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Diffstat (limited to 'lwip/src/include/lwip/sys.h')
| -rw-r--r-- | lwip/src/include/lwip/sys.h | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/lwip/src/include/lwip/sys.h b/lwip/src/include/lwip/sys.h new file mode 100644 index 0000000..1933590 --- /dev/null +++ b/lwip/src/include/lwip/sys.h @@ -0,0 +1,561 @@ +/** + * @file + * OS abstraction layer + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Adam Dunkels <adam@sics.se> + */ + +#ifndef LWIP_HDR_SYS_H +#define LWIP_HDR_SYS_H + +#include "lwip/opt.h" +#include "arch/sys_arch.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#if NO_SYS + +/* For a totally minimal and standalone system, we provide null + definitions of the sys_ functions. */ +typedef u8_t sys_sem_t; +typedef u8_t sys_mutex_t; +typedef u8_t sys_mbox_t; + +#define sys_sem_new(s, c) ERR_OK +#define sys_sem_signal(s) +#define sys_sem_wait(s) +#define sys_arch_sem_wait(s,t) +#define sys_sem_free(s) +#define sys_sem_valid(s) 0 +#define sys_sem_valid_val(s) 0 +#define sys_sem_set_invalid(s) +#define sys_sem_set_invalid_val(s) +#define sys_mutex_new(mu) ERR_OK +#define sys_mutex_lock(mu) +#define sys_mutex_unlock(mu) +#define sys_mutex_free(mu) +#define sys_mutex_valid(mu) 0 +#define sys_mutex_set_invalid(mu) +#define sys_mbox_new(m, s) ERR_OK +#define sys_mbox_fetch(m,d) +#define sys_mbox_tryfetch(m,d) +#define sys_mbox_post(m,d) +#define sys_mbox_trypost(m,d) +#define sys_mbox_free(m) +#define sys_mbox_valid(m) +#define sys_mbox_valid_val(m) +#define sys_mbox_set_invalid(m) +#define sys_mbox_set_invalid_val(m) + +#define sys_thread_new(n,t,a,s,p) + +#define sys_msleep(t) + +#else /* NO_SYS */ + +/** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */ +#define SYS_ARCH_TIMEOUT 0xffffffffUL + +/** sys_mbox_tryfetch() returns SYS_MBOX_EMPTY if appropriate. + * For now we use the same magic value, but we allow this to change in future. + */ +#define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT + +#include "lwip/err.h" +#include "arch/sys_arch.h" + +/** Function prototype for thread functions */ +typedef void (*lwip_thread_fn)(void *arg); + +/* Function prototypes for functions to be implemented by platform ports + (in sys_arch.c) */ + +/* Mutex functions: */ + +/** Define LWIP_COMPAT_MUTEX if the port has no mutexes and binary semaphores + should be used instead */ +#ifndef LWIP_COMPAT_MUTEX +#define LWIP_COMPAT_MUTEX 0 +#endif + +#if LWIP_COMPAT_MUTEX +/* for old ports that don't have mutexes: define them to binary semaphores */ +#define sys_mutex_t sys_sem_t +#define sys_mutex_new(mutex) sys_sem_new(mutex, 1) +#define sys_mutex_lock(mutex) sys_sem_wait(mutex) +#define sys_mutex_unlock(mutex) sys_sem_signal(mutex) +#define sys_mutex_free(mutex) sys_sem_free(mutex) +#define sys_mutex_valid(mutex) sys_sem_valid(mutex) +#define sys_mutex_set_invalid(mutex) sys_sem_set_invalid(mutex) + +#else /* LWIP_COMPAT_MUTEX */ + +/** + * @ingroup sys_mutex + * Create a new mutex. + * Note that mutexes are expected to not be taken recursively by the lwIP code, + * so both implementation types (recursive or non-recursive) should work. + * The mutex is allocated to the memory that 'mutex' + * points to (which can be both a pointer or the actual OS structure). + * If the mutex has been created, ERR_OK should be returned. Returning any + * other error will provide a hint what went wrong, but except for assertions, + * no real error handling is implemented. + * + * @param mutex pointer to the mutex to create + * @return ERR_OK if successful, another err_t otherwise + */ +err_t sys_mutex_new(sys_mutex_t *mutex); +/** + * @ingroup sys_mutex + * Blocks the thread until the mutex can be grabbed. + * @param mutex the mutex to lock + */ +void