2245
2246 // attach to the region
2247 addr = (char*)shmat(shmid, req_addr, 0);
2248 int err = errno;
2249
2250 // Remove shmid. If shmat() is successful, the actual shared memory segment
2251 // will be deleted when it's detached by shmdt() or when the process
2252 // terminates. If shmat() is not successful this will remove the shared
2253 // segment immediately.
2254 shmctl(shmid, IPC_RMID, NULL);
2255
2256 if ((intptr_t)addr == -1) {
2257 if (warn_on_failure) {
2258 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2259 warning(msg);
2260 }
2261 return NULL;
2262 }
2263
2264 // The memory is committed
2265 address pc = CALLER_PC;
2266 MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc);
2267 MemTracker::record_virtual_memory_commit((address)addr, bytes, pc);
2268
2269 return addr;
2270 }
2271
2272 bool os::release_memory_special(char* base, size_t bytes) {
2273 // detaching the SHM segment will also delete it, see reserve_memory_special()
2274 int rslt = shmdt(base);
2275 if (rslt == 0) {
2276 MemTracker::record_virtual_memory_uncommit((address)base, bytes);
2277 MemTracker::record_virtual_memory_release((address)base, bytes);
2278 return true;
2279 } else {
2280 return false;
2281 }
2282
2283 }
2284
2285 size_t os::large_page_size() {
2286 return _large_page_size;
2287 }
2288
2289 // HugeTLBFS allows application to commit large page memory on demand;
2290 // with SysV SHM the entire memory region must be allocated as shared
2291 // memory.
2292 bool os::can_commit_large_page_memory() {
2293 return UseHugeTLBFS;
2294 }
2295
2296 bool os::can_execute_large_page_memory() {
2297 return UseHugeTLBFS;
2298 }
2299
|
2245
2246 // attach to the region
2247 addr = (char*)shmat(shmid, req_addr, 0);
2248 int err = errno;
2249
2250 // Remove shmid. If shmat() is successful, the actual shared memory segment
2251 // will be deleted when it's detached by shmdt() or when the process
2252 // terminates. If shmat() is not successful this will remove the shared
2253 // segment immediately.
2254 shmctl(shmid, IPC_RMID, NULL);
2255
2256 if ((intptr_t)addr == -1) {
2257 if (warn_on_failure) {
2258 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2259 warning(msg);
2260 }
2261 return NULL;
2262 }
2263
2264 // The memory is committed
2265 NMTTrackOp op(NMTTrackOp::ReserveAndCommitOp);
2266 op.execute_op((address)addr, bytes, 0, CALLER_PC);
2267
2268 return addr;
2269 }
2270
2271 bool os::release_memory_special(char* base, size_t bytes) {
2272 // detaching the SHM segment will also delete it, see reserve_memory_special()
2273 NMTTrackOp op(NMTTrackOp::ReleaseOp);
2274 int rslt = shmdt(base);
2275 if (rslt == 0) {
2276 op.execute_op((address)base, bytes);
2277 return true;
2278 } else {
2279 op.abort_op();
2280 return false;
2281 }
2282
2283 }
2284
2285 size_t os::large_page_size() {
2286 return _large_page_size;
2287 }
2288
2289 // HugeTLBFS allows application to commit large page memory on demand;
2290 // with SysV SHM the entire memory region must be allocated as shared
2291 // memory.
2292 bool os::can_commit_large_page_memory() {
2293 return UseHugeTLBFS;
2294 }
2295
2296 bool os::can_execute_large_page_memory() {
2297 return UseHugeTLBFS;
2298 }
2299
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