From 47673b32ed4a907b380b70d5f4f366ba8be301d2 Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Thu, 15 Aug 1996 15:11:34 +0000 Subject: - added FAST_SHARE_MODES code - added some named pipe code from Jim (This used to be commit c94866e9e44ea1eb72da06bc65ef1c032ae8e0c9) --- source3/locking/locking.c | 246 +++++++++++++++- source3/locking/shmem.c | 722 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 967 insertions(+), 1 deletion(-) create mode 100644 source3/locking/shmem.c (limited to 'source3/locking') diff --git a/source3/locking/locking.c b/source3/locking/locking.c index 8f76ce43da..60428f2e98 100644 --- a/source3/locking/locking.c +++ b/source3/locking/locking.c @@ -17,6 +17,11 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + + Revision History: + + 12 aug 96: Erik.Devriendt@te6.siemens.be + added support for shared memory implementation of share mode locking */ #include "includes.h" @@ -226,6 +231,34 @@ BOOL do_unlock(int fnum,int cnum,uint32 count,uint32 offset,int *eclass,uint32 * return True; /* Did unlock */ } +#ifdef FAST_SHARE_MODES +/******************************************************************* + initialize the shared memory for share_mode management + ******************************************************************/ +BOOL start_share_mode_mgmt(void) +{ + pstring shmem_file_name; + + strcpy(shmem_file_name,lp_lockdir()); + trim_string(shmem_file_name,"","/"); + if (!*shmem_file_name) return(False); + strcat(shmem_file_name, "/SHARE_MEM_FILE"); + return shm_open(shmem_file_name, SHMEM_SIZE); +} + + +/******************************************************************* + deinitialize the shared memory for share_mode management + ******************************************************************/ +BOOL stop_share_mode_mgmt(void) +{ + return shm_close(); +} + +#else + +/* SHARE MODE LOCKS USING SLOW DESCRIPTION FILES */ + /******************************************************************* name a share file ******************************************************************/ @@ -251,6 +284,7 @@ static BOOL share_name_fnum(int fnum,char *name) return(share_name(Files[fnum].cnum,&st,name)); } +#endif /******************************************************************* get the share mode of a file using the fnum @@ -278,6 +312,78 @@ get the share mode of a file ********************************************************************/ int get_share_mode(int cnum,struct stat *sbuf,int *pid) { +#ifdef FAST_SHARE_MODES + share_mode_record *scanner_p; + share_mode_record *prev_p; + int ret; + BOOL found = False; + + *pid = 0; + + if(!shm_lock()) return (0); + + scanner_p = (share_mode_record *)shm_offset2addr(shm_get_userdef_off()); + prev_p = scanner_p; + while(scanner_p) + { + if( (scanner_p->st_dev == sbuf->st_dev) && (scanner_p->st_ino == sbuf->st_ino) ) + { + found = True; + break; + } + else + { + prev_p = scanner_p ; + scanner_p = (share_mode_record *)shm_offset2addr(scanner_p->next_offset); + } + } + + if(!found) + { + shm_unlock(); + return (0); + } + + if(scanner_p->locking_version != LOCKING_VERSION) + { + DEBUG(2,("Deleting old share mode record due to old locking version %d",scanner_p->locking_version)); + if(prev_p == scanner_p) + shm_set_userdef_off(scanner_p->next_offset); + else + prev_p->next_offset = scanner_p->next_offset; + shm_free(shm_addr2offset(scanner_p)); + *pid = 0; + + shm_unlock(); + return (0); + } + + *pid = scanner_p->pid; + ret = scanner_p->share_mode; + + if (*pid && !process_exists(*pid)) + { + ret = 0; + *pid = 0; + } + + if (! *pid) + { + if(prev_p == scanner_p) + shm_set_userdef_off(scanner_p->next_offset); + else + prev_p->next_offset = scanner_p->next_offset; + shm_free(shm_addr2offset(scanner_p)); + } + + if (*pid) + DEBUG(5,("Read share mode record mode 0x%X pid=%d\n",ret,*pid)); + + if(!shm_unlock()) return (0); + + return(ret); + +#else pstring fname; int fd2; char buf[16]; @@ -319,6 +425,7 @@ int get_share_mode(int cnum,struct stat *sbuf,int *pid) DEBUG(5,("Read share file %s mode 0x%X pid=%d\n",fname,ret,*pid)); return(ret); +#endif } @@ -327,6 +434,67 @@ del the share mode of a file, if we set it last ********************************************************************/ void del_share_mode(int fnum) { +#ifdef FAST_SHARE_MODES + struct stat st; + time_t t=0; + int pid=0; + BOOL del = False; + share_mode_record *scanner_p; + share_mode_record *prev_p; + BOOL found = False; + + + + if (fstat(Files[fnum].fd,&st) != 0) return; + + if (!shm_lock()) return; + + scanner_p = (share_mode_record *)shm_offset2addr(shm_get_userdef_off()); + prev_p = scanner_p; + while(scanner_p) + { + if( (scanner_p->st_dev == st.st_dev) && (scanner_p->st_ino == st.st_ino) ) + { + found = True; + break; + } + else + { + prev_p = scanner_p ; + scanner_p = (share_mode_record *)shm_offset2addr(scanner_p->next_offset); + } + } + + if(!found) + { + shm_unlock(); + return; + } + + t = scanner_p->time; + pid = scanner_p->pid; + + if( (scanner_p->locking_version != LOCKING_VERSION) || !pid || !process_exists(pid)) + del = True; + + if (!del && t == Files[fnum].open_time && pid==(int)getpid()) + del = True; + + if (del) + { + DEBUG(2,("Deleting share mode record\n")); + if(prev_p == scanner_p) + shm_set_userdef_off(scanner_p->next_offset); + else + prev_p->next_offset = scanner_p->next_offset; + shm_free(shm_addr2offset(scanner_p)); + + } + + shm_unlock(); + return; + +#else pstring fname; int fd2; char buf[16]; @@ -363,6 +531,7 @@ void del_share_mode(int fnum) strcpy(share_del_pending,fname); } } +#endif } @@ -371,6 +540,36 @@ set the share mode of a file ********************************************************************/ BOOL set_share_mode(int fnum,int mode) { +#ifdef FAST_SHARE_MODES + int pid = (int)getpid(); + struct stat st; + shm_offset_t new_off; + share_mode_record *new_p; + + + if (fstat(Files[fnum].fd,&st) != 0) return(False); + + if (!shm_lock()) return (False); + new_off = shm_alloc(sizeof(share_mode_record) + strlen(Files[fnum].name) ); + if (new_off == NULL_OFFSET) return (False); + new_p = (share_mode_record *)shm_offset2addr(new_off); + new_p->locking_version = LOCKING_VERSION; + new_p->share_mode = mode; + new_p->time = Files[fnum].open_time; + new_p->pid = pid; + new_p->st_dev = st.st_dev; + new_p->st_ino = st.st_ino; + strcpy(new_p->file_name,Files[fnum].name); + new_p->next_offset = shm_get_userdef_off(); + shm_set_userdef_off(new_off); + + + DEBUG(3,("Created share record for %s with mode 0x%X pid=%d\n",Files[fnum].name,mode,pid)); + + if (!shm_unlock()) return (False); + return(True); + +#else pstring fname; int fd2; char buf[16]; @@ -406,14 +605,58 @@ BOOL set_share_mode(int fnum,int mode) DEBUG(3,("Created share file %s with mode 0x%X pid=%d\n",fname,mode,pid)); return(True); +#endif } /******************************************************************* cleanup any stale share files ********************************************************************/ -void clean_share_files(void) +void clean_share_modes(void) { +#ifdef USE_SHMEM + share_mode_record *scanner_p; + share_mode_record *prev_p; + int pid; + + if (!shm_lock()) return; + + scanner_p = (share_mode_record *)shm_offset2addr(shm_get_userdef_off()); + prev_p = scanner_p; + while(scanner_p) + { + pid = scanner_p->pid; + + if( (scanner_p->locking_version != LOCKING_VERSION) || !process_exists(pid)) + { + DEBUG(2,("Deleting