sys_mutex_lock(sys_mutex_t *mutex); +/** + * @ingroup sys_mutex + * Releases the mutex previously locked through 'sys_mutex_lock()'. + * @param mutex the mutex to unlock + */ +void sys_mutex_unlock(sys_mutex_t *mutex); +/** + * @ingroup sys_mutex + * Deallocates a mutex. + * @param mutex the mutex to delete + */ +void sys_mutex_free(sys_mutex_t *mutex); +#ifndef sys_mutex_valid +/** + * @ingroup sys_mutex + * Returns 1 if the mutes is valid, 0 if it is not valid. + * When using pointers, a simple way is to check the pointer for != NULL. + * When directly using OS structures, implementing this may be more complex. + * This may also be a define, in which case the function is not prototyped. + */ +int sys_mutex_valid(sys_mutex_t *mutex); +#endif +#ifndef sys_mutex_set_invalid +/** + * @ingroup sys_mutex + * Invalidate a mutex so that sys_mutex_valid() returns 0. + * ATTENTION: This does NOT mean that the mutex shall be deallocated: + * sys_mutex_free() is always called before calling this function! + * This may also be a define, in which case the function is not prototyped. + */ +void sys_mutex_set_invalid(sys_mutex_t *mutex); +#endif +#endif /* LWIP_COMPAT_MUTEX */ + +/* Semaphore functions: */ + +/** + * @ingroup sys_sem + * Create a new semaphore + * Creates a new semaphore. The semaphore is allocated to the memory that 'sem' + * points to (which can be both a pointer or the actual OS structure). + * The "count" argument specifies the initial state of the semaphore (which is + * either 0 or 1). + * If the semaphore has been created, ERR_OK should be returned. Returning any + * other error will provide a hint what went wrong, but except for assertions, + * no real error handling is implemented. + * + * @param sem pointer to the semaphore to create + * @param count initial count of the semaphore + * @return ERR_OK if successful, another err_t otherwise + */ +err_t sys_sem_new(sys_sem_t *sem, u8_t count); +/** + * @ingroup sys_sem + * Signals a semaphore + * @param sem the semaphore to signal + */ +void sys_sem_signal(sys_sem_t *sem); +/** + * @ingroup sys_sem + * Blocks the thread while waiting for the semaphore to be signaled. If the + * "timeout" argument is non-zero, the thread should only be blocked for the + * specified time (measured in milliseconds). If the "timeout" argument is zero, + * the thread should be blocked until the semaphore is signalled. + * + * The return value is SYS_ARCH_TIMEOUT if the semaphore wasn't signaled within + * the specified time or any other value if it was signaled (with or without + * waiting). + * Notice that lwIP implements a function with a similar name, + * sys_sem_wait(), that uses the sys_arch_sem_wait() function. + * + * @param sem the semaphore to wait for + * @param timeout timeout in milliseconds to wait (0 = wait forever) + * @return SYS_ARCH_TIMEOUT on timeout, any other value on success + */ +u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout); +/** + * @ingroup sys_sem + * Deallocates a semaphore. + * @param sem semaphore to delete + */ +void sys_sem_free(sys_sem_t *sem); +/** Wait for a semaphore - forever/no timeout */ +#define sys_sem_wait(sem) sys_arch_sem_wait(sem, 0) +#ifndef sys_sem_valid +/** + * @ingroup sys_sem + * Returns 1 if the semaphore is valid, 0 if it is not valid. + * When using pointers, a simple way is to check the pointer for != NULL. + * When directly using OS structures, implementing this may be more complex. + * This may also be a define, in which case the function is not prototyped. + */ +int sys_sem_valid(sys_sem_t *sem); +#endif +#ifndef sys_sem_set_invalid +/** + * @ingroup sys_sem + * Invalidate a semaphore so that sys_sem_valid() returns 0. + * ATTENTION: This does NOT mean that the semaphore shall be deallocated: + * sys_sem_free() is always