| /** |
| * @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" |
| |
| #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 */ |