Ignore:
Timestamp:
Nov 1, 2018, 12:48:51 PM (5 years ago)
Author:
alain
Message:

Introduce a pause() syscall in mini-libc/unistd library.

File:
1 edited

Legend:

Unmodified
Added
Removed

  • trunk/libs/mini-libc/unistd.h

    r476 r589  
    2626
    2727/*****************************************************************************************
    28  * This file defines the user level, memory mapping related <mman> library.
     28 * This file defines the user level <unistd> library.
    2929 * All these functions make a system call to access the kernel structures.
    3030 * The user/kernel shared structures and mnemonics are defined in
    … …  
    3535
    3636/*****************************************************************************************
    37  * This function returns the pathname of the current working directory.
    38  *****************************************************************************************
    39  * buf     : buffer addres in user space.
    40  * nbytes  : user buffer size in bytes.
    41  * @ return 0 if success / returns -1 if failure.
    42  ****************************************************************************************/
    43 int getcwd( char       * buf,
    44             unsigned int nbytes );
    45 
    46 /*****************************************************************************************
    47  * This function read bytes from an open file identified by the <fd> file descriptor.
    48  * This file can be a regular file or a character oriented device.
    49  *****************************************************************************************
    50  * @ fd       : open file index in fd_array.
    51  * @ buf      : buffer virtual address in user space.
    52  * @ count    : number of bytes.
    53  * @ return number of bytes actually read if success / returns -1 if failure.
    54  ****************************************************************************************/
    55 int read( int            fd,
    56           void         * buf,
    57           unsigned int   count );
    58 
    59 /*****************************************************************************************
    60  * This function writes bytes to an open file identified by the <fd> file descriptor.
    61  * This file can be a regular file or character oriented device.
    62  *****************************************************************************************
    63  * @ fd       : open file index in fd_array.
    64  * @ buf      : buffer virtual address in user space.
    65  * @ count    : number of bytes.
    66  * @ return number of bytes actually written if success / returns -1 if failure.
    67  ****************************************************************************************/
    68 int write( int            fd,
    69            const void   * buf,
    70            unsigned int   count );
    71 
    72 /*****************************************************************************************
    73  * This function repositions the offset of the file descriptor identified by <file_id>,
    74  * according to the operation type defined by the <whence> argument.
    75  *****************************************************************************************
    76  * @ fd       : open file index in fd_array.
    77  * @ offset   : used to compute new offset value.
    78  * @ whence   : operation type (SEEK_SET / SEEK_CUR / SEEK_END defined in syscalls.h)
    79  * @ return 0 if success / returns -1 if failure.
    80  ****************************************************************************************/
    81 int lseek( int           fd,
    82            unsigned int  offset,
    83            int           whence );
     37 * This function sets a timer to deliver the signal SIGALRM to the calling process,
     38 * after the specified number of seconds.
     39 * If an alarm has already been set with alarm() but has not been delivered,
     40 * another call to alarm() will supersede the prior call.
     41 * The request alarm(0) cancels the current alarm and the signal will not be delivered.
     42 *****************************************************************************************
     43 * @ seconds   : number of seconds.
     44 * @ returns the amount of time left on the timer from a previous call to alarm().
     45 *   If no alarm is currently set, the return value is 0.
     46 ****************************************************************************************/
     47unsigned alarm( unsigned seconds );
     48
     49/*****************************************************************************************
     50 * This function change the current working directory in reference process descriptor.
     51 *****************************************************************************************
     52 * @ pathname   : pathname (can be relative or absolute).
     53 * @ return 0 if success / returns -1 if failure.
     54 ****************************************************************************************/
     55int chdir( const char * pathname );
    8456
    8557/*****************************************************************************************
    8658 * This function release the memory allocated for the file descriptor identified by
    87  * the <file_id> argument, and remove the fd array_entry in all copies of the process
    88  * descriptor.
     59 * the <fd> argument, and remove the fd array_entry in all process descriptor copies.
    8960 *****************************************************************************************
    9061 * @ fd   : file descriptor index in fd_array.
    … …  
    9263 ****************************************************************************************/
    9364int close( int fd );
    94 
    95 /*****************************************************************************************
    96  * This function removes a directory entry identified by the <pathname> from the
    97  * directory, and decrement the link count of the file referenced by the link.
    98  * If the link count reduces to zero, and no process has the file open, then all resources
