-    SIG8 = SIGFPE,
+    SIG8  = SIGFPE,  // Floating-point exception
-    SIG9 = SIGKILL,
+    SIG9  = SIGKILL, // Kill signal
-    SIG10 = SIGBUS,
+    SIG10 = SIGBUS,  // Bus error
-    SIG11 = SIGSEGV,
+    SIG11 = SIGSEGV, // Segmentation fault
-    SIG12 = SIGSYS,
+    SIG12 = SIGSYS,  // Bad system call
-    SIG13 = SIGPIPE,
+    SIG13 = SIGPIPE, // Broken pipe
-    SIG14 = SIGALRM,
+    SIG14 = SIGALRM, // Timer signal from alarm(2)
-    SIG15 = SIGTERM,
+    SIG15 = SIGTERM, // Termination signal
-    SIG16 = SIGURG,
+    SIG16 = SIGURG,  // Urgent condition on socket
-    SIG17 = SIGSTOP,
+    SIG17 = SIGSTOP, // Stop executing (cannot be caught or ignored)
-    SIG18 = SIGTSTP,
+    SIG18 = SIGTSTP, // Stop signal from keyboard to suspend execution
-    SIG19 = SIGCONT,
+    SIG19 = SIGCONT, // Continue if stopped
-    SIG20 = SIGCHLD,
+    SIG20 = SIGCHLD, // Child status has changed
-    SIG21 = SIGTTIN,
+    SIG21 = SIGTTIN, // Background read from control terminal attempted by background process
-    SIG22 = SIGTTOU,
+    SIG22 = SIGTTOU, // Background write to control terminal attempted by background process
-    SIG23 = SIGPOLL,
+    SIG23 = SIGPOLL, // Pollable event
-    SIG24 = 24, // SIGXCPU,
+    SIG24 = 24,      // SIGXCPU: CPU time limit exceeded
-    SIG25 = 25, // SIGXFSZ,
+    SIG25 = 25,      // SIGXFSZ: File size limit exceeded
-    SIG26 = 26, // SIGVTALRM,
+    SIG26 = 26,      // SIGVTALRM: Virtual timer expired
-    SIG27 = 27, // SIGPROF,
+    SIG27 = 27,      // SIGPROF: Profiling timer expired
-    SIG28 = SIGWINCH,
+    SIG28 = SIGWINCH,// Window size changed
-    SIG29 = 29, // SIGLOST,
+    SIG29 = 29,      // SIGLOST
-    SIG30 = SIGUSR1,
+    SIG30 = SIGUSR1, // User-defined signal 1
-    SIG31 = SIGUSR2,
+    SIG31 = SIGUSR2, // User-defined signal 2
-    SIGRT_MIN = 27, // SIGRTMIN,
+    SIGRT_MIN = 27, // SIGRTMIN: Minimum real-time signal number
-    SIGRT_MAX = 31, // SIGRTMAX,
+    SIGRT_MAX = 31, // SIGRTMAX: Maximum real-time signal number
-    SIGMAX = NSIG,
+    SIGMAX    = NSIG // Number of signals (total)
 };
 
 #ifdef __cplusplus