stale share mode record")); + if(prev_p == scanner_p) + { + shm_set_userdef_off(scanner_p->next_offset); + shm_free(shm_addr2offset(scanner_p)); + scanner_p = (share_mode_record *)shm_offset2addr(shm_get_userdef_off()); + prev_p = scanner_p; + } + else + { + prev_p->next_offset = scanner_p->next_offset; + shm_free(shm_addr2offset(scanner_p)); + scanner_p = (share_mode_record *)shm_offset2addr(prev_p->next_offset); + } + + } + else + { + prev_p = scanner_p ; + scanner_p = (share_mode_record *)shm_offset2addr(scanner_p->next_offset); + } + } + + + shm_unlock(); + return; + +#else char *lockdir = lp_lockdir(); void *dir; char *s; @@ -457,4 +700,5 @@ void clean_share_files(void) } closedir(dir); +#endif } diff --git a/source3/locking/shmem.c b/source3/locking/shmem.c new file mode 100644 index 0000000000..3a308d07ba --- /dev/null +++ b/source3/locking/shmem.c @@ -0,0 +1,722 @@ +/* + Unix SMB/Netbios implementation. + Version 1.9. + Shared memory functions + Copyright (C) Erik Devriendt 1996 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ + +#ifdef FAST_SHARE_MODES + + +#include "includes.h" + +extern int DEBUGLEVEL; + + +#define SHM_MAGIC 0x53484100 +/* = "SHM" in hex */ + +#define SHM_VERSION 1 + +/* WARNING : offsets are used because mmap() does not guarantee that all processes have the + shared memory mapped to the same address */ + +struct ShmHeader +{ + int shm_magic; + int shm_version; + int total_size; /* in bytes */ + BOOL consistent; + shm_offset_t first_free_off; + shm_offset_t userdef_off; /* a userdefined offset. can be used to store root of tree or list */ + struct { /* a cell is a range of bytes of sizeof(struct ShmBlockDesc) size */ + int cells_free; + int cells_used; + int cells_system; /* number of cells used as allocated block descriptors */ + } statistics; +}; + +#define SHM_NOT_FREE_OFF (-1) +struct ShmBlockDesc +{ + shm_offset_t next; /* offset of next block in the free list or SHM_NOT_FREE_OFF when block in use */ + int size; /* user size in BlockDescSize units */ +}; + +#define EOList_Addr (struct ShmBlockDesc *)( 0 ) +#define EOList_Off (NULL_OFFSET) + +#define CellSize sizeof(struct ShmBlockDesc) + +/* HeaderSize aligned on 8 byte boundary */ +#define AlignedHeaderSize ((sizeof(struct ShmHeader)+7) & ~7) + +static int shm_fd = -1; +static pstring shm_processreg_name = ""; + +static struct ShmHeader *shm_header_p = (struct ShmHeader *)0; +static int shm_times_locked = 0; + +static BOOL shm_register_process(char *processreg_file, pid_t pid, BOOL *other_processes) +{ + int old_umask; + int shm_processes_fd = -1; + int nb_read; + pid_t other_pid; + int free_slot = -1; + int erased_slot; + + + old_umask = umask(0); + shm_processes_fd = open(processreg_file, O_RDWR | O_CREAT, 0666); + umask(old_umask); + if ( shm_processes_fd < 0 ) + { + DEBUG(0,("ERROR shm_register_process : processreg_file open failed with code %d\n",errno)); + return False; + } + + *other_processes = False; + + while ((nb_read = read(shm_processes_fd, &other_pid, sizeof(other_pid))) > 0) + { + if(other_pid) + { + if(process_exists(other_pid)) + *other_processes = True; + else + { + /* erase old pid */ + DEBUG(2,("shm_register_process : erasing stale record for pid %d\n",other_pid)); + other_pid = (pid_t)0; + erased_slot = lseek(shm_processes_fd, -sizeof(other_pid), SEEK_CUR); + write(shm_processes_fd, &other_pid, sizeof(other_pid)); + if(free_slot < 0) + free_slot = erased_slot; + } + } + else + if(free_slot < 0) + free_slot = lseek(shm_processes_fd, -sizeof(other_pid), SEEK_CUR); + } + if (nb_read < 0) + { + DEBUG(0,("ERROR shm_register_process : processreg_file read failed with code %d\n",errno)); + close(shm_processes_fd); + return False; + } + + if(free_slot < 0) + free_slot = lseek(shm_processes_fd, 0, SEEK_END); + + DEBUG(2,("shm_register_process : writing record for pid %d at offset %d\n",pid,free_slot)); + lseek(shm_processes_fd, free_slot, SEEK_SET); + if(write(shm_processes_fd, &pid, sizeof(pid)) < 0) + { + DEBUG(0,("ERROR shm_register_process : processreg_file write failed with code %d\n",errno)); + close(shm_processes_fd); + return False; + } + + close(shm_processes_fd); + + return True; +} + +static BOOL shm_unregister_process(char *processreg_file, pid_t pid) +{ + int old_umask; + int shm_processes_fd = -1; + int nb_read; + pid_t other_pid; + int erased_slot; + BOOL found = False; + + + old_umask = umask(0); + shm_processes_fd = open(processreg_file, O_RDWR); + umask(old_umask); + if ( shm_processes_fd < 0 ) + { + DEBUG(0,("ERROR shm_unregister_process : processreg_file open failed with code %d\n",errno)); + return False; + } + + while ((nb_read = read(shm_processes_fd, &other_pid, sizeof(other_pid))) > 0) + { + if(other_pid == pid) + { + /* erase pid */ + DEBUG(2,("shm_unregister_process : erasing record for pid %d\n",other_pid)); + other_pid = (pid_t)0; + erased_slot = lseek(shm_processes_fd, -sizeof(other_pid), SEEK_CUR); + if(write(shm_processes_fd, &other_pid, sizeof(other_pid)) < 0) + { + DEBUG(0,("ERROR shm_unregister_process : processreg_file write failed with code %d\n",errno)); + close(shm_processes_fd); + return False; + } + + found = True; + break; + } + } + if (nb_read < 0) + { + DEBUG(0,("ERROR shm_unregister_process : processreg_file read failed with code %d\n",errno)); + close(shm_processes_fd); + return False; + } + + if(!found) + { + DEBUG(0,("ERROR shm_unregister_process : couldn't find pid %d in file %s\n",pid,processreg_file)); + close(shm_processes_fd); + return False; + } + + + close(shm_processes_fd); + + return True; +} + + +static BOOL shm_validate_header(int size) +{ + if( !shm_header_p ) + { + /* not mapped yet */ + DEBUG(0,("ERROR shm_validate_header : shmem not mapped\n")); + return False; + } + + if(shm_header_p->shm_magic != SHM_MAGIC) + { + DEBUG(0,("ERROR shm_validate_header : bad magic\n")); + return False; + } + if(shm_header_p->shm_version != SHM_VERSION) + { + DEBUG(0,("ERROR shm_validate_header : bad version %X\n",shm_header_p->shm_version)); + return False; + } + + if(shm_header_p->total_size != size) + { + DEBUG(0,("ERROR shm_validate_header : shmem size mismatch (old = %d, new = %d)\n",shm_header_p->total_size,size)); + return False; + } + + if(!shm_header_p->consistent) + { + DEBUG(0,("ERROR shm_validate_header : shmem not consistent\n")); + return False; + } + return True; +} + +static BOOL shm_initialize(int size) +{ + struct ShmBlockDesc * first_free_block_p; + + DEBUG(2,("shm_initialize : initializing shmem file of size %d\n",size)); + + if( !shm_header_p ) + { + /* not mapped yet */ + DEBUG(0,("ERROR shm_initialize : shmem not mapped\n")); + return False; + } + + shm_header_p->shm_magic = SHM_MAGIC; + shm_header_p->shm_version = SHM_VERSION; + shm_header_p->total_size = size; + shm_header_p->first_free_off = AlignedHeaderSize; + shm_header_p->userdef_off = NULL_OFFSET; + + first_free_block_p = (struct ShmBlockDesc *)shm_offset2addr(shm_header_p->first_free_off); + first_free_block_p->next = EOList_Off; + first_free_block_p->size = ( size - AlignedHeaderSize - CellSize ) / CellSize ; + + shm_header_p->statistics.cells_free = first_free_block_p->size; + shm_header_p->statistics.cells_used = 0; + shm_header_p->statistics.cells_system = 1; + + shm_header_p->consistent = True; + + return True; +} + +static void shm_solve_neighbors(struct