called before calling this function! + * This may also be a define, in which case the function is not prototyped. + */ +void sys_sem_set_invalid(sys_sem_t *sem); +#endif +#ifndef sys_sem_valid_val +/** + * Same as sys_sem_valid() but taking a value, not a pointer + */ +#define sys_sem_valid_val(sem) sys_sem_valid(&(sem)) +#endif +#ifndef sys_sem_set_invalid_val +/** + * Same as sys_sem_set_invalid() but taking a value, not a pointer + */ +#define sys_sem_set_invalid_val(sem) sys_sem_set_invalid(&(sem)) +#endif + +#ifndef sys_msleep +/** + * @ingroup sys_misc + * Sleep for specified number of ms + */ +void sys_msleep(u32_t ms); /* only has a (close to) 1 ms resolution. */ +#endif + +/* Mailbox functions. */ + +/** + * @ingroup sys_mbox + * Creates an empty mailbox for maximum "size" elements. Elements stored + * in mailboxes are pointers. You have to define macros "_MBOX_SIZE" + * in your lwipopts.h, or ignore this parameter in your implementation + * and use a default size. + * If the mailbox has been created, ERR_OK should be returned. Returning any + * other error will provide a hint what went wrong, but except for assertions, + * no real error handling is implemented. + * + * @param mbox pointer to the mbox to create + * @param size (minimum) number of messages in this mbox + * @return ERR_OK if successful, another err_t otherwise + */ +err_t sys_mbox_new(sys_mbox_t *mbox, int size); +/** + * @ingroup sys_mbox + * Post a message to an mbox - may not fail + * -> blocks if full, only to be used from tasks NOT from ISR! + * + * @param mbox mbox to posts the message + * @param msg message to post (ATTENTION: can be NULL) + */ +void sys_mbox_post(sys_mbox_t *mbox, void *msg); +/** + * @ingroup sys_mbox + * Try to post a message to an mbox - may fail if full. + * Can be used from ISR (if the sys arch layer allows this). + * Returns ERR_MEM if it is full, else, ERR_OK if the "msg" is posted. + * + * @param mbox mbox to posts the message + * @param msg message to post (ATTENTION: can be NULL) + */ +err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg); +/** + * @ingroup sys_mbox + * Try to post a message to an mbox - may fail if full. + * To be be used from ISR. + * Returns ERR_MEM if it is full, else, ERR_OK if the "msg" is posted. + * + * @param mbox mbox to posts the message + * @param msg message to post (ATTENTION: can be NULL) + */ +err_t sys_mbox_trypost_fromisr(sys_mbox_t *mbox, void *msg); +/** + * @ingroup sys_mbox + * Blocks the thread until a message arrives in the mailbox, but does + * not block the thread longer than "timeout" milliseconds (similar to + * the sys_arch_sem_wait() function). If "timeout" is 0, the thread should + * be blocked until a message arrives. The "msg" argument is a result + * parameter that is set by the function (i.e., by doing "*msg = + * ptr"). The "msg" parameter maybe NULL to indicate that the message + * should be dropped. + * The return values are the same as for the sys_arch_sem_wait() function: + * SYS_ARCH_TIMEOUT if there was a timeout, any other value if a messages + * is received. + * + * Note that a function with a similar name, sys_mbox_fetch(), is + * implemented by lwIP. + * + * @param mbox mbox to get a message from + * @param msg pointer where the message is stored + * @param timeout maximum time (in milliseconds) to wait for a message (0 = wait forever) + * @return SYS_ARCH_TIMEOUT on timeout, any other value if a message has been received + */ +u32_t sys_arch_mbox_fetch(sys_mbox_t *mbox, void **msg, u32_t timeout); +/* Allow port to override with a macro, e.g. special timeout for sys_arch_mbox_fetch() */ +#ifndef sys_arch_mbox_tryfetch +/** + * @ingroup sys_mbox + * This is similar to sys_arch_mbox_fetch, however if a message is not + * present in the