2786
2787 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
2788 bool exec) {
2789 return commit_memory(addr, size, exec);
2790 }
2791
2792 bool os::uncommit_memory(char* addr, size_t bytes) {
2793 if (bytes == 0) {
2794 // Don't bother the OS with noops.
2795 return true;
2796 }
2797 assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
2798 assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
2799 return VirtualFree(addr, bytes, MEM_DECOMMIT) != 0;
2800 }
2801
2802 bool os::release_memory(char* addr, size_t bytes) {
2803 return VirtualFree(addr, 0, MEM_RELEASE) != 0;
2804 }
2805
2806 // Set protections specified
2807 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2808 bool is_committed) {
2809 unsigned int p = 0;
2810 switch (prot) {
2811 case MEM_PROT_NONE: p = PAGE_NOACCESS; break;
2812 case MEM_PROT_READ: p = PAGE_READONLY; break;
2813 case MEM_PROT_RW: p = PAGE_READWRITE; break;
2814 case MEM_PROT_RWX: p = PAGE_EXECUTE_READWRITE; break;
2815 default:
2816 ShouldNotReachHere();
2817 }
2818
2819 DWORD old_status;
2820
2821 // Strange enough, but on Win32 one can change protection only for committed
2822 // memory, not a big deal anyway, as bytes less or equal than 64K
2823 if (!is_committed && !commit_memory(addr, bytes, prot == MEM_PROT_RWX)) {
2824 fatal("cannot commit protection page");
2825 }
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2786
2787 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
2788 bool exec) {
2789 return commit_memory(addr, size, exec);
2790 }
2791
2792 bool os::uncommit_memory(char* addr, size_t bytes) {
2793 if (bytes == 0) {
2794 // Don't bother the OS with noops.
2795 return true;
2796 }
2797 assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
2798 assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
2799 return VirtualFree(addr, bytes, MEM_DECOMMIT) != 0;
2800 }
2801
2802 bool os::release_memory(char* addr, size_t bytes) {
2803 return VirtualFree(addr, 0, MEM_RELEASE) != 0;
2804 }
2805
2806 bool os::create_stack_guard_pages(char* addr, size_t size) {
2807 return os::commit_memory(addr, size);
2808 }
2809
2810 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2811 return os::uncommit_memory(addr, size);
2812 }
2813
2814 // Set protections specified
2815 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2816 bool is_committed) {
2817 unsigned int p = 0;
2818 switch (prot) {
2819 case MEM_PROT_NONE: p = PAGE_NOACCESS; break;
2820 case MEM_PROT_READ: p = PAGE_READONLY; break;
2821 case MEM_PROT_RW: p = PAGE_READWRITE; break;
2822 case MEM_PROT_RWX: p = PAGE_EXECUTE_READWRITE; break;
2823 default:
2824 ShouldNotReachHere();
2825 }
2826
2827 DWORD old_status;
2828
2829 // Strange enough, but on Win32 one can change protection only for committed
2830 // memory, not a big deal anyway, as bytes less or equal than 64K
2831 if (!is_committed && !commit_memory(addr, bytes, prot == MEM_PROT_RWX)) {
2832 fatal("cannot commit protection page");
2833 }
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