ShmBlockDesc *head_p ) +{ + struct ShmBlockDesc *next_p; + + /* Check if head_p and head_p->next are neighbors and if so join them */ + if ( head_p == EOList_Addr ) return ; + if ( head_p->next == EOList_Off ) return ; + + next_p = (struct ShmBlockDesc *)shm_offset2addr(head_p->next); + if ( ( head_p + head_p->size + 1 ) == next_p) + { + head_p->size += next_p->size +1 ; /* adapt size */ + head_p->next = next_p->next ; /* link out */ + + shm_header_p->statistics.cells_free += 1; + shm_header_p->statistics.cells_system -= 1; + } +} + + + +BOOL shm_open( char *file_name, int size) +{ + int filesize; + BOOL created_new = False; + BOOL other_processes = True; + int old_umask; + + DEBUG(2,("shm_open : using shmem file %s to be of size %d\n",file_name,size)); + + old_umask = umask(0); + shm_fd = open(file_name, O_RDWR | O_CREAT, 0666); + umask(old_umask); + if ( shm_fd < 0 ) + { + DEBUG(0,("ERROR shm_open : open failed with code %d\n",errno)); + return False; + } + + if (!shm_lock()) + { + DEBUG(0,("ERROR shm_open : can't do shm_lock\n")); + return False; + } + + if( (filesize = lseek(shm_fd, 0, SEEK_END)) < 0) + { + DEBUG(0,("ERROR shm_open : lseek failed with code %d\n",errno)); + shm_unlock(); + close(shm_fd); + return False; + } + + /* return the file offset to 0 to save on later seeks */ + lseek(shm_fd,0,SEEK_SET); + + if (filesize == 0) + { + /* we just created a new one */ + created_new = True; + } + + /* to find out if some other process is already mapping the file, + we use a registration file containing the processids of the file mapping processes + */ + + /* construct processreg file name */ + strcpy(shm_processreg_name, file_name); + strcat(shm_processreg_name, ".processes"); + + if (! shm_register_process(shm_processreg_name, getpid(), &other_processes)) + { + shm_unlock(); + close(shm_fd); + return False; + } + + if (created_new || !other_processes) + { + /* we just created a new one, or are the first opener, lets set it size */ + if( ftruncate(shm_fd, size) <0) + { + DEBUG(0,("ERROR shm_open : ftruncate failed with code %d\n",errno)); + shm_unregister_process(shm_processreg_name, getpid()); + shm_unlock(); + close(shm_fd); + return False; + } + + /* paranoia */ + lseek(shm_fd,0,SEEK_SET); + + filesize = size; + } + + if (size != filesize ) + { + /* the existing file has a different size and we are not the first opener. + Since another process is still using it, we will use the file size */ + DEBUG(0,("WARNING shm_open : filesize (%d) != expected size (%d), using filesize\n",filesize,size)); + size = filesize; + } + + shm_header_p = (struct ShmHeader *)mmap( NULL, size, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, shm_fd, 0); + /* WARNING, shm_header_p can be different for different processes mapping the same file ! */ + if (shm_header_p == (struct ShmHeader *)(-1)) + { + DEBUG(0,("ERROR shm_open : mmap failed with code %d\n",errno)); + shm_unregister_process(shm_processreg_name, getpid()); + shm_unlock(); + close(shm_fd); + return False; + } + + + if (created_new || !other_processes) + { + shm_initialize(size); + } + else if (!shm_validate_header(size) ) + { + /* existing file is corrupt, samba admin should remove it by hand */ + DEBUG(0,("ERROR shm_open : corrupt shared mem file, remove it manually\n")); + munmap((caddr_t)shm_header_p, size); + shm_unregister_process(shm_processreg_name, getpid()); + shm_unlock(); + close(shm_fd); + return False; + } + + shm_unlock(); + return True; + +} + + +BOOL shm_close( void ) +{ + + DEBUG(2,("shm_close\n")); + if(shm_times_locked > 0) + DEBUG(0,("WARNING shm_close : shmem was still locked %d times\n",shm_times_locked));; + if ( munmap((caddr_t)shm_header_p, shm_header_p->total_size) < 0) + { + DEBUG(0,("ERROR shm_close : munmap failed with code %d\n",errno)); + } + + shm_lock(); + shm_unregister_process(shm_processreg_name, getpid()); + shm_unlock(); + + close(shm_fd); + + shm_fd = -1; + shm_processreg_name[0] = '\0'; + + shm_header_p = (struct ShmHeader *)0; + shm_times_locked = 0; + + return True; +} + +shm_offset_t shm_alloc(int size) +{ + unsigned num_cells ; + struct ShmBlockDesc *scanner_p; + struct ShmBlockDesc *prev_p; + struct ShmBlockDesc *new_p; + shm_offset_t result_offset; + + + if( !shm_header_p ) + { + /* not mapped yet */ + DEBUG(0,("ERROR shm_alloc : shmem not mapped\n")); + return NULL_OFFSET; + } + + if( !shm_header_p->consistent) + { + DEBUG(0,("ERROR shm_alloc : shmem not consistent\n")); + return NULL_OFFSET; + } + + + /* calculate the number of cells */ + num_cells = (size + CellSize -1) / CellSize; + + /* set start of scan */ + prev_p = (struct ShmBlockDesc *)shm_offset2addr(shm_header_p->first_free_off); + scanner_p = prev_p ; + + /* scan the free list to find a matching free space */ + while ( ( scanner_p != EOList_Addr ) && ( scanner_p->size < num_cells ) ) + { + prev_p = scanner_p; + scanner_p = (struct ShmBlockDesc *)shm_offset2addr(scanner_p->next); + } + + /* at this point scanner point to a block header or to the end of the list */ + if ( scanner_p == EOList_Addr ) + { + DEBUG(0,("ERROR shm_alloc : alloc of %d bytes failed, no free space found\n",size)); + return (NULL_OFFSET); + } + + /* going to modify shared mem */ + shm_header_p->consistent = False; + + /* if we found a good one : scanner == the good one */ + if ( scanner_p->size <= num_cells + 2 ) + { + /* there is no use in making a new one, it will be too small anyway + * we will link out scanner + */ + if ( prev_p == scanner_p ) + { + shm_header_p->first_free_off = scanner_p->next ; + } + else + { + prev_p->next = scanner_p->next ; + } + shm_header_p->statistics.cells_free -= scanner_p->size; + shm_header_p->statistics.cells_used += scanner_p->size; + } + else + { + /* Make a new one */ + new_p = scanner_p + 1 + num_cells; + new_p->size = scanner_p->size - num_cells - 1; + new_p->next = scanner_p->next; + scanner_p->size = num_cells; + scanner_p->next = shm_addr2offset(new_p); + + if ( prev_p != scanner_p ) + { + prev_p->next = shm_addr2offset(new_p) ; + } + else + { + shm_header_p->first_free_off = shm_addr2offset(new_p) ; + } + shm_header_p->statistics.cells_free -= num_cells+1; + shm_header_p->statistics.cells_used += num_cells; + shm_header_p->statistics.cells_system += 1; + } + + result_offset = shm_addr2offset( &(scanner_p[1]) ); + scanner_p->next = SHM_NOT_FREE_OFF ; + + /* end modification of shared mem */ + shm_header_p->consistent = True; + + DEBUG(2,("shm_alloc : request for %d bytes, allocated %d bytes at offset %d\n",size,scanner_p->size*CellSize,result_offset )); + + return ( result_offset ); +} + + + +BOOL shm_free(shm_offset_t offset) +{ + struct ShmBlockDesc *header_p ; /* pointer to header of block to free */ + struct ShmBlockDesc *scanner_p ; /* used to scan the list */ + struct ShmBlockDesc *prev_p ; /* holds previous in the list */ + + if( !shm_header_p ) + { + /* not mapped yet */ + DEBUG(0,("ERROR shm_free : shmem not mapped\n")); + return False; + } + + if( !shm_header_p->consistent) + { + DEBUG(0,("ERROR shm_free : shmem not consistent\n")); + return False; + } + + header_p = ( (struct ShmBlockDesc *)shm_offset2addr(offset) - 1); /* make pointer to header of block */ + + if (header_p->next != SHM_NOT_FREE_OFF) + { + DEBUG(0,("ERROR shm_free : bad offset (%d)\n",offset)); + return False; + } + + /* find a place in the