    99  * associated with the file are released.  If one or more process have the file open when
    100  * the last link is removed, the link is removed, but the removal of the file is delayed
    101  * until all references to it have been closed.
    102  *****************************************************************************************
    103  * @ pathname   : pathname (can be relative or absolute).
    104  * @ return 0 if success / returns -1 if failure.
    105  ****************************************************************************************/
    106 int unlink( const char * pathname );
    107 
    108 /*****************************************************************************************
    109  * This function creates in the calling thread cluster an unnamed pipe, and two
    110  * (read and write) file descriptors to access this pipe. The calling function must pass
    111  * the pointer on the fd[] array.
    112  * TODO not implemented yet...
    113  *****************************************************************************************
    114  * @ fd[0] : [out] read only file descriptor index.
    115  * @ fd[1] : [out] write only file descriptor index.
    116  * @ return 0 if success / return -1 if failure.
    117  ****************************************************************************************/
    118 int pipe( int fd[2] );
    119 
    120 /*****************************************************************************************
    121  * This function change the current working directory in reference process descriptor.
    122  *****************************************************************************************
    123  * @ pathname   : pathname (can be relative or absolute).
    124  * @ return 0 if success / returns -1 if failure.
    125  ****************************************************************************************/
    126 int chdir( const char * pathname );
    127 
    128 /*****************************************************************************************
    129  * This function removes a directory file whose name is given by <pathname>.
    130  * The directory must not have any entries other than `.' and `..'.
    131  *****************************************************************************************
    132  * @ pathname   : pathname (can be relative or absolute).
    133  * @ return 0 if success / returns -1 if failure.
    134  ****************************************************************************************/
    135 int rmdir( char * pathname );
    136 
    137 /*****************************************************************************************
    138  * This function implement the "fork" system call on the user side.
    139  * The calling process descriptor (parent process), and the associated thread descriptor
    140  * are replicated in a - likely - remote cluster, that becomes the new process owner.
    141  * The child process get a new PID is linked to the parent PID. The child process inherit
    142  * from the parent process the memory image, and all open files (including the TXT).
    143  * The child process becomes the TXT terminal owner.
    144  * The target cluster depends on the "fork_user" flag and "fork_cxy" variable that can be
    145  * stored in the calling thread descriptor by the specific fork_place() system call.
    146  * If not, the kernel function makes a query to the DQDT to select the target cluster.
    147  *****************************************************************************************
    148  * @ if success, returns child process PID to parent, and return O to child.
    149  * @ if failure, returns -1 to parent / no child process is created.
    150  ****************************************************************************************/
    151 int fork( void );
    15265
    15366/*****************************************************************************************
    … …  
    17487
    17588/*****************************************************************************************
     89 * This function implement the "fork" system call on the user side.
     90 * The calling process descriptor (parent process), and the associated thread descriptor
     91 * are replicated in a - likely - remote cluster, that becomes the new process owner.
     92 * The child process get a new PID is linked to the parent PID. The child process inherit
     93 * from the parent process the memory image, and all open files (including the TXT).
     94 * The child process becomes the TXT terminal owner.
     95 * The target cluster depends on the "fork_user" flag and "fork_cxy" variable that can be
     96 * stored in the calling thread descriptor by the specific fork_place() system call.
     97 * If not, the kernel function makes a query to the DQDT to select the target cluster.
     98 *****************************************************************************************
     99 * @ if success, returns child process PID to parent, and return O to child.
     100 * @ if failure, returns -1 to parent / no child process is created.
     101 ****************************************************************************************/
     102int fork( void );
     103
     104/*****************************************************************************************
     105 * This function returns the pathname of the current working directory.
     106 *****************************************************************************************
     107 * buf     : buffer addres in user space.
     108 * nbytes  : user buffer size in bytes.
     109 * @ return 0 if success / returns -1 if failure.
     110 ****************************************************************************************/
     111int getcwd( char       * buf,
     112            unsigned int nbytes );
     113
     114/*****************************************************************************************
    176115 * This function implements the "getpid" system call on the user side.
    177116 *****************************************************************************************
    … …  
    189128