mailbox, it immediately returns with the code + * SYS_MBOX_EMPTY. On success 0 is returned. + * To allow for efficient implementations, this can be defined as a + * function-like macro in sys_arch.h instead of a normal function. For + * example, a naive implementation could be: + * \#define sys_arch_mbox_tryfetch(mbox,msg) sys_arch_mbox_fetch(mbox,msg,1) + * although this would introduce unnecessary delays. + * + * @param mbox mbox to get a message from + * @param msg pointer where the message is stored + * @return 0 (milliseconds) if a message has been received + * or SYS_MBOX_EMPTY if the mailbox is empty + */ +u32_t sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg); +#endif +/** + * For now, we map straight to sys_arch implementation. + */ +#define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg) +/** + * @ingroup sys_mbox + * Deallocates a mailbox. If there are messages still present in the + * mailbox when the mailbox is deallocated, it is an indication of a + * programming error in lwIP and the developer should be notified. + * + * @param mbox mbox to delete + */ +void sys_mbox_free(sys_mbox_t *mbox); +#define sys_mbox_fetch(mbox, msg) sys_arch_mbox_fetch(mbox, msg, 0) +#ifndef sys_mbox_valid +/** + * @ingroup sys_mbox + * Returns 1 if the mailbox is valid, 0 if it is not valid. + * When using pointers, a simple way is to check the pointer for != NULL. + * When directly using OS structures, implementing this may be more complex. + * This may also be a define, in which case the function is not prototyped. + */ +int sys_mbox_valid(sys_mbox_t *mbox); +#endif +#ifndef sys_mbox_set_invalid +/** + * @ingroup sys_mbox + * Invalidate a mailbox so that sys_mbox_valid() returns 0. + * ATTENTION: This does NOT mean that the mailbox shall be deallocated: + * sys_mbox_free() is always called before calling this function! + * This may also be a define, in which case the function is not prototyped. + */ +void sys_mbox_set_invalid(sys_mbox_t *mbox); +#endif +#ifndef sys_mbox_valid_val +/** + * Same as sys_mbox_valid() but taking a value, not a pointer + */ +#define sys_mbox_valid_val(mbox) sys_mbox_valid(&(mbox)) +#endif +#ifndef sys_mbox_set_invalid_val +/** + * Same as sys_mbox_set_invalid() but taking a value, not a pointer + */ +#define sys_mbox_set_invalid_val(mbox) sys_mbox_set_invalid(&(mbox)) +#endif + + +/** + * @ingroup sys_misc + * The only thread function: + * Starts a new thread named "name" with priority "prio" that will begin its + * execution in the function "thread()". The "arg" argument will be passed as an + * argument to the thread() function. The stack size to used for this thread is + * the "stacksize" parameter. The id of the new thread is returned. Both the id + * and the priority are system dependent. + * ATTENTION: although this function returns a value, it MUST NOT FAIL (ports have to assert this!) + * + * @param name human-readable name for the thread (used for debugging purposes) + * @param thread thread-function + * @param arg parameter passed to 'thread' + * @param stacksize stack size in bytes for the new thread (may be ignored by ports) + * @param prio priority of the new thread (may be ignored by ports) */ +sys_thread_t sys_thread_new(const char *name, lwip_thread_fn thread, void *arg, int stacksize, int prio); + +#endif /* NO_SYS */ + +/** + * @ingroup sys_misc + * sys_init() must be called before anything else. + * Initialize the sys_arch layer. + */ +void sys_init(void); + +#ifndef sys_jiffies +/** + * Ticks/jiffies since power up. + */ +u32_t sys_jiffies(void); +#endif + +/** + * @ingroup sys_time + * Returns the current time in milliseconds, + * may be the same as sys_jiffies or at least based on it. + * Don't care for wraparound, this is only used for time diffs. + * Not