 RealView Libraries and Floating Point Support Guide | |
| Home Products Events Support | |
On-Line Manuals
RealView Libraries and Floating Point Support Guide
Preface Introduction The C and C++ Libraries About the C and C++ libraries
Features of the C and C++ libraries Namespaces Writing reentrant and thread‑safe code Introduction to reentrancy and thread‑safety Use of static data in the C libraries The __user_libspace static data area Managing locks in multithreaded applications Using the ARM C libraries with a multithreaded app Thread‑safety in the ARM C libraries Thread‑safety in the ARM C++ libraries Building an application with the C library Using the libraries with an application Building an application for a semihosted environme Building an application for a non semihosting envi Building an application without the C library Integer and FP helper functions Bare machine integer C Bare machine C with floating‑point Exploiting the C library The standalone C library functions Tailoring the C library to a new execution environ How C and C++ programs use the library functions __rt_entry Exiting from the program __rt_exit() __rt_lib_init() __rt_lib_shutdown() Tailoring static data access Tailoring locale and CTYPE using assembler macros Selecting locale at link time Selecting locale at runtime Defining a locale block LC_CTYPE data block LC_COLLATE data block LC_MONETARY data block LC_NUMERIC data block LC_TIME data block _get_lconv() localeconv() setlocale() _findlocale() The lconv structure Tailoring locale and CTYPE using C macros Selecting locale at link time Selecting locale at runtime Macros and utility functions _get_lc_ctype() _get_lc_collate() _get_lc_monetary() _get_lc_numeric() _get_lc_time() _get_lconv() localeconv() setlocale() _findlocale() __LC_CTYPE_DEF __LC_COLLATE_DEF __LC_TIME_DEF __LC_NUMERIC_DEF __LC_MONETARY_DEF __LC_INDEX_END The lconv structure Tailoring error signaling, error handling, and pro _sys_exit() errno __rt_errno_addr() __raise() __rt_raise() __default_signal_handler() _ttywrch() __rt_fp_status_addr() Tailoring storage management Avoiding the ARM‑supplied heap and heap‑using Support for malloc Tailoring the runtime memory model The memory models Controlling the runtime memory model Writing your own memory model __user_initial_stackheap() __user_setup_stackheap() __user_heap_extend() __user_heap_extent() __user_stack_cleanup_space() __rt_heap_extend() __rt_stack_postlongjmp() Tailoring the input/output functions Dependencies on low‑level functions Target‑dependent input/output support functions _sys_open() _sys_close() _sys_read() _sys_write() _sys_ensure() _sys_flen() _sys_seek() _sys_istty() _sys_tmpnam() _sys_command_string() #pragma import(_main_redirection) Tailoring other C library functions clock() _clock_init() time() remove() rename() system() getenv() _getenv_init() Selecting real‑time division ISO implementation definition ISO C library implementation definition Standard C++ library implementation definition C library extensions atoll() strtoll() strtoull() printf() snprintf() vsnprintf() lldiv() llabs() wcstombs() alloca() strlcpy() strlcat() _fisatty() __heapstats() __heapvalid() Library naming conventions Placing ARM libraries Helper libraries Identifying library variants The C Micro-library Floating‑point SupportWriting reentrant and thread‑safe code
  | |||
  |  | ||
| |||
| Home > The C and C++ Libraries > Writing reentrant and thread‑safe code | |||
The ARM C libraries support multithreading, for example, where you are using a Real Time Operating System (RTOS). When describing multithreading in the rest of this section, the following definitions are used:
- Threads
Mean multiple streams of execution sharing global data between them.
- Process
Means a collection of all the threads that share a particular set of global data.
If there are multiple processes on a machine, they can be entirely separate and do not share any data (except under unusual circumstances). Similarly, each process might be a single‑threaded process or might be divided into multiple threads.
Where you have single‑threaded processes, there is only one flow of control. In multithreaded applications, however, several flows of control might try to access the same functions, and the same resources, concurrently. To protect the integrity of resources, any code you write for multithreaded applications must be reentrant and thread‑safe.
| Copyright © 2007 ARM Limited. All rights reserved. | ARM DUI 0378A |
 PDF version | |
| Home > The C and C++ Libraries > Writing reentrant and thread‑safe code | |
| |
| Contact Site Map Press Privacy | Copyright © 2008 Keil™, An ARM® Company. All rights reserved. |
