diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/ChangeLog | 4 | ||||
| -rw-r--r-- | util/dotlock.c | 139 |
2 files changed, 104 insertions, 39 deletions
diff --git a/util/ChangeLog b/util/ChangeLog index e047de824..dc24d3851 100644 --- a/util/ChangeLog +++ b/util/ChangeLog @@ -1,3 +1,7 @@ +Fri Nov 27 21:37:41 CET 1998 Werner Koch <wk@isil.d.shuttle.de> + + * dotlock.c: Implemented + Wed Nov 25 11:30:07 1998 Werner Koch (wk@isil.d.shuttle.de) * iobuf.c (iobuf_pop_filter): Fixed sigsegv after error. diff --git a/util/dotlock.c b/util/dotlock.c index 917b90dd5..b57583004 100644 --- a/util/dotlock.c +++ b/util/dotlock.c @@ -23,14 +23,20 @@ #include <string.h> #include <errno.h> #include <ctype.h> +#include <errno.h> +#include <unistd.h> +#include <sys/utsname.h> +#include <sys/types.h> +#include <sys/time.h> +#include <sys/stat.h> +#include <fcntl.h> #include "types.h" #include "util.h" #include "memory.h" +static int read_lockfile( const char *name ); - -#if 0 /**************** * Create a lockfile with the given name. A TIMEOUT of 0 * returns immediately, -1 waits forever (hopefully not), other @@ -40,67 +46,122 @@ * * Notes: This function creates a lock file in the same directory * as file_to_lock with the name "file_to_lock.lock" - * A temporary file ".#lk.<pid>.<hostname> is used. + * A temporary file ".#lk.<hostname>.pid[.threadid] is used. * This function does nothing for Windoze. */ const char * make_dotlock( const char *file_to_lock, long timeout ) { - int rc=-1, fd=-1, pid; + int fd=-1, pid; char pidstr[16]; + const char *handle = NULL; + char *lockname = NULL; char *tname = NULL; - char *p; + int have_tfile = 0; + struct utsname uts; + const char *dirpart; + int dirpartlen; - log_debug("dotlock_make: lock='%s'\n", lockfile ); sprintf( pidstr, "%10d\n", getpid() ); - /* add the hostname to the second line (FQDN or IP addr?) */ + /* fixme: add the hostname to the second line (FQDN or IP addr?) */ /* create a temporary file */ - tname = CreateTmpFile2( p, ".#lk" ); - free(p); - if( !tname ) - log_fatal( "could not create temporary lock file '%s'\n"); - log_debug( "dotlock_make: tmpname='%s'\n", tname ); - chmod( tname, 0644 ); /* just in case an umask is set */ - if( !(fd = open( tname, O_WRONLY )) ) - log_fatal( "could not open temporary lock file '%s'\n", tname); - if( write(fd, pidstr, 11 ) != 11 ) - log_fatal( "error writing to temporary lock file '%s'\n", tname); + #if SYS_NMLN < 8 + #error Aiiih + #endif + if( uname( &uts ) ) + strcpy( uts.nodename, "unknown" ); + + if( !(dirpart = strrchr( file_to_lock, '/' )) ) { + dirpart = "."; + dirpartlen = 1; + } + else { + dirpartlen = dirpart - file_to_lock; + dirpart = file_to_lock; + } + + #ifdef _THREAD_SAFE + tname = m_alloc( dirpartlen + 6 + strlen(uts.nodename) + 11+ 20 ); + sprintf( tname, "%.*s/.#lk.%s.%d.%p", + dirpartlen, dirpart, uts.nodename, getpid(), &pid ); + #else + tname = m_alloc( dirpartlen + 6 + strlen(uts.nodename) + 11 ); + sprintf( tname, "%.*s/.#lk.%s.%d", + dirpartlen, dirpart, uts.nodename, getpid() ); + #endif + do { + errno = 0; + fd = open( tname, O_WRONLY|O_CREAT|O_EXCL, + S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR ); + } while( fd == -1 && errno == EINTR ); + if( fd == -1 ) { + log_error( "failed to create temporary file '%s': %s\n", + tname, strerror(errno)); + goto leave; + } + have_tfile = 1; + if( write(fd, pidstr, 11 ) != 11 ) { + log_fatal( "error writing to '%s': %s\n", tname, strerror(errno) ); + goto leave; + } if( close(fd) ) { - log_fatal( "error closing '%s'\n", tname); + log_error( "error closing '%s': %s\n", tname, strerror(errno)); + goto leave; + } + fd = -1; + + lockname = m_alloc( strlen(file_to_lock) + 6 ); + strcpy(stpcpy(lockname, file_to_lock), ".lock"); retry: - if( !link(tname, lockfile) ) - rc = 0; /* okay */ - else if( errno != EEXIST ) - log_error( "lock not made: link() failed: %s\n", strerror(errno) ); - else { /* lock file already there */ - if( (pid = read_lockfile(lockfile)) == -1 ) { + if( !link(tname, lockname) ) {/* fixme: better use stat to check the link count */ + handle = lockname; + lockname = NULL; + } + else if( errno == EEXIST ) { + if( (pid = read_lockfile(lockname)) == -1 ) { if( errno == ENOENT ) { - log_debug( "lockfile disappeared\n"); + log_info( "lockfile disappeared\n"); goto retry; } - log_debug("cannot read lockfile\n"); + log_info("cannot read lockfile\n"); } else if( pid == getpid() ) { log_info( "Oops: lock already hold by us\n"); - rc = 0; /* okay */ + handle = lockname; + lockname = NULL; } + #if 0 /* we should not do this without checking the permissions */ + /* and the hostname */ else if( kill(pid, 0) && errno == ESRCH ) { - log_info( "removing stale lockfile (created by %d)", (int)pid ); - remove( lockfile ); + log_info( "removing stale lockfile (created by %d)", pid ); + remove( lockname ); + goto retry; + } + #endif + if( timeout == -1 ) { + struct timeval tv; + log_info( "waiting for lock (hold by %d) ...\n", pid ); + /* can't use sleep, cause signals may be blocked */ + tv.tv_sec = 1; + tv.tv_usec = 0; + select(0, NULL, NULL, NULL, &tv); goto retry; } - log_debug( "lock not made: lock file exists\n" ); + /* fixme: implement timeouts */ } + else + log_error( "lock not made: link() failed: %s\n", strerror(errno) ); - if( tname ) { + leave: + if( fd != -1 ) + close(fd); + if( have_tfile ) remove(tname); - free(tname); - } - if( !rc ) - log_debug( "lock made\n"); - return rc; + m_free(tname); + m_free(lockname); + return handle; } /**************** @@ -140,7 +201,7 @@ release_dotlock( const char *lockfile ) lockfile); return -1; } - log_debug( "release_dotlock: released lockfile '%s'", lockfile); + m_free( (char*)lockfile ); return 0; } @@ -156,7 +217,7 @@ read_lockfile( const char *name ) if( (fd = open(name, O_RDONLY)) == -1 ) { int e = errno; - log_debug("error opening lockfile '%s'", name ); + log_debug("error opening lockfile '%s': %s\n", name, strerror(errno) ); errno = e; return -1; } @@ -175,4 +236,4 @@ read_lockfile( const char *name ) } return pid; } -#endif + |