free_list to put the header in */ + + /* set scanner and previous pointer to start of list */ + prev_p = (struct ShmBlockDesc *)shm_offset2addr(shm_header_p->first_free_off); + scanner_p = prev_p ; + + while ( ( scanner_p != EOList_Addr) && (scanner_p < header_p) ) /* while we didn't scan past its position */ + { + prev_p = scanner_p ; + scanner_p = (struct ShmBlockDesc *)shm_offset2addr(scanner_p->next); + } + + shm_header_p->consistent = False; + + DEBUG(2,("shm_free : freeing %d bytes at offset %d\n",header_p->size*CellSize,offset)); + + if ( scanner_p == prev_p ) + { + shm_header_p->statistics.cells_free += header_p->size; + shm_header_p->statistics.cells_used -= header_p->size; + + /* we must free it at the beginning of the list */ + shm_header_p->first_free_off = shm_addr2offset(header_p); /* set the free_list_pointer to this block_header */ + + /* scanner is the one that was first in the list */ + header_p->next = shm_addr2offset(scanner_p); + shm_solve_neighbors( header_p ); /* if neighbors then link them */ + + shm_header_p->consistent = True; + return True; + } + else + { + shm_header_p->statistics.cells_free += header_p->size; + shm_header_p->statistics.cells_used -= header_p->size; + + prev_p->next = shm_addr2offset(header_p); + header_p->next = shm_addr2offset(scanner_p); + shm_solve_neighbors(header_p) ; + shm_solve_neighbors(prev_p) ; + + shm_header_p->consistent = True; + return True; + } +} + +shm_offset_t shm_get_userdef_off(void) +{ + if (!shm_header_p) + return NULL_OFFSET; + else + return shm_header_p->userdef_off; +} + +BOOL shm_set_userdef_off(shm_offset_t userdef_off) +{ + if (!shm_header_p) + return False; + else + shm_header_p->userdef_off = userdef_off; + return True; +} + +void * shm_offset2addr(shm_offset_t offset) +{ + if (offset == NULL_OFFSET ) + return (void *)(0); + + if (!shm_header_p) + return (void *)(0); + + return (void *)((char *)shm_header_p + offset ); +} + +shm_offset_t shm_addr2offset(void *addr) +{ + if (!addr) + return NULL_OFFSET; + + if (!shm_header_p) + return NULL_OFFSET; + + return (shm_offset_t)((char *)addr - (char *)shm_header_p); +} + +BOOL shm_lock(void) +{ + if (shm_fd < 0) + { + DEBUG(0,("ERROR shm_lock : bad shm_fd (%d)\n",shm_fd)); + return False; + } + + shm_times_locked++; + + if(shm_times_locked > 1) + { + DEBUG(2,("shm_lock : locked %d times\n",shm_times_locked)); + return True; + } + + if (lockf(shm_fd, F_LOCK, 0) < 0) + { + DEBUG(0,("ERROR shm_lock : lockf failed with code %d\n",errno)); + shm_times_locked--; + return False; + } + + return True; + +} + + + +BOOL shm_unlock(void) +{ + if (shm_fd < 0) + { + DEBUG(0,("ERROR shm_unlock : bad shm_fd (%d)\n",shm_fd)); + return False; + } + + if(shm_times_locked == 0) + { + DEBUG(0,("ERROR shm_unlock : shmem not locked\n",shm_fd)); + return False; + } + + shm_times_locked--; + + if(shm_times_locked > 0) + { + DEBUG(2,("shm_unlock : still locked %d times\n",shm_times_locked)); + return True; + } + + if (lockf(shm_fd, F_ULOCK, 0) < 0) + { + DEBUG(0,("ERROR shm_unlock : lockf failed with code %d\n",errno)); + shm_times_locked++; + return False; + } + + return True; + +} + + +BOOL shm_get_usage(int *bytes_free, + int *bytes_used, + int *bytes_overhead) +{ + if( !shm_header_p ) + { + /* not mapped yet */ + DEBUG(0,("ERROR shm_free : shmem not mapped\n")); + return False; + } + *bytes_free = shm_header_p->statistics.cells_free * CellSize; + *bytes_used = shm_header_p->statistics.cells_used * CellSize; + *bytes_overhead = shm_header_p->statistics.cells_system * CellSize + AlignedHeaderSize; + + return True; +} + +#else /* FAST_SHARE_MODES */ + int shmem_dummy_procedure(void) +{return 0;} +#endif -- cgit