implementing this function means you cannot use some modules (e.g. TCP + * timestamps, internal timeouts for NO_SYS==1). + */ +u32_t sys_now(void); + +/* Critical Region Protection */ +/* These functions must be implemented in the sys_arch.c file. + In some implementations they can provide a more light-weight protection + mechanism than using semaphores. Otherwise semaphores can be used for + implementation */ +#ifndef SYS_ARCH_PROTECT +/** SYS_LIGHTWEIGHT_PROT + * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection + * for certain critical regions during buffer allocation, deallocation and memory + * allocation and deallocation. + */ +#if SYS_LIGHTWEIGHT_PROT + +/** + * @ingroup sys_prot + * SYS_ARCH_DECL_PROTECT + * declare a protection variable. This macro will default to defining a variable of + * type sys_prot_t. If a particular port needs a different implementation, then + * this macro may be defined in sys_arch.h. + */ +#define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev +/** + * @ingroup sys_prot + * SYS_ARCH_PROTECT + * Perform a "fast" protect. This could be implemented by + * disabling interrupts for an embedded system or by using a semaphore or + * mutex. The implementation should allow calling SYS_ARCH_PROTECT when + * already protected. The old protection level is returned in the variable + * "lev". This macro will default to calling the sys_arch_protect() function + * which should be implemented in sys_arch.c. If a particular port needs a + * different implementation, then this macro may be defined in sys_arch.h + */ +#define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect() +/** + * @ingroup sys_prot + * SYS_ARCH_UNPROTECT + * Perform a "fast" set of the protection level to "lev". This could be + * implemented by setting the interrupt level to "lev" within the MACRO or by + * using a semaphore or mutex. This macro will default to calling the + * sys_arch_unprotect() function which should be implemented in + * sys_arch.c. If a particular port needs a different implementation, then + * this macro may be defined in sys_arch.h + */ +#define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev) +sys_prot_t sys_arch_protect(void); +void sys_arch_unprotect(sys_prot_t pval); + +#else + +#define SYS_ARCH_DECL_PROTECT(lev) +#define SYS_ARCH_PROTECT(lev) +#define SYS_ARCH_UNPROTECT(lev) + +#endif /* SYS_LIGHTWEIGHT_PROT */ + +#endif /* SYS_ARCH_PROTECT */ + +/* + * Macros to set/get and increase/decrease variables in a thread-safe way. + * Use these for accessing variable that are used from more than one thread. + */ + +#ifndef SYS_ARCH_INC +#define SYS_ARCH_INC(var, val) do { \ + SYS_ARCH_DECL_PROTECT(old_level); \ + SYS_ARCH_PROTECT(old_level); \ + var += val; \ + SYS_ARCH_UNPROTECT(old_level); \ + } while(0) +#endif /* SYS_ARCH_INC */ + +#ifndef SYS_ARCH_DEC +#define SYS_ARCH_DEC(var, val) do { \ + SYS_ARCH_DECL_PROTECT(old_level); \ + SYS_ARCH_PROTECT(old_level); \ + var -= val; \ + SYS_ARCH_UNPROTECT(old_level); \ + } while(0) +#endif /* SYS_ARCH_DEC */ + +#ifndef SYS_ARCH_GET +#define SYS_ARCH_GET(var, ret) do { \ + SYS_ARCH_DECL_PROTECT(old_level); \ + SYS_ARCH_PROTECT(old_level); \ + ret = var; \ + SYS_ARCH_UNPROTECT(old_level); \ + } while(0) +#endif /* SYS_ARCH_GET */ + +#ifndef SYS_ARCH_SET +#define SYS_ARCH_SET(var, val) do { \ + SYS_ARCH_DECL_PROTECT(old_level); \ + SYS_ARCH_PROTECT(old_level); \ + var = val; \ + SYS_ARCH_UNPROTECT(old_level); \ + } while(0) +#endif /* SYS_ARCH_SET */ + +#ifndef SYS_ARCH_LOCKED +#define SYS_ARCH_LOCKED(code) do { \ + SYS_ARCH_DECL_PROTECT(old_level); \ + SYS_ARCH_PROTECT(old_level); \ + code; \ + SYS_ARCH_UNPROTECT(old_level); \ + } while(0) +#endif /* SYS_ARCH_LOCKED */ + + +#ifdef __cplusplus +} +#endif + +#endif /* LWIP_HDR_SYS_H */ |