    190129/*****************************************************************************************
    191  * This function sets a timer to deliver the signal SIGALRM to the calling process,
    192  * after the specified number of seconds.
    193  * If an alarm has already been set with alarm() but has not been delivered,
    194  * another call to alarm() will supersede the prior call.
    195  * The request alarm(0) cancels the current alarm and the signal will not be delivered.
    196  *****************************************************************************************
    197  * @ seconds   : number of seconds.
    198  * @ returns the amount of time left on the timer from a previous call to alarm().
    199  *   If no alarm is currently set, the return value is 0.
    200  ****************************************************************************************/
    201 unsigned alarm( unsigned seconds );
     130 * This function repositions the offset of the file descriptor identified by <fd>,
     131 * according to the operation type defined by the <whence> argument.
     132 *****************************************************************************************
     133 * @ fd       : open file index in fd_array.
     134 * @ offset   : used to compute new offset value.
     135 * @ whence   : operation type (SEEK_SET / SEEK_CUR / SEEK_END)
     136 * @ return 0 if success / returns -1 if failure.
     137 ****************************************************************************************/
     138int lseek( int           fd,
     139           unsigned int  offset,
     140           int           whence );
     141
     142/*****************************************************************************************
     143 * This function stops the calling process until any signal is received.
     144 *****************************************************************************************
     145 * @ return 0 if success / returns -1 if failure.
     146 ****************************************************************************************/
     147int pause( void );
     148
     149/*****************************************************************************************
     150 * This function creates in the calling thread cluster an unnamed pipe, and two
     151 * (read and write) file descriptors to access this pipe. The calling function must pass
     152 * the pointer on the fd[] array.
     153 * TODO not implemented yet...
     154 *****************************************************************************************
     155 * @ fd[0] : [out] read only file descriptor index.
     156 * @ fd[1] : [out] write only file descriptor index.
     157 * @ return 0 if success / return -1 if failure.
     158 ****************************************************************************************/
     159int pipe( int fd[2] );
     160
     161/*****************************************************************************************
     162 * This function read bytes from an open file identified by the <fd> file descriptor.
     163 * This file can be a regular file or a character oriented device.
     164 *****************************************************************************************
     165 * @ fd       : open file index in fd_array.
     166 * @ buf      : buffer virtual address in user space.
     167 * @ count    : number of bytes.
     168 * @ return number of bytes actually read if success / returns -1 if failure.
     169 ****************************************************************************************/
     170int read( int            fd,
     171          void         * buf,
     172          unsigned int   count );
     173
     174/*****************************************************************************************
     175 * This function removes a directory file whose name is given by <pathname>.
     176 * The directory must not have any entries other than `.' and `..'.
     177 *****************************************************************************************
     178 * @ pathname   : pathname (can be relative or absolute).
     179 * @ return 0 if success / returns -1 if failure.
     180 ****************************************************************************************/
     181int rmdir( char * pathname );
     182
     183/*****************************************************************************************
     184 * This function removes a directory entry identified by the <pathname> from the
     185 * directory, and decrement the link count of the file referenced by the link.
     186 * If the link count reduces to zero, and no process has the file open, then all resources
     187 * associated with the file are released.  If one or more process have the file open when
     188 * the last link is removed, the link is removed, but the removal of the file is delayed
     189 * until all references to it have been closed.
     190 *****************************************************************************************
     191 * @ pathname   : pathname (can be relative or absolute).
     192 * @ return 0 if success / returns -1 if failure.
     193 ****************************************************************************************/
     194int unlink( const char * pathname );
     195
     196/*****************************************************************************************
     197 * This function writes bytes to an open file identified by the <fd> file descriptor.
     198 * This file can be a regular file or character oriented device.
     199 *****************************************************************************************
     200 * @ fd       : open file index in fd_array.
     201 * @ buf      : buffer virtual address in user space.
     202 * @ count    : number of bytes.
     203 * @ return number of bytes actually written if success / returns -1 if failure.
     204 ****************************************************************************************/
     205int write( int            fd,
     206           const void   * buf,
     207           unsigned int   count );
    202208
    203209#endif
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