Ignore:
Timestamp:
Feb 14, 2018, 3:40:19 PM (4 years ago)
Author:
alain
Message:

blip

File:
1 edited

Legend:

Unmodified
Added
Removed
  • trunk/kernel/syscalls/syscalls.h

    r421 r433  
    171171/******************************************************************************************
    172172 * [10] This function implement the exit system call terminating a POSIX process.
     173 * In the present implementation, this function implements actually the _exit():
     174 * - it does not flush open ourput steams.
     175 * - it does not close open streams.
    173176 ******************************************************************************************
    174177 * @ status   : terminaison status (not used in present implementation).
     
    421424
    422425/******************************************************************************************
    423  * [34] This function implements the "kill" system call.
     426 * [34] This function implements the "kill" system call on the kernel side.
    424427 * It register the signal defined by the <sig_id> argument in all thread descriptors
    425428 * of a target process identified by the <pid> argument. This is done in all clusters
     
    432435 ******************************************************************************************
    433436 * @ pid      : target process identifier.
    434  * @ sig_id   : index defining the signal type (from 1 to 31).
     437 * @ sig_id   : index defining the signal type.
    435438 * @ return 0 if success / returns -1 if failure.
    436439 *****************************************************************************************/
     
    439442
    440443/******************************************************************************************
    441  * [35] This function implements the "getpid" system call.
     444 * [35] This function implements the "getpid" system call on the kernel side.
    442445 ******************************************************************************************
    443446 * @ returns the process PID for the calling thread.
     
    446449
    447450/******************************************************************************************
    448  * [36] This function implement the "fork" system call.
    449  * The calling process descriptor (parent process), and the associated thread descriptor are
    450  * replicated in the same cluster as the calling thread, but the new process (child process)
    451  * is registered in another target cluster, that is the new process owner.
    452  * The child process and the associated main thread will be migrated to the target cluster
    453  * later, when the child process makes an "exec" or any other system call... TODO [AG]
     451 * [36] This function implement the "fork" system call on the kernel side.
     452 * The calling process descriptor (parent process), and the associated thread descriptor
     453 * are replicated in a - likely - remote cluster, that becomes the child process owner.
     454 * The child process get a new PID, and is linked to the parent PID. The child process
     455 * inherit from its parent the memory image, and all open files (including the TXT).
     456 * The child process becomes the TXT terminal owner.
    454457 * The target cluster depends on the "fork_user" flag and "fork_cxy" variable that can be
    455458 * stored in the calling thread descriptor by the specific fork_place() system call.
    456  * If not, the sys_fork() function makes a query to the DQDT to select the target cluster.
     459 * If not, the kernel function makes a query to the DQDT to select the target cluster.
    457460 ******************************************************************************************
    458461 * @ if success, returns child process PID to parent, and return O to child.
     
    462465
    463466/******************************************************************************************
    464  * [37] This function implement the "exec" system call, that creates a new process
    465  * descriptor.
    466  * It is executed in the client cluster, but the new process descriptor and the main
    467  * thread are created in a server cluster, that is generally another cluster.
    468  * - if the server_cluster is the client cluster, it calls directly the process_make_exec()
    469  *   function to create a new process, and launch a new thread in local cluster.
    470  * - if the target_cluster is remote, it calls the rpc_process_exec_client() to execute
    471  *   process_signedmake_exec() on the remote cluster.
    472  * In both case this function build an exec_info_t structure containing all informations
    473  * required to build the new process descriptor and the associated thread.
    474  * Finally, the calling process and thread are deleted.
     467 * [37] This function implement the "exec" system call on the kernel side.
     468 * It creates, in the same cluster as the calling thread, a new process descriptor,
     469 * and a new associated main thread descriptor, executing a new memory image defined
     470 * by the <filename> argument. This new process inherit from the old process the PID
     471 * and the PPID, as well as all open files (including the TXT).
     472 * The old process descriptor, and all its threads are blocked, and marked for deletion.
     473 * Therefore the exec syscall does not return to the calling thread in case of success.
     474 * This function build an exec_info_t structure containing the new process arguments,
     475 * as defined by the <arv> argument, and the new process environment variables,
     476 * as defined by the <envp>  argument.
     477 * TODO : the <argv> and <envp> arguments are not supported yet (both must be NULL).
    475478 ******************************************************************************************
    476479 * @ filename : string pointer on .elf filename (pointer in user space)
    477480 * @ argv     : array of strings on process arguments (pointers in user space)
    478481 * @ envp     : array of strings on environment variables (pointers in user space)
    479  * @ returns O if success / returns -1 if failure.
     482 * @ does not return if success / returns -1 if failure.
    480483 *****************************************************************************************/
    481484int sys_exec( char  * filename,
     
    495498
    496499/******************************************************************************************
    497  * [39] This blocking function wait a change of a child process state. A change can be:
    498  * - a termination of child following a child exit.
    499  * - a termination of child following a SIGKILL signal.
     500 * [39] This blocking function waits a change of a child process state, that can be:
     501 * - a termination of child following a process_make_exit().
     502 * - a termination of child following a process_make_kill().
    500503 * - a blocking of child following a SIGSTOP signal.
    501  * It returns the PID of the involved child process, after storing in the memory slot
    502  * pointed by the <status> argument relevant information on the child state change.
     504 * In case of a multi-thread process, this function must be called by the main thread
     505 * runningin the reference cluster.
     506 * When a change has been observed, it returns the PID of the child process, and stores
     507 * in the <status> argument relevant information on the child state change.
    503508 * The following macros can be used to extract information from status:
    504509 * - WIFEXITED(status)   : is true if the child process terminated with an exit().
     
    506511 * - WIFSTOPPED(status)  : is true if the child process is stopped by a signal.
    507512 * - WEXITSTATUS(status) : returns the low-order 8 bits of the exit() argument.
    508  * A status of 0 indicates a normal termination.
    509513 * If a parent process terminates without waiting for all child processes to terminate,
    510514 * the remaining child processes are attached to the init process.
    511  ******************************************************************************************
    512  * @ status : pointer on the child PID status.
    513  * @ return child PID if success / return -1 if failure.
     515 * WARNING: negative values for the <pid> argument are not supported.
     516 ******************************************************************************************
     517 * @ searched_pid : searched child process identifier.
     518 * @ status       : [out] child termination status.
     519 * @ return child PID if success / return -1 if searched PID not found.
    514520 *****************************************************************************************/
    515521int sys_wait( uint32_t * status );
Note: See TracChangeset for help on using the changeset viewer.