lib: posix: syscall for pipe(2)

arch/posix/include/posix_cheats.h

@@ -221,6 +221,9 @@ void zephyr_app_main(void);
 #define stat		zap_stat
 #define mkdir		zap_mkdir
 
+/* Non-network communications */
+#define pipe            zap_pipe
+
 #endif /* CONFIG_POSIX_API */
 
 #endif /* ZEPHYR_ARCH_POSIX_INCLUDE_POSIX_CHEATS_H_ */

include/posix/unistd.h

@@ -28,6 +28,9 @@ extern ssize_t write(int file, const void *buffer, size_t count);
 extern ssize_t read(int file, void *buffer, size_t count);
 extern off_t lseek(int file, off_t offset, int whence);
 
+/* Non-network communications */
+extern int pipe(int fildes[2]);
+
 /* File System related operations */
 extern int rename(const char *old, const char *newp);
 extern int unlink(const char *path);

lib/posix/CMakeLists.txt

@@ -22,6 +22,7 @@ zephyr_library_sources_ifdef(CONFIG_PTHREAD_IPC semaphore.c)
 zephyr_library_sources_ifdef(CONFIG_PTHREAD_IPC pthread_key.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_MQUEUE mqueue.c)
 zephyr_library_sources_ifdef(CONFIG_POSIX_FS fs.c)
+zephyr_library_sources_ifdef(CONFIG_POSIX_PIPE pipe.c)
 
 zephyr_library_include_directories(
   ${ZEPHYR_BASE}/kernel/include

lib/posix/Kconfig

@@ -42,6 +42,28 @@ config SEM_VALUE_MAX
 
 endif # PTHREAD_IPC
 
+config POSIX_PIPE
+	bool "POSIX pipe support"
+	default y if POSIX_API
+	help
+	  This enables a mostly-standards-compliant implementation of
+	  pipe(2) for inter-process communication. The resulting file
+	  descriptors can be used with read(2), write(2), close(2),
+	  fcntl(2), fstat(2), and ioctl(2).
+
+if POSIX_PIPE
+# min and max to support fcntl F_SETPIPE_SZ?
+# allow size to be 0?
+config POSIX_PIPE_SIZE
+	int "POSIX Pipe capacity"
+	default 64
+	range 64 1048576
+	help
+	  This option specifies the fixed size of POSIX pipes. For more
+	  information see 'man 7 pipe'.
+
+endif # POSIX_PIPE
+
 config POSIX_CLOCK
 	bool "POSIX clock, timer, and sleep APIs"
 	default y if POSIX_API