sys_mutex_valid() function

Signals a semaphore

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.

Releases the mutex previously locked through 'sys_mutex_lock()'.

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.

Blocks the thread until the mutex can be grabbed.

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.

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.

Deallocates a semaphore.

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.

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.

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.

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.

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.

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.

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.

Sends a message to TCPIP thread to call a function. Caller thread blocks on on a provided semaphore, which ist NOT automatically signalled by TCPIP thread, this has to be done by the user. It is recommended to use LWIP_TCPIP_CORE_LOCKING since this is the way with least runtime overhead.

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.

Post a message to an mbox - may not fail -> blocks if full, only to be used from tasks NOT from ISR!

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.

Deallocates a mutex.

Wait (forever) for a message to arrive in an mbox. While waiting, timeouts are processed.

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.