diff options
Diffstat (limited to 'ACE/ace/Shared_Memory_Pool.cpp')
| -rw-r--r-- | ACE/ace/Shared_Memory_Pool.cpp | 459 |
1 files changed, 459 insertions, 0 deletions
diff --git a/ACE/ace/Shared_Memory_Pool.cpp b/ACE/ace/Shared_Memory_Pool.cpp new file mode 100644 index 00000000000..c61334485b7 --- /dev/null +++ b/ACE/ace/Shared_Memory_Pool.cpp @@ -0,0 +1,459 @@ +// $Id$ + +// Shared_Memory_Pool.cpp +#include "ace/Shared_Memory_Pool.h" +#include "ace/OS_NS_sys_shm.h" +#include "ace/Log_Msg.h" + +ACE_RCSID(ace, Shared_Memory_Pool, "$Id$") + +#if !defined (ACE_LACKS_SYSV_SHMEM) + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + +ACE_ALLOC_HOOK_DEFINE(ACE_Shared_Memory_Pool) + +ACE_Shared_Memory_Pool_Options::ACE_Shared_Memory_Pool_Options (const char *base_addr, + size_t max_segments, + size_t file_perms, + off_t minimum_bytes, + size_t segment_size) + : base_addr_ (base_addr), + max_segments_ (max_segments), + minimum_bytes_ (minimum_bytes), + file_perms_ (file_perms), + segment_size_ (segment_size) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool_Options::ACE_Shared_Memory_Pool_Options"); +} + +void +ACE_Shared_Memory_Pool::dump (void) const +{ +#if defined (ACE_HAS_DUMP) + ACE_TRACE ("ACE_Shared_Memory_Pool::dump"); +#endif /* ACE_HAS_DUMP */ +} + +int +ACE_Shared_Memory_Pool::in_use (off_t &offset, + size_t &counter) +{ + offset = 0; + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + shmid_ds buf; + + for (counter = 0; + counter < this->max_segments_ && st[counter].used_ == 1; + counter++) + { + if (ACE_OS::shmctl (st[counter].shmid_, IPC_STAT, &buf) == -1) + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("shmctl")), + -1); + offset += buf.shm_segsz; + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("(%P|%t) segment size = %d, offset = %d\n"), buf.shm_segsz, offset)); + } + + return 0; +} + +int +ACE_Shared_Memory_Pool::find_seg (const void* const searchPtr, + off_t &offset, + size_t &counter) +{ + offset = 0; + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + shmid_ds buf; + + for (counter = 0; + counter < this->max_segments_ + && st[counter].used_ == 1; + counter++) + { + if (ACE_OS::shmctl (st[counter].shmid_, IPC_STAT, &buf) == -1) + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("shmctl")), + -1); + offset += buf.shm_segsz; + + // If segment 'counter' starts at a location greater than the + // place we are searching for. We then decrement the offset to + // the start of counter-1. (flabar@vais.net) + if (((ptrdiff_t) offset + (ptrdiff_t) (this->base_addr_)) > (ptrdiff_t) searchPtr) + { + --counter; + offset -= buf.shm_segsz; + return 0; + } + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("(%P|%t) segment size = %d, offset = %d\n"), buf.shm_segsz, offset)); + } + + return 0; +} + +int +ACE_Shared_Memory_Pool::commit_backing_store_name (size_t rounded_bytes, + off_t &offset) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::commit_backing_store_name"); + + size_t counter; + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + + if (this->in_use (offset, counter) == -1) + return -1; + + if (counter == this->max_segments_) + ACE_ERROR_RETURN ((LM_ERROR, + "exceeded max number of segments = %d, base = %u, offset = %u\n", + counter, + this->base_addr_, + offset), + -1); + else + { + int shmid = ACE_OS::shmget (st[counter].key_, + rounded_bytes, + this->file_perms_ | IPC_CREAT | IPC_EXCL); + if (shmid == -1) + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("shmget")), + -1); + st[counter].shmid_ = shmid; + st[counter].used_ = 1; + + void *address = (void *) (((char *) this->base_addr_) + offset); + void *shmem = ACE_OS::shmat (st[counter].shmid_, + (char *) address, + 0); + + if (shmem != address) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) %p, shmem = %u, address = %u\n", + "shmat", + shmem, + address), + -1); + } + return 0; +} + +// Handle SIGSEGV and SIGBUS signals to remap shared memory properly. + +int +ACE_Shared_Memory_Pool::handle_signal (int , siginfo_t *siginfo, ucontext_t *) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::handle_signal"); + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("signal %S occurred\n"), signum)); + + // While FreeBSD 5.X has a