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  1. Unison Kernel
    1. Pthreads
      1. pthread_create()
      2. pthread_exit()
      3. pthread_self()
      4. pthread_equal()
      5. pthread_join()
      6. pthread_detach()
      7. pthread_setschedparam()
      8. pthread_getschedparam()
      9. pthread_attr_init()
      10. pthread_attr_destroy()
      11. pthread_attr_setstackaddr()
      12. pthread_attr_getstackaddr()
      13. pthread_attr_setstacksize()
      14. pthread_attr_getstacksize()
      15. pthread_attr_setschedparam()
      16. pthread_attr_getschedparam()
      17. pthread_attr_setdetachstate()
      18. pthread_attr_getdetachstate()
      19. pthread_stackinfo()
      20. pthread_setprio()
      21. pthread_getprio()
      22. sched_get_priority_max()
      23. sched_get_priority_min()
      24. sched_yield()
    2. Pthread Cancellation
      1. pthread_cleanup_pop()
      2. pthread_cleanup_push()
      3. pthread_cancel()
      4. pthread_setcanceltype()
      5. pthread_setcancelstate()
      6. pthread_testcancel()
    3. Mutex
      1. pthread_mutex_init()
      2. pthread_mutex_destroy()
      3. pthread_mutex_lock()
      4. pthread_mutex_trylock()
      5. pthread_mutex_unlock()
    4. Semaphores
      1. sem_open()
      2. sem_close()
      3. sem_unlink()
      4. sem_init()
      5. sem_destroy()
      6. sem_wait()
      7. sem_trywait()
      8. sem_timedwait()
      9. sem_post()
      10. sem_getvalue()
    5. Message Queues
      1. mq_open()
      2. mq_close()
      3. mq_unlink()
      4. mq_send()
      5. mq_receive()
      6. mq_notify()
      7. mq_setattr()
      8. mq_getattr()
      9. mq_timedreceive()
      10. mq_timedsend()
    6. Conditional Variables
      1. pthread_cond_init()
      2. pthread_cond_destroy()
      3. pthread_cond_wait()
      4. pthread_cond_timedwait()
      5. pthread_cond_signal()
      6. pthread_cond_broadcast()
      7. pthread_condattr_init()
      8. pthread_condattr_destroy()
    7. Barriers
      1. pthread_barrier_init()
      2. pthread_barrier_destroy()
      3. pthread_barrier_wait()
    8. Timers
      1. timer_create()
      2. timer_delete()
      3. timer_settime()
      4. timer_gettime()
      5. timer_getoverrun()
      6. timer_tick()
      7. nanosleep()
    9. Clocks
      1. time()
      2. uptime()
      3. sleep()
      4. clock_settime()
      5. clock_gettime()
      6. clock_getres()
      7. clock_init()
    10. Memory Allocation
      1. POSIX.1
        1. malloc()
        2. free()
      2. Variable Length (Pools)
        1. pool_create()
        2. pool_destroy()
        3. pool_alloc()
        4. pool_free()
      3. Fixed Length (Partitions)
        1. pt_create()
        2. pt_destroy()
        3. pt_getblock()
        4. pt_freeblock()
    11. Rendezvous
      1. mr_init()
      2. mr_send()
      3. mr_receive()
      4. mr_reply()
      5. mr_sigrecv()
      6. mr_sigpost()
    12. Interrupts
      1. interrupts
      2. i_disable()
      3. i_restore()
    13. Directory Services
      1. dir_register()
      2. dir_deregister()
      3. dir_lookup()
      4. dir_lookup_string()
    14. Miscellaneous
      1. checkIstack()
      2. NanoStart() or DSPexec_Start()
      3. _isrStackFill
      4. Kernel Scaling
      5. kfatal()
      6. kalloc()
      7. kfree()
      8. mpu or mmu
      9. pthreadStackFill
      10. thread_numb()
      11. thread_utilization_start()
      12. thread_utilization_stop()
      13. xprintf()
      14. xputs()
      15. xputchar()
  2. Unison I/O Library
    1. accept()
    2. bind()
    3. chmod()
    4. close()
    5. connect()
    6. creat()
    7. fstat()
    8. getpeername()
    9. getsockname()
    10. getsockopt()
    11. ioctl()
    12. link()
    13. listen()
    14. lseek()
    15. mkdir()
    16. mkfs()
    17. mount()
    18. open()
    19. read()
    20. recv()
    21. recvfrom()
    22. rename()
    23. renameat()
    24. rmdir()
    25. select()
    26. send()
    27. sendto()
    28. setsockopt()
    29. shutdown()
    30. socket()
    31. stat()
    32. sync()
    33. umount()
    34. unlink()
    35. write()
  3. Unison STDIO Library
    1. STDIO Library Calls
      1. clearerr()
      2. dprintf()
      3. fclose()
      4. fdopen()
      5. feof()
      6. ferror()
      7. fileno()
      8. fflush()
      9. fgetc()
      10. fgetpos()
      11. fgets()
      12. fopen()
      13. fprintf()
      14. fputc()
      15. fputs()
      16. fread()
      17. freopen()
      18. fscanf()
      19. fseek()
      20. fseeko()
      21. fsetpos()
      22. ftell()
      23. ftello()
      24. fwrite()
      25. getc()
      26. getc_unlocked()
      27. getchar()
      28. getchar_unlocked()
      29. getdelim()
      30. getline()
      31. gets()
      32. get_stderr_ptr()
      33. get_stdin_ptr()
      34. get_stdout_ptr()
      35. noperprintf()
      36. perprintf()
      37. perror()
