Ajout de l'exo 1 dans le README

TP2/Exo1/fadvise.c

@@ -0,0 +1,155 @@
+#include <linux/falloc.h>
+#include <linux/fadvise.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/unistd_64.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+//#include <linux-ftools.h>
+#define LINUX_FTOOLS_VERSION "1.0.0"
+/** 
+
+SYNTAX: filename mode [offset] [,length]
+Where mode can be:
+
+  POSIX_FADV_NORMAL       No further special treatment.  
+  POSIX_FADV_RANDOM       Expect random page references.  
+  POSIX_FADV_SEQUENTIAL   Expect sequential page references.  
+  POSIX_FADV_WILLNEED     Will need these pages.  
+  POSIX_FADV_DONTNEED     Don't need these pages.  
+  POSIX_FADV_NOREUSE      Data will be accessed once.  
+
+Allows an application to to tell the kernel how it expects to use a file handle,
+so that the kernel can choose appropriate read-ahead and caching techniques for
+access to the corresponding file. This is similar to the POSIX version of the
+madvise system call, but for file access instead of memory access. The
+sys_fadvise64() function is obsolete and corresponds to a broken glibc API,
+sys_fadvise64_64() is the fixed version. The following are the values for the
+advice parameter:
+
+FADV_NORMAL
+
+No special treatment.
+
+FADV_RANDOM
+
+Expect page references in random order.
+
+FADV_SEQUENTIAL
+
+Expect page references in sequential order.
+
+FADV_WILLNEED
+
+Expect access in the near future.
+
+FADV_DONTNEED
+
+Do not expect access in the near future. Subsequent access of pages in this
+range will succeed, but will result either in reloading of the memory contents
+from the underlying mapped file or zero-fill-in-demand pages for mappings
+without an underlying file.
+
+FADV_NOREUSE
+
+Access data only once.
+
+*/
+int main(int argc, char *argv[]) {
+
+    if ( argc < 3 ) {
+        fprintf( stderr, "%s version %s\n", argv[0], LINUX_FTOOLS_VERSION );
+        printf( "SYNTAX: fadvise filename mode [offset] [,length]\n" );
+
+        printf( "Where mode can be:\n\n" );
+
+        printf( "  POSIX_FADV_NORMAL       No further special treatment.  \n" );
+        printf( "  POSIX_FADV_RANDOM       Expect random page references.  \n" );
+        printf( "  POSIX_FADV_SEQUENTIAL   Expect sequential page references.  \n" );
+        printf( "  POSIX_FADV_WILLNEED     Will need these pages.  \n" );
+        printf( "  POSIX_FADV_DONTNEED     Don't need these pages.  \n" );
+        printf( "  POSIX_FADV_NOREUSE      Data will be accessed once.  \n" );
+
+        exit( 1 );
+    }
+
+    char* path = argv[1];
+    char* param_mode = argv[2];
+
+    printf( "Going to fadvise %s\n", path );
+
+    int flags = O_RDWR;
+    int fd = open( path, flags );
+
+    if ( fd == -1 ) {
+        perror( NULL );
+        return 1;
+    }
+
+    struct stat fd_stat ;
+
+    if ( fstat( fd, &fd_stat ) < 0 ) {
+        perror( "Could not stat file: " );
+        return 1;
+    }
+
+    loff_t offset = 0;
+    loff_t length = fd_stat.st_size;
+
+    if ( argc >= 4 ) {
+        offset = strtol( argv[3], NULL, 10 );
+    }
+
+    if ( argc >= 5 ) {
+        length = strtol( argv[4], NULL, 10 );
+    }
+
+    printf( "offset: %ld\n", offset );
+    printf( "length: %ld\n", length );
+
+    int mode = -1;
+
+    if ( strcmp( param_mode , "POSIX_FADV_NORMAL" ) == 0 ) {
+        mode = POSIX_FADV_NORMAL;
+    } else if ( strcmp( param_mode , "POSIX_FADV_RANDOM" ) == 0 ) {
+        mode = POSIX_FADV_RANDOM;
+    } else if ( strcmp( param_mode , "POSIX_FADV_SEQUENTIAL" ) == 0 ) {
+        mode = POSIX_FADV_SEQUENTIAL;
+    } else if ( strcmp( param_mode , "POSIX_FADV_WILLNEED" ) == 0 ) {
+        mode = POSIX_FADV_DONTNEED;
+    } else if ( strcmp( param_mode , "POSIX_FADV_DONTNEED" ) == 0 ) {
+        mode = POSIX_FADV_DONTNEED;
+    } else if ( strcmp( param_mode , "POSIX_FADV_NOREUSE" ) == 0 ) {
+        mode = POSIX_FADV_NOREUSE;
+    } else {
+        printf( "Invalid mode %s\n", param_mode );
+        exit( 1 );
+    }
+
+    printf( "mode: %s\n", param_mode );
+
+    long result = syscall( SYS_fadvise64, fd, offset, length , mode );
+
+    if ( result != 0 ) {
+
+        if ( result != -1 ) {
+            errno=result;
+            perror( "Unable to fadvise" );
+        } else {
+            printf( "Unable to fadvise: %ld\n" , result );
+        }
+
+        return 1;
+    }
+
+    printf( "WIN\n" );
+
+    close( fd );
+    return 0;
+
+}