siginfo_t struct with a si_addr field, + // it does not define SEGV_MAPERR. +#if defined (ACE_HAS_SIGINFO_T) && !defined (ACE_LACKS_SI_ADDR) && \ + (defined (SEGV_MAPERR) || defined (SEGV_MEMERR)) + off_t offset; + // Make sure that the pointer causing the problem is within the + // range of the backing store. + + if (siginfo != 0) + { + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("(%P|%t) si_signo = %d, si_code = %d, addr = %u\n"), siginfo->si_signo, siginfo->si_code, siginfo->si_addr)); + size_t counter; + if (this->in_use (offset, counter) == -1) + ACE_ERROR ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("in_use"))); +#if !defined(_UNICOS) + else if (!(siginfo->si_code == SEGV_MAPERR + && siginfo->si_addr < (((char *) this->base_addr_) + offset) + && siginfo->si_addr >= ((char *) this->base_addr_))) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) address %u out of range\n", + siginfo->si_addr), + -1); +#else /* ! _UNICOS */ + else if (!(siginfo->si_code == SEGV_MEMERR + && siginfo->si_addr < (((unsigned long) this->base_addr_) + offset) + && siginfo->si_addr >= ((unsigned long) this->base_addr_))) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) address %u out of range\n", + siginfo->si_addr), + -1); +#endif /* ! _UNICOS */ + } + + // The above if case will check to see that the address is in the + // proper range. Therefore there is a segment out there that the + // pointer wants to point into. Find the segment that someone else + // has used and attach to it (flabar@vais.net) + + size_t counter; // ret value to get shmid from the st table. + +#if !defined(_UNICOS) + if (this->find_seg (siginfo->si_addr, offset, counter) == -1) +#else /* ! _UNICOS */ + if (this->find_seg ((const void *)siginfo->si_addr, offset, counter) == -1) +#endif /* ! _UNICOS */ + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("in_use")), + -1); + + void *address = (void *) (((char *) this->base_addr_) + offset); + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + + void *shmem = ACE_OS::shmat (st[counter].shmid_, (char *) address, 0); + + if (shmem != address) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) %p, shmem = %u, address = %u\n", + "shmat", + shmem, + address), + -1); + + // NOTE: this won't work if we dont have SIGINFO_T or SI_ADDR +#else + ACE_UNUSED_ARG (siginfo); +#endif /* ACE_HAS_SIGINFO_T && !defined (ACE_LACKS_SI_ADDR) */ + + return 0; +} + +ACE_Shared_Memory_Pool::ACE_Shared_Memory_Pool (const ACE_TCHAR *backing_store_name, + const OPTIONS *options) + : base_addr_ (0), + file_perms_ (ACE_DEFAULT_FILE_PERMS), + max_segments_ (ACE_DEFAULT_MAX_SEGMENTS), + minimum_bytes_ (0), + segment_size_ (ACE_DEFAULT_SEGMENT_SIZE) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::ACE_Shared_Memory_Pool"); + + // Only change the defaults if <options> != 0. + if (options) + { + this->base_addr_ = + reinterpret_cast<void *> (const_cast<char *> (options->base_addr_)); + this->max_segments_ = options->max_segments_; + this->file_perms_ = options->file_perms_; + this->minimum_bytes_ = options->minimum_bytes_; + this->segment_size_ = options->segment_size_; + } + + if (backing_store_name) + { + // Convert the string into a number that is used as the segment + // key. + + int segment_key; + int result = ::sscanf (ACE_TEXT_ALWAYS_CHAR (backing_store_name), + "%d", + &segment_key); + + if (result == 0 || result == EOF) + // The conversion to a number failed so hash with crc32 + // ACE::crc32 is also used in <SV_Semaphore_Simple>. + this->base_shm_key_ = + (key_t) ACE::crc32 (ACE_TEXT_ALWAYS_CHAR (backing_store_name)); + else + this->base_shm_key_ = segment_key; + + if (this->base_shm_key_ == IPC_PRIVATE) + // Make sure that the segment can be shared between unrelated + // processes. + this->base_shm_key_ = ACE_DEFAULT_SHM_KEY; + } + else + this->base_shm_key_ = ACE_DEFAULT_SHM_KEY; + + if (this->signal_handler_.register_handler (SIGSEGV, this) == -1) + ACE_ERROR ((LM_ERROR, + ACE_LIB_TEXT ("%p\n"), + ACE_LIB_TEXT ("ACE_Sig_Handler::register_handler"))); +} + +ACE_Shared_Memory_Pool::~ACE_Shared_Memory_Pool (void) +{ +} + +// Ask system for more shared memory. + +void * +ACE_Shared_Memory_Pool::acquire (size_t nbytes, + size_t &rounded_bytes) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::acquire"); + + rounded_bytes = this->round_up (nbytes); + + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("(%P|%t) acquiring more chunks, nbytes = %d, rounded_bytes = %d\n"), nbytes, rounded_bytes)); + + off_t offset; + + if (this->commit_backing_store_name (rounded_bytes, offset) == -1) + return 0; + + // ACE_DEBUG ((LM_DEBUG, ACE_LIB_TEXT ("(%P|%t) acquired more chunks, nbytes = %d, rounded_bytes = %d\n"), nbytes, rounded_bytes)); + return ((char *) this->base_addr_) + offset; +} + +// Ask system for initial chunk of shared memory. + +void * +ACE_Shared_Memory_Pool::init_acquire (size_t nbytes, + size_t &rounded_bytes, + int &first_time) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::init_acquire"); + + off_t shm_table_offset = ACE::round_to_pagesize (sizeof (SHM_TABLE)); + rounded_bytes = this->round_up (nbytes > (size_t) this->minimum_bytes_ + ? nbytes + : (size_t) this->minimum_bytes_); + + // Acquire the semaphore to serialize initialization and prevent + // race conditions. + + int shmid = ACE_OS::shmget (this->base_shm_key_, + rounded_bytes + shm_table_offset, + this->file_perms_ | IPC_CREAT | IPC_EXCL); + if (shmid == -1) + { + if (errno != EEXIST) + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("shmget")), + 0); + first_time = 0; + + shmid = ACE_OS::shmget (this->base_shm_key_, 0, 0); + + if (shmid == -1) + ACE_ERROR_RETURN ((LM_ERROR, + ACE_LIB_TEXT ("(%P|%t) %p\n"), + ACE_LIB_TEXT ("shmget")), + 0); + + // This implementation doesn't care if we don't get the key we + // want... + this->base_addr_ = + ACE_OS::shmat (shmid, + reinterpret_cast<char *> (this->base_addr_), + 0); + if (this->base_addr_ == reinterpret_cast<void *> (-1)) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) %p, base_addr = %u\n", + "shmat", + this->base_addr_), + 0); + } + else + { + first_time = 1; + + // This implementation doesn't care if we don't get the key we + // want... + this->base_addr_ = + ACE_OS::shmat (shmid, + reinterpret_cast<char *> (this->base_addr_), + 0); + if (this->base_addr_ == reinterpret_cast<char *> (-1)) + ACE_ERROR_RETURN ((LM_ERROR, + "(%P|%t) %p, base_addr = %u\n", + "shmat", + this->base_addr_), 0); + + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + st[0].key_ = this->base_shm_key_; + st[0].shmid_ = shmid; + + st[0].used_ = 1; + + for (size_t counter = 1; // Skip over the first entry... + counter < this->max_segments_; + counter++) + { + st[counter].key_ = this->base_shm_key_ + counter; + st[counter].shmid_ = 0; + st[counter].used_ = 0; + } + } + + return (void *) (((char *) this->base_addr_) + shm_table_offset); +} + +// Instruct the memory pool to release all of its resources. + +int +ACE_Shared_Memory_Pool::release (int) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::release"); + + int result = 0; + SHM_TABLE *st = reinterpret_cast<SHM_TABLE *> (this->base_addr_); + + for (size_t counter = 0; + counter < this->max_segments_ && st[counter].used_ == 1; + counter++) + if (ACE_OS::shmctl (st[counter].shmid_, IPC_RMID, 0) == -1) + result = -1; + + return result; +} + +int +ACE_Shared_Memory_Pool::sync (ssize_t, int) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::sync"); + return 0; +} + +int +ACE_Shared_Memory_Pool::sync (void *, size_t, int) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::sync"); + return 0; +} + +int +ACE_Shared_Memory_Pool::protect (ssize_t, int) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::protect"); + return 0; +} + +int +ACE_Shared_Memory_Pool::protect (void *, size_t, int) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::protect"); + return 0; +} + +void * +ACE_Shared_Memory_Pool::base_addr (void) const +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::base_addr"); + return this->base_addr_; +} + +// Implement the algorithm for rounding up the request to an +// appropriate chunksize. + +size_t +ACE_Shared_Memory_Pool::round_up (size_t nbytes) +{ + ACE_TRACE ("ACE_Shared_Memory_Pool::round_up"); + if (nbytes < this->segment_size_) + nbytes = this->segment_size_; + + return ACE::round_to_pagesize (nbytes); +} + +ACE_END_VERSIONED_NAMESPACE_DECL + +#endif /* !ACE_LACKS_SYSV_SHMEM */ |