      38. posix_compat()
      39. printf()
      40. putc()
      41. putc_unlocked()
      42. putchar()
      43. putchar_unlocked()
      44. puts()
      45. remove()
      46. rewind()
      47. scanf()
      48. setbuf()
      49. setvbuf()
      50. snprintf()
      51. sprintf()
      52. sscanf()
      53. stderr_init()
      54. stderr_close()
      55. stdin_init()
      56. stdin_close()
      57. stdout_init()
      58. stdout_close()
      59. vdprintf()
      60. vscanf()
      61. vsscanf()
      62. vfscanf()
      63. vprintf()
      64. vsnprintf()
      65. vsprintf()
      66. vfprintf()
      67. ungetc()
    2. Do-nothing Stubs
      1. ctermid()
      2. flockfile()
      3. fmemopen()
      4. ftrylockfile()
      5. open_memstream()
      6. pclose()
      7. popen()
      8. tempnam()
      9. tmpfile()
      10. tmpnam()
  4. Unison LIBC Library
    1. LIBC Library Calls
      1. assert()
      2. realloc()
      3. strcasecmp()
      4. strdup()
      5. strncasecmp()
      6. strftime()
    2. Do-nothing Stubs
      1. abort()
      2. execve()
      3. exit()
      4. _Exit()
      5. fork()
      6. getpid()
      7. isatty()
      8. kill()
      9. sbrk()
      10. times()
      11. wait()
    3. Do-nothing Wide-character Stubs
      1. <wchar.h>
      2. <wctype.h>
  5. Unison I/O Servers
    1. File Servers
      1. Multimedia File Server - fsys
      2. FAT File System - fatfs
      3. NAND File Server - nandfsys
      4. NOR File Server - norfsys
      5. Network File Server - nfs
  6. Graphics, Camera, Video, Audio
    1. Vendor Graphics
    2. Prism++ Graphics
    3. ADPCM Services - adpcmd
    4. Camera
  7. Network Protocols
    1. TCP and UDP Server - tcpd
      1. IPv4 only server
      2. IPv4/IPv6 server
    2. DHCP Client Service - dhcp client
    3. DHCP Server - dhcpd
    4. Telnet Server - telnetd
    5. Tiny FTP Server - tftpd
    6. Point to Point - pppd
    7. Network Translation - NAT with PAT
    8. Firewall
      1. Packet filter: pf
      2. Packet filter control: pfctl
      3. Fitler rules: pf.filtering
      4. Translation rules: pf.nat
    9. Tiny HTTP Server - thttpd
    10. Tiny HTTP Server with TLS
    11. POP3 Server
    12. Simple Mail Transfer Protocol Services (SMTP)
    13. Bootp Protocol
    14. File Transfer Protocol Server (FTP)
    15. File Transfer Client Services
    16. RPC / XDR
    17. DNS Client
    18. HTTP/HTTPS Client
    19. REST Client
    20. AutoIP Service - autoip client
    21. mDNS server - mdnsd
    22. SNTP Client
    23. SNMP Agent - Snmpd server
    24. SSL/TLS library
    25. SSH server
    26. IP security
      1. IPsec description
      2. IPsec administration: ipsecadm
      3. Virtual Private Network: VPN
    27. Power Control
      1. Motor and Motion Control Servers
      2. PWM, Encoders
    28. Serial I/O
      1. Asynchronous Serial I/O Server - ttyserver
      2. CAN Server - cand
      3. I2C Server - i2cd
      4. I2S Server - i2sd
    29. System Services
      1. Power Management Servers
      2. Login Service - login_services
      3. XML
      4. POSIX Shell and Login Service - posh
    30. Universal Serial Bus (USB)
      1. USB Server
      2. USB Device Server
      3. USB Embedded Host Server
    31. Wireless
      1. Wireless Servers and Drivers
      2. 802.15.4 Radio Servers
      3. TCP/v6 with 6loWPAN
      4. ZigBee
      5. BlueTooth Server
      6. 802.11 Wi-Fi
      7. GPRS, UHF and GPS Radio Servers
    32. Remedy Tools for Unison
      1. Remedy Data Logging and Event Display Tools
      2. Remedy Diagnostics
      3. Remedy Flash Downloader/Bootloader
      4. Remedy Power On Self Test - POST
      5. Remedy OS Object Viewer
      6. Remedy Remote Control Tools

1.10.1.2.free() #

NAME

malloc, free – memory allocator

SYNOPSIS

#include <stdlib.h>

void *malloc(size_t size );
void free(void *ptr );

DESCRIPTION

malloc() and free() provide a simple general-purpose memory allocation package. malloc() returns a pointer to a block of at least size bytes.

The argument to free() is a pointer to a block previously allocated by malloc(). After free() is performed this space is made available for further allocation. If ptr is a NULL pointer, no action occurs.

Undefined results will occur if the space assigned by malloc() is overrun or if some random number is handed to free() .

malloc() will fail if there is not enough available memory.

There is interesting things that can be done underneath the facade of malloc() and free() to improve the system performance. The memory pools and partitions can be used along with kalloc() to generate the necessary optimizations to better utilize fast memory and to move certain constants and structures into FLASH.

RETURN VALUES

malloc() will return a NULL pointer if there is no available memory; otherwise, it returns a pointer to a memory area of at least size bytes.

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